LS7 block question

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Jul 23, 2019 | 06:49 AM

Orange Juice

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From: Hamilton Ontario

LS7 block question

Car was down on power, leak down test show cylinder 7 is bad. What are my options, can the block be honed or should I just get a new block?

Jul 23, 2019 | 07:27 AM

Double06

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You could try a hone but not a bore. Your machinist will be able to assess situation. The stock LS7 block can not go any more then what you have (GM sleeves very thin and material is just regular iron). I have seen people do .005 over as a clean up. You could also Darton (ductile iron) sleeve the entire block and bore up to 4.185 or just leave it a 4.125.

Jul 23, 2019 | 09:42 PM

xBoostx

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How much power where you making to the tires

Jul 23, 2019 | 10:09 PM

Orange Juice

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From: Hamilton Ontario

It made 500 rw down 50 with more intake. Leak down on #7 dropped 60%.

Jul 24, 2019 | 09:27 AM

AgFormula02

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You can go 4.130 or even 4.135.
Will depend on the machine shop, their skill, and also the true size of the liner.
Contact LME or someone with experience before you let someone ruin a 2500 dollar block

Jul 24, 2019 | 11:51 PM

Steve - Race Eng

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Ls7

Quote:

Originally Posted by Orange Juice

Car was down on power, leak down test show cylinder 7 is bad. What are my options, can the block be honed or should I just get a new block?

Make sure cylinder 7 cylinder wall isn't cracked. Is there any coolant in the oil?

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Jul 25, 2019 | 07:00 AM

Orange Juice

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From: Hamilton Ontario

Haven't seen any coolant in the oil but have noticed that coolant level does drop. I think getting the blocked sleeved is the better idea. My builder has a shop in Detroit he recommended. I didn't get the name. Tough being in Canada, at least i'm close to a border.