New motor project

[littlejohn]

Just picked up a 360 to go into my CJ. Had been looking for a 401, but haven't come across one. I have a 360 from a waggy in there now, completely stock with an MC2100. It runs well (even on it's side), but am looking to get some more power- both on and off road. I mostly play in rocks, so low rpm torque is what I'm looking for. Considering TBI to maintain off road-ability. Looking for around 300hp, with a good, broad, torque curve. Anyone got a recipe?

[tufcj]

I'm getting about 325. I have a 360 w/stock pistons. I'm running 291-C heads (ported, polished, gasket matched, unshrouded w/1.68" ex valves), Edlebrock performer package, roller rockers, and Howell TBI. Out factory manifolds into a 3" single exhaust. Mine has enough torque (and 72:1 low/low) that it can spin all four tires (Detroits in both ends) at idle while rock crawling.

Bob
tufcj

[littlejohn]

What is a 291-c Head?
I'm hoping to use the stock heads, with a good vavle job. I've heard the performer stuff works well.

I'm locked at both ends as well. I'm only running a 45:1 crawl ratio, but supposedly double that for the automatic.


I'm thinking Performer cam& intake then a TBI. Any idea of where I'll be?
Is there a better cam to use?

[fifesjeep]

I personally like COMP CAMS... the 270h cam is nice for the 360... It has a little better performance than a stock cam (more hp and torque from idle, with a noticable idle)... With your heads, If you have the bridged rockers.. you're sort of limited unless you have them machined to fit rocker studs (There are bolt on rockers but you'll be looking at $$$) Ask around here, I'm certain they sell them here for a good price. Toss on a performer intake, and a TBI and then some headers or have the stock exhaust manifolds and gaskets matched to the heads... then run a 2 into 1 exhaust running through either 2 1/2" or 3" exhaust pipe.. she'll be free flowing then with more than enough grunt/performace and decent mpg on the road. Also a good 3 angle valve job will help wonders, You could always drop some 1.7:1 Roller Rockers to give you a little more umph, (torque etc) at the lower end as-well.. Just make sure the valve geometry is correct so that you don't wear the valve guides sooner than normal due to too much side loading...
The 291-C heads are highly sought after due to the CC... and valve sizes etc... Honestly don't even worry about these heads.. that later heads seem to flow better anyway... Given they have a larger CC they're IMO the better choice for performance gains for cheap $$$ plus the 291C heads are next to impossible to get your hands on.... Too many AMC junkies running around grabbing them up and letting them collect dust in the garages/sheds/closets, etc... I know a couple!!!! :(:
With the Comp Cam 270H set, performer intake with TBI, 3 angle valve job, headers or a set of matched or "worked" stock exhaust manifolds with a two into one and running that into a 2 1/2" to 3" exhaust pipe... and even toss on some 1.6:1 Roller Rockers... you'll be pushing 290-330hp some where in that range depending on set-up etc.. I'm sure others will jump on this...

I'll sell you my 360 which is pushing well past the 300hp range!... I have around $6000 into it with receipts (parts/machining)... I'll let it go for $4500 :shock: 8) :razz:

[AMX69PHATTY]

Guess y'all have seen last years January 2006 Car Craft Magazine
with the article where the built an AMC 360 that made 480 HP ?
Same mag also has coverage of the 2005 AMC Nationals,
and a Pontiac 455 with aluminum heads that made less than 400 HP.
The 480HP AMC 360, actually a 370, offset ground crank to 3.48 stroke,
is for a Car Craft project RAMBLER ! they say wieghs only 2500 lbs.

