Technical Help needed, Not for the weak at heart

[fifesjeep]

I need some in-depth knowledge from the masters of building powerful/reliable engines... I've been racking my brains with formulas and there seems to be no end in sight. I'm not the sharpest "tool" in the shed but when I'm pointed in the right direction I'm dangerous. :?
So... here's my story (or what-ever you want to call it)...
I wanted power, I naively purchased parts and tossed them together without thoroughly matching parts for optimal performance. So I didn't get the right bang for the buck. Now that I have been reading about mechanical efficiency, various formulas, etc... I definitely want to go through my 360 with a fine tooth comb and do it right for maximum performance and reliability. Here is a list of my parts:
Holley 750cfm
Torker Intake
AMC 360 bored .030"
Harland Sharp 1.7:1 Roller Rockers
Comp Cams 280H K-Kit
Ross 10:1 FF Race pistons (-16cc/.140" Dish Depth) (CH 1.596")
Scat Forged H-Beam Rods (5.885")
Crank turned 10/10
DynoMax 1 5/8" Fenderwell headers
ROL head gasket .045"
3 angle valve job
The head and Block were machined but I honestly can't remember how much material was removed from either... so, for simplistic reasons I'm using the stock numbers (Block height/CC's) etc for the formula(s).
With all of those goodies I figured I'd get a nice response and I honestly did... but, I want more... :!: I want this engine to be more mechanically efficient without dumping too much money back into it.

- I definitely want more HP... and I want this motor to be 11:1 CR with a nice .035" to .040" quench... Problem is... My Pistons are dished with a -16cc or .140" Dish Depth and I figured them to sit in the Hole about .017"...

- Obviously sitting in the hole with a dished piston isn't what I want when it comes to performance.

- I really don't want to purchase flat top pistons... I thought about Machining the pistons flat and then having eyebrows cut into them but I'm not sure the thickness of the pistons etc... Plus I'd probably be better off purchasing flat top pistons.

- Ideally, what would be the best positioning for these pistons given these circumstances... Zero Deck or poke them out of the hole a little?

- My heads are the 58cc's... in-order for me to achieve a 11:1 CR with my current pistons I would have to shave my heads .034" which would roughly bring me to 49cc's. (Providing pistons were Zero decked with the dish). My math is probably a little off so please, if you see something that isn't correct jump in and correct me.

-My head gasket is .045" thick which I figured to be roughly +9.78cc's (I didn't figure for the wider opening)

:oops: I totally brain-farted and lost my train of thought. :shock: #-o

- With the given information above what would be the best solution to achieve 11:1 compression with an adequate quench... given the -16cc/.140 Dish depth pistons?

- With the .140" Dish Depth... If i were to mill .017" from the block, .034" from the heads, bump my valve lift up into the mid .600" range with a head gasket compressed thickness of .045" how likely would it be that my pistons slap the valves?

- Does anybody have the average valve to piston clearance for a stock 360?

- With my 1.7:1 Roller Rockers how do I figure how much timing is needed? I was told that with the 1.7:1 Roller rockers the valves will open and shut quicker and I would have to adjust my timing accordingly.

- Would you guys suggest another hydraulic cam (I have one now and I don't care for it)... Mechanical Flat tappet or a roller set-up? I am leaning towards a Mechanical Flat tappet...

- I am planning on tossing in some Chevy SS valves and hardened seats...

Hopefully the AMC minds will read this and give me some insight.
Thanks In advance;
Fife

[AMX69PHATTY]

Vacuum Secondary or Double Pumper Holley ? List Number ?
If a Vacuum Secondary, try the Green #38R-515 Secondary Spring
only available individually from Holley, not in the #20-13 Kit.

