Running an IMCA stock with a 355, and wondering what cam I should run. Heads are untouched 882's, weiand intake, around 9:1 comp. Wanting to run solid lifter.
what would be a good starting point? anyone?
If your going to change the cam why not mill the heads for some compression and get rid of the weind intake?
If its a hobby motor you had I would say run the same cam you ran in it.
IMCA Modified #66
Heads are gonna get milled, just estimating 9:1 for the final ratio.
And its a IMCA stock engine, 500 cfm carb spec.
Why get rid of the weiand intake?
Weind is junk, a slightly modded q jet is better. We are allowed a Edelbrock 2701 for IMCA stock car, its much better.
IMCA Modified #66
I havent got the heads milled yet, so i was guessing. 355, with 76cc's, how far down could a set of 882's be milled?
Im on the lookout for the edelbrock intake, have the weiand cause i got it dirt cheap.
anywho! cam suggestions?
Is this a used hobby motor if so just run that cam.
My 487s were milled to 67cc. 882 are the worst castings to use, I dont think you can mill them much at all, they are prone to cracking without any milling I am pretty sure. I am just going off what Ive read, Ive never used any for a motor.
I got my heads from a shop in MN on ebay ready to bolt on to my door for 751.00 total.
comp 651-5 is very popular with sportmods, hobbys and I run it or a variation of it in ALL my motors
IMCA Modified #66
...NOT a hobby motor.
Its an engine I've run in my IMCA stock last season, under the 350 carb rule, going to the 500 carb. So no vacuum rule, no lift rule.
It was purchased used, with no information to the cam specs. I ran it cause I had to at the time.
Now I'm changing heads, since i cant run my double humps, and wanting to put in a fresh cam and go to solid lifters at the same time.
Well you can run your double humps, you would just have to stick with the 350 carb.
I would ditch the 882s myself but thats just me.
Last edited by stock car driver; 02-21-2011 at 12:29 PM.
IMCA Modified #66
As far as flow.....the 882's flow the same as the 441, 487, 993, etc. The 882's can't be milled as much because they are a lightweight casting and the area around the spark plug hole is hollow....meaning the more you mill...the less area you have between the chamber and the water port. Have seen guys mill them a bunch and end up leaking water in that spot. The 882's work fine if they are on a 9:1 engine where they don't need to be milled much.
If you are needing a set. I have a set of 487's and 2 sets of 441's. I get $650 a set + shipping.
yeah...650 is way out of what I can afford right now.
I'm still looking for, and would like to get a set of 487's, 441's or 993's ( i think 993's), but for now I have these to run.
Its not a question of if I'm going to run a 350 or 500 cfm carb, or if i'm going to run my double humps, since they're sold...I'm asking a cam question.
With a 9:1-10:1 engine, stock style head, alluminum intake, 500 cfm carb, 5.83 gear...3/8ths dirt oval that gets nasty slick....what would be a good cam to start with?
should i concentrate more on duration?
Im a fan of speedway cams, great quality....just wondering where I should start.
Since cams are one of the main factors of power.....once I get all the parts rounded up to do an engine....I just call comp cams and they put me in the right direction. Takes all the guess work out of it.
Alrighty, i knew the people at those help lines are good with street cams, but never tried them with a race cam.
Are you not wanting my help? If so say so. I already answered your cam question. In my 3rd reply.
IMCA Modified #66
stock car driver, i do appreciate your help. I'm looking into that series of comp cams tonight. thanks for the insight
When running a stocker engine with minimal rules on RPM the way to win is to turn more than the next guy!!! More power strokes to the ground can be accomplished with any set of heads. Compression is almost a not even a consideration if you know what you are doing.
I have asked many times how did they get 725hp from a 9:1 - 358" w/390 carb? I have a couple of the engines sitting in the shop collecting dust just in case I want to go back Super racing on pavement if they ever get the purse about $5000 to win for 250 laps.
