cam

[littleherc]

so i just purchased a compcam nitrous hp...(it was cheap and brand spanking new)
Can i run this cam even though i won't be running nitrous?
and can i expect some gains in hp?
Ill be running this is a 350 with intake headers and edelbrock carb...

 

[rich weyand]

I assume Comp Cams number 12-552-4.

Yeah, it'll do OK. 288 hp @ 4000, 407 ftlb @2500. Pretty nice numbers, and the torque comes in low enough to make it a fun driver. Stock torque converter will work fine.

Make sure you replace lifters and valve springs with the recommended parts, and follow the break-in procedures.

 

[littleherc]

I assume Comp Cams number 12-552-4.

Yeah, it'll do OK. 288 hp @ 4000, 407 ftlb @2500. Pretty nice numbers, and the torque comes in low enough to make it a fun driver. Stock torque converter will work fine.

Make sure you replace lifters and valve springs with the recommended parts, and follow the break-in procedures.

First of all, thank you very much for this information!!
But I have the 12-564-4 cam.... Will this one give the same stats? I'm sorry for my lack of knowledge on cams....
Thank you

 

[rich weyand]

Download the Camquest software from the Comp Cams site and enter the parameters for the Chevy small block.

That's a street/strip cam. 314 hp @ 5000, 375 ft lb @2500. Says cam RPM range is 2400 to 6500 -- from that you would expect to need a 2500 rpm torque converter, but the torque curve looks like it would be OK with a stock torque converter. Be prepared to have to change it, though. Lift is .487/.501, so be sure to use the recommended springs and lifters. No way stock springs and lifters will accommodate that much lift.

Also says you are gonna get a choppy idle, which also argues for a torque converter change.

 

[MikeB]

But I have the 12-564-4 cam....

230/244 degrees duration is a LOT MORE than you'll want for a 350 in a vehicle that's primarily street-driven. It will have a very rough idle and low manifold vacuum, which makes for for poor throttle response and idle/off-idle carb tuning issues. Also, anything less than 10:1 compression will make things even worse. And even with the recommended 2500 RPM stall, I suspect you'll need at least 3.73 gears.

What does Cam Quest suggest for your truck's weight and engine? Be honest with yourself when selecting "usage". Unfortunately, the program doesn't ask for rear axle ratio, which is important. My guess is the program's recommendation would be somewhere in the range of 204-212 intake, and 210-220 exhaust range.

FYI, for a few points of reference, a stock late 70s/early 80s 350 cam was probably around 195/202 duration, and even the GM Performance 330hp/350 crate engine cam has only 212/222 duration.

Finally, Comp Cam's 268H cam (218/218 is probably one of their most popular small block cams, and is just under the threshold of requiring more compression, higher stall, and lower gears.
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=73&sb=2

Using the wrong cam just because it's cheap is sort of like painting your house red because the paint was free!

Good luck with whatever choice you make.

 

[littleherc]

230/244 degrees duration is a LOT MORE than you'll want for a 350 in a vehicle that's primarily street-driven. It will have a very rough idle and low manifold vacuum, which makes for for poor throttle response and idle/off-idle carb tuning issues. Also, anything less than 10:1 compression will make things even worse. And even with the recommended 2500 RPM stall, I suspect you'll need at least 3.73 gears.

What does Cam Quest suggest for your truck's weight and engine? Be honest with yourself when selecting "usage". Unfortunately, the program doesn't ask for rear axle ratio, which is important. My guess is the program's recommendation would be somewhere in the range of 204-212 intake, and 210-220 exhaust range.

FYI, for a few points of reference, a stock late 70s/early 80s 350 cam was probably around 195/202 duration, and even the GM Performance 330hp/350 crate engine cam has only 212/222 duration.

Finally, Comp Cam's 268H cam (218/218 is probably one of their most popular small block cams, and is just under the threshold of requiring more compression, higher stall, and lower gears.
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=73&sb=2

Using the wrong cam just because it's cheap is sort of like painting your house red because the paint was free!

Good luck with whatever choice you make.

thank you for the advice. i truly do appreciate it and it will not fall on deaf ears...i won't be using this cam... ohh and it won't be going into my truck... i was going to put into my chevelle.. 72 to be exact .. I wanted to spruce it up a little.. ( your example made me laugh like no other.... i actually know someone who did receive free red paint.... and guess what he did?? hahahah yup he made that house look like an old barn=bad idea)

thank you

(ps... thank you for mentioning cam quest)

 

[rich weyand]

For a fun street cam for a low-compression 350, look at 12-235-2 or 12-231-2.