mild 360 build opinions

[204wagoneer]

ok, so I just turned over :shock: 184k on my Wagoneer 360/727/208. I am in the process of buying a running 360 fron a 79 cherokee. I want to build a mild 360, mild like 200 hp is fine. I am willing to overbuild(spend the extra money) for reliability, but not real interested in big hp, but torque would be nice.

What do the experts here suggest??
:sa:

[jeepsr4ever]

A lower end camshaft like a Summit K8600, Edelbrock performer. Something with less than .495 lift and less than 230 duration. I would look at simple things like smaller oiling hole rocker arms and some smaller hole cam bearings. You could also think about a performer intake and a 600cfm carb. That with a rebuild should get you gobs of usable torque.

[204wagoneer]

does the rebuild include the oiling upgrades beyond the cam bearings and rockers listed at this site, or is that not needed for a lo-performance daily driver??

[jeepsr4ever]

I would venture to say no I dont think you need an extra capacity oil pan but if you start to get crazy it is a good idea. I would also add that if you use the stock pan run it at least 1/2qt over full.

[204wagoneer]

cool, great advise. Thank you.

when I start putting this together I will buy the parts suggested, I hear Bulltear is a good source.........


Thanks again

[73hornut]

I would venture to say no I dont think you need an extra capacity oil pan but if you start to get crazy it is a good idea. I would also add that if you use the stock pan run it at least 1/2qt over full.
I agree. Work on improving drainback in the lifter valley.

[204wagoneer]

so hey, any idea where I might get a good set of reman. heads??

It might be cheaper and since stock is gonna be fine, is this decent option??

exhaust? stock manifolds ok?

carb choices? edelbrock vs holley vs jet prepped q-jet?

I will be upgrading cooling and fuel sysems in the name of reliability, any opinions on electric fan set ups??

man I am full of questions tonite......

[Goose]

The following would be my humble opinions.. put a performer manifold on it and a 600 edel electric choke, and a decent set of headers..with the summit cam MC recommended. ANd you will have a nice torqey (sp?) engine that will still get decent fuel mileage.. oh and If you have the bucks upgrade the ignition box with a davis or mallory..

as for electric fans.. I have one on a CJ.. But I put the belt fan back on and use the electric for aux cooling after I burned up a wiring harness on the trail once.. K.I.S.S.

[82Waggy]

Hate to be the one that always seems to disagree, but unless you are planning on bumping your compression up a bit from stock and/or adding taller gears I would look for a shorter duration cam than the Summit 8600.

Does'nt sound like you are planning for more than 4-4500rpm in a daily driver. Look for an LSA of 112 and a .050 intake duration closer to 204-207 in order to help build cylinder pressure and torque. Intake valve lift much in excess of .450 in stock heads for your application will gain you next to nothing. A Crower 258H Baja Beast or an Engle 35018H comes to mind for good power with stock compression from off idle to 4-4500rpm.

[jeepsr4ever]

Hate to be the one that always seems to disagree, but unless you are planning on bumping your compression up a bit from stock and/or adding taller gears I would look for a shorter duration cam than the Summit 8600.

Does'nt sound like you are planning for more than 4-4500rpm in a daily driver. Look for an LSA of 112 and a .050 intake duration closer to 204-207 in order to help build cylinder pressure and torque. Intake valve lift much in excess of .450 in stock heads for your application will gain you next to nothing. A Crower 258H Baja Beast or an Engle 35018H comes to mind for good power with stock compression from off idle to 4-4500rpm.

That is an extremely small camshaft in a AMC 360. From experience the 220-225 duration works extremely well in a AMC V8 above 343CI for low end grunt.

[82Waggy]

That is an extremely small camshaft in a AMC 360. From experience the 220-225 duration works extremely well in a AMC V8 above 343CI for low end grunt.

Well, most of the cam manufacturers rate cams with that much duration in the 1500 and up RPM range, with peak numbers near 4000 rpm, and generally recommend an increase in compression ratio to around 9.5:1. With stock compression and gears, I would expect low end to be pretty anemic with something like that.

The Summit 8600 cam has a very late intake closing point (65ABDC) and 53 degrees of overlap, neither of which are good for bottom end torque.

For comparison, don't forget donwags 401 with 9:1CR running a Comp XE256, 212/216 @.050 and only 54ABDC intake closing point with 42degrees overlap - made over 400ftlbs from 2-4400rpm with peak torque of 428 at 3400 and 348hp at 4800 on the dyno.

401's have a higher intake valve size to displacement ratio but more dwell time than a 360, so neither need a lot of overlap to make good power.

Remember that all duration does is shift the point at which peak torque is produced around 500 rpm per each ten degrees of duration - the downside is that too much overlap and a late intake closing point makes bottom end power evaporate.

Anyway, not saying the 8600 won't run in a 360 and may even be better than stock, but I doubt it is the best you can do - especially not without a bump in compression and some taller gears to let the engine rev up quickly.

First piece of advice before choosing a cam should be to analyze seriously what RPM range you are really operating in. Do you really rev over 4000 rpm consistantly or are you typically cruising in the 2000-2500rpm range? Are you willing to increase gear ratio to raise engine speed? Are you willing to accept the decrease in fuel milage that comes with higher rpm operation? Will you change pistons to raise CR? Do you have a free flowing exhaust system? Bet most Jeep operators would do better with lower duration cams.

[jeepsr4ever]

You have to take in the head flow and port volume into account as well. This changes the recommendations from a chevy cam to a AMC. I do agree with you on many points however when your done building your engine you will build more power with the camshaft I recommended over the others. Also take into account the lock up torque converter and the stall that is being used.

[Goose]

ya know guys.. What we really need to do (I say we as in mouse in my pocket) is put a mild engine on the dyno.. much as what we dscribe here and just try the different cams out there and see what the numbers are..

My experience has been Small block chevy and Big block mopar.. and in thos instances the cam mfrs are usually pretty close.. now the AMC which appears to have ports bigger than a 440 mopar..or 454 chev for that matter and will probably outflow them both, has me cornfused ..For instance the edelbrock performer cam that works so well in SBC applications only works well in the 304..why would that be?

[82Waggy]

You have to take in the head flow and port volume into account as well. This changes the recommendations from a chevy cam to a AMC. I do agree with you on many points however when your done building your engine you will build more power with the camshaft I recommended over the others. Also take into account the lock up torque converter and the stall that is being used.


Since the person starting this thread specified "mild 360" at about 200hp with nice torque for use in a Wagoneer, a relatively heavy vehicle, I see no point in discussing high rpm power or high stall torque converters.

If you want to compare an AMC to a Chevy, consider valve size to displacement ratio. A Big Block Chevy can benefit from more duration and overlap due to the relatively small valve size compared to the displacement they have to feed. An AMC 360 has a valve size to displacement ratio very similar to a Chevy small block - cam grinds similar to what works for an SBC will have the same basic results in an AMC 360, though a more aggressive lobe ramp can be taken advantage of in an AMC due to the larger diameter lifters.

