Safe overbore?

[Slipstream]

Just wondering if anyone knows what is a safe overbore for a S13 blacktop motor? Also if anyone can tell me what type of metal the cylinder walls are made of. I'm rebuilding my block and have some scarring that needs to be honed. Want to make sure I don't take off too much.

[Slipstream]

ttt

[ILikeMy240sx]

From the FSM. You will see the different grades they have. I would not go over the largest value found in the grade.

Also, consult the wear limit as well. If the wear is too much you might need a new block.

The walls are iron. The block it self cast alum

[Slipstream]

Thanks for the info. Especially on the material for the cyl walls. Is it safe to go by the S15 FSM for the specs on a S13 blcktop block? That is what I used for my main caps, and everything was within .0002"+ from the middle range of tolerance. I know the head and some things will be different, but the block should be fairly right, right?

Also, is it possible to put S15 oversized pistons in, or is it better to go with aftermarket such as JE? It has Wiseco in it now, but once I bore it out, then I'll need something new.

[ILikeMy240sx]

block specifications like cylinder bore should be the same for all SRs.

If you have the money then why not go with aftermarket forged ones and sell the ones you have now.

[Slipstream]

The blaock had wiseco pistons in it already, but I was gonna go with something different. But today while measuring the cylinders, found out it was already bored .020" over, and I'm not sure if it's safe enough to take it .040" over. Plus the crank was ground .020" under and needs another .010" taken off. Almost thinking about giving up on the project and going KA-T.