robertbartsch

Can someone please help with my confusion; I thought I could order a new LS1 aluminum block and Lunati rotating assembly and avoid all machine costs?

The dementions of a new LS1 stock engine block are 3.898 inches, right?

The dementions of the bore for a Lunati stroker kit are listed as 3.903, right?


Dumb question #1: I assume that Lunati assumes that you have a used block that will be cleaned up to match their bigger pistion size?

Dumb question #2: I assume the piston has to be a tad smaller than the bore; does Lunati's measurement refer to their piston size or are they telling you how much your bore should measure to match their piston set?

Dumb question #3: When I order my new block will it have a finish hone of 3.898 inches or do they ship it with a smaller bore which means you have to incurr machining costs to get it to a finished hone state?

Is this a vast right-wing conspiracy to help the machinsts generate engine block honing business?

Thanks...

2001CamaroGuy

iTrader: (6)

It’s the Russians.......



1) 3.903 is a 0.005" overbore (standard clean up) and is done because "most" people out in the world are going to use the block they already have in the car (ex: 50K miles) so it will need a little cleaning.....

2) I "think" pistons are a few thousandths smaller than the bore and the rings make the difference (ex: 3.900 piston)....Lunati is telling you the kit is designed to work with a 0.005" overbore.....

3) The blocks that come from GM should already be honed to a stock bore and be ready for stock pistons to be installed......in the SDPC2000 catalog, the add for the LS1/LS6 block says "This block comes with a 3.898" bore and will accept up to a 4.000" stroke without any machining of the block."


Can I ask why your not just using the block you have in the car now? A 0.005" clean up will not cost you NEAR what the new block will and you will actually have a better engine (seasoned block).

StevieZ

iTrader: (3)

Lunati DID make a 3.898 kit and it still may be listed on the website and even maybe available at the present time but I was told they are definitely going to discontinue it

2001CamaroGuy

iTrader: (6)

well....now that I think about it, you "should" be able to swap out the overbore pistons for stock sized pistons.....

when Lunati assembles the kit, have them put in stock bore instead of overbore....

Pro Stock John

iTrader: (34)

If you buy a new block it should just need cleaning and no more honing.

I bought a new LS6 bare block but then bored it out to 3.905.

robertbartsch

Camaro Guy:
I will likley buy a new block since I have a complete extra top end from my H/C swap and I could sell the old complete engine for $2,500 or so ...after my stroker project is complete....

L-EATER

iTrader: (2)

I just ruined a set of custom diamond pistons and now I am going to have to bore .030 I put a set of 4.00 pistons in a stock bore 6 liter with only the cleanup of a brush hone. I didn't measure the piston to bore clearance-just assumed it would be OK. I guess the hyper pistons used tighter clearances than forged. Lesson learned, I guess.

robertbartsch

So it is a very good idea to have a shop measure the bores and pistons before assembly.

AP-Engineering

L-EATER, What exactly happened with your engine? Give me a call and I might be able to help you out. Just matters what you had happen, I am sure I can at least help you out in some way.

Thanks,
Chris Gelineau
Diamond Pistons
877-552-2112 toll free