The cam you need for stock heads moves the valve off the seat really fast and accelerates the lifter as quick as possible. Big lift at .100", .200", and .300" lift. With the area these cams provide it is almost like porting the heads as the engine has access to more air early on in the valve event and in some cases the flow numbers on a stock head with these cam lobes will outperform ported heads with regular cams. That being said I would say 250*-258* around .450" lift ( would like to flow heads to make sure ) on a 104* LS stick, with the intake installed at 100*. This cam should rock your world and everybody elses and has 10-20% more area under the low-lift curve than anything out there I have checked to date. This thing hits so hard it will sound like the engine has 16:1 compression. Cams take about 2-3 weeks depending on how busy I am, each one gets Cam Doctored and measured for perfection.
I have a series of lobes that I R&D'd about 5 years ago when we ran lift rule engines in Hooters Cup. These lobes run as high as 9500rpm with minimal harmonics and in your case with your heads you should be able to run 7500rpm. You will need to purchase a Super Victor intake and bite the bullet if you want to make big power with your 882's. Don't mill them any as you don't want to have to pull that compression braking around with a stock head that does not flow air.
Low airflow, hi-compression engines starve the engine for fuel under deceleration when the throttle blades close. This is even more exaggerated with a 2-BBL even though you will be running a 500CFM. In the old days, that's why they burned up engines, when Nascar ran 16-17:1 Compression they would burn engines up on re-starts. Well after about 2 years of trying to convince them it was under deceleration rather than acceleration. I finally got a couple customers to listen and then they caught on. That is one of the big reasons you need a manifold with some volume.
You can pm or e-mail me if you need further info or help.
I know all of my loving fans and post jumpers are going to reply, now I am in the cam business but I just had a 3 year non-compete, non-disclose agreement expire Jan.1 2011. ( related to camshafts / lobe design ). I have been in that business since about 15 years ago when I was an operations manager at Reed Cams.
The Comp 651 is a nice shaft for an off the shelf piece. Those are pretty extreme lobes for valve control on the top end and that is where my stuff differs from most. I am radical about getting valvetrain harmonics eliminated. My lobe is about 5% bigger at .050" with almost 20% less lift. When you do the math the head flow increases almost 15% thru the lift curve making a 180cfm head flow
( approximation on stock 882's ) almost 210cfm ( +30cfm ) and still maintaing low lift to keep from killing valves, seats and springs.
Anybody that checks leak-down regularly knows how important the valve seats are to maintaining long term power.
You can also check with any knowledgable engine builder around and +30cfm on heads can produce almost double that in Engine HP. On crate heads I flow them and have dyno'd enough of them to know that +10cfm on the heads is 20HP. The same thing applies to almost every race engine around as a Cup engine needs about 400cfm heads to make 800HP.
Crate heads flow 210-235cfm, better hope you get the good ones.
These numbers are from my SF-600 bench at 25" and is probably different from most folks but I have been using it for 30 years without a problem.
I still think the biggest gain you can make on any race engine is having your carb and ignition system matched to the accleration curve of the fuel you are using. Pump gas A -vs- Pump gas C has a 20hp difference every time I test it and I can tell a difference when I run either one in my Suburban.
Last edited by dynoman14; 03-02-2011 at 12:27 AM.
Reason: left something out
Do you know Steve Demos from Reed Cams?
Originally Posted by dynoman14
elgin 1090 avail. competition products @ 120.00 cam/lifters. thats my 2cents
That Elgin cam is pretty close to what my head guy suggested I run, its a JR motorsports cam, i think .53?/intake .54?/exhaust, its what they put in their IMCA stock engines.
That elgin is what I used to run with a 4 barrel on 377 or larger cubes.
Originally Posted by roybeckett13j
256/264 @ 50 is a lot of duration for a 2 barrel small cube motor, Im not sure it would get out of its own way until 6000 rpm.
IMCA Modified #66
I ran this Comp 12-651-5 when they first came out in a dart head and a vortec motors. The advertisement looked great for a 500 2 bbl. application. I found in both motors the cam was too lazy on starts and traffic driving. They were in a California Super Street with dirt Boss Hoosiers. I tried various things to help , but I finally gave up on it. After talking to 3 different "tech advisors" at comp I found this cam was designed for asphalt. 108 lc drops the low end torque and promotes grip on the inital acceleration on asphalt. I found this too slow for me.
Being this would go in a small tire and depending on the drivers skill level , this will be a forgiving cam. It would do well on a larger momentum track (1/2 or more). Gear the rear end easy and when you need more gear it up. Good luck.
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