Said 9.218" was used for Block Deck Height,
think 9.208" is the stock '70 & up Block Deck Height
--------------------------------------------
Using:
4.110 Bore <-- Stock 360 +.030
3.440 Stroke <-- Stock 360
9.208 Deck Ht <--- Stock '70 & Up
5.885 Con Rod
1.596 Comp Ht
0.007 Deck Clearance <-- assumes no block deck mill
16.00cc Dish Volume
57.92cc Comb Cham
0.045 x 4.265 dia. FelPro Head Gasket

Result:
9.70:1 Static CR
--------------------------------------------
Using:
52.32cc Comb Cham <-- heads milled 0.035, -0.16cc per 0.001 head mill
-0.008 Deck Clearance <--- slugs above deck, block milled 0.015, = 9.193 Deck Height

Result:
10.70:1 Static CR

If block deck was milled 0.015, and heads are/were milled 0.035,
should already have about 10.7:1 Static Compression Ratio and pretty good 0.037 "quench" ?

Understanding is, should have a minimum of 0.100 Piston to Valve Clearance.
Claying a piston is only way to know with all that's been changed.
Was Cam degree'd in ? Straight up ? Maybe retard for more top end ?

Timing, about 37-40 degrees total not counting vacuum advance
all in by about 2500-3000 rpm as long as it doesn't detonate.
What Distributor / Ignition ? Re-Curved ?

What kinda HP is the target ?
With what's there about 400 HP at the Flexplate oughta be possible.

That's alotta questions :shock: :wink:

[fifesjeep]

AMX69PHATTY:
Thanks for your quick response and detailed information.
The Carb is a double pumper... I want to say the part number is 04779c.... I'm having issues reading my own writing #-o $h!t, when I ordered the carb I thought that I read it was slightly under $400... when I checked my statement it was damn near $500... My ol' lady is going to kill me once she looks at my statement... :!: My buddy told me that this carb is over kill for my engine... I think he want's it for his pontiac 400 (70 Lemans)... I'm just now starting to read about Air Capacity and Volumetric Efficiency... My head is already spinning/throbbing. :?

I'm definitely looking at Milling the heads .035"....
Alright, now I'm almost certain that the block was already milled .008" and my heads were milled .014" (Seeing what you wrote sparked a memory)... Of course, when I rip her apart I will double check this.

* I'll definitely check the piston to valve clearance using clay.
The Cam wasn't degreed in, it was installed straight up...

My Distributor is a MSD ProBillet with an MSD 6al ignition module. I haven't got the slightest idea about re-curving... I know that every engine has a certain sweet spot for full advance... I ahve yet to read on this etc.

I'd like to see at a minimal, 420-430hp at the flywheel... more is always welcomed. :t:

I am going to bump the valve sizes up to 2.08 int 1.74 exh

My buddy said that this motor should breath really good with a .600+ lift... with those valves and that I might want to consider tossing the 1.6 rockers on the intake... He also mentioned something about putting a 30 degree angle on the exh valves... I'm not understanding the philosophy behind this...

I always thought that a 3 angle grind would flow better than a single grind... ie? 45* or 30*... am I missing something?

[AMX69PHATTY]

Always thought duration was more important than lift ?
Not convinced more lift will net more HP at these levels.

imho the 4779 Holley 750 double pump is just right for a 360.
Manual or Auto trans ? Stall ? Rear end Gears ? Vehichle weight ?
It's what I run on my 360, 12.6 @ 107, 3200lbs, through exhaust, ~400 HP gross.
Only .488/.488 - 214/214 - 284/284 Cam with 10.2:1 CR dished cast pistons, Torker.

Come up with right at 10:1 CR using 9.201 deck ht, .000 deck clear, and 56.6cc heads.

MSD distributor come out of the box with a very conservitive slow advance curve.
Should have came with pieces to recurve it, springs and stop bushings.
Going by memory, use the Blue stop bushing and the blue springs, check the instructions.
If the advance is set-up slow, fast curve may add 30 HP maybe.

Valves same way as Lift, at these levels not convinced bigger will help.
Understanding is nowadays pretty much any standard valve job is a 3 angle.
Have read for AMC 30* or 45* is better, but don't remeber which.

Milling the heads for 11:1 CR, re-curving the dizzy, and degreeing the cam to get
~8.5 to 9 to 1 Dynamic Effective CR should get it to higher HP levels.
Use the Dynamic Compression Calculator at the Keith Black SilVoLite web site to calculate Dynamic CR.

