Curious about something. I was told that if you run more than about 12.0:1 compression in a B20 bottom end, you run a high risk of cracking the sleeves. So, I was wondering how high can you go in a stock B20 bottem end, without having to worry about this problem.

To answer future questions, the setup is a CR-VTEC, 12.0:1 Endyne pistons, B16 head, and Hondata stage2, tuned properly on a dyno using a wideband...also, a future mod list of high compression skunk valves, springs, retainers, and stage 2 cams, and Cometic head gasket.

So, lastly, is this too high of a c/r to run using a stock B20 bottem end? If so, how high can I go for a safe daily street monster?

Thanks in advance!


Modified by ntensehonda at 8:44 PM 12/13/2004

 

I bought a b20 vtec off ebay about 2 years ago. It has 12.7to1 compression with a mostly stock bottom end, besides pistons, rods, and knife edged crank. It's still holding up, but the rings are starting to go I think because its starting to eat some oil. Hope this might help you.

 

the sleeves are known to crack with detonation. i believe it doesn't matter how much CR your running (to a point) it's all in your tuning and the octane fuel your running.

keep it under 13:1 and you should be good to go (properly tuned of course).....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by non-VTEC &raquo;</TD></TR><TR><TD CLASS="quote">the sleeves are known to crack with detonation. </TD></TR></TABLE>

That's why I said, "...tuned properly on dyno using a wideband o2..."

 

i would just run the b20 stock until you can afford to resleeve.

just my .02

 

If I wanted to resleeve, I'd do my B16 block and sleeve that for the sleeper-motor

 

its all about the tuning.
also for b20's i would post the block

 

are we talking about the little rod looking deals that go in between the sleeve and block? I was thingking about just putting in a block gaurd

 

anyone else have any ideas on this?

 

Block guards are a bad idea. I used on in a motor build. It was a B20 with CP12.5:1 comp and a B16 head with Jun 3's. The guard moved the sleeves a little and made them crack straight down 2&3. Ditch the guard. Either sleeve it or post it. BTW, fully tuned with Hondata and only lasted 3 months!

 

See, I think your c/r was too high. I've conferring w/ the owaer of a local Honda tuning shop, and he's telling me that any higher than about 12.0:1 c/r is too high, and the sleeves will crack.

That's why I ask.

 

Looking for anyone else experienced with CR-VTEC's...