PTV Issues? 370" Build

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Mar 30, 2018 | 02:02 AM

NateLS1Mustang

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PTV Issues? 370" Build

I am planning on rebuilding my LQ4. Going to punch it out to a 370ci, put 799s on it with a decently sized cam high 23x/low 24x +.600" lift. I want to use Wiseco +4cc domed pistons. I'm aiming for 11.5-.6:1 CR.

I can achieve that couple different ways but I'm wondering if I will have PTV clearance issues either way. With the pistons I want to use (and them being dome tops) and stock 799s with a .036 head gasket will get me to my desired CR I believe, but will it have PTV problems? Or I could go with a thicker gasket and instead mill my heads but thinking either way I might run into clearance issues? I'm not quite sure, just wanted some advice on the matter. Thanks for any information and/or advice.

Mar 30, 2018 | 02:28 AM

98CayenneT/A

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Even with the dished Lq4 pistons you still might run into ptv issues depending on cam due to the outside of the piston is raised and the exhaust valve could hit there, again depending on the cam. The dish does not give extra clearance on both valves.

Why not flat top pistons with reliefs. Heads milled .035" and .040" head gasket?

Mar 30, 2018 | 02:56 AM

NateLS1Mustang

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I can look at other piston options I suppose. I have plenty of time. I was just interested in these Wiseco +4cc domed pistons for the price they are and trying to hit my desired CR.

Mar 30, 2018 | 06:21 AM

Che70velle

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Throw up a part number for the pistons your looking at. Wiseco makes some dome units, with nice sized reliefs in them.

Mar 30, 2018 | 07:39 AM

KCS

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Wiseco usually puts deep reliefs in their pistons so you probably will have miles of PTV clearance.

Mar 30, 2018 | 08:25 AM

NateLS1Mustang

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Now that I look at it again, it does look like the pistons I want to use do have reliefs cut in them already.

It's the Wiseco PTS523A3 Pro Tru Street Series.

Mar 30, 2018 | 07:40 PM

Che70velle

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Quote:

Originally Posted by NateLS1Mustang

Now that I look at it again, it does look like the pistons I want to use do have reliefs cut in them already.

It's the Wiseco PTS523A3 Pro Tru Street Series.

Those units have nice reliefs in them.