I do not dispute that the cam you are recommending is "capable" of making more total power, but only if you are going to increase compression ratio, increase gear ratio and/or stall speed, use headers and a free flowing exhaust, and run premium gas. IF this is what the builder wants to do, OK.

My understanding was he was looking for low end torque in a basically stock rebuild and specifically stated he was "not real interested in big hp" - which suggests to me an rpm range from off idle-4000. With that in mind, a shorter duration cam on a 112 LSA will build better cylinder pressure and make more torque.

[82Waggy]

ya know guys.. What we really need to do (I say we as in mouse in my pocket) is put a mild engine on the dyno.. much as what we dscribe here and just try the different cams out there and see what the numbers are..

My experience has been Small block chevy and Big block mopar.. and in thos instances the cam mfrs are usually pretty close.. now the AMC which appears to have ports bigger than a 440 mopar..or 454 chev for that matter and will probably outflow them both, has me cornfused ..For instance the edelbrock performer cam that works so well in SBC applications only works well in the 304..why would that be?

Love to see that myself Goose.

Another point to be made however is that because AMC heads flow pretty well, extended overlap is not necessary.

But I think everybody knows that long cams need higher compression ratios, right? So I don't understand why I see so many recommend long cams for stock compression engines. And why does the donwag 401 dyno sheet, and others, not seem to prove these points?

[jeepsr4ever]

I wasnt talking about high revs I am talking about making the power at a low rpm without having a cam fall flat on its face at 3000rpm. If you have a small lift and small duration with the large valve sizes AMC head have your velocity and the amount of fuel/air and combustion efficiency can go down. The 304 works well with smaller cams because it has smaller valves. When you take all the parts of what makeup the power in a AMC 343 or larger you will then understand why cams with less than 220 duration or .480 lift dont work as well as cams in that range. Donwag has a good example and did a good job of building his grunt motor however I believe that he could have made more power with a different camshaft. You very close to being accurate 82Wag but without taking into account the head characteristics a cam suggestion may not be as accurate as you have led it to be.

I need a set of 304 heads BTW anyone got a set they will send up here?

[82Waggy]

I wasnt talking about high revs I am talking about making the power at a low rpm without having a cam fall flat on its face at 3000rpm. If you have a small lift and small duration with the large valve sizes AMC head have your velocity and the amount of fuel/air and combustion efficiency can go down. The 304 works well with smaller cams because it has smaller valves. When you take all the parts of what makeup the power in a AMC 343 or larger you will then understand why cams with less than 220 duration or .480 lift dont work as well as cams in that range. Donwag has a good example and did a good job of building his grunt motor however I believe that he could have made more power with a different camshaft. You very close to being accurate 82Wag but without taking into account the head characteristics a cam suggestion may not be as accurate as you have led it to be.

I need a set of 304 heads BTW anyone got a set they will send up here?

I just can't reconcile your points MC. High velocity and large wide open valves at low rpm do not go together. ALL flow data suggests that dogleg heads with 2.025 intake valves start to lose velocity at about .480 or so lift, and there is very little significant difference in flow/velocity between .450 and .480 lift. If a 304 in fact has a relatively smaller valve size to displacement ratio or lower flowing heads than a 360 then it would stand to reason that it would show a benefit of using a cam with more overlap than a 360 (RELATIVELY SPEAKING), assuming exhaust system backpressure did not hinder cylinder scavenging. If you are not running the rpm to take advantage of the port and valve size at max attainable lift, velocity can go down - you can get velocity back up in this circumstance by not opening the valve as far - cubic feet ingested can remain constant. High volume at low velocity, or low volume at high velocity can both equal the same CFM. High valve lift is not always, therefore, the best deal for low rpm engines.

A simple cam fact is that duration in and of itself only shifts the rpm at which peak torque is produced - raise this point and you make more horsepower, but at some sacrifice to low rpm torque due to the relatively later intake closing point. It is possible to regain some of the low rpm torque loss by raising compression ratio, but, as I have tried to convey, doing so means addressing higher octane fuel use, higher gear ratios, free flowing exhaust, etc. The question is at what point do you draw the line.

Use too much overlap with a restrictive (stock style) exhaust system and you start diluting the intake charge at low rpm - once again, bottom end power suffers.

Sure donwag could probably increase his peak numbers with more duration and higher rpm, assuming the intake closing point did not fall behind where it is now. IMO he could also increase peak torque within his current rpm range, widen his torque curve, and even increase peak hp numbers, and do all of that at a lower rpm than where his peak numbers fall now -simply by going to a cam with a 112LSA and slightly less duration.


Look, I am not trying to be a contrarian here. If there is something special about an AMC engine in these regards that I have overlooked, please enlighten me.

[jeepsr4ever]

82 Sorry I have been so brief on my replies...its been a hectic day. I am not a cam expert and will not claim to be. The factory cams are as follows

304/360 Intake duration 263.5
401 intake duration 296.32
304/360 Intake duration 263.5
401 intake duration 303.55

Valve overlap
304/360 41.5
401 68.32

Cam lift
304/360 .266
401 .286

Here is my experience with the 256xe. Every single one I have used or sold minus one (Donwag) have had low power at idle and dumped off at 3200rpm. They have been a huge dissapointment. The 256Xe specs are as follows

Duration 256/268
Lift .477/.484

We have had bad experiences building power with this cam over stock and we believe it is due to the low lift and duration. On the flipside we had great experience on a 304 with a Edelbrock performer camshaft, mixed results with a 360 and poor results with a 401. Here are the numbers for the Edelbrock.

Duration 278/ 288
Lift .448/ .472

The summit camshaft (K8600) had given the greatest amount of power from idle to 4000rpm in a 360 and 401 and from 2000-4500rpm in a 304. Here is the Summit numbers

Duration 272/ 282
Lift .472/ .496

The Sumit cam seemed to give the best power out of the 3 for the low end. Personally I have built just over 100 AMC V8s and experienced about 25 of them in my vehicles. These opinions I posted are based on a .030 bore with nothing special about compression other than a small hike from oversizing the cylinder from boring. I understand LSA's effects and lift/duration numbers but in my experience the rules tweak with a AMC V8 I dont think they change all that much but a Chevy grind camshaft certainly doesnt make as much power as a grind tailored to a AMC V8. Some of the smaller cam houses like Lazer have some specs posted.

