hey there guys im putting a B21 crank in my B20 what rods do i use for this LS costume what rods and has any one ever done thiss before and if so how well did it work

 

It's been done before, but you need some machining done to the crank. And the rod length is going to be custom. Lot's of money to put this in, and also, your rod to stroke ratio is going to suck. Check out Endyne's site for more info.

 

Which B20 are you talking about, the late 80's prelude motor, or the one in the CRV?

Why arent you keeping the stock crank?

 

Boy if you're doing what I think your doing you need to use 134mm rods.

Stock LS rods 137mm

Stock LS crank 89mm
Stock B20A crank 95mm

95-89 = 6/2 = 3mm

137 - 3 = 134mm rods.


134/95 = 1.41 rod ratio.

I hope you don't plan on reving this past 7k rpm.

 

Ew....and I thought the rod/stroke ratio in the Mazda BP engines was shitty....

Why not just use an H22a if you despirately need all that displacement?

 

Seriously, at that point, I'd go H22.