has anyone done this?
is it ok?

 

It can be done. You should sonic check the cylinder walls when you get out that far. In fact, the 350 in my Nova is 60 over with no problems.

 

ya the block is going to require the sonic check and other tests. Why bore it so much? Not the best idea, weakens the strength of the block.

 

wel........... long story short, i had a lot of rust in my cylinders, and .60 was the only way to get it out.....but we were supposed to go .030 over and i got a call saying that i need to chang my piston order cause the shop went 0.060 over and got all the stuff out.

so i now am stuck with that and cant go back so i was curious as to if i can pull this off and what i should do or what i should look for, etc.

 

I'd say the first thing to begin looking for is another block. You might be one of the lucky ones that can get away with it but if you are, go to church and light candles, then buy lottery tickets. Every time I've tried it, there have eventually been problems. Not necessarily right away but eventually.

Good luck.

 

is there any specific oil i should be putting in there or stuff like that????

 

When cylinder walls are cut too thin there isn't much you can do in terms of things like oil viscosity. If your block was originally cast without core shift and you were blessed with the optimum wall thickness on the critical thrust surfaces from the beginning you won't necessarily see problems immediately. I've run .060 overbore for a full season without problems but when the walls eventually crack, the game is over. I sincerely hope that your block was one of the good ones. If you were to have had the block sonic tested at some point you'd know how favorable the odds might be. You will certainly want to avoid things like nitrous, turbos, superchargers, excessive RPM, etc. The last one we lost to a cracked cylinder wall had never seen any of the over-the-top modifications. It just sprang a leak at the worst possible time.

 

you should be able to pick up a block for a few hundred. go for one out of a vette, they come with 4 bolt mains.

 

Blocks from long ago were typically thicker than they are today. Most late model small blocks shouldn't be .060 over anymore. They are lighter than the older blocks, most likely to help with fuel economy.

Maybe someone can chime in here. I am trying to find where I read this( I am in Pennsylvania for work right now, so I don't have much to work with right now) I did check summit and they DO sell a LT1 engine kit that is .060 over. As of right now, all I can say is to get it sonic checked.

 

Anyone know if a final hone is enough to take care of the distorsion caused by block filler??? My guess is no, but I think it is a topic that should be addressed here. Since they do not have the pistons yet they should not have done the final hone and this could help you prop things up a little. I know the Stock Eliminator guys run .060 over BUT they have the blocks carefully inspected first.

 

Yeah, I had a couple of old SBCs that were bored .125".

 

Years ago I took a 327 block that I had filled to the machine shop. It was my intention to have it honed clean because it was already bored to within a few thousandths of the limit of the rules. The shop told me that when they put the torque plate on it and torqued it down, the cylinders were so out-of-round that they experienced a high degree of chatter in the hone. They stopped the job. I ended up giving that block to a Super Stock racer who could bore to .060. He ran it for several years. I suspect that if I had fully torqued the heads or a torque plate on the block with a gasket as soon as the fill was complete, it MIGHT have been better.

These days, every block gets sonic tested, any block going bigger than .030 gets filled, and every block that gets filled is bored before honing. An element to remember is that practically everything I work on goes into a drag car and that I fill them to just above the bottom of the water pump hole. I don't know if that would be advisable for the street. The five or six small blocks I have running out there right now seem to have no problems. At least three of them are LT1s.

 

Do I hear 283 blocks with a 4" bore for a 301? (For the new generation it was also known as the 302 in the 67-69 Z28).

 

Lol, yeah. I also had a 265 block I had bored to a 283. The 265s looked like they had a ridiculous amount of meat on them. (obviously, because the pistons were so small)

 

You can go .060" with no problems.

If you were trying actually bore it out to .125", then that would be another story. Then you would really consider a thickness check.