[littlejohn]

Toss on a performer intake, and a TBI and then some headers or have the stock exhaust manifolds and gaskets matched to the heads... then run a 2 into 1 exhaust running through either 2 1/2" or 3" exhaust pipe.. she'll be free flowing then with more than enough grunt/performace and decent mpg on the road. Also a good 3 angle valve job will help wonders, You could always drop some 1.7:1 Roller Rockers to give you a little more umph, (torque etc) at the lower end as-well.. With the Comp Cam 270H set, performer intake with TBI, 3 angle valve job, headers or a set of matched or "worked" stock exhaust manifolds with a two into one and running that into a 2 1/2" to 3" exhaust pipe... and even toss on some 1.6:1 Roller Rockers... you'll be pushing 290-330hp some where in that range depending on set-up etc.. I'm sure others will jump on this...



This is the kind of rebuild I'm looking for. Simple, straightforward with decent power and driveability. The heads need to be machined to put a 1.6 or 1.7: roller rocker on?

[tufcj]

The 291-C heads (last 4 digits of the casting #) were used in 1970 and early 1971. They were a factory high compression head with a smaller cumbustion chamber than the late 71-up heads. Used on a stock bottom end, they increase compression just with a head change. Like said above, they do have their problems. They are rare and aren't cheap. They need some port work and unshrouding of the valves in the cumbustion chamber to flow as well as the later heads.

Money spent on head work really seems to wake up the AMC engines. Port, polish, gasket match (manifold too), 3 angle valve job. Most say you don't need roller rockers unless you're going high RPM, but I use them just to cut valve guide wear.

The later heads can be fitted with rollers, but you'll need to buy giude plates, then have the rocker pedestals milled about .250" + the thickness of the plates. They will also have to drill/tap the holes to 7/16". You can then use small block chevy studs and AMC (or Ford) rollers.

Bob
tufcj

[John N]

John, you're looking to do the same as me....again. :lo1l: I want to build another 360. Are you going to build it yourself or do you know of someone in the area? I not going to try to build it myself, time/knowledge issues.

[JERSEYJOE]

I have a BRAND NEW NOT REBUILT 360 that I bought from a dealer mechanic a long time ago. It is a short block less camshaft. The block, crank, pistens ect are BRAND NEW.

I was saving it for a project but since then I have obtained a few 401's and a couple of 390's.

I have the 360 wrapped in plastic in my garage.

might want to sell it or trade for something interesting, like a clean CJ 7 tub

[Holeshot]

If you use a 401 block with 3.25" stroke you will get 358 cu. in., I do believe that this is the combo that Shirley Shahan, Wally Booth, & others were using for ProStock, but they didn't have the heads we have now. Close to 560 HP with unported Indy SR-1s. Beats Hell out of 480 HP CC Mag engine!!!

WAIT!!! - This is NOT a rock crawler engine combo!!!!

This would be for someone who wants to go FAST, not slow!!!


http://home.comcast.net/~dhoelcher/amc/post/340_rev.gif

[Holeshot]

Same engine gets 617 HP with 11~1, the heads ported, & Hedman stepped race headers. I also bored it another .010" to get to the common 401 overbore size of 4.195", which can use Chevy 400 smallblock O.S. pistons.

http://home.comcast.net/~dhoelcher/amc/post/360_rev.gif

[Blown7]

I that with boost ?
:razz:



Jeff

[SHARPMACHINE]

I that with boost ?
:razz:



Jeff


Wow 600, how much does yours make with nos and boost???

[Holeshot]

That blown motor should be between 900 & 1200 HP before it scatters!!!

Could have started with a 290 or 304 block & either use a cut-down 401 crank or a custom forged crank. The 390/401s don't have (as much) cylinder wall thickness to contain the massive compression that can be generated in a high boost engine & they can distort & let blow by past the pistons, which can burn a piston & rapidly become a very expensive boat anchor. (maybe concreting the water passages would fix that?)

At least this is what ppl knowledgeable in boosting the AMC engine say (Dick Datson, 21st Century Turbo).

I'm not knocking your project in ANY way!!! I'd give my left nut for that blown engine!!!!

[milnersXcoupe]

AMC rethought the block castings for the 1978 and up models.

How is the nickle content - wall thickness - block strength in these last years 360s ?

Would a 1972 be a better choice ?