LSX 454 and Boost

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Oct 17, 2021 | 06:16 PM

#21

01CamaroSSTx

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From: Conroe, Texas

Does NRE build boosted 454 LSX's?

NO!

If you had a tall deck then maybe so.

Oct 17, 2021 | 08:06 PM

#22

Corona

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How to build a FI 454.....it's done using a Tall Deck.

There's a young man who did this yrs before with his fire chicken ...

https://www.enginebuildermag.com/201...rbo-ls-engine/

Memory and Google search 😉
https://www.motortrend.com/features/...ntiac-formula/

Oct 17, 2021 | 08:15 PM

#23

01CamaroSSTx

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From: Conroe, Texas

What he doesn't tell you is that it was with a tall deck block.

Oct 17, 2021 | 09:28 PM

#24

NAVYBLUE210

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From: Coast of San Mateo County Between Pacifica & HMB

For ANY longevity 4.155" is the max recommended bore by many builders for FI.
This is largely for having enough gasket material between bores as well as
cylinder/block strength.

Oct 17, 2021 | 10:00 PM

#25

Launch

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Quote:

Originally Posted by 20SS06

MY BAD! I compiled images from a WhatsApp chat between me and the shop and failed to realize the dates as well as the differences in the pics! lol.

I guess the question still remain,

Would you boost a 4.200 LSX block? If so, by how much? Obviously will also be running Meth.

Thanks!

Nope not worth the risk, the head gasket seal between bores is more than likely going to end up an issue. Stay N/A or sell the block and buy another one.

Oct 17, 2021 | 10:04 PM

#26

Che70velle

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From: Dawsonville Ga.

Quote:

Originally Posted by NAVYBLUE210

For ANY longevity 4.155" is the max recommended bore by many builders for FI.
This is largely for having enough gasket material between bores as well as
cylinder/block strength.

This. Headgasket between the cylinders is very small, which makes it weaker. I personally wouldnt hesitate to put 10lbs (ten pounds at most here) on an Iron LSX block with a 4.2 bore. The MLS headgaskets are very robust. With an aluminum block 4.2 bore you have a very thin iron liner up against a paper thin (literally) aluminum water jacket housing. With an iron block, it’s all iron, so there’s a little more strength. Is it ideal? Heck no. But for 10lbs of boost I’d try it. I’d want the best tuner in the world, AKA Darth, to ensure that there is ZERO detonation anywhere.
But indeed, 4.155 is largest recommended bore sizing for safely boosting an LS/LT engine.

Oct 18, 2021 | 09:52 AM

#27

Mickyinks

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From: Melbourne, Australia

id try it with an oring and reciever groove setup, 1/2 inch head studs

Oct 18, 2021 | 12:42 PM

#28

ramairws6

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From: Hicksville MN!

I was running 300 shot on a LSX 445 almost 10 years in a sleeved LS7 block that finally gave up the ghost. The block was done so guess what i did? Reused everything internally in a new Dart block with some Mast heads. Only major replacement was the pistons. Now i'm a little smaller cubic inch at 440 with a little room to grow in the cylinders. If you know how to build these things and use the right parts i wouldn't be afraid of boost at all.