Thread: 383 Low rwhp, tq

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330rwhp/330 rwtq. Not enuf. Here is my stuff: 383, Edelbrock Vic. Jr. heads (215 cc, 2.08/1.60), C.R. 10.25, Vic. Jr. intake w/1 in. spacer, 6 in rods, Crower 00426S cam, soild roller (250/252@.050, .570,.584,lsa=112, 108 centerline), Holley 750dp., 1-3/4 in. headers, 2.5 in. w/ 40 series Flow's. I'm thinking cam is too big (dyno shows still climbing at 6,500.) Any suggestions? TIA

Originally posted by big_G1
330rwhp/330 rwtq. Not enuf. Here is my stuff: 383, Edelbrock Vic. Jr. heads (215 cc, 2.08/1.60), C.R. 10.25, Vic. Jr. intake w/1 in. spacer, 6 in rods, Crower 00426S cam, soild roller (250/252@.050, .570,.584,lsa=112, 108 centerline), Holley 750dp., 1-3/4 in. headers, 2.5 in. w/ 40 series Flow's. I'm thinking cam is too big (dyno shows still climbing at 6,500.) Any suggestions? TIA

YOUR COMBO. DOES NOT SEEM THAT FAR OFF TO ME OTHER THAN THE PORT VOLUME OF THE HEADS IS A LITTLE LARGE.I WOULD THINK IT WOULD WORK BETTER WITH SAY 190 CC HEAD OR A WELL PORTED 180 CC HEAD.WHAT COULD BE HAPPENING IS YOUR CAM IS OUT OF IT'S POWER BAND BEFORE THE HEADS ARE.

put it on the bottle.............

Is the hp still climbing or the torque?

Originally posted by 86Diablo
put it on the bottle.............

LOBE SEPERATION IS GOOD FOR N20 BUT IT WOULD WORK A LOT BETTER IF HE HAD MORE EXHAUST DURATION.

Originally posted by 76GMC1500
Is the hp still climbing or the torque?

The hp is still climbing. The cam is spec'ed for 7000 max hp, 7500 redline.

Originally posted by big_G1
330rwhp/330 rwtq. Not enuf. Here is my stuff: 383, Edelbrock Vic. Jr. heads (215 cc, 2.08/1.60), C.R. 10.25, Vic. Jr. intake w/1 in. spacer, 6 in rods, Crower 00426S cam, soild roller (250/252@.050, .570,.584,lsa=112, 108 centerline), Holley 750dp., 1-3/4 in. headers, 2.5 in. w/ 40 series Flow's. I'm thinking cam is too big (dyno shows still climbing at 6,500.) Any suggestions? TIA

THIS COMBO. SHOULD DO ANY EASY 500 OR A LITTLE MORE AT THE FLEXPLATE.WHAT ARE WE MISSING?

Well, if you allow 30% loss in the drivetrain, it's makin' 470 at the flexplate. Pull the plugs, wire the throttle blades open and check cylinder pressure. I think I'd have backed off on the intake volume in the heads if I used a cam that made power to 7,500. In my opinion, you've got more heads than cam.

Originally posted by techinspector1
Well, if you allow 30% loss in the drivetrain, it's makin' 470 at the flexplate. Pull the plugs, wire the throttle blades open and check cylinder pressure. I think I'd have backed off on the intake volume in the heads if I used a cam that made power to 7,500. In my opinion, you've got more heads than cam.

When I was looking at head flow numbers, the Vic.'s did not flow as well as AFR 190's or 195's. Now I have to decide how to pick up the torque. Smaller runners? Or will a cam with less duration and overlap raise the torque enough to bring the hp. up enough at 6500 rpm? (I don't have to rev. to 7000 rpm). My cranking compression is 150 psi.

I agree, the heads are too big,......sucks though, they are'nt cheap.......but you definately have a problem, those numbers are far from what is expected from your combo.....some times when building a motor camshaft selection and port volume are missed. I would suggest a smaller port volume as stated in an earlier post......

Originally posted by big_G1
When I was looking at head flow numbers, the Vic.'s did not flow as well as AFR 190's or 195's. Now I have to decide how to pick up the torque. Smaller runners? Or will a cam with less duration and overlap raise the torque enough to bring the hp. up enough at 6500 rpm? (I don't have to rev. to 7000 rpm). My cranking compression is 150 psi.

YES,THE SMALLER PORT VOLUME WILL HELP.THE WHOLE IDEA IS TO HAVE A SMALLER PORT VOLUME AND GREAT FLOW NUMBERS.THERE IS STILL SOMETHING WAY OFF.330 RWHP IS WAY TO LOW.GO BACK AND CHECK EVERYTHING YOU CAN THINK OF TIMING,JETTING ETC.

I'd be changin' the cam to one with an earlier intake closing point to raise the cylinder pressure to around 170-180 if I had a good tight squish in the motor.

Originally posted by techinspector1
I'd be changin' the cam to one with an earlier intake closing point to raise the cylinder pressure to around 170-180 if I had a good tight squish in the motor.

Yea, I think that would be the less costly route, maybe a 230/236. That and I'll keep my ears open for some AFR190's...lol..Thanks for the good advice.

I think Erik is right. Something aint right. Check the balancer, to see if the deg. marks are correct. You may have a small vacuum leak or running a little lean. Just check everything and check it again.
Sometimes you over look some of the dumbest things and kick yourself after. LOL

Originally posted by Joe Scalley
I think Erik is right. Something aint right. Check the balancer, to see if the deg. marks are correct. You may have a small vacuum leak or running a little lean. Just check everything and check it again.
Sometimes you over look some of the dumbest things and kick yourself after. LOL

Yea, been all around this problem for a while. Good SFI balancer, tried 30 to 40 deg total advance,(not any power above 34 deg.) all in by 2300. O2 sensor on dyno shows 12.5 a/f ratio, tried BG850 Mighty Demon as well as the Holley 750 dp. I'm gonna degree the cam this weekend just to see how it was installed, then pull it to check the part no. and lobes. BTW, it runs 12.40's, but I know I'm down a bunch...