so i bought this motor and i don't know what compression piston this is the seller told me it was 14:1 but I highly doubt that because that would be a custom piston and would have to run it on e85 im thinkin its either a 12 or 12.5:1 due to the dome....its a cp piston. i know there is no real way to tell other than some mathematical method that only works if the motor is assembled, since its not together i was wondering if any1 has purchased cp high comp pistons and if they look anything like this, thanks

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tryin2Rip &raquo;</TD></TR><TR><TD CLASS="quote"> would have to run it on e85 </TD></TR></TABLE>


wtf?

 

thats not a 12.5:1 piston.
that looks like an 11.0:1 or 11.5:1
this is a 12.5:1 je pistons

 

this is a Wiseco 13.1-14.1cr

 

bump

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cartune network &raquo;</TD></TR><TR><TD CLASS="quote">thats not a 12.5:1 piston.
that looks like an 11.0:1 or 11.5:1
this is a 12.5:1 je pistons

</TD></TR></TABLE>

That looks like alot more than 12.5:1 to me but then agan im not used to seeing anything other than a d-series.
Deffinatly not a d-series.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by spun Vtec &raquo;</TD></TR><TR><TD CLASS="quote">

That looks like alot more than 12.5:1 to me but then agan im not used to seeing anything other than a d-series.
Deffinatly not a d-series. </TD></TR></TABLE>

i think it is. i bought them directly from je and specificly said no higher than 12.5:1 and thats what they sent me.

idunno if u can see it in the picture but the last head that was one this had all the valves bent by the pistons lol. the bottom end is fine nothing is wrong with it and i was using itr cams in the head. lol i have a feeling there more along the lines of 13:1 but i could be wrong. it ran on 93 with 0 knocking.

 

yup they look like 12:5-13:1...that dome is pretty high there buddy

 

yea i know. the valve reliefs are pretty deep too. but thats what je sent me when i said 12.5:1.

 

Its hard to say what it is. Someone may have a small dome00like 3.5-4.0cc, but have 0.040" taken off the head and 0.015" off the block running a 2 layer HG and wind up with 14.5:1. Or you can have a big dome with piston 0.030" down in the hole and CC opened up and get only 11.0:1.

It looks like the piston you show would be "advertised" as an 11.5 or around there by the piston manufacturer.

 

well thats all i'm really concerned about because i got the motor for a exteremely good price and couldnt turn it down, whether there 11:1 or 12:1 or watever thats what i was hoping for because i want to run a street setup i just didnt want to get the motor assembled and then find out im running into stupid problems like knocking, detination, or p2v clearance i figured someone might have an idea so thanks for the info