340 max bore?

[don melvin]

I recently acquired a 340 block on the cheep and when i inspected the bore size it had already turned .o60 over ,,the block has ben sitting around for a while (in doors) and has enough surface rust to require at the minimum a good honing to restore the cross hatches ,, my question is,,, what if any parts are available for a over bore of greater then .060,,, the motor would be used as a cruiser, as in no more then stock performance. or should i plant flowers in it?

[roadman5312]

                     http://www.cuda-challenger.com/cc/index.php?topic=44447.0

[Topcat]

.060 is definitely needing to get sonic checked how much meat is still on the bone.

My engine was bored to .063 and the builder said that's all she can do.
Anymore than that and he recommended sleeving the cylinders. 

Every engine is different so you need to get it sonic checked after being hot tanked.
Then a determination can be made how much further out it can go to.

[blown motor]

When I had to get mine rebuilt six weeks after I bought it we found it was already 60 over. Had to sleeve two cylinders, not recommended to make the holes any bigger.

[rUNCHARGER]

You need to sonic check it and don't expect it to be usable.

Sheldon

[Chryco Psycho]

now you know why you got it cheap , @ +.060 it is done , the sonic check if you spend the $$ will tell you the same thing .
 Can you save it ? Yes but it will need sleeves or you could put the $$ towards an R3 block instead .

[AussieMark]

A lot of engine guys are used of dealing with 4 inch standard bores like Ford and Chev small blocks the 340 is 4.040 standard so if the bore measures 4.060 some assume it is .060 oversize but it is really only .020 oversize, if it measures 4.100 then it is .060 over and will need sleeves fitted to save it. I have had a few blocks sleeved (not 340's) and some will say it makes it better then original because the sleeves are better quality material, not porous and you will know the exact thickness of your cylinder walls. Nearly all diesel engines have blocks that contain sleeves for this reason they run extremely high compression and if they didn't run sleeves the compression would push the combustion gas through the cylinder walls and into the cooling system.

[Chryco Psycho]

I agree once a block is sleeved it is stronger than when it was first cast assuming the sleeves are properly installed