Posted By: 451Mopar
Comp PP292H 0.509" cam with stock valve springs? - 03/31/13 06:45 AM
Anyone run a cam like this with stock valve springs?
Comp recommends the #924 dual valve spring with 112 psi @ 1.9", 293 open @ 0.509" lift using 355#/in rate.
The stock springs are 90 psi @ 1.88 install height, and 222 open @ 0.509" about 260#/in rate.
This is for the 8.8:1 compression 440 with stock heads,intake, and manifolds
Posted By: Dodgem
Re: Comp PP292H 0.509" cam with stock valve springs? - 03/31/13 01:35 PM
Great cam installed a 102 to 104 make tons of power. need upgraded cam springs 924 or I used these mopar springs P3690933 on my .509 cam.
Posted By: Exit1965
Re: Comp PP292H 0.509" cam with stock valve springs? - 03/31/13 03:19 PM
I run the cam in a 440, probably less compression than yours, in a 67 Dart. With eddy heads, RPM intake, double pumper and headers. 3800 stall converter and 3.91 rear.
It would not work well with all those stock parts you want to run. That cam especially likes some stall in the converter.
It would be a noisy dog with stock parts. If you want the sound, which I'll admit is nice, look into those whiplash cams from Hughes. If you want to upgrade some other parts and your converter, that Comp 509 would be a decent pick WITH the right combination of aftermarket parts (even if the compression isn't optimal).
Posted By: GODSCOUNTRY340
Re: Comp PP292H 0.509" cam with stock valve springs? - 03/31/13 03:47 PM
Putting that cam in that engine will make it run worse than stock. Not enough compression AND your retainers will possibly hit your valve guides. The long duration will bleed off even more of your compression which is already lacking.
Posted By: 451Mopar
Re: Comp PP292H 0.509" cam with stock valve springs? - 04/01/13 04:10 AM
I told the owner the cam is a bad match for the combination, but he insisted he wanted to use it because of how it will sound? The car is a 4-speed.
I may have some springs off of my 440 source stealth heads, they would work ok with the cam. I also have a Crower compu-pro 271 duration, 220/230 @ 0.050", 0.486"/0.494" lift cam I was trying to talk the owner into using.
I guess what irks me is the owner asks for my advice, then totally ignores everything I told him
Posted By: 451Mopar
Re: Comp PP292H 0.509" cam with stock valve springs? - 04/01/13 05:02 AM
Odd situation. The owner is a friend of a friend, and my friend is assembling the engine for the owner, and I was just helping my friend because I have a bunch of the high end assembly and measuring tools (dial indicators, indicator bridge, degreewheel, balancer installer, head cc kit, valve spring mics, valve spring pressure gauges, various mics, dial bore gauge, etc.)
Originally the owner just wanted to re-ring the engine and put a bigger cam in, but the cylinders were so worn the my friend had a time just getting the pistons out past the cylinder ridge.
Working with my friend, we put together a parts list for a 10:1 compression engine using a healthy sized 276/284 (234/242 @ 0.050), 0.513"/0.533" lift Voodoo cam. The owner then just buys a stock rebuild kit from the machine shop. 8.84:1 compression pistons (with a 0.020" head gasket, and the heads cut 0.010".) The "kit" has a stockish cam, but only around 0.430"/0.440" lift.
Really the totally stock combination should have run pretty good, but not have the big cam sound the owner wants. So after the cam and heads are installed, the owner decided he wanted the Comp PP292H cam...
Posted By: Exit1965
Re: Comp PP292H 0.509" cam with stock valve springs? - 04/01/13 05:07 AM
Well I'm sure there have been people who stuffed the regular 509 into a smog engine, did little/nothing else, and had fun. If he does go with that cam, he may be motivated to bring the rest of the combo up to snuff someday. He'll get a nice sound, I can vouch for that.
Posted By: 1_WILD_RT
Re: Comp PP292H 0.509" cam with stock valve springs? - 04/01/13 05:10 AM
Well, the good news is he's got 3/4 of a point more compression that I expected...
Posted By: GTX MATT
Re: Comp PP292H 0.509" cam with stock valve springs? - 04/01/13 05:35 AM
Don't run stock springs. The springs off the Stealth heads would work okay I'm sure, but the stock springs will not only float before it can make any power, but he may end up with some serious damage when he floats a valve into a piston and drops one.
It may pull decent, with all those stock parts he can certainly go faster with less cam though. If anything at least get him to put headers on it.
Posted By: 451Mopar
Re: Comp PP292H 0.509" cam with stock valve springs? - 04/01/13 06:00 AM
We talked him out of using the stock springs, just to prevent damage from valve float. The owner was going to order the comp 924 springs, but he din't realize they are a double spring and his heads are not cut for dual springs. As usual, we advised that he have the heads cut for dual springs when doing the valve job, just more advice ignored, but we tried...
Anyhow, the stealth springs will work if I can find them? I may have sold them at the swap meet.
The owner tells me he dosen't plan to drive the car hard, just wants it to sound good because he plans to sell the car. I think it is more of a show than go car? I just can't wrap my head around the owners logic?
Posted By: dogdays
Re: Comp PP292H 0.509" cam with stock valve springs? - 04/02/13 12:20 AM
Yeah, my suggestion is to mill the block, because as not everyone has noted, you are a MILE HIGH and that also affects cylinder pressure.
The Whiplash cam needs Hughes springs but sounds like what the guy "really" wants. Not what he thinks he wants, etc. Going to a half-inch lift cam almost guarantees either stock spring stackup or retainers hitting valve guides/seals. The Whiplash cam claims to avoid this issue with a slightly shorter lift. Not that I have any part in the company.....
R.
Posted By: bobby66
Re: Comp PP292H 0.509" cam with stock valve springs? - 04/02/13 06:54 PM
The Hemi grind cam would sound great in that combination. Plus, he could say,"Hemi" whenever he talked about his car.