Seems the right pieces are there, just need to tweak it a bit.

[fifesjeep]

So you're saying... go with a cam that has a bigger duration and not necessarily a larger lift. From what I understand the duration will help to keep the valves open longer at higher rpms. What about at lower rpms? Would the larger duration affect the dynamic compression? Or does that strictly depend on the Lobe Separation?...
-I read an article that said with a Smaller the lobe separation the intake will close sooner and the exhaust will stay open longer making the engine think it has a higher CR.
-So where would the fine line be for a smaller lobe separation and a larger duration?
-I also started reading about scavenging and what is considered efficient scavenging and I had to stop reading... because at that point I felt like I was learning a new language... My head was going to explode... :-|
-I think I am trying to figure out/understand way too much way too fast... lol. On top of understanding the compression ratios, formulas, the quenching effects, cam designs etc. I'm stuck on trying to understand the affects of polytrophic values, atmospheric pressures etc... wtf!? Some of these formulas I swear are at Einstein's level... 111!!!
-Earlier I was figuring the Air Capacities and volumetric efficiency... but, I didn't get too far for the reasons listed above.
-This motor will be going into a Rambler or a beat-up looking Javelin... But, until then, this motor will be in one of my Jeeps :!: T-18, 4.56 gears I'm not sure about the weight though... lol
I have a pretty good tech article about the distributor and re-curving it... I haven't read it though... (I'm slowly getting there).
Please bear with me as I back track a little...
-If I have a Deck Height of 9.193" My pistons will poke out of the hole .008" and that will essentially put me with-in my proper quench window is that correct?

[AMX69PHATTY]

Yes, if block deck was milled .015 from 9.208 to 9.193 the 1.72 throw, 1.596 CompHt, 5.885 Rods
will stick the piston out .008 above deck and give .037 Quench, around the piston lip anyways.
Idealy, the piston dish shape should match combustion chamber shape, wouldn't sweat it to much.

Cam, more or less impossible to have a cam that's good at both low & high rpm.
Horsepower is a product of torque and rpm, ship torque peak up, and HP is increased,
but low end grunt is compromised, one cam can not make torque at both low & high rpm.
Working rpm range is first selected, this dictates cam selection optimized for that rpm range.
Cam Intake Valve Closing Angle then dictates target Static Compression Ratio
that yields target 8.5 to 9.0 Dynamic Effective CR, assuming it's being built for pump premium.
No expert either and not fluent in effects of lobe centers or lobe seperation
but understand that yes, Dynamic Effective CR is "key" and is directly related
to Duration, Intake Valve Closing Angle, Overlap, and Static Compression Ratio.
This is why in some cam catalogs the spec out a minimum CR for a given cam.
Understand tha AMC V8's like a little more exhaust lift and/or duration than on the intake
to promote cylinder scavanging and volumetric efficiency.
Used to have a dual pattern cam, and that 360 worked pretty good with an 4781 Holley 850 cfm DP.
When cam was changed to a slightly smaller single pattern grind, 850 was too big, changed to 750,
and car ran same times and speeds with the smaller cam & carb as it did with larger cam & carb.

Farther one goes for more HP, the more low end HP is compromised, what it takes to make
Torque at higher RPM's, and more HP as a result, the less efficient it will work
at lower RPM's because of what it takes to make it flow at high RPM's.
This is why modern hi-tech high HP engines used variable valve timing and intake runner volumes.
At least that's as it is understood to be.

Select target HP, then rpm range, then Cam, then Static and Dynamic CR dictates engine parts, imho.
Over my head, but cylinder head intake runner flow volume is directly related to HP potential.
Haveing the Heads ported by an experienced AMC head porting person will increase flow & HP.
Combustion chambers can also be worked to unshroud the valves from combustion chamber edges
which increase flow and HP, but on the negative side increase chamber volume and lowers CR.
It's all just a vicious circle #-o guess this is why good builders make the big bucks.

