Hey all, I'm helping my son with his first car and we've had a few speed bumps along the way, to say the least. We had his H22A4 type-SH block sleeved. It's a 99 Prelude Type SH, yeah, I know now we should have swapped to a base, but that ship has sailed. Where we are now is the very reputable machine shop that appears to have done an excellent job with the sleeve and rebuilding the head sold us 8:1 pistons. I guess there was some confusion as we said "stock plus" and "someday he might boost it, but that's on my son's dime, down the road." We need stock compression, just to get it back on the road as his daily. We figure it's going to be another $3-4k to swap the tranny, remove the ATTS, custom mid-shaft, convert to OBD1 w/ Hondata, and tune it. This project is way over budget so we can't spend any more on it for now. The machine shop agreed to exchange the pistons to a stock compression but can't find any. I'm hoping to get a refund and source them myself. According to the service manual, stock is 10:1. The CP SC7130 is 10:0 and stock bore. Can anyone confirm these are as close to stock as I'm gong to find, or any other recommendations out there? It appears parts for this are getting harder to come by, new or used. Thanks in advance!

 

Geez, that's a lot of effort to mess up an SH.

Weren't these FRM sleeves? Probably why aftermarket pistons don't exist.

If CP catalog says they have a stock bore piston for the application it's probably correct. Will need to verify the piston to bore clearance when you get those pistons in hand.

 

OP, are you trying to use the stock type sleeves for this rebuild or do you intend to have the block modified and have a company install iron sleeves ? If you are trying to use the STOCK FRM (Fiber Reinforced Matrix) sleeves, the only forged piston that works is the Mahle Gold Series product. I believe they only offer two compression ratios with this piston: 9:1 and 11.5:1. If you have conventional ductile iron sleeves installed in the block, you can then use CP, JE, Wiseco, Arias, Ross, etc.

 

Thank you both for your reply. Turns out there was some miscommunication between my son and the machine shop. Looks like we're getting the Arias 10:1 pistons ordered. Just a 4-8 week lead time. We've already waited about 9 months so this baby's due soon! It has been sleeved so forged pistons are still available, just not 'on the shelf'. If we had picked the right machine shop in the beginning, could have saved a ton of time and probably gone with the Mahle FRM compatible gold pistons, but that's water under the bridge.

 

Tell me about it! Mental note, type SH might not be the best choice if a motor job is a possibility. This has turned into a huge, time and money sucking project, but at 18 you couldn't tell me anything either. It's his graduation present, just hoping to get it back on the road before he finds a wife, has kids, and they graduate!