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I have some AFR 315's would they flow enough to support a 13.5:1 540c.i. at 6500RPM? Are all of the AFR heads based on the same casting, could these be opened up to support a larger engine? Thanks in advance.

Chris
 

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steelcomp was here
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I have some AFR 315's would they flow enough to support a 13.5:1 540c.i. at 6500RPM? Are all of the AFR heads based on the same casting, could these be opened up to support a larger engine? Thanks in advance.

Chris
Excellent head for that engine at that rpm. Perfect.
Yes, as far as I know, the AFR's are all the same casting but you don't need to open those up. There are some things that can be done to make them better, but making them bigger is not one of them...not for your application.
If you're interested in some options for making them even better, drop me a PM.
 

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Funny how things change. When I built my 557 BBC to turn 6500 and asked this same question my 335,s were to small. Wonder what has changed.
I guess that would depend on the head. I would never say a Merlin 345 would handle a 572 to 6500, but a AFR 345, easy.
A good 335 head on a 557 at 6500 is easily enough. The OP stated they were AFRs. Steel said they can be made better, and they can. He didn't say they can be made bigger. He said BETTER. As in more flow without adding CCs/cross section to the port. Adding CCs to a port is the worse way to improve flow. Its what you do after you have done everything else.



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I guess that would depend on the head. I would never say a Merlin 345 would handle a 572 to 6500, but a AFR 345, easy.
A good 335 head on a 557 at 6500 is easily enough. The OP stated they were AFRs. Steel said they can be made better, and they can. He didn't say they can be made bigger. He said BETTER. As in more flow without adding CCs/cross section to the port. Adding CCs to a port is the worse way to improve flow. Its what you do after you have done everything else.
I was using AFR heads.
 

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Funny how things change. When I built my 557 BBC to turn 6500 and asked this same question my 335,s were to small. Wonder what has changed.
Oh come on now, you know the drill, it's motorsports marketing 101!! Whatever you have is JUNK according to the guy trying to sell you something different, even if it's the exact same guy that sold you the JUNK in the first place.
FWIW & IMHO, the AFR 335s are a great choice for your 557.
 

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Oh come on now, you know the drill, it's motorsports marketing 101!! Whatever you have is JUNK according to the guy trying to sell you something different, even if it's the exact same guy that sold you the JUNK in the first place.
FWIW & IMHO, the AFR 335s are a great choice for your 557.

I did to. That is why I used them. Thank You David.
 

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Did I tell you that?

Yes. We talked about it. I do not believe in to big of ports myself. I am a firm believer in velocity. Would rather be on the smaller side with good velocity. Same with valves. A big valve has its place but it do cause other things to deal with. I am glad I don't know shit and get lucky as hell in my parts pick. Still Love you guys. Even though you pic on me. :happy:
 

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steelcomp was here
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I always wondered if that guy lived an alternative lifestyle.



741 HP @ 6000 557cid with ported Merlin oval ports. Who'da thunk it.
I guess they flow a shit load more than a set of AFR 335sOf course, what the hell does Byrce Mulvey know about cross section vs flow.
LINK 741HP 557
:indifferent0001:
 

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My Dart 335 CNC Pro 1's let my 565 pull to 7500, and made a little over 800.
 

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Yes. We talked about it. I do not believe in to big of ports myself. I am a firm believer in velocity. Would rather be on the smaller side with good velocity. Same with valves. A big valve has its place but it do cause other things to deal with. I am glad I don't know shit and get lucky as hell in my parts pick. Still Love you guys. Even though you pic on me. :happy:
Well either you misunderstood, or I did, because there's no way I'd ever say those were too small for a 557 turning 6500. I might have told you they could use a bigger intake valve. :D

...oh, and we pick on you because you deserve it.
 

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Well either you misunderstood, or I did, because there's no way I'd ever say those were too small for a 557 turning 6500. I might have told you they could use a bigger intake valve. :D

...oh, and we pick on you because you deserve it.
I still need to hook up with you. Want to try one with all the coated combustion chambers and piston coatings. This is a twin to another I built several years back so I could see what these coatings do for all that money. I know how the other did on the Dyno and it would be identical except your porting vs mine and the coatings.
 
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