[ironman_gq]

figure out your heads and block then call up a good cam grinder (Engle comes to mind) tell them what you have and what you want to do with it and have a custom cam ground. You could also try a good porting on the heads or go to aluminum heads (run more compression/ timing without detonation.)

[fifesjeep]

I stumbled upon a decent tech article on the net which I could understand pretty easily... it's about static and dynamic CR's... here is the link. http://www.team-integra.net/sections/articles/showArticle.asp?ArticleID=233
The book that I have has a lot of formulas but it doesn't give details/examples/reasons etc like the listed site.
- You mentioned that the AMC's like to breath so use a little more exhaust lift... Maybe this is why my buddy suggested using the 1.7 rockers on the exhaust and go with the 1.6 rockers on the intake? The only thing I don't understand is why he suggested a 30* exhaust angle. I emailed him, I'm waiting on his reply... (It's the small things that get me)... lol.
- If I take what you and he said as-well-as what I read that would steer me to the following cam design... lobe separation say around 108* up to 110* a smaller LCA a Larger Duration and the intake lift should be smaller than the exhaust lift... But still be able to flow adequate numbers to satisfy the vloumetric efficiency requirements?
- If that is correct, then ultimately the air velocity is the next critical factor in achieving maximum volumetric efficiency. Now I see why people keep stressing intake/head design and flow bench testing to maximize power numbers.
If I am incorrect please jump in before I get into the snowball affect and lose myself in my bable.
- My current cam has a .230" duration @ .050" of lift... (advertised duration is .280") the valve lift is .520" (with the 1.7 rockers) and the Lobe Separation is 110*
- I can't seem to load the Engle page for some reason... :(:
I normally go with CompCams... and with that I have used hydraulic cam/lifters... I'm looking to get away from the Hydraulic Flat tappet and go to a mechical flat tappet... any thoughts or concerns... I basically want circle track specs but I don't want to get carried away with rpm... contradicting myself I know.
I'd like to achieve maximum HP around 5800rpms to 6200rpms... I'd like to see her start coming alive around 2800 rpms...
I like the rough idlers so what would you suggest or recommend for a decent cam that will produce the power from 2800-6200, This is what I have planned... 10.75 to 11:1 CR, 2800-6200 rpm range, torker intake, O-4779c Holley 750, 1.7 Rockers, 1 5/8 to 3" Fenderwell headers, 3" exhaust, mechanical flat tapet.

[fuzz401]

look at crower solid cams

[fifesjeep]

Thanks Fuzz... I'm trying to load the site and hopefully if it loads I'll be able to print it out for watch reading material... :shock:
Nope no go... there seems to be a block on all of these performance company's.
Could somebody copy and paste some AMC cam specs to this post from Crower and Engle? This way I can check the cam designs and compare what's what...
Thanks: Fife

[fuzz401]

http://www.crower.com/misc/m_cat.shtml

[ironman_gq]

engle has a special blower grind for AMC if im remembering properly

[ironman_gq]

sorry wrong post :oops: Engle will make custom grinds http://englecams.com/

[fifesjeep]

I Still can't view those sites from these computers... There is a block on them... I can view JEGS and Summit Racing but not Crane, Crower, Engle, CompCams, Edelbrock, etc. I can't even get on evil-bay from here...

[ironman_gq]

Try their phone (310) 450-0806 :t:

[fifesjeep]

I'd love to call them but I am half way around the world floating in a can... :?

[AMX69PHATTY]

Not being able to view the web sites might be something to do with Java enabled settings or Adobe PDF maybe ? Half way around the world floating in a can ? Thanks for your service :sa:

[ironman_gq]

email? Fax? :-|

[fuzz401]

hope it is not one of mudrats cans #-o :-|

[fifesjeep]

AMX69PHATTY:
Somebody has to do it, and I just happen to enjoy it. I guess being a machinist (MR) makes it what it is. If I couldn't machine parts I would have to get out and machine else where. :t:
ironman_gq
I'd love to email them... Do you have an email address to the technical assistant for Crower & Engle? I can't fax from here.
fuzz401
I'm not sure if mudrat worked on this can or not... I know I have done A LOT of machining... The Day I checked onboard I was put to work and it hasn't stopped yet... lol.
MUDRAT
Have you been onboard yet? And will you be home the month of February? I have the T18-1b Granny set-a-side for you... (If you're still interested).
__________________________________________________ ___

Alright back to business. Now, after doing all of this math/formulas/brain racking etc... I know the concept of a motor is simple but I never realized how critical things are in-order to have an efficient/powerful motor. I love this stuff!

