LuckyH

Long story short, I have a complete B16 swap right now but unfortunatly the block needs rebuilt (i believe it to be rod knock). I've been looking into getting it rebuilt but it seems like it's going to cost at least a grand to fix. I've been looking around on the net and it seems like the cheapest route would be to get a B20 block and just use my B16 head and Intake manifold on this motor. This swap is a left over from a previous car and it's going into a project car. This will be not be a daily driver, just a fun car to mess around with on the weekends. My question is, how much truth is there to the rumors of B20's grenading themselves when people rev them to 7600-8000 rpms. I've looked around on various websites and it seems like people have had good luck with these setups, some who have had it for 2-3 years and had no problems. Has anyone on this board had any personal experience on this setup rather than the usual, "heard it from a friend of a friend who read it on a car forum???"

mtber

Facts are:
1. A b20 is a 84mm block which has low compression pistons.
2. 84mm aftermarket pistons are not cheap.
3. Stock b20/ls rod bolts are not reliable after 7k.

They make nice power if they are built properly but it will get a little pricey.

Miles

another thing to think about

open deck block + 84mm bore = thin, relatively unsupported cylinder walls.

thin, relatively unsupported cylinder walls + high revs = cracked sleeve a go go.

ask big truck driver... he was rocking the cr/vtec to 9k rpms... managed to crack all 4 sleeves.

LuckyH

I think it matters on which B20 you get. I thought the stock B20z had 9.5/1 compression with a redline of 6800. And isn't there a B20b which has lower compression, like 8.5/1 and a redline of 6200. I wonder what's the difference in volume between the stock B20 head and the B16 head as far as raising/lowering compression just from switching heads. I wouldn't mind having to install some aftermarket rod bolts if it meant a lot more reliability, the motors probably only going to see aboe 7200rpms a couple times a month. It just seems like a waste of money to spend $1500 to have a stock motor.

LuckyH

Damn that's insane both cracking all sleeves and revving that motor up that high. I wouldn't mind buying a used B16 or B18c shortblock but, good luck finding a good one for a decent price. Secondly i already got burned on my current motor by someone on this board, so im a little leary about buying again. I bought the complete swap got it in my car only to find out that the motor knocked upon the first time starting it up.

styles999

hmmmmm, all im gonna say is high rev head and sorry bottom end= boom, or if it doesnt your going to have to spend abit to get it right/keep it running, id say save and just throw in a gsr or type-r , then decide

the b20's are well known for bad sleevees<<sp? sorry its late. sleepy

Frankie Figs

the b20b and b20z are the same block strength. you dont wanna rev it passed 8K cuz of the stroke and the sleeve strength. just get a ls, sleeve it to 84mm put 11.5:1 pistons in it, and arp rod bolts and you're done. or sell it and get a chip and a turbo-back for the gti

Miles

where did the general hide his armies?
























in his sleevies.


(i actually laughed out loud when i read that post because all i could think of was that joke. and what a joke it is.)

styles999

its about the same as the ls/vtec build, too much work and money (for me anyway), but i will say i have seen some that throw good numbers on the dynos, although track testing isnt that great for those hybrids. tends to disappoint me because you can get better numbers just building it right with top and bottoms that actually match.

LuckyH

What's up man, where have you been hiding?? Yeah right i would probably barely ever rev it out past 7k, you seen how i drive the vw lol. I think i might have to either have neil try and rebuild the b16 or get me another shortblock. I just don't want to spend over 1300 to have a good block. Bottom line-This shit's just depressing lol.