how do you tell the compression of a piston ?

**no_sir** · 07-31-2008 09:40 PM

id like to get my motor build on its way and the pistons are the only thing holding me up before going to lht to sleeve the block , i just like to know how i can tell what the compression of the pistons that i have are ? i know sounds crazy but i was under the impression they were higher then what they really are in other words i was lied to from the person i bought them from .

thanks in advance

justin

**MrLHT** · 07-31-2008 10:07 PM

Most low compression pistons will be either a flat top or they will have a slight dish to them. If you post a picture of them I will be able to give you an idea.

**no_sir** · 08-01-2008 07:18 PM

**MrLHT** · 08-02-2008 08:43 AM

They look like Wiseco pistons, With that done in 81mm I would say the compression will be around 10 to 1. 84mm they will be 11 to 1 +.
This is just a guess, either way I wouldn't re-use those rings and locks.

**no_sir** · 08-02-2008 05:23 PM

there stamped je 85mm underneth....

**MrLHT** · 08-03-2008 12:19 AM

It's hard to tell, with them being 85mm I would say there close to 11 to 1 comp.

**no_sir** · 08-03-2008 08:21 AM

hmm.. so how do i tell exactly i would like to use them with the jrsc ?

**MrLHT** · 08-03-2008 01:18 PM

I would contact JE and see if they can give you some exact specs on them. We only use CP Pistons so I can't get you any numbers on those.

**no_sir** · 08-03-2008 08:27 PM

oh ok ill get with je and find out .. were you driven down 49th st today in a red s2000 ?

**no_sir** · 08-04-2008 03:08 PM

ok i just called je directly and they confirmed its 11-1 so now the question is can i use these with the jrsc or is it to high ?

**MrLHT** · 08-04-2008 05:29 PM

I think that was me in the S.

I have built 11to 1 motors with the JRSCs but it's pushing it, It's on the high side of safety. I would really like to see the compression to be around 10 to 1 for blower motors, It's not like a turbo that builds boost later and allows for a little over lap in the higher RPMs. Blowers make boost the second you crack the throttle.

**no_sir** · 08-04-2008 06:05 PM

ill give you a call tomm .. thanks

**MrLHT** · 08-04-2008 06:30 PM

Please give us a call at the shop, it will be much faster.

727 344 1800

**I_C_Sharp** · 08-04-2008 06:40 PM

if your putting a jrsc on get lower compression and run more boost

**DAMPACHI** · 08-04-2008 10:43 PM

Originally Posted by slo_94_civic

if your putting a jrsc on get lower compression and run more boost

Thats not the way to go...Call us at the shop and we will point you in the right direction.

Thread: how do you tell the compression of a piston ?

LinkBack

Thread Tools

Display

how do you tell the compression of a piston ?

build

Thread Information

Users Browsing this Thread

Posting Permissions