Re: AFR BBC Heads
 

Monty put the exhaust flow numbers on a later thread and I wrote them down. While using the Del West exhaust valves, and WITHOUT the use of a 6" pipe as he stated above, here are the flow numbers on the exhaust side of the AFR 315cc CNC ported heads and they look to be quite impressive...

Lift...CFM
.200 147
.300 187
.400 245
.500 281
.600 304

Re: AFR BBC Heads
 

With that % of around 80% your looking at a single pattern cam @ .050" and probly a reverse split of 4 degrees at .200". It will also require a split ration rocker set.

Chris

Oh yeah, when back cutting a valve in my schooling, no this does not represent one of the angles on the valve job. 3, 5, 7 whatever is cut/ground on the seat in the head.

Re: AFR BBC Heads
 

Kaama,
AFR offers an upgrade for the 305cc/315cc exhaust side that will increase exhaust flow by about 9% throughout the lift range. The upgrade (part#7632) includes tulip exhaust valves for a $40.00 premium at the time of purchase. This brings the exhaust flow inline with the 335 CNC port. Considering the 315 intake port outflows the 335 head until .600" lift, adding the tulip valve on the exhaust side makes for the best of both.
Bob
AFR 315 Intake
0.2 169
0.3 249
0.4 312
0.5 353
0.6 380
0.7 387
335cc AFR 335 Intake
0.2 164
0.3 240
0.4 304
0.5 352
0.6 385
0.7 404

Re: AFR BBC Heads
 

CStraub,

What ratio of rocker arm? Also, which side should it go on---intake?


rmbuilder,

Does AFR have the actuall flow numbers available with the tulip valves for the 315cc head on the exhaust side? I also wonder if the Del West valve will out flow the upgraded exhaust valve from AFR? I suppose the only way to find out would be to buy a Del West exhaust valve and test it against the AFR exhaust valve part #7632. I know I may be splitting hairs here but I am curious and if I am going to buy the AFR heads and new valves I might as well buy the ones that work the best---right?

Re: AFR BBC Heads
 

Kaama,
It will vary per application but the exhaust will have quite a bit less lift then the intake side for optimum performance.

Chris

Re: AFR BBC Heads
 

Thanks for the info guys,GREATLY appreciated as ive got a set of 315 cnc's coming any day now!! :D :D
Kaama,are you buying a pair to try or are you interested in trying mine,the offer still stands but i see you mentioned"santa" getting you some,Smitty

Re: AFR BBC Heads
 

Smitty,

Thanks---that is one awefully kind offer, but I believe this time around I have gotten good, reliable info. Therefore, I am going to take my chances, and just give it a "GO" on this one. I am going to do a cam and head swap. Should be interesting none the less. :)