Geoffman72 Posted February 6, 2016 Share Posted February 6, 2016 Looking at ordering a new short block for my '05 OBXT and I'm searching around trying to find out the compression ratio with my B25 heads. I've got two options. '09+ EJ257 (10103AC050). I've seen the pistons in these are dished more for the D25 heads so, I'd have a drop in CR using B25s.'04-'08 EJ257 (10103AC030). This would give me the factory 8.2 CR unless I've overlooked something. Link to comment Share on other sites More sharing options...
cBax Posted February 6, 2016 Share Posted February 6, 2016 I was under the impression that all of the EJ257s and early EJ255s were the same. Meaning, you'd be looking at a 8.28:1 compression ratio with the B25 heads. FWIW, I don't have any experience with the topic other than the link below. And I just thought the 050 and 030 shortblocks were the same. http://forums.nasioc.com/forums/showthread.php?t=1667168 '05 Outback XT www.facebook.com/baxleysspeedshop www.baxleysspeedshop.com Link to comment Share on other sites More sharing options...
Max Capacity Posted February 8, 2016 Share Posted February 8, 2016 It really doesn't matter that much, the CR is so close its really not anything to worry about. 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
FuJi K Posted February 14, 2016 Share Posted February 14, 2016 Go with what is factory. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.