Re: 496 - AFR315 Heads?
 

Thank you for the suggestions. Just to make sure we are speaking the same language:

Check the valve seat run out? Not quite sure what you mean by that… Are you saying make sure the seat is concentric with the valve? I never run a new set of heads without checking the guide clearance, the seats and the stack height and opening and max lift pressures. Not to mention making sure the valves are all the same height in the head and the same length. I always try to get the coil bind as close to .080 - .060 as I can. I don’t know how critical that is for a low rpm (7200) bracket racer like me.

Vent the heads? Are you saying have breathers with an exhaust extraction? Which I do.

Open the oil return passages…. Very understandable, and I wouldn’t have paid much attention to that without the heads up from you… Thanks.

Back Flow? Are you referring to reversion? I do run and ET Genie because I slow the car down to run 9.0 in Div 6 and for the Heritage race. I have found that it not only serves as a great power reducer, but when running all out, serves as a good reversion plate when using a .5” open spacer under the ET Genie.

I assume you have had some extensive experience with AFR heads. Thanks for sharing you experience.

Any other suggestions you would like to provide will always be welcome. Thanks again Sir..

Re: 496 - AFR315 Heads?
 

Pictures of the vent holes behind the intake face. This video will explain the run out. AFR was working on fixing these issues.

https://youtu.be/N3jn2ER455Y

Re: 496 - AFR315 Heads?
 

Thanks. That is a question I am going to ask. I would expect better from a new set of heads... You have now messed with my head... LOL

Re: 496 - AFR315 Heads?
 

Just trying to help you, you will find its a simple fix, you just have to do it. Some people might ask how a S/S 295 HP 350 runs mid 9s @ 3100 pounds..........well its the details.