Lazer cam specs, although some will disagree that these make power in their range

http://i2.photobucket.com/albums/y29/bulltear/laser1.jpg
http://i2.photobucket.com/albums/y29/bulltear/laser2.jpg
http://i2.photobucket.com/albums/y29/bulltear/laser3.jpg

Lazer has specs that closer represent what your recommending than what I am posting. I guess knowing the vehicle tha the postee is trying to cam really made my decision. Like I said I am not going to pretend to be a camshaft expert but I have alot of experience with these low end camshafts and some of these buggers dont even have a place in a AMC engine :?:

[mycj7]

I put the Comp Cams 268h in my 360 on a recent rebuild (was gonna be either that cam or the 256XE cam). Loads of low end, strong until 5,000 rpm. I built this one for my CJ that will rarely hit rpm's that high, and am so far impressed. Best guess is 325 hp and 400 ft lbs, without doing anything crazy during the rebuild. It has enough power to smoke a 37" Bogger on pavement.

The idle has a bit of lope to it, but barely noticable. I run the Holley Pro- Jection 2D throttle body fuel injection and it has a very snappy throttle response.

This was my first engine rebuild and I did a lot researching/reading on line (tons of great info on this sight and the AMC forums) also talked to some friends that rebuilt their 360's to see what worked for them.

I had the block bored .030, new pistons, block/heads shot peened, magnafluxed, crank ground 10/10, mild port/polishing on the heads, 3 angle valve job, new valve guides, both heads planed, went with the entire Comp Cams k-kit (cam, lifters, valve seals, retainers, double roller timing chain, valve springs), Edelbrock Air gap intake. Did the lifter valley oil line mod, new oil pump gears (had a decent cover :)). Nothing fancy, mainly just stuff you are gonna do while you are in there.

I know you are only looking for 200 hp, but it is so easy to get 300 out of these motor without spending any extra money.

Hope some of this helps and doesn't make the decisions more difficult. :t:

[82Waggy]

For instance the edelbrock performer cam that works so well in SBC applications only works well in the 304..why would that be?

Because both engines have about the same intake valve size to displacement ratio.

SBC 350 with 2.02 valve, 350cid/8cyl/2.02 = 21.65
AMC 304 with 1.787 valve, 304/8cyl/1.787 = 21.26

For comparison:

Ford 351C4V/8/2.190 = 20.03
AMC 360/8/2.025 = 22.22
AMC 401/8/2.025 = 24.75
BBC 502/8/2.4 = 26.15

Lower resulting number means a bigger valve to displacement.

As you can see from the above comparisons, a 502 cid BBC is way undervalved, even with a 2.4" intake valve, and therefore can benefit from a lot more intake/exhaust valve overlap - the result of a tighter LSA and/or more duration.

A 360 does not need the duration of the 401 to get the job done, nor does a 304 need that of 360, assuming you are trying to achieve peak torque values at about the same rpm.

[82Waggy]

82 Sorry I have been so brief on my replies...its been a hectic day. I guess knowing the vehicle that the postee is trying to cam really made my decision. Like I said I am not going to pretend to be a camshaft expert but I have alot of experience with these low end camshafts and some of these buggers dont even have a place in a AMC engine :?:

I know I have had way too much free time on my hands lately - I hate winter.

It would seem that, in general, the results you post seem to coincide with what I just posted regarding valve size to displacement, but it is because of the wide variation in practical results that you and others whom I respect seem to have experienced that I have been trying to determine where the disparity is. Perhaps it has just been the various differences in combinations that have drastically effected the cams' expected performance - just a change from a single to a dual plane manifold on the same cam can really twist the expected results.

And I wholly appreciate the fact that many run of the mill grinds have no place in an AMC.

Regarding that Summit 8600, I wonder if it is really ground as specified. This is the one cam that, based upon users comments, seems to defy what I would have expected from it, which was to be a torque loser in a low compression motor at low rpm ranges.

Then there is donwags and crazy's 401 dyno sheets which are the only hard documented results I have had to use as a baseline for AMC cam comparisons, other than my past experience with other engine makes, both cams of which seem to perform in the rpm range you would expect of them. donwags XE256 certainly does not seem to be falling flat on its' face at 3400rpm, rather, the dyno sheet shows it to be strong out to 4800rpm and beyond.

So, I don't know what to say. For my own AMC projects I expect I'll have to try more than one cam before I am satisfied, and will base the first choice on the best evidence I have to support my theories. Seat of the pants from then on out once I have a baselin in my own build. I'll certainly post my results.

Anybody interested in following my 401 build? I am about ready to start and could post pictures. I'm even writing a manual of my build as I go.

[82Waggy]

I put the Comp Cams 268h in my 360 on a recent rebuild (was gonna be either that cam or the 256XE cam). Loads of low end, strong until 5,000 rpm.

It has enough power to smoke a 37" Bogger on pavement.



If you don't mind responding, what axle gears are you running, and do you have 3spd, 4spd, or auto tranny?

[82Waggy]

Just for the hell of it I thought I would throw this out there for you all to consider.

These are the .050 duration specs for the three following cams.

Crwr276HDP, Comp XE256, Summit272 (8600)
Int = 212, 212, 214

Not much difference there eh, yet the .006 duration figures are way different.

[204wagoneer]

wow my little engine build started quite the thread, Thanks for all the good info.

I can see that 300 hp appears to be very attainable.

200 hp= good
300 hp= good-er

so long as I do not build the reliability out of the motor.

I think I will do the zero deck block and .045 head gaskets. Then only mill the head to make them good and flat.

What comp. ratio are the HD pistons sold here?? would I still be at 8.25 ish to 1?

I will be doing an free flow exhaust of some time since my rig is old enuf to get away from emissions.

well, keep the info coming, this is awesome for me as a new guy to AMC rebuilds.

Thanks again

[mycj7]

I put the Comp Cams 268h in my 360 on a recent rebuild (was gonna be either that cam or the 256XE cam). Loads of low end, strong until 5,000 rpm.

It has enough power to smoke a 37" Bogger on pavement.



If you don't mind responding, what axle gears are you running, and do you have 3spd, 4spd, or auto tranny?

Do not mind at all, I love chatting about my Jeep!

Axle are D44 front, 9" rear mini spooled with 4.88's.
Auto Tranny TF727 (3 speed auto).
D300 t-case.

[82Waggy]

wow my little engine build started quite the thread, Thanks for all the good info.

I can see that 300 hp appears to be very attainable.

200 hp= good
300 hp= good-er

so long as I do not build the reliability out of the motor.

I think I will do the zero deck block and .045 head gaskets. Then only mill the head to make them good and flat.

What comp. ratio are the HD pistons sold here?? would I still be at 8.25 ish to 1?

I will be doing an free flow exhaust of some time since my rig is old enuf to get away from emissions.

well, keep the info coming, this is awesome for me as a new guy to AMC rebuilds.

Thanks again

Well, now we are getting somewhere.

Since new pistons are in order and you plan on opening up your exhaust, I would recommend bumping compression to 9:1, .045 quench, and would be more comfortable with a longer duration cam recommendation, BUT NOT TOO MUCH LONGER!!!!

:!:

[82Waggy]

I put the Comp Cams 268h in my 360 on a recent rebuild (was gonna be either that cam or the 256XE cam). Loads of low end, strong until 5,000 rpm.

