cam change to a EPS custom grind
#1
cam change to a EPS custom grind
I have a 64 chevy II Nova with a fiberglass front clip, doors, trunk lid and lexan windows. This is a race only car, not street legal.
I am running a 347 c.i ls1 with stock crank, scat i-beam rods(7/16 rod bolts) and Mahle -4cc power pak pistons. 5.3 heads ported by Al Petre out of New Olreans and flow in the hi 280's intake, 220 on the exh side. 2.0 intake and 1.60 exh valves. Heads are milled to 54 cc to get the compression to 11.64/1. Running a truck intake right now eventually looking to try the Edelbrock Pro FLow intake.
The race weight of the car is 2600 with me in it, rear is a 12 bolt with 4.10 gears running 31x13x15 m/t slicks.
The cam in it now is a futral grind that i picked up from a friend out of his 383 nitrous motor that has done ok so far but just wrong for my motor. 239/243 .612/.612 lift 112lsa +2.
Car has ran a best of 10.24 @128 mph with a 1.42 60 ft. (d.a at -1300)corrects to 10.40at 0 da on pump gas.
This cam wants 7400 rpms in this set up even with the truck intake, thats where it runs its best shifting hi.
I talked to Geoff at EPS and he knows my car well so he came up with a grind of 238/250 .60?/.596 110 lsa+4
I just picked the cam up from him last night , should have it installed by monday evening. Race next saturday
This cam should move the power band to a more reasonable range and leave the line much better and matcht the power band of the intake.
Also Im running a th350 with a 8" tci converter. around 5200 stall but not confirmed.
Any one care to predict what it will run with this Cam?
I am running a 347 c.i ls1 with stock crank, scat i-beam rods(7/16 rod bolts) and Mahle -4cc power pak pistons. 5.3 heads ported by Al Petre out of New Olreans and flow in the hi 280's intake, 220 on the exh side. 2.0 intake and 1.60 exh valves. Heads are milled to 54 cc to get the compression to 11.64/1. Running a truck intake right now eventually looking to try the Edelbrock Pro FLow intake.
The race weight of the car is 2600 with me in it, rear is a 12 bolt with 4.10 gears running 31x13x15 m/t slicks.
The cam in it now is a futral grind that i picked up from a friend out of his 383 nitrous motor that has done ok so far but just wrong for my motor. 239/243 .612/.612 lift 112lsa +2.
Car has ran a best of 10.24 @128 mph with a 1.42 60 ft. (d.a at -1300)corrects to 10.40at 0 da on pump gas.
This cam wants 7400 rpms in this set up even with the truck intake, thats where it runs its best shifting hi.
I talked to Geoff at EPS and he knows my car well so he came up with a grind of 238/250 .60?/.596 110 lsa+4
I just picked the cam up from him last night , should have it installed by monday evening. Race next saturday
This cam should move the power band to a more reasonable range and leave the line much better and matcht the power band of the intake.
Also Im running a th350 with a 8" tci converter. around 5200 stall but not confirmed.
Any one care to predict what it will run with this Cam?
#2
TECH Enthusiast
iTrader: (1)
That is a really tall tire for 4.10 gears. Have you tried more gear or 29 in tire? I think your 60 ft could be better. Staying with your current gear/tire I would guess 9.90. I bet if you change tire or gear it would pick up some more. What is your Rpm through the traps?I also would be willing to bet that converter is not very efficient on the big end which is hurting your trap speed.
#3
I wanted a cam for my motor, i have 4.56 gears that will be put in soon but want one change at a time.
I cross the traps at 6400 and hoping the gears will make the converter a little more efficient. Tires are starting to get old and will be replaced with 315x60x15 m/t drag radials . so that will help on gear as well.
I cross the traps at 6400 and hoping the gears will make the converter a little more efficient. Tires are starting to get old and will be replaced with 315x60x15 m/t drag radials . so that will help on gear as well.
#5
TECH Enthusiast
iTrader: (1)
I think the 4.56 is a good choice for N/A setup. 315/60- 15 is what 29 in tire? Generally an ideal gearing/ tire setup will have you going through the traps couple hundred rpm higher than shift points like you are shooting for. You are definitely headed in the right direction. Also you shift extension on your converter is a good way to tell if it is too loose. I think usually you want to see about 800- 1000 rpm drop after the shifts. Get it all working together and you might see some 9.60 -9.70 's out of it.
#6
I started tearing the front of the engine down last night but only had about 30 minutes to work on it. Got the water pump and radiator out the way.
have to get a 3 jaw puller to take the ballancer off. will do that tonight or tomorrow morning.
the 315's are 30" tall. when i get it running I will data log with efi live and see what my shift extension looks like.
have to get a 3 jaw puller to take the ballancer off. will do that tonight or tomorrow morning.
the 315's are 30" tall. when i get it running I will data log with efi live and see what my shift extension looks like.