Big Block Chevy best conventional cylinder head

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Sweet P
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Big Block Chevy best conventional cylinder head

Post by Sweet P » Fri Sep 21, 2018 10:34 am

565 cid
7500-9000 peak RPM
alcohol

The rules say the intake port layout can't be spread port or symmetrical, what heads do you think are the best?

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Re: Big Block Chevy best conventional cylinder head

Post by Frankshaft » Fri Sep 21, 2018 11:36 am

Actual "conventional", or something​ like a Dart, or Sr20 allowed? Sometimes the latter aren't allowed, because let's be real, they aren't "conventional" but are often called such.

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Re: Big Block Chevy best conventional cylinder head

Post by mag2555 » Fri Sep 21, 2018 12:12 pm

What level of HP do you need to make?

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Re: Big Block Chevy best conventional cylinder head

Post by Frankshaft » Fri Sep 21, 2018 12:17 pm

mag2555 wrote:
Fri Sep 21, 2018 12:12 pm
What level of HP do you need to make?
The rpm range he is targeting tells the tale.

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Re: Big Block Chevy best conventional cylinder head

Post by Sweet P » Fri Sep 21, 2018 1:06 pm

mag2555 wrote:
Fri Sep 21, 2018 12:12 pm
What level of HP do you need to make?
Its an all out engine
Frankshaft wrote:
Fri Sep 21, 2018 11:36 am
Actual "conventional", or something​ like a Dart, or Sr20 allowed? Sometimes the latter aren't allowed, because let's be real, they aren't "conventional" but are often called such.
"Conventional" as in not spread port and not symmetrical, so yes Dart or SR20 are allowed.

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Re: Big Block Chevy best conventional cylinder head

Post by user-17438 » Fri Sep 21, 2018 6:33 pm

Frankshaft wrote:
Fri Sep 21, 2018 12:17 pm
mag2555 wrote:
Fri Sep 21, 2018 12:12 pm
What level of HP do you need to make?
The rpm range he is targeting tells the tale.
Good luck with that inch.. It will take a lot of work to any real conventional head. You would be better off with a smaller engine to turn that rpm

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Re: Big Block Chevy best conventional cylinder head

Post by user-17438 » Fri Sep 21, 2018 6:36 pm

Sweet P wrote:
Fri Sep 21, 2018 1:06 pm
mag2555 wrote:
Fri Sep 21, 2018 12:12 pm
What level of HP do you need to make?
Its an all out engine
Frankshaft wrote:
Fri Sep 21, 2018 11:36 am
Actual "conventional", or something​ like a Dart, or Sr20 allowed? Sometimes the latter aren't allowed, because let's be real, they aren't "conventional" but are often called such.
"Conventional" as in not spread port and not symmetrical, so yes Dart or SR20 are allowed.
Are you positive, because SR20 in my book is far from conventional, and many sanctions have banned it.

If that fly's use them and go to town on them. If not, profilers or headhunters, and a lot of work.

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Re: Big Block Chevy best conventional cylinder head

Post by ProPower engines » Fri Sep 21, 2018 7:17 pm

So that said if a std port layout mist be used is there a post size max in the rules. Reason I ask is moving the air in a slightly different direction can be done with the right port work.
What heads are not allowed by the class rules you must follow would be a better starting point.
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Re: Big Block Chevy best conventional cylinder head

Post by grant6395 » Fri Sep 21, 2018 8:36 pm

Check out the profiler XL head. There are a few good porters that do these and I belive they flow around 520ish. They are big so rpm will be your friend.its a conventional layout I belive.

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Re: Big Block Chevy best conventional cylinder head

Post by Newold1 » Fri Sep 21, 2018 11:19 pm

If the SR20's are allowed, contact Slick Rick and have him do a set for your specific application and spec your intake manifold for your engine. His successes with those heads is pretty unprecedented and not inexpensive though. :wink:
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Re: Big Block Chevy best conventional cylinder head

Post by shoedoos » Sat Sep 22, 2018 12:39 am


user-17438

Re: Big Block Chevy best conventional cylinder head

Post by user-17438 » Sat Sep 22, 2018 1:26 am

grant6395 wrote:
Fri Sep 21, 2018 8:36 pm
Check out the profiler XL head. There are a few good porters that do these and I belive they flow around 520ish. They are big so rpm will be your friend.its a conventional layout I belive.
Yes they are 24 degree, not 20. But woukd still need work for a 565 the make power at 9000. Don't be fooled by flow numbers.. They aren't big enough.

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Re: Big Block Chevy best conventional cylinder head

Post by mag2555 » Sat Sep 22, 2018 6:50 am

You need a big port with Alky at that rpm so even a ported 345 head my not top 900 hp.

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Re: Big Block Chevy best conventional cylinder head

Post by Walter R. Malik » Sat Sep 22, 2018 10:36 am

Most sanctioning bodies who have that kind of "conventional" rule will usually limit an amount the intake port can be raised above a production intake port floor height from the deck of the engine
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Re: Big Block Chevy best conventional cylinder head

Post by pdq67 » Sat Sep 22, 2018 4:11 pm

Are the old 360 cc intake port Merlin type heads any good here? Grind hell outta them to up flow here also...

Or are they just too old a tech?

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