Ls Intakes

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Jan 1, 2023 | 05:41 PM

bjrs2k

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Ls Intakes

I’m building a turbo ls engine. 4.8 rotating assembly with ls7 pistons, I’m trying to decide whether or not to use a stock intake. I was told the ls6 ones crack under too much boost, I’ve also seen that the aluminum hi flow intakes are really loud and amplify the noise of the valvetrain. Any suggestions or can anyone tell me if these are true or are not

Jan 1, 2023 | 06:40 PM

Che70velle

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Quote:

Originally Posted by bjrs2k

Give us details of your setup please. What block are you using to get a 4.125 bore? Rods? Crank? Details first please.

Jan 1, 2023 | 07:01 PM

bjrs2k

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Quote:

Originally Posted by Che70velle

Give us details of your setup please. What block are you using to get a 4.125 bore? Rods? Crank? Details first please.

Lq9 bored out to 4.185” with a 4.200” .041” thick gasket and 4.8 rods and crank
rods are 6.298” and the stroke is 3.268”
243 heads and the combustion chamber is being opened up from 65cc to 70cc

Jan 1, 2023 | 07:25 PM

LS1Formulation

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LQ9 cannot be bored that far. It's not a siamesed bore block for one thing. For another, hitting .060 over is pushing it. .185 over? Uh... no.

Jan 1, 2023 | 07:33 PM

Che70velle

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Quote:

Originally Posted by bjrs2k

.185 bore? If there’s any cylinder wall left, and that’s a big IF…you don’t want to boost it. Just not enough wall left to handle any boost. Bad idea. Now the crank is interesting. Is it a billet Bryant crank by chance? What rod is that? Cool build for sure. Interesting head choice also for that bore size.

Jan 1, 2023 | 08:14 PM

99 Black Bird T/A

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Quote:

Originally Posted by LS1Formulation

LQ9 cannot be bored that far. It's not a siamesed bore block for one thing. For another, hitting .060 over is pushing it. .185 over? Uh... no.

Most I've ever read about was on SpeedTalk where Joe Sherman/Joe Sherman Racing did a lot of sonic checks on LQ4/LQ9 and discovered ~1 in 10 or so could be bored to about ~4.125

Jan 2, 2023 | 08:05 AM

LS1Formulation

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I've definitely seen them taken to 4.100 on an NA build, and could see them possibly going to 4.125 on a block with zero core shift, but 4.185 seems ludicrous to me. The cylinder walls would be transparent!