Seems to be a common problem with the B21A1, the guy that owned the 91 SI I had says its oil starvation from hard cornering. I don't have my prelude anymore unfortunately, stolen and stripped, after I had just put a B20A5 in it. They didn't take the engine though, but I didn't feel it was worth paying to get it back from the tow yard. It had a metal plate welded in where the front right suspension meets the wheel well, so it was never gonna be at 100% of its potential ever again, figured it was a good time to let it go. I've moved on to an 89 Supercharged MR2 now, and loving it. Anyway, when I got my prelude from my friend (who had gotten it with a B20A5 from the original owner, who I mentioned at the beginning of this post, after it had spun the bearing) it wasn't running. I had the head from the B20A5 that was in it rebuilt, but then decided to have a machine shop rebuild the B21A1 that was originally in it, big mistake. The shop I took it to must have really sucked, because it only lasted 15k miles before a bearing went, so that is when I got another B20 from an importer (which was in really good shape, they even painted the oil pan and block, very clean), had gotten a used tranny too, and had a guy swap it all, around $1,500 for everything, just to have my car stolen about a month later. I guess what im getting at is, if you are going for the B21, just remember it may not be as reliable as the B20. Run some good oil (I use mobil 1 full synthetic) and maybe upgraded oil pump if you can find one. BTW, selling the B20A5 head that I had rebuilt in another post, if anyone knows someone who is looking for one.

-Mike