Stock LS1 Block - Max HP
let me start off by saying yes I did use the search. In fact, I've searched this issue and googled the crap out of this topic.
What I'm looking to find out is the maximum horsepower one would call 'reasonably safe' for a stock ls1 block. By stock I mean stock pistons, rods, bearings, all stock bottom end. Top end is stock 241's and I'm thinking of putting a tick turbo cam in there with springs, pushrods, head gasket and studs.
If it matters: I'm using a huron speed hot and cold side kit with a pt7675 turbo
I will be running this on 93 octane and will buy a meth kit if necessary (for the added safety blanket)
Please reply if you have hands-on experience with boosting a STOCK ls1 and know the limits of the internals and block. I mean to not be rude but please if you do not have experience and you are just going to repeat what you read on ls1tech or any other forum, then don't. I say this because there is SO much misinformation being spewed about this topic online.. I have seen anywhere from 500whp as a safe number to over 800.
Second question. What would be the limits of the BLOCK if one were to replace all internals with a forged assembly? I ask this because I want to compare the cost effectiveness of that vs a 5.3 swap.
For what its worth the block has 20k miles on it (just 13k on the clock 4 months ago)
Thanks for any and all replies!
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Anyone know what power level splits the block? can this thing hold ~1k with forged assembly?[/Q
I have a forged ls1 That's stroked to 383 That I will be using to replace my 5.3, I plan on putting 20psi of boost to it and Will be shooting for the 900 to 1000whp goal. Just getting ready to start swapping them out. Should be on the dyno in a couple of months. I believe several years ago Harlan was making over 1000whp with a nonfilled stock block and it was holding up.
According to Steve Darmijian who owns RED and developed the sleeves for LSx motors.......the LS1 block from 1997-1998 is actually the strongest, or the next strongest behind the LS2 block.
So you're off to a good start.
I wouldn't go over 600 RWHP with a bone stock LSx anything......
Stock crank is good to 1,000 RWHP plus. But you if you do a forged rotating assembly you can easily make 1,000 RWHP +
Re-sleeve it and go more.......
.
Gen 4 rods and pistons will take much more power. The LS1 block itself is questionable as far as power goes. Lots of mixed results. It seems the only safe aluminum block for big numbers without modifying the block at all is the 5.3 blocks.
I cant comment on splitting the block, but I dont think you would have an issue with that on the stock bottom end. Real question-what is your goal? Is it a power goal or an ET goal? My set up was designed to come on late to keep the motor alive. If you make full boost much earlier, your torque spike will be harder on the motor and you stand a better chance at bending a rod. That being said-I think a fast spooling 600whp will last forever on a bone stock Ls1. If you are willing to take it to 7000 RPM and put a GT55 on it, I bet it would see close to 1000whp, but the set ups would not at all be comparable.
Its all relative.
Ls1curt you have any details on the setup?











