DO NOT GET THE B21A1 unless you are going to resleeve the block! It's the aluminum to aluminum contact between the rings and sleaves that creates a high amount of friction and causes them to wear, if honda had moly coated the rings there would be no problems with the b21Not enough oil changes will make ANYTHING burn as much oil as a b21 does when you don't change the oil, the real question is why it's so hard to repair them correctly. Which someone said was because you need a special tool to hone the FRM sleeves(i believe it) and if you don't hone them or hone them with the wrong tool (like one for iron sleeves) it doesn't leave the correct crosshatching in the cylinder walls and the rings don't seat correctly. I forget who said that, but it makes very good sense to me, and matches what i know about rebuilds in general.

NSX's have the same sleeves, and nobody complains about them burning oil. Then again they are in the "supercar" land of 1k-3k mile oil changes, which means they won't wear and start burning oil.
Of course most people also expect supercars to burn oil, seeing as ferrari's are well known for it (they used really really soft sleeves, oops)

I thought that the rings were steel also, and that the gnarly alum-alum friction was on the piston and sleeve.

Both of those can be solved by getting the pistons/rings coated with the ceramic "hardened lube" that theoldone(.com) uses, it's also hard as hell, but it's also slippery as hell, cuts friction and wear by a lot.


If you have anymore questions please let me know because I am one of few that know about both of the blocks and what they can do together when done right.

The best cheap combo is the B21A1 bottom end with the B20A (not CRV) head with B18A1 cams with more goodies! I have done it in my white Lude... I have owned 5 Preludes