I bought a '95 Civic coupe with a JDM d15b vtec swap in it and I plan to turbo it on stock internals first and then build the motor when I get all my parts together. I've done A LOT of research and it seems as though to run certain aftermarket forged pistons and rods, I have to have the block bored out for clearance or have a custom set of rods/pistons made. I'd rather not have to bore out the block because the car is my daily driver and I'm not looking for anything crazy fast; just something quicker and more fun to drive so does anyone know any piston/rod combo I could run without having to bore out the block? I've seen a lot of people use Vitara pistons, but I think they knock or scrap against something if you don't notch the block. Does it actually sounds that bad if you don't notch the block? Are there actually any pistons/rods I could use without having to bore the block? Any suggestions or ideas anyone?

 

No. you have to at minimum bore the block to at least what works minimally with the piston-ring gaps of the new aftermarket pistons. Even if you hone it to work, you still need the machine shop.

Bottom line, if you want to boost, you have to pay... (or have the resources to do it yourself, your choice).

 

Thanks for the info. I'll most likely just end up running low boost on stock internals. Maybe I'll give in and bore the block at some point

 

Cylinder overbore - Unless the cylinders are perfect, you'll want to do a mild overbore to ensure proper fitment, Piston-to-wall (p2w) clearance, etc.

Block Notching - If you run an H or I beam aftermarket rod in a D series, you'll have to notch the block. If you were to skip this step, it doesn't "sound bad", it simply won't turn over as the big end of the rod will hit the inside of the crankcase and possibly the main girdle.

You can notch the block yourself at home with simple tools like a Dremel: Block Notching - D-series.org