496 - AFR315 Heads?

[Wilson1]

HP Hunter – Thanks a bunch for posting those two threads. Lots of good information in both, which helps me feel much better about the path I am going down. While there are some differences in each approach, I think the expected results should be in the same ball park. I have been getting some flak from my local engine builder about my head choice… He is a Brodix guy. Good heads, I have Brodix on my 468.

If I get anywhere from the low HP number to the high HP number minus the 20% loss for my altitude, I will be very happy. I feel that is very doable based on the results of those two builds.

It will be interesting to see just what the final outcome is based on the different parts I am selecting. My cam is 274/278 .765 lift on 108LC installed at 106. The 315’s are a little bigger port, but my car is a lot lighter. I am going to run a 454R manifold and I will take my Gary Williams 1050 off my 468 and put it on this motor. I don’t think I am going to be too far off. I am getting excited…

Thanks again Sir

[HP HUNTER]

Originally Posted by Wilson1

HP Hunter – Thanks a bunch for posting those two threads. Lots of good information in both, which helps me feel much better about the path I am going down. While there are some differences in each approach, I think the expected results should be in the same ball park. I have been getting some flak from my local engine builder about my head choice… He is a Brodix guy. Good heads, I have Brodix on my 468.

If I get anywhere from the low HP number to the high HP number minus the 20% loss for my altitude, I will be very happy. I feel that is very doable based on the results of those two builds.

It will be interesting to see just what the final outcome is based on the different parts I am selecting. My cam is 274/278 .765 lift on 108LC installed at 106. The 315’s are a little bigger port, but my car is a lot lighter. I am going to run a 454R manifold and I will take my Gary Williams 1050 off my 468 and put it on this motor. I don’t think I am going to be too far off. I am getting excited…

Thanks again Sir

At the very least:

1. Check the valve seat run out
2. Vent the heads, a MUST
3. Open up the oil return holes
4. Check for back flow @ .750 lift

Hopefully AFR has addressed these issues.

[Wilson1]

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..

[HP HUNTER]

Originally Posted by Wilson1

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..

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

[Wilson1]

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

[HP HUNTER]

Originally Posted by Wilson1

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

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.