It has enough power to smoke a 37" Bogger on pavement.



If you don't mind responding, what axle gears are you running, and do you have 3spd, 4spd, or auto tranny?

Do not mind at all, I love chatting about my Jeep!

Axle are D44 front, 9" rear mini spooled with 4.88's.
Auto Tranny TF727 (3 speed auto).
D300 t-case.

Tall gears on those tires yielding higher rpm range with that cam makes sense. Your turning nearly 3000rpm in third at 60mph in a vehicle that is lighter than the subject Wagoneer of this thread turning 2.73 or 3.31 stock gears.

Big difference.

[204wagoneer]

ok, so going to 9.0 comp pistons is good, do I buy them or do I mill the heads to get 9.0?

[82Waggy]

The factory cams are as follows

304/360 Intake duration 263.5
401 intake duration 296.32
304/360 Intake duration 263.5
401 intake duration 303.55

Valve overlap
304/360 41.5
401 68.32

Cam lift
304/360 .266
401 .286

Here is my experience with the 256xe. Every single one I have used or sold minus one (Donwag) have had low power at idle and dumped off at 3200rpm. They have been a huge dissapointment. The 256Xe specs are as follows

Duration 256/268
Lift .477/.484

We have had bad experiences building power with this cam over stock and we believe it is due to the low lift and duration. On the flipside we had great experience on a 304 with a Edelbrock performer camshaft, mixed results with a 360 and poor results with a 401. Here are the numbers for the Edelbrock.

Duration 278/ 288
Lift .448/ .472

Do you know what he .050 duration is for the stock cams?

The XE256 and Edelbrock performer cams both have an LSA of 110. Narrow LSA's tend to make the torque curve peakier, increase overlap, and decrease low end torque.

Longer LSA's tend to extend the torque curve out the rpm range and build better low end vacuum and torque. It is my "feeling" that an LSA of 112 or better is more suited to AMC engines. Perhaps it is the shorter LSA of 110 that is the reason for mixed results with the performer and XE256.

The LSA for a stock 401 cam is 116, for a stock 360 cam LSA is 113.

Here are the general effects of LSA on cam performance:

LSA Effects, Narrow, Wide
Intake Open, Earlier, Later
Intake Close, Earlier, Later
Exhaust Open, Later, Earlier
Exhaust Close, Later, Earlier
Overlap, More, Less
Cylinder Pressure, Gain, Lose
Idle Quality, Worse, Better
Idle Vacuum, Less, More
Torque Curve, Peakier, Flatter
Peak Torque, More, Less
High RPM, Drops Off ,Hangs On

The effects of longer LSA is why I generally recommend what may seem like relatively shorter duration cams - in order to close the intake valve sooner to help build/retain cylinder pressure and the longer LSA to extend the torque curve.

[82Waggy]

ok, so going to 9.0 comp pistons is good, do I buy them or do I mill the heads to get 9.0?

Check with Bulltear on a piston recommendation. Short of going with a custom forged piston, I think there are only two or three choices for off the shelf pistons that are all cast with the trough head design and I am not sure about compression ratios acheived with these.

Nothing wrong with cast pistons in general for your application.

One of the problems I see with a 360 is the rather large piston to deck clearance (.012 stock) and less than optimum stock piston head style that makes it difficult to acheive good quench.

[mycj7]

I put the Comp Cams 268h in my 360 on a recent rebuild (was gonna be either that cam or the 256XE cam). Loads of low end, strong until 5,000 rpm.

It has enough power to smoke a 37" Bogger on pavement.



If you don't mind responding, what axle gears are you running, and do you have 3spd, 4spd, or auto tranny?

Do not mind at all, I love chatting about my Jeep!

Axle are D44 front, 9" rear mini spooled with 4.88's.
Auto Tranny TF727 (3 speed auto).
D300 t-case.

Tall gears on those tires yielding higher rpm range with that cam makes sense. Your turning nearly 3000rpm in third at 60mph in a vehicle that is lighter than the subject Wagoneer of this thread turning 2.73 or 3.31 stock gears.

Big difference.

Aye, just giving an opinion as to what worked for my application. I am not a cam expert by any means. Just offering information that will hopefully help someone make a good decision on thier build up.

[82Waggy]

Aye, just giving an opinion as to what worked for my application. I am not a cam expert by any means. Just offering information that will hopefully help someone make a good decision on thier build up.

Understand.

I am just trying to point out that application is critical to performance.

Very good information.

[204wagoneer]

ok, how does this sound

360 block, overbore will be determined by whats there when I tear it down. zero decked w/.045 head gaskets

rebuilt/reman heads- stock

9.0 to 1 pistons

summit 8600 cam kit/ double roller timing set

bulltear cam bearings and rocker arms

new front cover

edelbrock performer manifold and 600 carb

thorley headers and a single exhaust 2.5 or 3 inch

full rebuild kit/ bearings seals etc.

upgraded ignition HEI/MSD or the like.

will upgrade cooling and fuel system for reliabilty sake.

sound like a plan?? decent first build for 84 wag w 3.31 gears and 31 inch tires. If I go to 33 inch tires I will re-gear to match.

=D> :!: =D>

[jeepsr4ever]

The factory cams are as follows

304/360 Intake duration 263.5
401 intake duration 296.32
304/360 Intake duration 263.5
401 intake duration 303.55

Valve overlap
304/360 41.5
401 68.32

Cam lift
304/360 .266
401 .286

Here is my experience with the 256xe. Every single one I have used or sold minus one (Donwag) have had low power at idle and dumped off at 3200rpm. They have been a huge dissapointment. The 256Xe specs are as follows

Duration 256/268
Lift .477/.484

We have had bad experiences building power with this cam over stock and we believe it is due to the low lift and duration. On the flipside we had great experience on a 304 with a Edelbrock performer camshaft, mixed results with a 360 and poor results with a 401. Here are the numbers for the Edelbrock.

Duration 278/ 288
Lift .448/ .472

Do you know what he .050 duration is for the stock cams?

The XE256 and Edelbrock performer cams both have an LSA of 110. Narrow LSA's tend to make the torque curve peakier, increase overlap, and decrease low end torque.

Longer LSA's tend to extend the torque curve out the rpm range and build better low end vacuum and torque. It is my "feeling" that an LSA of 112 or better is more suited to AMC engines. Perhaps it is the shorter LSA of 110 that is the reason for mixed results with the performer and XE256.

The LSA for a stock 401 cam is 116, for a stock 360 cam LSA is 113.

