After getting my block back from honing and new cam bearings, I noticed a "divot" in one of the the cylinder walls. It is about .21"" down from the top of the cylinder, and about .125" in diameter. I have no idea how it got there (I suppose it could've been there before the rebuild)- any ideas? Is the block still usable?

Thanks

Ben

 

Well, I wouldn't say the block is junk. I don't think the block was like that prior to it going to the machine shop. Any shop worth a damn would have said something about that. As for it being junk. If it can't be bored out anymore, then your only real option is to have that cylinder resleeved. You can try to have it built up with weld and remachined. I've seen that done to old tractor engines which they can't get replacement sleeves for the motor or crank. That is very tricky to do though. Resleeving the block is the better of the two options here if you want to retain the existing block. A new LS1/LS6 block is like $600 I think from SDPC2000, that might be an option too.

 

Hmm...so the sleeve can definitely not be used in its current condition?

I had the shop do 3 things- cam bearing install, hone, and clean the block. Maybe something happened with the hone to take a chunk out of the sleeve?

Thanks again
Ben

 

I wouldnt worry about it, after you put it together and get it runnin- you wouldnt know it was there. Looks like it will be above the ring land at TDC anyway or close to it.

 

It will be above the ring land @ TDC. The ring land height @ TDC is right around a depth of .182" from the deck. The divot is about .217" from the deck. The divot isn't long enough to span the two compression rings, so I'm not thinking it is going to cause leakage during compression.

Thanks
Ben

 

Not to hijack but I have a buddy from up around Rochester, he tells me its nice up there- when its not snowin lol.

 

Yeah...I'm building my car at the moment. 15 degrees makes things a little tougher, but not too bad. I'm building the engine in the back hallway to keep the engine parts at a normal temp. It is quite an odd scene.

Anyway...I'm going to put this together with the divot unless someone can convince me otherwise...any final thoughts???

Ben

 

I don't know how anyone could think that the damage was caused at the machine shop. It's obvious it's a seperation/rust or porosity, not some damage caused. And I agree that it will be of zero consequence. Even if it were at the height of the ring land....It wouldn't amount to squat. It's easy for everyone to jump on the bandwagon and it's obviously not perfect or optimum....But it's funny how someone is always to blame over some of the dumbest things....But I'm sure if you find the right dyno, someone will tell you how it accounted for a 10HP loss. LOL

 

use it..as long as it isn't burred. which it isn't you will never know it was there. It would really only affect you if like stated above it spanned accross 2 ringlands. in this case it will only retain a little oil till it gets built up and covers the divot with the charred oil buildup that is common around the top of the cylinders over time.

 

Thanks again for the replies guys, I feel much more confident continuing with the build. The LS1-RX7 project marches on...

Ben