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Total Lift - updated, replace the cam?

cmayna

cmayna

DILLIGARA?
Donator
How can I figure out what type of cam I have in Shag's upcoming Cleveland engine? Will what I have work for me? What is the total lift?

Grind Number: 10354 SSI
Engine Ident: Ford V8 351C-351M-400

Spring height 1.850
85 lbs

Valve Setting: INTAKE Hyd EXHAUST Hyd

Lift: Intake: @ CAM: .297 @valve .514 Rocker Arm Ratio
Exhaust: @CAM: .297 @valve .514 1/73 - 1

Cam Timing S.A.E. Opens Closes S.A.E Dur
@.006 Intake 50 * BTDC 78 * ABDC 308*
Valve Lift Exhaust 78* BBDC 56* ATBC 314*

Cam Timing: SAE.050 Opens Closes .050 DUR. Lobe Centers
@.050 INTAKE: 8* btdc 36* abdc 224* 104* ATDC
Tappet Lift EXHAUST: 47* bbdc 5* atdc 232* 112* BTDC
 
Re: Total Lift

Total valve lift is .514" with 1.73 rockers. (.297" cam lift x 1.73 rocker ratio = .514" valve lift)

Comparing that cam to some others shows it should have a power range of about 2500-6000 rpms and have a nice lopey idle.
 
Re: Total Lift

Ryan,
Thanks for deciphering the specs. I don't want it to be too lopey though. Tad in your opinion, a borderline situation? Goes to show you guys what I know about cams. = zero.
 
Re: Total Lift

Craig,
I've done a bit more digging on your SSI (Super Stock Industries) camshaft, and found out it is PAW's house brand of cams. If you are not familiar with PAW, they are a budget mail order engine parts warehouse. The cam you have isn't listed in their current catalog. The 351C cam they do have is $65, so don't feel that you have to use that one if you are unsure about it. Personally, I'd talk to the Comp Cams tech line, or fill out their cam sheet. You can then tell them about your engine and car, your expectations, and let them make a recommendation for you.
 
From the little I know about you build objectives (and I really don't know engine tech spec), I think you'd be happier with a cam built for torque not revs. Like you said, something with a power range targeted for lower rpms... is that what they call a RV cam, because it's for low end torque?
 
Yes, I'd rather have lower end torque, so I can install a line lock and see how fast I can go through a set of rubber.
 
"cmayna" said:
If this cam has a power range of 2500-6000RPM, would I be better off with a cam maybe in the 1800-5800 range? Here's a comp cam that ORP thought might be a little more streetable.

http://www.summitracing.com/parts/CCA-32-224-4/


Now's the time for me to swap cams if I'm considering it.
Click to expand...

Craig,
I'm not sure any of us are qualified to pick a cam for you. There are so many things that come into play like compression ratio, heads (2V, 4V, etc), gear ratio, car weight, personal preferences, etc. It's kinda like picking a stock, where you'd like some professional advice. I think we all here are pretty ignorant on Clevelands; I know I am at least.
 
I'd be EXTREMELY careful picking a cam for a cleveland, or else you could wind up with a stereotypical cleveland with no low end like everyone seems to want to complain about. SSI is some vintage stuff too, personally, I wouldn't use it unless I had to. After reading the recent FordMuscle article on cam help 1-800-numbers, I wouldn't call Comp and ask; they called 3 different times and got 3 entirely different recommendations.

You might consider a custom cam from Ed Curtis or MME Racing. Curtis only charges $220 for a custom cam, which is pretty close to the cost of most comp cams, and MME has been kicking arse in the Engine Masters Challenge with a Cleveland for a couple years. They can tailor to your desires too, so you wouldn't have to live with a cam that's "too lumpy" or doesn't have enough low end.
 
4V Clevelands love to wind high RPMs. Typically, the HP/TQ curve is almost a diagonal line on the charts. Getting a 4V to make great HP/TQ at lower RPMs may take a custom camshaft as most aftermarket pre-ground cams are going to support the high winding inherent design tendancies of the overall engine.
 
I'd be hesitant to try to make low end power with 4V heads, especially with the stock stroke crank. They want to breathe, and you don't run into that kind of breathing until higher rpm's. That's why I think the cam you have is a bit tame for that motor. I run a Comp Cams Magnum 280H designed for 2000-6000rpm in my 331 with much smaller ports and I drive it every day. Your motor is going to want to wind up even more than mine, and with proper gearing (3.73+) and your 5sp, you shouldn't have a problem with driveability. It'll still have gobs of torque, but it's going to make it at a higher rpm than I think you're shooting for. If you want to make low-end torque, you're going to need some 2V (or aftermarket 3V) heads.

Ed Curtis, MME, and the venerable Mr Horsepower (Clay Smith Cams) are all good places to call for custom cam information. That's definitely the way I'd go for this motor, assuming budget permits. Custom cams will always make more power than an off-the-shelf grind.

But first you need to figure out compression ratio. That's one of the first things any cam manufacturer is going to ask you.
 
Craig:

Consider talking to Doug at Precision Oil Pumps in Clovis (559) 325-3553. Among other things, he is an engine builder and in my experience he knows his stuff when it comes to FE's. If he doesn't have Cleveland suggestions, he probably can make a good referral.

For a custom ground FE cams, I hear that Oregon Camshaft 360-256-7985
is a competent outfit as well.
 
I just learned that the cam I have has a power range of 2,000 - 6,000rpm. Not so bad as what we previously thought. I'm also hearing that using Rhoads bleed down lifters is a way to still have low end torque while using a higher cam.

http://www.rhoadslifters.com/
 
They'll help, yes, but I'd still recommend more cam in that motor. For one thing, that's barely more lift than I run. Lift is power, and I believe you can run lots more lift without running into clearance issues.

I run Rhoads lifters in my car and I like them (they really do work), but they're LOUD. You can come down and listen to them, if you want. You can hear the tapping down the street. What happens is that the valves smack the seats as the lifters collapse, creating all sorts of racket under the hood, almost akin to solid lifters. It doesn't bother me, but a lot of people don't like it.
 
Jeff,
Just spoke with Doug in Clovis. He recommends staying as is. He also said like Tad, that the rhoads lifters are noisy.
 
Craig

I don't want to confuse you any more then neccesary but i always thought that cleveland engines where high rev engines because they breath properly on high rev.I would get some information by some engine builders exp by cleveland engine builders.
My opinion . :conf
 
Under Rocker Arm Ratio, I'm going to guess that "1/73 - 1" means 1.73:1 ratio.

You were asking about rockers in another post. Keep in mind that what rocker arm ratio you choose will have a direct impact on valve lift. For example, I'm running a 1.7 ratio rocker in my 408, instead of the stock 1.6 ratio rockers. This makes my F-303 cam have a valve lift of .544 @ .050, instead of the .512 that it would have with 1.6 ratio rockers.

.514 is a significant amount of lift in a 351 cubic inch engine. Personally, unless your intended use is a lot different than what I think it's going to be, I wouldn't go with a lot more cam than the one you have.

You will have a lope with that cam, but it won't be totally radical. If it's too lopey, you can always bump the idle a tad and smooth some of it out.

One thing to consider, is that valve-to-piston clearance has probably already been figured out with this cam, your pistons, and your heads. When you pick a cam, that has to be a consideration, especially with an already assemble short block. Otherwise, you could be pulling the pistons out and having them fly-cut. Obviously, though, I'd still check your piston-to-valve clearance, though, even if you stay with that particular cam.
 
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