Here are the general effects of LSA on cam performance:

LSA Effects, Narrow, Wide
Intake Open, Earlier, Later
Intake Close, Earlier, Later
Exhaust Open, Later, Earlier
Exhaust Close, Later, Earlier
Overlap, More, Less
Cylinder Pressure, Gain, Lose
Idle Quality, Worse, Better
Idle Vacuum, Less, More
Torque Curve, Peakier, Flatter
Peak Torque, More, Less
High RPM, Drops Off ,Hangs On

The effects of longer LSA is why I generally recommend what may seem like relatively shorter duration cams - in order to close the intake valve sooner to help build/retain cylinder pressure and the longer LSA to extend the torque curve.

Yep and I still recommend the K8600

Here is his original question


ok, so I just turned over 184k on my Wagoneer 360/727/208. I am in the process of buying a running 360 fron a 79 cherokee. I want to build a mild 360, mild like 200 hp is fine. I am willing to overbuild(spend the extra money) for reliability, but not real interested in big hp, but torque would be nice.

What do the experts here suggest??


If he is running a 1979 360 he will want a little more midrange without sacrificing lows. When I say midrange I am talking about 2500-4500. Asking for 200hp wont be hard at all on a re-ring and a cam if you have a 4bbl intake on that 79 (Cherokee) AMC 360. Chances are if cam complete you have a 4bbl and a 4bbl intake. Most Cherokees has the power option of the wagons of the 70's and alot of them were 4bbl. 79 was a funky year for for all because alot of big block motors and our beloved 401 was taken out of service. Its hard to say if it does have a 4bbl but I would bet $5 on it :?: Having alot of personal experience with power gains on 4wd jeep drivetrain I really would suggest the K8600 if you re-ring.

[82Waggy]

Well,

With 3.31 gears and 31" tires, RPM in third gear at 60MPH is 2274, at 70MPH your RPM is still only 2653 (you happen to be running the same set up as me).

Your maximum useful RPM based on TF727 gear ratios is 4000-maybe 4500. Based upon 1st and 2nd gear acceleration you should shoot for peak torque at around 2500-3000rpm (peak will probably end up closer to 3500 or more with a K8600) with as wide a curve as possible.

Personally, I would use a single pattern cam with less overlap and duration for more torque in this rpm range, something along the lines of an Engle 5052H (254d) or maybe a 5054H(260d). These cams have fast ramps that take advantage of the large diameter AMC lifter, yielding relatively longer .050 duration for their total duration than run of the mill cheby grinds while keeping overlap low for good torque.

But hey, try what you want and change it if you don't like it. I plan to try both of these Engle's in my 401 with 9:1cr, and maybe a Crwr 276HDP for grins.

[82Waggy]

For the sake of discussion, a word about overlap and piston dwell time as it relates to AMC 360's and 401's.

The longer stroke of the 401 means that the piston hangs around at top dead center a little longer during the intake to exhaust valve overlap period (longer arc between say when the intake opens at 18degrees BTDC and the exhaust valve closes at 12deg ATDC), meaning that the 30deg overlap period in this example has more time for the exhaust scavenging through the intake valve to work (or more time for intake dilution to take place at lower rpm). The shorter stroke of the 360 results in less dwell time for scavenging.

This suggests that, if you were trying to get both engines to make peak torque at a similar rpm, the 401 would need less cam overlap than the 360 to get the job done.

However, the intake valve size to displacement ratio is better for the 360, meaning that it is easier to fill the chamber in the 360 than the 401 (same size intake valves in both engines). The 360 would therefore need less valve lift than the 401.

Remember, duration alone only shifts the point along the rpm curve at which peak torque is acheived, and has very little effect on how high peak torque actually is.

For what it is worth.

[82Waggy]

When I say midrange I am talking about 2500-4500.

To clarify myself, when I talk about better low rpm torque for Jeep motors, I am talking about the practical range from off-idle to 4000rpm.

Lower duration, shorter overlap, wider LSA, good lift cams result in higher torque with a wider curve and snappier throttle response in this rpm range.

Gear yourself accordingly!

:t:

[SHARPMACHINE]

Wow,

Awesome thread fellas. I respect how people can differ in opinion here, but not take it personal. :t:

[82Waggy]

ok, how does this sound

360 block, overbore will be determined by whats there when I tear it down. zero decked w/.045 head gaskets

rebuilt/reman heads- stock

9.0 to 1 pistons

summit 8600 cam kit/ double roller timing set

bulltear cam bearings and rocker arms

new front cover

edelbrock performer manifold and 600 carb

thorley headers and a single exhaust 2.5 or 3 inch

full rebuild kit/ bearings seals etc.

upgraded ignition HEI/MSD or the like.

will upgrade cooling and fuel system for reliabilty sake.

sound like a plan?? decent first build for 84 wag w 3.31 gears and 31 inch tires. If I go to 33 inch tires I will re-gear to match.

=D> :!: =D>

Looks about right. I've got tri-y's myself, 31" tires. 3.31 gears, 9:1 cr.

Performer manifold and 600 vac secondary holley should be spot on for your rpm range.

[82Waggy]

Wow,

Awesome thread fellas. I respect how people can differ in opinion here, but not take it personal. :t:

Nothing personal at all.

Just looking for why things work or not.

We are probably just splitting hairs.

[jeepsr4ever]

:mrgreen:

[Goose]

See it's all good here.. (I'm thinking it is equal parts respect, Brotherly love (Blecchh) and copius quantities of mood and mind altering substances) Of course it may have to do with spending too much time in the garage with the engine running playing air guitar to old molly hatchet tunes...(Or is that just me? :oops: )

:mrgreen: 8)

[82Waggy]

See it's all good here.. (I'm thinking it is equal parts respect, Brotherly love (Blecchh) and copius quantities of mood and mind altering substances) Of course it may have to do with spending too much time in the garage with the engine running playing air guitar to old molly hatchet tunes...(Or is that just me? :oops: )

:mrgreen: 8)

It's just you Goose!

Around here, deep in the heart of central Texas, its Margaritaville all the way baby!

:razz:

[Dusty]

im still with mc these engine have plenty of smooth torque off idle even with the 220-224 dur cams, true the 112 lobe sep is a smoother curve the 114 is even smoother still. thats why i think the 480 lift 222dur @ .050 114 lobe sep cam works so well in 401s. but with an amc i hate when i run out of power at 4000 rpm. these motors do exceptionly well with a peak torque being produced at 3500-4000 rpm and a curve from 1500-5000 (5500) vs peak at 2000-2500 with a curve from idle to 4000 because the curve and power level you are more in the middle of the power than at the peak when driving.

IMHO i like having the extra umph when i want or need it just a few more rpms and a set of secondaries away vs cruising down the highway at 2800-3200 rpm and knowing that downshifting or kicking down a gear and knowing my motor wont peter out at 3500-4000 rpm like the smaller cams like to do. my 260 comp cam is too small in my 401 wshen passing someone the thing pulls hard to 3500 rpm about there though you can feel it flatten out and by 4k its still pulling but noticibly not as hard. then 4500-4800 when you wish it was still pulling well so you didnt have to drop into another gear to maintain speed the speed you are at. 82 wagg makes good points but all my amcs aside from this abortion have been geared with 3.73s-4.56s with 33's and 35's cruise down the highway between 2500-3000 rpm in direct and have cams that keep em open to 5500 rpm and the motors do just as well as what my buddies who run smaller cams do.

