Alright, I wanted to see what you guys think about boring a stock 400 casting over .060. I have it bored .030 right now but an unfortunate blow up scored up the walls pretty bad and it smokes like crazy now. I knew the walls had some scratches on them but I replaced the broken items and put it back together hoping to get away with no machine work, needless to say that didn't work and I can't drive it smoking like that. It smokes like one of those late 80's dodge caravans. If the magnaflux comes out alright and the block is still good I'll hope .040 over can clean it up, but if not .060 here I come. I just wondered if a stock casting can handle that size of bore, also its a 4 bolt main block.

 

Your machine shop should be able to sonic check the block for you. You're borderline on the .060 over, some blocks can take it, some can't. You could always sleeve the cylinders if you need to, though whether that's cost effective is up to you.

 

Sleeving is definitely a possibility. .060 might be a little much. The water port on the low side of the deck is pretty close there and might be too thin. Guess it depends which casting.

 

How much is sleeving relative to boring? I know each machine shop is different but just an estimation of costs.

 

I have a 400 bored .030 over and I asked my machinist/mechanic about boring another .030. He said it makes the walls too thin. If you bore a 400 it is best to bore it .060 to start but not to bore another .030 once you have .030 already. Four bolt mains are weaker than two bolts. You probably can put sleeves in. Whatever you think is best for you. I wouldnt go over .060. Just my 2 cents.

 

It costs more because they first need to bore it out straight and true then get the sleeves machined to fit (if they don't come in the size you need) then heatthe block, freeze the sleeve and press the sleeve into the bore. If you shop around you can probably get another 400 block cheaper.

 

if you have only 1 hole messed up i'd sleeve it. for me it cost 30 dollars a hole to sleeve a block, plus cost of the sleeve.

 

id sleeve maybe to like .040 over, sleeves are stronger than the original casting and a 400 to either .030 or .040 over is about 100ci more than most of us stockers have