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Apache heads on a 5.7?

Posted By: gregsdart

Apache heads on a 5.7? - 01/06/16 06:40 AM

After reading the other post on Apache heads, it sounds like the Apache heads have too big of a chamber to be used on a 5.7 block? I was hoping to use a set on a 5.7 core I currently have. I also have the Apache heads, new in the box.
Has anybody successfully run Apache heads on a 5.7 block, and what issues did you have?
Posted By: sixpackgut

Re: Apache heads on a 5.7? - 01/06/16 05:25 PM

I'm thinking the only thing you will need to do is get a cometic head gasket for a 5.7 block with a 4.10 bore. or whatever the 6.4 bore is and maybe notch the bore slightly
Posted By: Triple Threat

Re: Apache heads on a 5.7? - 01/06/16 05:58 PM

Ask me again in a month...
Posted By: Max Weg

Re: Apache heads on a 5.7? - 01/06/16 06:50 PM

I will let you know in a day or so.

Max Weg
Posted By: gregsdart

Re: Apache heads on a 5.7? - 01/06/16 10:11 PM

up
Posted By: Max Weg

Re: Apache heads on a 5.7? - 01/07/16 09:32 PM

I installed the appache heads on the freshly decked and honed block with a 0.025" gasket and measured the radial clearance at 0.032".

Max Weg

Attached picture image.jpg
Posted By: 496 A-body

Re: Apache heads on a 5.7? - 01/07/16 10:31 PM

Nice! What bore size is the block?
Posted By: sixpackgut

Re: Apache heads on a 5.7? - 01/07/16 10:38 PM

Originally Posted By Max Weg
I installed the appache heads on the freshly decked and honed block with a 0.025" gasket and measured the radial clearance at 0.032".

Max Weg


cometic gasket?
Posted By: Max Weg

Re: Apache heads on a 5.7? - 01/07/16 10:43 PM

The Bore is 3.929" and I used a stock 5.7 gasket.

Max Weg
Posted By: gregsdart

Re: Apache heads on a 5.7? - 01/08/16 05:13 AM

Did you check the gasket against the head to make sure the fire ring is out side the chamber? It must get real close!
Posted By: Max Weg

Re: Apache heads on a 5.7? - 01/08/16 08:01 PM

You would jot be able to use a 5.7 gasket. I was using it purely for its thickness as your not going to use a thinner gasket, therefore the radial clearance would be at it's worst.

Max Weg
Posted By: Triple Threat

Re: Apache heads on a 5.7? - 02/14/16 08:40 PM

Intake valve clears on my .010 over 5.7 with no head gasket.

We're going to eye brow the top of the bore slightly just because it should help unshroud the valve at low lift and provide more radial clearance.

Using a 4.100 Cometic for final assembly.
Posted By: gregsdart

Re: Apache heads on a 5.7? - 02/15/16 04:32 PM

From what I understand, two things make notching the block for intake valve de shrouding of little value? First, the valve is moving away from the cylinder wall as it opens. Two, the flow on the short side radius of a port is very poor in most cases, although the Apache heads may have the best short side situation of any head on a stock motor. Still, I bet the flow difference would show very little power gain between notched and un notched bores.
Posted By: Triple Threat

Re: Apache heads on a 5.7? - 02/15/16 06:10 PM

Probably true, but the added radial clearance makes it worth doing IMO.
Posted By: gregsdart

Re: Apache heads on a 5.7? - 02/16/16 04:48 PM

Originally Posted By Triple Threat
Probably true, but the added radial clearance makes it worth doing IMO.

Makes sense.
Depending on where the top of the top ring is, plus .040 for keeping the ring sealed under any situation, it might get a little tough to notch the block much. I assume though that the rings have to be moved down a lot lower than a stock type piston, so valve notches can be used for bigger cams? Anyone have an idea how far down the rings have to go? I hope to bore mine to 4.000 or close.
Posted By: gregsdart

Re: Apache heads on a 5.7? - 04/04/16 12:02 PM

Bump, hope fully someone can provide info on my previous post?

"Anyone have an idea how far down the rings have to go? I hope to bore mine to 4.000 or close"
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