Funny they always wonder why on donner summit ect i pull away more so than they can when we are both running 401s in our waggys.

Gearing and cam selection are key.
82waggy had some great info in this thread as well there was some other debates about camshafts in 401's and intake carb combos that yeilded different results.


http://www.bulltear.com/forums/viewtopic.php?t=5924&postdays=0&postorder=asc&start=0

[Goose]

Im good with the parrot head thing.. It's just that I never got any 8 tracks of Jimmy buffet, but Molly hatchett and the police
..and since my old pioneeer supertuner is still working!! (did you know you can still buy 8 track shells and tapes.

[Dusty]

Yeah Yeah Yeah. DY----NO----MITE ...... BABY

[82Waggy]

IMHO i like having the extra umph when i want or need it just a few more rpms and a set of secondaries away vs cruising down the highway at 2800-3200 rpm and knowing that downshifting or kicking down a gear and knowing my motor wont peter out at 3500-4000 rpm like the smaller cams like to do.

all my amcs aside from this abortion have been geared with 3.73s-4.56s with 33's and 35's cruise down the highway between 2500-3000 rpm in direct and have cams that keep em open to 5500 rpm and the motors do just as well as what my buddies who run smaller cams do.

Gearing and cam selection are key.


You are clearly geared lower than most Dusty.

All I can say is that donwags dyno sheet and jeepman401's dyno sheet seem to confirm what I have been talking about.

I am not a fan of the 260H either. With only 447 lift and an LSA of 110 I would expect it to run out of steam pretty early with your gears.

Good lift helps extend the rpm range as well as a wider LSA.

An additional trick is to choose a lift in excess of that necessary to acheive best flow so that the valve passes the optimal lift point twice, once while opening and once while closing. This theoretically helps so long as the excessive lift does not cause turbulence. Might be kind of hard on the valve train as well.

[82Waggy]

thats why i think the 480 lift 222dur @ .050 114 lobe sep cam works so well in 401s.

Which cam is that?

[Dusty]

3.54's with 32's my 260h the cam card calls out 112 lobe sep.

the 4.56's were on 35's in a cj most of my cherokees and waggys are 3.73/ 3.92/ 4.10 or 4.27. i preffer the 4.27 gears for cruising and towing :lo1l:

Ive seen thier dyno sheets i studied them and decided i wanted to move the power about 500 rpm + higher than thier setups. somewhere ive got a couple of my engine dyno sheets. good luck finding them in my garage 111!!! but when i did my last build the torque and hp numbers ended up similar at the same rpms as don wags very close like within 5-10 (hp and/or ft/lbs) across the low rpm range upto 3500 rpm but my peak numbers were defiantely higher and my operating range .... the curve was broader and the power was available longer.



food for thought i love these threads so many ways to do the same thing

[82Waggy]

You also be runnin some pretty stout compression there Dusty, (helps retain bottom end torque when running longer cams).

Comp catalog says 110lsa for the 260h, but that would not be the first time I have found errors like that.

I'm probably going to try this cam first in my 9:1cr 401 with 3.31 or 3.54 gears on 31" tires.

Engle 5054-H
112lsa
260,260adv
214,214@050
501,501Lift
36deg Overlap
1200 - 5200rpm

[jeepsr4ever]

82 I like the specs on that cam!

[82Waggy]

I used a spreadsheet to plot out my rpm range in each gear at various speeds.

Using 3.31's at 70mph I'm only turning 2653rpm. If I slow to 60mph in third I'm turning 2300rpm, then drop into second to accelerate/pass I'm at 3300 and wind out in 2nd to only 3847 at 70mph. Rarely would this setup see much over 4000rpm in normal operation, if that.

Based on that, hoping for some mpg's at hwy cruise rpm, and 1st gear grunt, I'm shooting for a power range out to only 4000rpm, but do not expect to suffer too much out to 4500 should I choose to hold it in low gear for a while.

If I end up with a power curve similar to donwags I would be pleased, but I hope to shift to the bottom end a bit more with slightly higher overall numbers. For those that don't know, Donwags engine made 400ftlbs from 2000-4400rpm with a peak of 428ftlbs at 3400rpm - pretty flat and strong for a 256 duration cam - with that curve I would want to run taller gears than 3.31's.

[82Waggy]

82 I like the specs on that cam!

Yup. I keep coming back to it in all my research.

Compared to donwags Comp XE256, the Engle 5054H is a single pattern cam with 2 degrees more LSA, 6degrees less overlap, more lift, and quicker ramps (slightly more .050 duration). It should widen and raise the curve a little with out sacrificing anything.

We'll see. I guess I should spring for a day on the dyno. $1000 bucks to find out I screwed up! :smile:

[82Waggy]

Beleive it or not, I have a question!

I have not checked myself yet so here goes, how much lift before we start running into valve to piston clearance problems on these things?

[Dusty]

howards offers it as a single pattern .479 lift 222 dur@.050 292 adv dur 114lobe sep. (in a 8.7:1 401 motor torquer intake (I KNOW) and a 600 edelbrock) 3.73 gears 33" tires and a 4 spd in a cj5 chugs down to 400 rpm and will wind right up to 5500-6k


Crower also offers a similar grind to it as well #293hdp .477lift 223 dur @.050 on a 114. (i have no experience with this one though)


comp did the 270h which had a narrower lobe sep but similar lift and dur numbers.....


.512/.525 and no clearance problems..... :-|

i like those specs too

[82Waggy]

howards offers it as a single pattern .479 lift 222 dur@.050 292 adv dur 114lobe sep. (in a 8.7:1 401 motor torquer intake (I KNOW) and a 600 edelbrock) 3.73 gears 33" tires and a 4 spd in a cj5 chugs down to 400 rpm and will wind right up to 5500-6k


Crower also offers a similar grind to it as well #293hdp .477lift 223 dur @.050 on a 114. (i have no experience with this one though)


comp did the 270h which had a narrower lobe sep but similar lift and dur numbers.....


.512/.525 and no clearance problems..... :-|

i like those specs too

Dang Dusty!

You seem to get away with breaking all the rules. :sa:

I was actually going to say before that at the rpm ranges you like to run up the pass a torker may be pretty good. Have you played with both single a dual planes in your applications?

[82Waggy]

I think I now have a pretty good mental picture of what Dusty must look like with his crazy motors in little CJ's.

Remember those old Rat Fink cartoon hotrod monsters with bulging eyes, big toothy grins, and hair on fire with shifters sticking through the roof.

I'm all cracked up!

111!!!

