do i need a new ls1 block now?
Thread Starter
Staging Lane
Joined: May 2010
Posts: 95
Likes: 0
From: whiteland,IN
do i need a new ls1 block now? ok long story short i had a 383 ls1 that was at 3.903 lost a set of rings and am rebuilding now, my engine builder said i now need to go to atleast a 3.907 or 8 and get custom pistons made i have never heard of a ls1 being bored this much i wouldn't think there would be anything left to the walls and i plan i spraying a 250 shot through a direct port kit this year. now for the price difference of buying custom pistons it would prob be about the same as getting a used block and standard wesico. also is it true you can bore a 5.3 aluminum block to 3.903 without any issues and basically make it a ls1 block? any help would be great
You can get iron 5.3 blocks brand new for really cheap and bore them to stock ls1 bore size and still have them be able to handle lots of power. With a 250 shot an iron block would handle that much better than aluminum.
Thread Starter
Staging Lane
Joined: May 2010
Posts: 95
Likes: 0
From: whiteland,IN
what year is your block? If its 99-up you can safely take it out to an overbore of .010 over stock which would put you at 3.908. They also make replacement pitons for this size so its not hard to find them however idk if I would feel comfortable running a 250 shot on a stock ls1 block let alone an overbored one
TECH Apprentice
Joined: Nov 2011
Posts: 337
Likes: 1
From: Murray, KY
I saw a guy in Jacksonville, FL spray 200-250 direct port on a completely stock internals in a 99 T/A for 2 years almost every weekend, over and over and over. It finally got to smoking pretty bad and he rebuilt with forged pistons and rods and stepped it up to 300 shot and had very good success with it. I do not know however what size bore he had.
Thread Starter
Staging Lane
Joined: May 2010
Posts: 95
Likes: 0
From: whiteland,IN
what year is your block? If its 99-up you can safely take it out to an overbore of .010 over stock which would put you at 3.908. They also make replacement pitons for this size so its not hard to find them however idk if I would feel comfortable running a 250 shot on a stock ls1 block let alone an overbored one
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Verdad Gallardo ya if its a 98 your already maxxed out. I'd start looking or either another ls1 block or perhaps you could find a 6 liter iron block and use that if you dont already have the lunati pieces
Thread Starter
Staging Lane
Joined: May 2010
Posts: 95
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From: whiteland,IN
Your machinst should be able to tell you max.
Stock bore is 99mm or 3.898 with a "safe" hone up to 0.0040" which puts you to 3.902" and I have heard people push it but you should be cutting through the sleeved or be paper thin.
- As per HP Boks CHevy LS1/LS6 High perf. which is older info but still relevant.
You could choose to bore out the sleeves and put Darton Sleeves in and go big bore, or pony for a LS2/3 block. Or take on some nose weight on a 5.3 IMO I would look for a LS2 used/new as you will get a 4" bore and open up cyl head choices.
*Note* Later LS1's (1999+) did allow for a 0.010" BORE for max vs the 0.0040" HONE.
I would really research what the cost of doing sleeves vs a new LS2 type block. Going aftermarket on the sleeve would make the block better and give you room to bore in the future if you have another engine issue.
Stock bore is 99mm or 3.898 with a "safe" hone up to 0.0040" which puts you to 3.902" and I have heard people push it but you should be cutting through the sleeved or be paper thin.
- As per HP Boks CHevy LS1/LS6 High perf. which is older info but still relevant.
You could choose to bore out the sleeves and put Darton Sleeves in and go big bore, or pony for a LS2/3 block. Or take on some nose weight on a 5.3 IMO I would look for a LS2 used/new as you will get a 4" bore and open up cyl head choices.
*Note* Later LS1's (1999+) did allow for a 0.010" BORE for max vs the 0.0040" HONE.
I would really research what the cost of doing sleeves vs a new LS2 type block. Going aftermarket on the sleeve would make the block better and give you room to bore in the future if you have another engine issue.
