Cam help

Speedy

Speedy

Club Member
This is my father in laws buddy's car. Car is a 72 Camaro. He has a hyd. flat tappet cam in it now but wants to go mech. roller. Its a bracket car that he runs about twice a month with very little street use. He wants to know what a good cam for him to run to pick up some hp. He don't know the specs on the current cam but the lift is in .540s. He wants to go 11.40s. Cars best so far11.79@113MPH
Heres his current combo
10:1 383ci SBC
Quickfuel 850cfm 4150 double pump
Flat top pistons with valve relief’s
Edelbrock performer heads
64cc Chambers
Intake 2.02” exhaust 1.60”
.575 lift springs
Turbo 400 w/trans brake TCI reverse valve body
TCI 8” 5500 stall converter in right now. My car stalls at 4000 with this converter
Rear end gear is 4.86 (I’m thinking about going to a 4.56 gear) I’m going through the traps at about 6500 rpm now
Tire size is 29” tall 12” wide


Thanks for the help!
 
At first glance, I would say his stall speed is too high. To get good efficiency out of a 8" converter, you need run the engine about 1500 rpm higher than the stall. But when I do the math, It comes out with a little over 1% mph loss.
I suspect your numbers are inaccurate. 4-6% loss is more realistic with a perfect converter for the application.
You left out weight and current 60' times.
MPH is HP. going 113 in a quarter mile is not going to change with out more hp. Are the heads out of the box or has some one ported them?
 
With that kind of combo just run a hydrualic roller. Cheaper and easier on parts.

Speedy said:
This is my father in laws buddy's car. Car is a 72 Camaro. He has a hyd. flat tappet cam in it now but wants to go mech. roller. Its a bracket car that he runs about twice a month with very little street use. He wants to know what a good cam for him to run to pick up some hp. He don't know the specs on the current cam but the lift is in .540s. He wants to go 11.40s. Cars best so far11.79@113MPH
Heres his current combo
10:1 383ci SBC
Quickfuel 850cfm 4150 double pump
Flat top pistons with valve relief’s
Edelbrock performer heads
64cc Chambers
Intake 2.02” exhaust 1.60”
.575 lift springs
Turbo 400 w/trans brake TCI reverse valve body
TCI 8” 5500 stall converter in right now. My car stalls at 4000 with this converter
Rear end gear is 4.86 (I’m thinking about going to a 4.56 gear) I’m going through the traps at about 6500 rpm now
Tire size is 29” tall 12” wide


Thanks for the help!
Click to expand...
 
My first thought was the combo is all over the map and didn't know where to start. I'm surprised it runs as good as it does. I told him to go Hyd. roller too. He's looking for a recommendation on a grind. He doesn't know what cam is in the car now
 
I more or less copied my reply from another site...I just now see this thread so, my answer is somewhat redundant. In a nutshell, a roller cam swap is expensive. A hydraulic cam of ANY nature beyond 6500 rpm is not good! From what I can see it is a heavy car with a small engine, a big carb and OOTB heads...It runs pretty good for what he's using. What was the D.A.( approx.) at the MPH. What is the 1/8 mi, MPH? What is the converter efficiencey? seriously. Does it have a WORKING hood scoop? I would have to know much more about the car to make a suggestion that he would be happy with because, right now I see many 'bottle necks' that work in harmoney. My pointed questions to him would be "What are your goals? and... What is your budget? It sounds like he just wants to pick it up to 11.40's but, HE's decided the only way is to put a roller in it?
 
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The intake is a Professional Products Hurricane Intake which has an RPM range of 3500 to 7800rpm. I think this intake isn't helping him either. Where should he start to get this combo running better. I was thinking of some head porting, good valve job and milling to get the compression up. Gear change to 4.56. Smaller converter. Thoughts???? Don't be afraid to change things in the combo. I know its a miss matched set up
 
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