moving cam centerline, big motors

Posted By: gregsdart

moving cam centerline, big motors - 07/30/11 04:57 PM

Just curious if it is worth trying other center lines. I am at 110 on a 283/296/112 cam, making about 880 hp. 528 cubes 440-1 heads on alky.
If it is not worth more than say 5 hp over a range of 6400 to 7400, I won't mess with it. In the past on other motors, I haven't seen much gain, if any if I stay within the recomended icl by say 2 degrees advanced or retarded.

Posted By: MR_P_BODY

Re: moving cam centerline, big motors - 07/30/11 05:14 PM

Are you looking for more torque or HP and do you want
to move the power band up or down

Posted By: gregsdart

Re: moving cam centerline, big motors - 07/30/11 06:48 PM

Looking to improve the torque at 6500. as dynoed, peak torque below 5500, hp peak was 6900, but may have changed due to dyno headers being 2 inch and 40 inch long. Current headers, 2 1/8 by 30 x 4.

Posted By: MR_P_BODY

Re: moving cam centerline, big motors - 07/30/11 06:54 PM

Quote:

Looking to improve the torque at 6500. as dynoed, peak torque below 5500, hp peak was 6900, but may have changed due to dyno headers being 2 inch and 40 inch long. Current headers, 2 1/8 by 30 x 4.

I dont think you'll pick up any in that RPM range

Posted By: Bob_Coomer

Re: moving cam centerline, big motors - 07/30/11 09:50 PM

I had a custom Comp Roller spec'd from Dewayne Porter I ran in a 493 with cnc -1's. Compression was on the mild side at 12:1 or so. I had good Jesel Rockers and valve train..
The engine ran well...
I finally built a real short block with a Indy Maxx block 4.5" stroke crank 4.44 bore for 557 CID. Compression was up there north of 15:1.. I upgraded the induction also with a 4" Toilet Rons setup..
I went ahead and used the Comp Roller from the 493 in the new short block.
Cam was a ground on a 112 LSA .770+ lift and duration was mid to high 270's at .050 lift. I installed it in at a 108 ICL. It ran very well in the new engine.
I had decided that maybe a new cam for this motor might be worth the money. I could afford to go bigger and not worry to much about tq loss down low cause now the weight went from a 3000 lb Dakota to a 2100 lbs race car...
So the new cam had a hair over .800 lift dur was 280 or so at .050 and now on a 113 LSA.
This cam was spec'd by Chuck Millen from best machine...
The car didnt show any improvement, didnt loose any either.... ran within a few numbers either way.

I think if one's in the ball park, there isnt going to be much there.

Posted By: gregsdart

Re: moving cam centerline, big motors - 07/31/11 12:35 AM

Thanks, Bob. Kind of what I figured. I have run two cams, one an Isky rr735 .760 lift 278/288/110 in at 110 and the one above. Car didn't respond much if any to the bigger cam. I was looking for power up top, mainly because of the narrow window I run the motor in, 6500 to 7100.