An Old Timer once told me...

[dodgetkboy78]

Mullin, how does it run over say, 4500RPM?

What are the cam specs on the .474?? I never have ran Mopar cams. A quick google search and all I found was the .280 adv dur....

As someone who has ported tons of 302 heads, I'm not going to say the numbers are a fib, but back cutting the valves usually is a couple/few CFM, right? Wild may know more, he has a bench.

 

[1wild&crazyguy]

Do you think the flow numbers are a fib?
I do remember him telling me that back cutting the valves will make a significant rise in flow. So do you think that back cutting is capable of producing 30 cfm of flow? I mean what does a stock 302 head flow anyways... 174 cfm?

What do you mean "fix the ratio"?

I dont know.. I would have to test them myself or see an outside test result before I would say that.

I have heard people advertise up to 20 cfm with their 'special' valve job, but I dont know...I dont do valve jobs.

They sound like they might be lightly blended, as in just the area below the seat smoothed left over factory throat cut angles.

when I look at stan weiss head flow chart and see 302's flowing into the 190's w/ 160 cc port volumes...I have to scratch my head sum because the stock 302's I HAVE measured 124cc...and flow in the 160-170's, if I remember right. In fact...it took bowl/ssr/roof work to get it to 200 on a factory VJ & valve.

Tomorrow I will put one on and check it to be sure, but remember Im talking stock on a factory pos valve job, they could flow whatever diff depending on the type of valve job/angles done by this or that guy.

 

[Hysteric]

302's flowing into the 190's w/ 160 cc port volumes

This doesnt sound right at all!

I have mine at 228 cfm @ .500 at 140 cc with a 1.88 valve. And theres still plenty left in the port for more, not to mention a bigger valve 1.92 or 2.02 and some more ssr work.

Hysteric

 

[mullinax95]

Mullin, how does it run over say, 4500RPM?

What are the cam specs on the .474?? I never have ran Mopar cams. A quick google search and all I found was the .280 adv dur....

As someone who has ported tons of 302 heads, I'm not going to say the numbers are a fib, but back cutting the valves usually is a couple/few CFM, right? Wild may know more, he has a bench.

I've got the rev limiter set at 6K RPM .... its hard to believe but she is slightly start to lay down on just before I bump the rev limiter. I think all that velocity plays a role into it.

Cam Style Hydraulic flat tappet
Basic Operating RPM Range 2,000-6,000
Intake Duration at 050 inch Lift 238
Exhaust Duration at 050 inch Lift 238
Duration at 050 inch Lift 238 int./238 exh.
Advertised Intake Duration 280
Advertised Exhaust Duration 280
Advertised Duration 280 int./280 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.474 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.474 in.
Valve Lift with Factory Rocker Arm Ratio 0.474 int./0.474 exh.
Lobe Separation (degrees) 110

I dont know.. I would have to test them myself or see an outside test result before I would say that.

I have heard people advertise up to 20 cfm with their 'special' valve job, but I dont know...I dont do valve jobs.

They sound like they might be lightly blended, as in just the area below the seat smoothed left over factory throat cut angles.

when I look at stan weiss head flow chart and see 302's flowing into the 190's w/ 160 cc port volumes...I have to scratch my head sum because the stock 302's I HAVE measured 124cc...and flow in the 160-170's, if I remember right. In fact...it took bowl/ssr/roof work to get it to 200 on a factory VJ & valve.

Tomorrow I will put one on and check it to be sure, but remember Im talking stock on a factory pos valve job, they could flow whatever diff depending on the type of valve job/angles done by this or that guy.

BJR did something on the valve job as well not that you mention valves... but gosh I can't remember what.... 4 or 5 angle valve job I think it was??

 

[baracus]

I had a 71 scamp with a stock 360 with 318 heads that were ported, dont know the numbers, an LD4B, Holley 750, MP purpleshaft 484 cam, 904 with factory high stall, and 355 sure grip. This car ran super strong low to mid range, pulled like a beast. I never had it at the track but in was in the low 13's with sticky tires. It was brown with a white vinyl top and white bench interior, supposed to be in Wichita, Ks now.

 

[toolmanmike]

I was talking to an Older Gentleman at a car show and he told me about his first Mopar he had back in the 70s. He said that he ran a 360 with 318 heads to increase compression.

Does this sound likely or even a good idea?

I have a buddy that had a 318 with J heads that screamed. I think it's not just the parts but the right combination that makes a screamer. Mike

 

[dodgetkboy78]

I've got the rev limiter set at 6K RPM .... its hard to believe but she is slightly start to lay down on just before I bump the rev limiter. I think all that velocity plays a role into it.

Cam Style Hydraulic flat tappet
Basic Operating RPM Range 2,000-6,000
Intake Duration at 050 inch Lift 238
Exhaust Duration at 050 inch Lift 238
Duration at 050 inch Lift 238 int./238 exh.
Advertised Intake Duration 280
Advertised Exhaust Duration 280
Advertised Duration 280 int./280 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.474 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.474 in.
Valve Lift with Factory Rocker Arm Ratio 0.474 int./0.474 exh.
Lobe Separation (degrees) 110




BJR did something on the valve job as well not that you mention valves... but gosh I can't remember what.... 4 or 5 angle valve job I think it was??

Well, I was curious, really, just because I have a 390 with ported 302 heads, and while it makes monster trailer pulling torque, it will also run well past 5000. They are ported though, with the small port single plane street dominator, and the 268/276 voodoo cam.

 

[toolmanmike]

Well, I was curious, really, just because I have a 390 with ported 302 heads, and while it makes monster trailer pulling torque, it will also run well past 5000. They are ported though, with the small port single plane street dominator, and the 268/276 voodoo cam.

My guess is that the intake is helping there. Sounds like a nice combo.