Rebuilding a 98 block
Thread Starter
Joined: Nov 2005
Posts: 2,155
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From: Gainesville, GA
Rebuilding a 98 block In a thread over on the FI section I spoke of finding an LQ4 in a junk yard and using it in a FI setup. Another member recommended buying forged pistons off the shelf, a basic rebuild kit, ARP studs and rod bolts, and having about as much in that (and be better prepared for boost) as I would in the whole truck engine.
Honestly I never even gave any thought to putting some low compression forged pistons in my stock block. I had seen magazine writeups where it seemed as though all of the block was stock with exception to the pistons, but I never really question how they went about doing it.
What is required as far as machining and block prep? Is there any boring that needs to be done, or for that matter, can be done?
Or even better, could someone better assist me in how to search for this information on this site? I know its been discussed but I just couldnt find it. Or perhaps there's a book that details the rebuilding of an LS1.
Honestly I never even gave any thought to putting some low compression forged pistons in my stock block. I had seen magazine writeups where it seemed as though all of the block was stock with exception to the pistons, but I never really question how they went about doing it.
What is required as far as machining and block prep? Is there any boring that needs to be done, or for that matter, can be done?
Or even better, could someone better assist me in how to search for this information on this site? I know its been discussed but I just couldnt find it. Or perhaps there's a book that details the rebuilding of an LS1.
I found 2 books that look good on Amazon.com....haven't read either yet. Search "rebuilding LS engines" and you should find them. SA books
To answer your question, you can buy pistons 3.905 or similar, which would then allow you to have the stock block bored a couple thou, and re-honed. I'd suggest finding a machine shop that hones with a torque plate if you are planning to push this motor with boost. The torque plate bolts to the block, and simulates a head torqued down (distorting the block as it would be in use). Then the final hone is done so the holes are perfectly round when torqued up.
You might also want a slight deck cut to seal the head gaskets good...and check alignment of the main bores while it is in the machine shop. Machine work is going to cost the same whether you use a LQ4 or a LS1 alum. block to do it right.
To answer your question, you can buy pistons 3.905 or similar, which would then allow you to have the stock block bored a couple thou, and re-honed. I'd suggest finding a machine shop that hones with a torque plate if you are planning to push this motor with boost. The torque plate bolts to the block, and simulates a head torqued down (distorting the block as it would be in use). Then the final hone is done so the holes are perfectly round when torqued up.
You might also want a slight deck cut to seal the head gaskets good...and check alignment of the main bores while it is in the machine shop. Machine work is going to cost the same whether you use a LQ4 or a LS1 alum. block to do it right.
clean up .005, set deck to pistons for proper quench, line hone, of course balance rotating assemby. Just plan on doing those things if you want it done right. Some guys will skip the line hone and justify it some how. We never do.