- I read last night that some of the later AMC heads (74 and up) were 64cc's. Does anybody have any information with head casting numbers that can support this? I knew about the 51cc and 58cc heads but this is the first time I heard about 74cc heads.
- Does anybody have the flow numbers for the Stock AMC heads?

- So this is what I have so far that will help me decide what cam to use, if I am missing something please jump in.
Carb: Holley 750 0-4479c
Intake: I have a Torker but I am looking at an Air-Gap
MSD Pro Billet Dist.
MSD 6al
10.75-11:1 CR w/.037" quench
Bore: 4.110"
Stroke: 3.44"
Crank: Turned 10/10
CH: 1.596"
Con. Rod: 5.885"
Desired RPM Range 2800-6200 or 1500-6500*
I'd like a Dual Pattern Cam with a small LCA... maybe 107*-108* (I'm still trying to research this) a Big duration with nominal lift. I have noticed that the lift goes in tandem with the duration...
I am currently looking at something around these specs .249/.259 Duration @ .050", .579"/.598" lift with stock rockers the Lobe separation is 108*.... I'm trying to play with the numbers a little as I think this cam might be too much...
- I'm trying to find stock flow numbers for the AMC heads so I can figure the math and then I'll be able to match what intake will work best.
- Now, I'm not sure how the 1.7:1 Rockers will help or hurt this set-up...
- I'm thinking maybe get rid of the 1.7's go back to the 1.6's and go with larger valves especially with a smaller lift cam... I'm not fully understanding the affects of smaller larger valves in relationship with duration/lift etc... (flow/velocity differences)... I'm Still trying to grasp this as I have no numbers to go off of as a reference point.
Slowly but surely things are starting to fall into place...
- I read that high compression motors should have hardened seats installed due to from what I understood was added heat and lack of lead additive in the fuel? :-| ... when I have the hardened seats installed I think that I might move up to the Chevy SS valves to lighten things up a little... I'd hate to float a valve and smack the piston... #-o
- I haven't done the math for piston speed etc... I glanced at it and I have to dig a little further to see the importance.
- I do have a question though... Seeing that an engine is basically an air pump... and say that the engine isn't an efficient pump... would you select a cam with a wider centerline to try and optimize volume efficiently?
And this is where I get partially lost... if you go with a wider centerline, the valves will stay open longer (past BDC) and as the piston begins it's upward travel you would lose some volumetric pressure... so, no matter how good or bad a motor is at pumping air wouldn't it be better to go with a smaller centerline so that an engine can optimize majority of the cylinder volume?
So here is My theory based off of what I said above with my current understanding... For a motor that doesn't pump air efficiently, you showed go with a cam that has a smaller centerline and a larger duration... If the motor doesn't pump the required amount air into the cylinder you'll lose power/efficiency so in-order to compensate for that you would have to increase the Air velocity to maximize the cylinder volume and pressure which directly leads to more performance... Would this be correct to assume?

[ironman_gq]

the valve can stay open beyond bdc because of the ram effect of the air in the manifold pushing a pressure wave down the intake runner forcing more air into the cylinder even as the piston begins its upstroke. the same goes for scavanging on the exhaust side of things.

