high milage high compression...

HondaChild · Post by **HondaChild** » Fri Jul 04, 2008 11:18 pm

Okay so I recently acqiured some PM7 dome top pistons with rods but no end caps or bearings. I was wondering how hard of an install? If I can swap rods with my Y7 ones? and also how hard would it be on my motor with around 200,000 miles on it? the head has 110,000 on it. I used an online compression calculator made for D-series hondas, and it said compression would be some where around 13.5:1.

N2HIFI · Post by **N2HIFI** » Fri Jul 04, 2008 11:36 pm

13.5:1 unstreetable and usless for a daily driver

just pick up some p29 psitons and go from there

ZC dohc pistons are the BEST oem piston for a d-series N/A build

HondaChild · Post by **HondaChild** » Sat Jul 05, 2008 3:45 am

N2HIFI;123822 wrote:13.5:1 unstreetable and usless for a daily driver

just pick up some p29 psitons and go from there

ZC dohc pistons are the BEST oem piston for a d-series N/A build

pm7=p29 I got these out of an 89 integra D16a1 a.k.a USDM ZC.

90CivicEx · Post by **90CivicEx** » Sat Jul 05, 2008 3:49 am

HondaChild;123841 wrote:pm7=p29 I got these out of an 89 integra D16a1 a.k.a USDM ZC.

As stated by Chris though, that high of compression plus the mileage on your motor your gonna look at a fresh rebuild on the motor.

I thought ZC pistons in a single slam D-series put it to high 11 compression ratios. Me and Jake had this convo like 2 years ago.

N2HIFI · Post by **N2HIFI** » Sat Jul 05, 2008 3:49 am

HondaChild;123841 wrote:pm7=p29 I got these out of an 89 integra D16a1 a.k.a USDM ZC.

thats the right ones i think your compression calc is way off

90CivicEx · Post by **90CivicEx** » Sat Jul 05, 2008 3:53 am

Read a forum thread on d-series.org and pm7 pistons in a D15 gave it 10.5:1 compression, and a D16a6 gave it 11.3:1 compression so I'm guessing it will give high 11 compression ratio's

N2HIFI · Post by **N2HIFI** » Sat Jul 05, 2008 4:03 am

i just put in my ls/v motor which is 12.9 and it said it was 19:1 so i dont think that calc is very accurate

90CivicEx · Post by **90CivicEx** » Sat Jul 05, 2008 4:09 am

N2HIFI;123848 wrote:i just put in my ls/v motor which is 12.9 and it said it was 19:1 so i dont think that calc is very accurate

Like I said I would say it is high 11's on the compression which is streetable, wouldn't take much of a revuild and from what I found you should be able to match you y7 rods with the pm7 pistons.

You will need new bearings, rings, main caps though seeing as how it's high mileage on the motor it wouldn't hurt to freshin it up, but I'd lay out a bit more and buy some good rods that way you won't have to open it again.

JustRob · Post by **JustRob** » Sat Jul 05, 2008 11:34 pm

Well, I'm not sure which calculator you guys are using or if your setup changed. But, last I knew, you have a stock Y7 block with a stock Y8 head. When you add P29's without changing headgasket thickness, bore, and without milling the block and head, you C/R should be 12.65:1, which is a little on the high side. Probably wouldn't be the greatest DD either. I would bump it down to around 12.0:1 by switching to a Z6 head or getting a thicker head gasket. One thats around .050 in. And as stated before, if you do decide to do this, do a complete rebuild.

90CivicEx · Post by **90CivicEx** » Sun Jul 06, 2008 12:05 am

SilverStreak;123896 wrote:Well, I'm not sure which calculator you guys are using or if your setup changed. But, last I knew, you have a stock Y7 block with a stock Y8 head. When you add P29's without changing headgasket thickness, bore, and without milling the block and head, you C/R should be 12.65:1, which is a little on the high side. Probably wouldn't be the greatest DD either. I would bump it down to around 12.0:1 by switching to a Z6 head or getting a thicker head gasket. One thats around .050 in. And as stated before, if you do decide to do this, do a complete rebuild.

Ahhh I didn't know he was running a mini-me. Glad someone knew cause I though he was running his stock y7 block and head.