[Dusty]

i have no idea why that combo works so well in the cj. it shouldnt. the motor is a throw together and is the best running out of our bunch of 401s

Your logic is better founded. Believe me I never thought this thing would run worth a hoot. It happened to be I had the cam sitting her and my buddy had a 401 in a wagoneer that had 150k miles low oil pressure ect ect ect smoked barely ran….. and his cj the 360 was dust. We took a set of heads in had then gone through for dirt cheap and it was a poor valve job at that. Slid this cam in kept the stock pistons and stock bore reringed it with cast rings el cheepo polished the crank didn’t even turn it. Honed the cylinders, threw in some new std bearings, new cam bearings, new oil pump gears from bulltear the torquer just happened to be there so it was free. And since building the thing does nothing but blow my mind.

IT shouldn’t work as well as it does, its in my buddies jeep ….. I just don’t get it on that one but since then ive really started pushing the rules on these 401s and been having a lot of fun. Performer is preferred over the torquer

[82Waggy]

Sh!!#$T

I'm still laughing!

:oops:

[82Waggy]

Quit it.

Your Killing me.

I'm going to go take a pill and walk through the woods now.

[Dusty]

thats what im sayin man its like the motor that should have never worked and it embarasses the rest of us every fricken time. :(:

too bad you arent out in sacramento, theres an open invitation if you ever want to ride in it.

I laugh too because the story of that cam is one that i laugh about. when first researching 401s and before i had found bulltear... back in the 1990's i ended up on the phone with Don Johanson the son of Howard johanson of howards cams and he suggested trying this cam in my motor at the time which was going to be 9.5:1 but instead i ended up going with a different cam and this one got filed

[82Waggy]

too bad you arent out in sacramento, theres an open invitation if you ever want to ride in it.

That would be a blast!

Then I could say I survived the one that wasn't sposed to work.

Same invitation goes to you, if ever your in Texas.

[Dusty]

You also be runnin some pretty stout compression there Dusty, (helps retain bottom end torque when running longer cams).

Comp catalog says 110lsa for the 260h, but that would not be the first time I have found errors like that.

I'm probably going to try this cam first in my 9:1cr 401 with 3.31 or 3.54 gears on 31" tires.

Engle 5054-H
112lsa
260,260adv
214,214@050
501,501Lift
36deg Overlap
1200 - 5200rpm


I think this will be a really nice setup. my 3.54's with 31's were a nice combo

[82Waggy]

I think this will be a really nice setup. my 3.54's with 31's were a nice combo

Thanks, I hope so.

I just posted my 401 machining and parts list in a new thread if anyones interested - may help others organize their engine projects..

[Dusty]

Im going to repost... copy this and slide it in, food for thought on some of the combos and how they seemed to work

360-270h 9.2:1 ran good
360- 258EX 9.0:1 ran good
401 - Crower 284hdp? 512/525 lift 112 lobe 9.8:1 r4B combo ran great, towed was lots of fun
401- 8601 9:1 51cc heads on 8.5:1 pistons with the 8601 / performer - good. fun with a t-18
401 - howards .479 222dur@.050 292dur 114 lobe sep- 8.5:1 torker (dotn ask) and 600 - good
401 - Howards .479 cam - 10.2:1 and FI - so so think it may have been the fuel injection hindering performance
401 - 512 lift 274 dur 226@.050 112 lobe sep 10.2:1 with performer and 750 pretty fun mild idle great through to 5000/ 5500 4.56's with 35's
401 - 9.6:1 270H Air gap and 770 so-so with a 670 and performer the same motor picked right up works great as a tower and mileage getter 3.92's on 33's
390 - 10:1 R4B -700 - 276HDP Crower- OK performance done too soon rpm/power wise left a little to be desired on the mid upper and top end. in a 72 Wagoneer with T18 4.10s 32's
401 - 9.8:1 EX262h Comp - airgap and 750 pretty nice combo was snappier off the line with a performer but the airgap opened up mid and tops. tows pretty good in a J20 they said it was a 110 lobe sep but when it arrived the card said 112
360 - 10:1 343 pistons - EP20HYD Engle - Performer/700. Nice combo compression could have been a little lower but overall liked this combo it did really well with a TF727 and 3.92's in a J10. Had no problem on pump gas but towing it liked premium from time to time.

theres a few others in there
Oh yeah current cherokee is a 401 9.8:1 witht he 260h in it and 354 gears on 31's (&32's) and a TH400 performer and 750 edelbrock tows great but she is done at 4000 rpm so kicking down to passing gear and trying to extract a few more rpms out of the motor with a trailer is not an option just staying in direct gear does pretty good on most hills loaded


i know its always been weird, the power does always seem to be there i can say the 280h in a 360 with a torquer and 800 was Way too much lol on 9.2:1. the PAW cam was close to the 270h in profile not the 8601.


On a recent 401 built i liked that 262EX from comp i think it would be pushing it for a low compression 360 but then again maybe not it might be a little large but may offer an interesting package.

several friends run the 8601 and 8600 and both of which have seemed to work well in the right applications the 8601 in a 401 with higher compression and 8600 in a lower compression 401's and in 360's the 8600 has proved to be nice when coupled to a 9:1 or 8.8:1 a performer and 600 or so carb. but i have not recently built anything personally that i can comment on, just what others have done and how it has performed

[82Waggy]

So Dusty,

Just to summarize, would you say that in general your impressions were based upon looking for best towing power in the 3000 - 5000 rpm range?

Just my general observations on gearing versus cam used and your impressions suggest that a little more appropriate matching of gear ratios and probably all of those cams would have felt pretty good.

You've got some pretty big gears in that list so I suspect you never felt lacking for bottom end - also assume you had to shift pretty fast through first and second in some of those setups!

PS: Stop confusing everybody LOL! #-o

[Dusty]

correct. which is where your philosophies and proper matching of gears to hp comments and data play a huge role.


though i like to think the world over 5k is relevent, reality is it is not.

though i do like b uilding a motor that functions up to 5500 or redlines at 6k thats about the max of my operating range i still do most my driving between 2000-3000rpm at 1/4 to 1/2 throttle .....WOT with full load is the only time the engine operates outside of that range. Like a hard hill climb but even then most the time im right at or in the 3500 rpm range singing right along 111!!! #-o I think best towing power is between 2500-5000 with the peak at in the area of 3500-4000 but still carrying the torque at or above 400 ft/lbs to 5k is important and having 400 ft/lbs from 2000 rpm up is essential too.



I know i just went against everything else i was thinking and typing.

Does that make any sense. probably not. shoot i'll get back to this thought maybe i can explain myself in different words in amoment. LOL

[82Waggy]

I know i just went against everything else i was thinking and typing.

Does that make any sense. probably not. shoot i'll get back to this thought maybe i can explain myself in different words in a moment. LOL

Makes all the sense in the world.

