Ok, I recently picked up a b20b4 block for a b20/vtec build. my original plan was to go full out turbo, but looks likes funds have gone to ****.

so my question is this. can i run cp 12:5:1 pistons with the stock sleeves.. I have heard horror stories of people cracking the sleeves because of the massive jump in cylinder pressures.

Another thing is can i get teh 12:5:1 to run happily on 93 octane.

I do have some more questions that ill post up later, but right now i need sleep

 

I have a built b20/vtec b20b4 block with a gsr head. I currently have 11.6:1 compression on stock sleeves actually there bored out .5mm to 84.5 mm. From my experience on 11.6:1 compression 93 octane doesn't go over to well with the motor thats why i dont drive car everyday on 93 the car tends to detonate i should probably retune my hondata with a wideband this time. I have heard the same horror stories about cracking sleeves but i haven't experienced any problems. But when i take apart my motor in the next few months i plan to send it off and get the block sleeved. Personally i would sleeve the block it will last longer then fixing a problem later on down the road.

 

well, now that i think about it, it will be a weekend car and only driven like 2 days a week. I have wholesale access to any vp fuel i want, so it would probably be a race fuel diet.

My biggest question is what cr can to stock sleeves handle without letting go, this will all be tuned of course, using uberdata

 

"broken " will be a common word among you and your buddies

 

well, ive changed my mind.. im going back to my original plans of sleeves, low compression and a really big turbo

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by no mods &raquo;</TD></TR><TR><TD CLASS="quote">"broken " will be a common word among you and your buddies</TD></TR></TABLE>

I think hes right, best thing to do would be sleeve it but that will nearly double your build price.

Ive seen a tuned b20 on 93 with 12:1 compression crack the sleeves from detonation. (maybe not tuned as great as it shoulda been but they thought the detonation was gone) Or it could be it was screwed up fromt he detonation before the tune and that did it in.

Either way, that much compression is ok if you want to run higher than 93 octane, and retard the timing, and get cams with big overlap, but you could always run a little less compression and it wont effect power much, and you'll be happier, and your motor wont need torn down every year.

Good luck though, I'm sure this post will be followed by a couple "ive had my 17:1 compression 86mm on the street for years, but thats rare IMHO"