Hi everyone, I’ve searched everywhere and I can’t find a straight answer to my question. I have a b16a3 all stock motor, I’m installing new itm 12.0:1 pistons. My question is will there be any clearance issues with these high compression pistons? Plan to build the head later down the road with some stage 1 cams and upgraded valve springs and retainers. I don’t really have a hp goal. The engine needed new pistons and I just wanted to up the compression a little bit and not go super crazy. So bottom line is can I install these 12.0:1 pistons with everything else being stock.

 

I'm not familiar with ITM pistons.

Stock B16 cams are very unlikely to cause P2V issues, as are any brand's "stage 1" cams. You should check P2V clearance regardless, and V2V clearance when you put in the cams. Different piston manufactures may have slight differences in the dome designs and the way the valve reliefs are cut, which can impact P2V.

If your head or block have been excessively decked/milled then there's cause for more concern.

 

these pistons are standard size with stock measurements, but with 12.0:1 compression. I don’t think any major decking has been done so I’m not too worried about that. I know the type r b16 had a higher compression ratio than the stock 10.4:1 on my b16. How do you check the p2v clearance?

 

Standard size and all stock except for where it matters with regards to your question, which is the dome shape and volume. The only way to know what you have is to measure, and if you properly map P2V clearances at build time you'll have that data if you want to try another set of cams down the road. There's at least a dozen good posts on this forum and a ton of good video walkthroughs on the interent at large, try searching for 'Honda B-series P2V' or something. You'll need some basic precision measuring tools, a degree wheel, and a piston stop of your choice. It's difficult to do with the engine in the car or fully assembled, so plan on getting as much done as you can while assembling.

 

I have finished with my repairs, the 12.0:1 pistons worked perfectly with no issues. Everything else stock and clearance was good.