Hi guys,

sorry there's only so much one can read.ive read allot of build threads but havent found anything on the strength of the stock b20 sleeves

Im in South africa,And ive got a few friends that went b20 with stock sleeves rs /wiseco pistons..most over 12cr and the sleeves tend to crack

now what i want to know is ..does the cr make the sleeves crack.or cant the block handle the revs ???

normally 8500-9000rpm.they use eagle/crower rods as weve broken too many oem +arp rod combo's

so what causes the cracking of the sleeve's..one of the builders says that if you maintain the coolant levels you wont have any problems.but he runs about 11.3cr

now allot of the guys are opting for b18b blocks with darton replacement sleeves but at this point that option is alil too pricey for me

suggestions

Thanks!

 

the strength of the sleeve basically comes down to cylinder pressure and the tune. Cooling is also very important though, because of the design of the b20 block, you really dont want uneven temperatures across the engine.
If the tune was bad the sleeves may have cracked due to pre-ignition.
from my experience the block will actually handle quite a bit of knock. Doing some experimenting on my b20, i pushed it very hard, although it was internally stock (only arp rod bolts).
I was knocking the motor hard enough that a couple times I ended up with aluminum specs on the spark plugs, a sign that detonation is knocking bits of the piston off. That being said the motor never lost any power or showed any signs of being hurt.

If the tune is mild i would say that the cracking is likely a result of the rpm since there is more side loading occuring at higher rpms which the b20 sleeves probably don't like.

 

if i look at the guys that cracked sleeves it probably was due to bad tunning as the one guys car was tuned in like 5 mins and the other guy had his car tuned at a place that usually tunes almost stock cars

 

i think im going to end up sleeving my gsr block

 

Sleeving sounds like a good idea. Like the other guy stated it's all in the tune. We've had multiple stock sleeve b20 vtecs spinning 9500 rpm with no problems. Making from 220-250 whp.

 

reasons for cracked sleeves and blocks on the b20 are the weak point which are the rod bolts cant handle the pressure so they snap causing the rod to ruin your hard work of course havent seen that heat is another factor what i plan on doin is a simple build b20v rod bolts hopefully stayin stock bore if not 85mm YCP high comp pistons its mainly goin to DD stock dished valves with dual springs 310 or 370 inj im goin with a gsr lsd a friend of built something similar with a great tune went 11.6 in gutted bubble im sticking with stock exedy clutch its going in a 4door EG

 

honda tests every single motor 300,000 plus beat the living **** out of all there motors b20 sleeves are not weak they constructed differently

 

Again, this has been covered a number of times.

B20 sleeves are strong.. the only weak link to these sleeves is knock or pinging @ low rpm high load areas. This is where tuning comes into play.. i spin my b20vtec to around 9400-9600rpms. Stock sleeves. Again this has been coveraged and also there's a thread with b20vtec stock sleeves build going as well.

 

do you have any examples of engines that failed in these conditions?
I knocked the hell out of my B20 quite a bit and nothing happened, and it has a lot of kms of abuse on it.
I would say the sleeve design calls for a very good cooling system, also
any type of machining introduces different states of stress in different areas, i dont really have experience with machining b20 blocks specifically, but i bet alot that cracked were bored over even a small amount.