need help choosing a cam for my BBC...

[gmjj13]

like the title says, i need a little help. i am in the process of building a 496 for my 69. as of now i have the following parts:

Demon 850
Dart 1x4 intake
AFR 325cc heads (CNC'd chambers and cut to 114cc)
pro magnum roller rockers
bottom end is completely forged and studded
compression ratio will be 9:1

for a trans i am going with a t-56 that has been built to hold up to 700hp and 700tq

rear gear will be a 3.73

anybody have any suggestions? i was thinking about the mutha thumpr cam from comp, but not quite sure. the car will mainly be used on the street with an occasional jaunt to the strip. i tried to call the cam helpline at comp, but never can seem to get through. just stay on hold forever.:dunno:

thanks for any help.

[Yelcamino]

I was thinking about this one for my 468. It would probably be a nice one in your 496...

http://store.summitracing.com/partdetail.asp?part=CRN%2D139011&FROM=MG

[bbcc]

Not sure wether you are looking for a solid or mechanical, flat tappet or roller, so i guessed and chose a solid roller to take advantage of the heads high lift flow numbers. Comp offers a solid roller #11-772-8 that would fit your engine quite nicely. It has 248*/254* .653"/.660" (intake/exhaust respectevly) on a 110* lobe sep. Such a cam will net you 600 hp@6000rpm and 600tq@4500rpm, but power doesn't start to drasticly fall off till after 6500rpm. This cam may seem like its on the small size, expecialy for your displacement, but with such low compression the thing will turn into a dog at high rpm's. Add some more squeze(even just one point to bring you to 10:1) and your power will jump 35 horse and tq with the same cam. You can then step up to a slightly larger cam and bring the peak power into the 6500 rpm range to really take advantage of those heads. But for a mostly street engine, that cam will work quite well. Anywho, hope this helps ya out. Its hard to really nail down a good cam without a more thorough breakdown of parts and specs, intended use, lifter preference, vehicle weight and so on. Definitly try and get ahold of comp's tech line again though. They will really help nail down the right bump stick for you.

cheers bbcc

[justanova]

check out the 496 buildup in the (I think its october) issue of popular hot rodding, they used the big mutha thumper and had over 600 ft lbs at 3100 rpm's and kept it there till almost 6000 rpms with over 600 hp's too. I just looked its not on there website yet, but they named it the howitzer.

[hotrdblder]

i built the 496 in vinnys screen name volt68 68 camaro
here it is
4.310 bore
4.250 stroke scat 4340 internal balanced
6.385 rod scat h beam
dart intake,pro systems custom built carb based off hp1000
afr 315 cnc heads, angle milled
wiseco custom pistons to yield 10.9-1 cr,pump gas with 35 total timing
ultra dyne solid roller, .710 lift, 262,266 @.50 on a 110,4/7 swap
isky red zone solid roller lifters,manley push rods
extruded alum roller rockers
2 inch headers
4l80e tranny,muscle drive tq convertor, 3.73 rear gears
its on the edge of roudy ness for driving a ton, but it revs like a 18 degree smallblock, and does not stop pulling. its 675-700 hp at crank, not dynoed will be rwhp dynoed soon, but vinny walked away from a hennesy supercharged viper rolling on from 50 mph to 145. viper has been modded beyond hennesy and rwhp 584. goodluck

[1969CamaroRS]

Go with a Hydraulic roller cam, like a thumpr cam:

http://www.compcams.com/information/whatsnew/Files/ThumprCamBrochure.pdf

3 varieties to choose from depending on how radical you want to go. I am still building my engine but I have the mildest (11-600-8) ready to go in.

[hotrdblder]

Go with a Hydraulic roller cam, like a thumpr cam:

http://www.compcams.com/information/whatsnew/Files/ThumprCamBrochure.pdf

3 varieties to choose from depending on how radical you want to go. I am still building my engine but I have the mildest (11-600-8) ready to go in.

why even have afr cnc heads if your not gonna put a cam real cam in it, .560 lift in a 500ci bbc is small very small

[wendell]

Please, please call a cam grinder and let them help you. Don't solicit opinions on the most important component in your engine from strangers. The wrong cam will waste the money you spent on those heads. With those heads and 500", 650+ should happen. Is it too late to add a point of compression?

[hotrdblder]

Please, please call a cam grinder and let them help you. Don't solicit opinions on the most important component in your engine from strangers. The wrong cam will waste the money you spent on those heads. With those heads and 500", 650+ should happen. Is it too late to add a point of compression?
exactely, call tim goulsby at ultradyne,
not sure if you want to pro charge it or something but if you go n/a i would go 10.5-1 at a min,

[gmjj13]

thanks for all the responses on this. for now i am going to run the carb and intake, and hopefully not too far off in the next year or so, switch to EFI and use this Vortech V7 that I have sitting around. which means i'll end up switching the cam again anyway. the most expensive part seems to be retro fit roller lifters for the roller cams. they cost 2-3 times what it costs for a cam:banghead: . unfortunately i have a MK IV block, which i was told means i must use the retro fit lifters. i had thought about the mutha thumpr cam, but now i'm not sure...

as far as bumping up the compression, its a little late to do that, considering that the short block is buttoned up and ready to go. as soon as i get my cam and lifters, i can start putting the motor together. i will probably be ready to buy one in about a week or two, until then. thanks for the responses.

[wendell]

I'd shy away from compromising. Forced induction and NA are so different that trying to play in the middle is tough. If you're going to run in NA, cut the heads to get to around 10.5:1 and call a cam grinder.

[hotrdblder]

bbc needs a high quality roller lifter, isky redzone or crower period.

[gmjj13]

the heads were already milled to 114cc combustion chambers. the motor was originally 8.75:1, perfect for some forced induction. by milling the heads, it brought me up to just over 9:1.

as far as going with a nice roller cam and lifters, is it possible to change the cam to work with EFI and a blower and retain the roller lifters?

i know i'm not going to get what i could out of my motor running NA, but my reasoning is to be able to break in the motor and get the chassis and drivetrain straight prior to going EFI (also the money factor comes in to play here). then there will be less factors that could affect drivability...etc. am i going about this the wrong way or what? i will look into isky and crower, and see what i can find.

does anyone know if there are any site sponsors who deal with those companies? how much can i expect to pay for a custom ground cam? any ideas? i've never looked into that option before.

thanks for all the :help: ...