Dart vs AFR heads on HP 500
#71
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Re: Dart vs AFR heads on HP 500
Originally Posted by jspeeddemon
I have 357 magnum AFR heads...We flowed these heads against a set of 355 Darts's and actually the Darts were 4 cfm stronger at .700 lift, on the same bench. Both exhausts were very close at .700. I will point out that the AFR heads were a little stronger at .500, .600, .650, on the intake side. Overall they were very close. I would say that given the quality of both CNC heads, go with the best deal.
Probably the main reason I chose the AFR's is because of their low lift flow numbers up to .600" lift....especially with the smaller 2.25" intake valve on their 315cc head. My friend with the same boat as mine (32' Active Thunder) who has supercharged 556cid engines just shakes his head in comparison of how well mine runs compared to his. And I am right there at his side from 3000rpm up to the top! Not too bad from a little 315cc head on a big ol' 565cid naturally aspirated engine with a little hydraulic roller cam that idles at 600rpm in neutral. I'm really starting to have a lot fun with it!
Last edited by KAAMA; 10-03-2006 at 10:02 PM.
#72
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Re: Dart vs AFR heads on HP 500
I have always been partial to AFR because they seem to make the most power on any given combination, so it's good to hear that their numbers on the CNC heads are close to their published figures. I guess flowbenches are like dynos, every one gives a little different reading?
Jspeeddemon:
How fast does that 26' Daytona run with that combo? Must be a beast!
Jspeeddemon:
How fast does that 26' Daytona run with that combo? Must be a beast!
#75
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Re: Dart vs AFR heads on HP 500
Here is some more Jim Valako work. This hand port head was used going to be used as the basis for developing a marketable CNC cast iron head. At the end, we scrapped the project as we didn't see the commercial value.
At this point, Jim then hand ported a set (second set being completed now) based around be best ports on the head we used for the port development. Jim's results were confirmed at Flowmotion, TX.
The final ports we picked are highlighted. These heads supported 800+ HP with 505 CID at Keith Eickert's. Not bad for cast iron!
Want a set? Call Jim V.
At this point, Jim then hand ported a set (second set being completed now) based around be best ports on the head we used for the port development. Jim's results were confirmed at Flowmotion, TX.
The final ports we picked are highlighted. These heads supported 800+ HP with 505 CID at Keith Eickert's. Not bad for cast iron!
Want a set? Call Jim V.
#76
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Re: Dart vs AFR heads on HP 500
BenPerfected -
Wow !!!!
Wow !!!!
#77
Charter Member#330
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Re: Dart vs AFR heads on HP 500
Good info here
What intakes are you using with the AFR's?
Mark
What intakes are you using with the AFR's?
Mark
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If you like it rough do it OFFSHORE!!!
If you like it rough do it OFFSHORE!!!
Last edited by MrCIG; 11-29-2006 at 08:10 PM.
#78
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Re: Dart vs AFR heads on HP 500
Mark, There are a few different intakes that would probably work well, but I am using the Dart single plane intake with 4150 carb base, but I believe they can be had in the 4500 Dominator base as well.
#79
Charter Member#330
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Re: Dart vs AFR heads on HP 500
Mark did you port match the intake to the heads?
Thanks
Mark
Thanks
Mark
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If you like it rough do it OFFSHORE!!!
If you like it rough do it OFFSHORE!!!
#80
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Re: Dart vs AFR heads on HP 500
Originally Posted by woody1
How many people here have cams custom ground? And Im not talking about calling a 9 dollar an hour comp cams hotline tech that picks blindly from the catalog? I bet the truthful answer is very, very few
As I said, this is not a slam against any engine builders here on OSO. The engine builders on OSO now have been here a very long time and have excellent reputations.