:!:

[Dusty]

So Dusty,



PS: Stop confusing everybody LOL! #-o
:wink:
i know what im trying to get at but sometimes communicating it doesnt come out the right way. i think the list of cams/ cabs and engine combos speaks best for my intentions and what has worked for me and what i liked and how they worked.
I just like emphisise not cutting these motors off at the knees and i feel like 4k-4500 redline is doing just that and not allowing them to take full advantage of how well they can perform.

Yes i do get confusing some times. :idea: and i know it kinda like a pin ball sometimes

we'll meet someday and we should all have a bulltear gathering ---- in colorado so that its about middle for everyone and still have a jeep trip.

[82Waggy]

So Dusty,



PS: Stop confusing everybody LOL! #-o
:wink:
i know what im trying to get at but sometimes communicating it doesnt come out the right way. i think the list of cams/ cabs and engine combos speaks best for my intentions and what has worked for me and what i liked and how they worked.
I just like emphisise not cutting these motors off at the knees and i feel like 4k-4500 redline is doing just that and not allowing them to take full advantage of how well they can perform.

Yes i do get confusing some times. :idea: and i know it kinda like a pin ball sometimes

we'll meet someday and we should all have a bulltear gathering ---- in colorado so that its about middle for everyone and still have a jeep trip.

I understand completely. I meant confusing everybody with all those wacky motors LOL.

I think everybody starts jumping up and down everytime somebody comes on wanting a cam recommendation without thinking about it being for a stock compression rebuild. I know for sure some of the longer cams you have used would kill the bottom end torque of a stocker on factory gears. Most Waggy's came with 2.73's for goodness sake!

So I always try to back people down to more realistic rpm ranges until they realize that to do a rebuild right new pistons are usually required, so you might as well bump compression a bit if you can. If new gears are in order too than I don't mind talking about more cam.

I once made the mistake of overcamming an SBC I had swapped into a Toy FJ40. I also stuck a Torker and a 700 dbl pumper on at the same time. Bottom end went by by and had less peak power than before (600vac sec and corvette dual plane originally). No throttle response, nuthin. Never got a chance to put the smaller carb back on or try anything else before a kid thought it sounded so cool it just had to be fast and bought it off me.

Look forward to a Jeep trip.

Anyway, I am sure between you and I we have completely confused the original poster of this thread LOL.

Glad to be of service!

:?:

[204wagoneer]

The original poster of this thread is THRILLED to get so much good advise.

Its nice to have people that are willing to chat without a bunch of BS drama. Its all for a silly little ol jeep, well not so little I guess.

anyway, I'll be starting in on this build in about a month. I see a smooth, reliable 300 ish hp 360 gleaming on the horizon.

here's to 200 k more miles of Jeep Lovin............

:lo1l: :t: :lo1l:

[82Waggy]

The original poster of this thread is THRILLED to get so much good advise.

Its nice to have people that are willing to chat without a bunch of BS drama. Its all for a silly little ol jeep, well not so little I guess.

anyway, I'll be starting in on this build in about a month. I see a smooth, reliable 300 ish hp 360 gleaming on the horizon.

here's to 200 k more miles of Jeep Lovin............

:lo1l: :t: :lo1l:


It's always fun. Cam questions always spur debate.

One nice thing about cams, if you don't like the results, try a different one. I'm sure Dusty always has a spare laying around LOL!

Kind of a pain to pull timing covers but the intakes and valve covers come off easy on an AMC. Once you have established a baseline for your setup and gain an understanding of the effects of different cam specs, choosing the second one is usually easier.

[1980_Cj7]

Yeah, the worstest part is the timing cover with all the accessories with all their different length bolts and spacers and what have you. Don't know about the intake coming off so easily either. We could have picked up our engine by the intake WITHOUT any of the bolts in it, when we had to pull it. Guess we had it sealed well, ha, ha.

I'm gonna throw our cam specs out one more time for discussion. From what I've been reading, sounds like it should be reasonable. Hard to tell from our first rebuild with the timing gear having been installed wrong and the timing all screwed up though.

Clevite part number 229-1972.
Advertised duration: 294
.050 duration: 218/218
Lift: .488/.488
Lobe C/L: 110
Intake lobe center: 105
Exhaust lobe center: 115
Intake open @ .050: 4 BTC
Intake close @ .050: 34 ABC
Exhaust open @ .050: 44 BBC
Exhaust close @ .050: 6 BTC

One thing that has me confused though is in that great cam article that 82Waggy put me on to a while back...

http://www.compcams.com/Community/Articles/
(Scroll down to the article titled "Be The Camshaft Expert")...

they say LCA is the most critical thing in chosing a cam, and show how you calculate what it should be by using engine displacement and intake valve size and a graph they have. According to that, our .040 over 401 should have an LCA of 104 degrees.

[82Waggy]

One thing that has me confused though is in that great cam article that someone put me on to a while back, they say LCA is the most critical thing in chosing a cam, and show how you calculate what it should be by using engine displacement and intake valve size and a graph they have. According to that, our .040 over 401 should have an LCA of 104 degrees.

Yup. Keep in mind they were talking about obtaining max peak output, not necessarily a wide torque curve in the lower rpm ranges. Remember also that they were relating this to the intake/exhaust valve overlap phase as the key to making peak power and stated that you only wanted a lot of it if your exhaust system sucked, literally - any restriction/backpressure and you were sunk, due to intake dilution. Short LSA = increased overlap. Might also note that lower duration with higher lift made more total power, and did so at a lower rpm range.

[1980_Cj7]

Well, after looking up that old post, after only 6 edits, ha, ha, I finally managed to give credit to 82Waggy for originally posting the link to that cam article, and actually reposted the link.

I swear, the more I read about cams, the more confused I get.

[82Waggy]

I swear, the more I read about cams, the more confused I get.

Understand. It was my own frustration with seat of the pants recommendations many years ago that lead me to study this stuff for myself. Unfortunately there is a lot of co-mingling of terms (LCA vs LSA for example) and advertising hype that adds to the confusion. Bigger is not always better.

Just use the cam you have to establish a baseline, see if you can determine at what rpm it pulls well for your setup. If you are not satisfied with it, try to apply what you have learned to make a decision on an alternative cam - make changes in small steps.

Hell, I don't expect to hit my choice for a cam dead on the first time either.

[1980_Cj7]

The other thing we're going to do, is not count on the machine shop this time, even though this one is supposed to be really good. When we get the engine back, it won't have the timing cover on yet, so I'm planning on taking it down to Fuzz's while it's still in the back of the truck, and degree the cam and double check it for ourselves. He's got all the tools to do it. (We just didn't tell Fuzz yet, ha, ha, so don't let it slip. We're gonna surprise him some night that Mrs. Fuzz is having something good for supper!)

We have all kinds of adjustability with the Rollmaster timing set. I have a pretty good idea of what changing the intake events does, but not such a good feel for what changes to the exhaust events that have to follow along will do. But...I don't want to be hyjacking the thread here.