[fuzz401]

my cam
not a lot of lift but a lot of duration and over lap

http://img.photobucket.com/albums/v31/fuzzcj7/camcard401.jpg

[fifesjeep]

Fuzz
Do you have specs on your cam... I can't view pictures from this computer either... gov control. :(:
I was told to look into the CompCams 292H for this build and set the cam 2* advance... what do you think about that?
I think the specs for this cam are as follows 244/244 duration @ .050" and .514/.514" lift... I want to say the lobe separation is 110* not sure though... Do you think it would be better going with a dual grind or something that is listed above? I'd like to use a solid cam/lift but my buddy said probably not a good choice if I will drive this from time to time on the road... What are your thoughts with that? I'm basically going to run this piss out of it while I am driving it... I like my heavy foot and the after pucker face moments... I think the 68 olds 442 ingrained that into my sole... "mashed the gas doing about 50 and the ass end swung around" ever since then it's been about power... then again that was a big block... but the sounds of a small block screaming are just as inviting as a big block rumpling.

[fuzz401]

crower solid cam 292 fdp #45316

intake dur 292 lift .500
exhaust dur 298 lift .510

duration @ .050
intake 246
exhaust 250
intake lift .313
exhaust lift .320

LC at intake center 104 deg

[fifesjeep]

crower solid cam 292 fdp #45316

intake dur 292 lift .500
exhaust dur 298 lift .510

duration @ .050
intake 246
exhaust 250
intake lift .313
exhaust lift .320

LC at intake center 104 deg

How choppy does your engine sound? How many degrees did you set your cam at?

[AMX69PHATTY]

64cc AMC heads
Valve Seats - Hardened or Not
AMC head Flow numbers
Flow - Rocker Ratio - Valve Head Size - Lift - Duration - LCA - LCL

All this is over my head :oops:
There are post on here somehwere about flow numbers though.
Don't have hardened seats in the '70 heads on my motor.

[fuzz401]

not to choppy I put it in stright up

[fifesjeep]

I was reading that with milling the heads to 52cc will restrict a lot of flow and a lot of de-shrouding/bowl blending will have to be done is this correct?
If so, would you guys recommend milling the block, shaving the pistons to -8cc vice -16cc... have them poke out .008" from the hole... and order a couple of .025" head gaskets...
What do you guys think about that?

[fifesjeep]

Re-did some figures and decided to mill block so that the piston pokes out +.008" I am staying with the .045" Head gaskets... Heads are getting Shaved down to 52cc and then the 2.08" int and 1.74" exh valves will be installed... Next step will be to have my heads flow tested and then a little smoothing of the ports and deshrouding of the valves etc and then another flow test etc... I'm Still checking cams trying to match the best for this set-up... Once I get the flow numbers I will decide on a cam... PITA... this project will be a timely one...
:t:

[msalaba]

There is one thing being overlooked in this.

Performance American Style reccommends a min. Piston to Head Clearance of:

0.045" for steel rods
0.075" for aluminum rods

0.000" deck height with a Fel Pro head gasket would be correct for a steel rod.

With a -0.008" deck height wouldn't there be a good chance to loose a piston at high RPM?

[fifesjeep]

No worries about the valve to piston clearance... that will be checked as soon as I get back from this deploy. I'll use my findings as a baseline and then compare those with my current plans to ensure everything pans out... I'm not worried though... especially with the heads only getting shaved down to 52cc's... The pistons have .140" dish... which, I might turn the pistons in a lathe to reduce the dish depth... just a little :t: and then have the block milled a little more... of course this all depends on what my measurments turn out to be.

[Mudrat]

I Still can't view those sites from these computers... There is a block on them... I can view JEGS and Summit Racing but not Crane, Crower, Engle, CompCams, Edelbrock, etc. I can't even get on evil-bay from here...
That's 'cause you're still deployed dude!!!

And yes! :t: I have the T18-1b Granny set-a-side for you... (If you're still interested).

[fifesjeep]

I Still can't view those sites from these computers... There is a block on them... I can view JEGS and Summit Racing but not Crane, Crower, Engle, CompCams, Edelbrock, etc. I can't even get on evil-bay from here...
That's 'cause you're still deployed dude!!!

And yes! :t: I have the T18-1b Granny set-a-side for you... (If you're still interested).

Yeah I know man... Time is short. I'll be on medical leave (surgery) fortwo weeks and then I go on two weeks scheduled leave... so I should have some time to heal and slowly get back into working out/working on the Jeep :? I'll swing by your work.