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That is the question.

Honda b20b series boosted 350whp on a non sleeved block

 
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B20 walls are thin as it is...

 
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ouch, nice crack.

 
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CRVtec or just plain old B20b?

 
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thats beautiful.

 
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+1 stock b20 walls are nortouris for cracking.

 
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so much for my ek b20 swap plans.

 
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Not sure

 
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If you have the money to make it reliable than you really don't have to worry. It really depends on your hp goals and how rev happy of a motor you want.
http://www.honda-tech.com/zerothread?id=1676914
I don't know if you've read that already but if you haven't it's a great read.

 
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+1 thanks for the info.

 
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+1 for that right up. I wish someone would do that for the d17 but only a handful of ppl have experimented with N/A.

 
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sleeve that bitch! y not?

 
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Yes, b20 sleeves are very thin for boosting. No telling what really caused the crack, it could have been due to detonation......

 
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do it!

 
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do it, i dare you to!

 
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whya a b20 is still a great motor. havent you seen cracked sleeves before. it can happen to all vehicle with an open deck block and thin sleeves. the b20 is actually the best bang for the buck when building a n/a honda motor. the weekest point is the rod bolts and sleeve thickness. but 350whp is not the breaking point. there was obviously something that caused this to happen, probably bad tune or trying to rev to high under boost.
the b20 isnt a high revving motor. it doesnt have the best RS ratio. the best way to build a 2.0l bseries is to take a b18 and sleeve it with a 84mm bore with the stock crank and same rod length. this give a 1.954l displacement basically a 2.0l and allows you to rev to a much higher rpm because it has a lower mean piston speed. the only difference in the b20 vs the b18 is the bore size a cyl wall thickness. it still uses the same rods and crank.
swapping on a vtec head yeilds great power. and if you can pick up a b20z the pR3 head that it has flow almost as well as any dohc vtec head honda has made.
in case it isnt obvious i own a b20b swapped DC4_. with the ls I/M swapped and E/M swapped it will pull right with a gsr. its a very trqy motor and very fun to drive. went toe to toe with a rx8 the other day and we were pretty even. with a simple swap of the cams from the ls to the b20 you can yeild a 7whp gain. that is what most gain from a crower stg1 cam swap here. and these are stock ls cams. the motor responds to mods very well!!

 
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Well, I heard different opinions and arguments and although the point of he matter is not directed to the B20 block but all blocks in general.
Two things come to mind, any block could crack the sleeves, it would be because the block was taken to it's breaking point or because of backfire/poor tuning.
This can happen to any one during the building/ tunning of a racing engine, things don't always go as planned.
So, with that said; after doing lot's of internal mods is it worth to sleeve the block while you at it?
Or not?

 
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I think whether it is worth it or not depends on your ultimate horsepower goal and what block you plan to use.

 
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you are 100% correct, but also remember that the RS ratio plays a HUGE role in cylinder wall pressure and the amount of RPMs a motor can spin. over revving a motor more likely will cause a broken rod or spun bering. but you have to remember that pressure the cyl wall has in that scenario. the more pressure your putting on them the more proned they are to walking and cracking. a lot of guys bolt on vtec heads and think they can spin 8k. b20s actually are only good for about 6700-7200. it has trq unlike its siblings

like i said 350whp is definately not the limit that the sleeves can withstand this is more likely due to a bad tune or trying to rev to high under boost.

 
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235 for the sleeves and the cheap install cost to install them at darton, I would sleeve it every time just so i could feel safer, whether i need them or not at least if i do i have them and if i dont i feel safe. The b20 should always be sleeved imo because of its thin cylinder walls.

 
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Damn that suck's.

 
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Just do it! swoosh

 
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Umm screw it and k-sawp it lol!

 
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putting sleeves in a b20 block is pointless. they dont hold. like i said the best way to get a 2.0l b series is to use a b18 block and sleeve with a 84mm bore using the stock rod length and stock crank.

 
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or you could go the cheap way of building it and use a block guard.. heck using a block guard is better than using nothing at all.. lol.. but if you gonna sleeve it then thats better imo...everytime i built a b20 for a customer i always tell them that the sleeves are thinner than the other b-motors and suggest using a b18 instead... but if they do i always tell them to either sleeve, block guard, or both... because even though sleeving a b20 still doesnt hold.. at least it will hold more than the stock sleeves

 
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Man, I love reading older threads... only two months ago when people actually knew stuff. Now the only threads you see are "what rims are these" and "what car will you trade in for?" You guys get +1's in my book. Let me hand em out till I get stopped. Anyways.

Did you end up going sleeved or what?

 
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Dam right I sleeved it, block guard it and ARP studed it.
Is running strong ever since.

 
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you made the right choice..

 
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NICE JOB SUPERMEX, VERY NICE PIC OF THE BLOCK. REP FOR YOU.
ILL BE THERE SOON. WITH THE BOTTOM END . NICE THREAD , A POINT WELL TAKEN.