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Author Topic:   Cam for Limited?
George Gilliland
Member
posted September 17, 2003 09:22 PM
I am going to run a limited mod. 9:1 compression, Holley 500 two barrel(stock), unaltered cast iron four barrel intake with adapter plate, headers with short glass pack mufflers and turn downs, 2500 pounds. What suggestions would you have for a cam? I expect to turn 7,000-7,200 max. Thanks George.


twofast
Member
posted September 17, 2003 10:40 PM
with an unaltered 4bbl intake and a 500 cfm 2bbl carb that combo isn't going to make good power in the 7000 RPM range... I'll bet the intake is really limiting after 6000-6200 MAX... Might think about matching a cam that will make good torque and HP in a lower RPM range where that intake will work. Most of the race cams at MWMS have too low of a LSA to make good power down low.

Never tried it, but I would call Comp Cam's Cam-help line and see what they suggest

George Gilliland
Member
posted September 18, 2003 05:11 PM
I can run a stock two barrel intake if that is better for the application, but none of the parts can be altered.


George Gilliland
Member
posted September 18, 2003 05:16 PM
With this 500 cfm carburator I think the max horse power is below 6,000 some. The point of going higher is to help it come out of the corner fairly good. I am hoping for some replies from people that have run these so that I am somewhat close to start out next year.


George Gilliland
Member
posted September 18, 2003 05:18 PM
With this 500 cfm carburator I think the max horse power is below 6,000 some. The point of going higher is to help it come out of the corner fairly good. I am hoping for some replies from people that have run these so that I am somewhat close to start out next year.


racer17j
Member
posted September 18, 2003 08:09 PM
i'd talk to dougy mac next week if you run the challange don't think he would steer ya wrong if not him tapper will help ya out i'm sure


wizzard
Member
posted September 21, 2003 09:30 AM
one more thing - hydraulic or flat tappet cam? Assuming it's hydraulic then something in the 225-230* @.050 and .330-.350 cam lift (mult by 1.5 or 1.6 depending on rockers chosen) - that should make good broad power with the restrictive heads/intake/exhaust. If you can run solid then you can run a little more agressive cam - but the factory heads will really stop flowing around .450-.500" lift, so no use going real huge...

For exhaust - can you run the early "center dump" manifolds? If so get a set with the 2.5" outlet, run them to 2.5" pipe then take a 3" glass-pack and fit a 2.5" pipe inside of them - or cut apart a 2.5" glasspack and make them straight through for a little extra power... If staying "by-the-book" then look for the glasspacks using dimples going "out" from the center and not the ones coming "in" to the tube...

George Gilliland
Member
posted September 24, 2003 06:32 PM
This will have a solid lifter cam. We are also allowed to run headers but there has to be some mufflers and turn downs due to noise rules. The mufflers that I run are welded right to the headers and are about 5" long with about a 3" hole in the middle. There are a few prong like scoops that stand in the flow and I assume fiberglass between the inter and outer walls, but I have never taken one appart. This combination cuts the noise in about half, but without a meter you would have to run them side by side to hear a difference.


nate 11
Member
posted September 26, 2003 11:38 PM
didnt know you could run solid lift cam in limited mod.


racer17j
Member
posted September 27, 2003 03:00 AM
nate our rules up here in iowa a different then sims our class is imca chassis with imca hobby stock engine rules and 4412 carb


nate 11
Member
posted September 28, 2003 03:04 AM
oh ok thanks for the info.