1990 740, B230 NA engine with approx 125,000 miles. This engine started to develop the typical cold engine piston slap quite early in its life. The car typically a short haul vehicle - Three miles to wife's job. It's really starting to get noisy and requiring the temp needle to climb higher and higher before it quiets down, and of course there is never time allowed for a half minute of warm up in the garage or gentle driving for the first mile or so. The body and interior are still quite good, it still drives real nice, and overall it still looks pretty darn good. But I'm starting to weigh my options in terms of what to do about the engine....

I could have it rebuilt for mega $'s (maybe with the longer pistons?). Or I could try to find another engine to swap in, but with each passing year there is a less chance of finding a replacement engine in any better shape than what I've got. Most wrecking yards will stand behind their used engines, but they aren't the ones that have to yang the thing back out of there if it turns out to be a bad one. Also, it seems the last couple years of the B230's included more turbos than NA's.

A few questions at this point:

Would the block from a turbo be compatible with my NA head? (The simple capping of a couple oil lines, etc. would be acceptable)

Were the last B230's (turbo OR NA) built with the short pistons?

Should I pick up any worn out engine and have it rebuilt and ready to swap in when the time is "right"? (I assume it would cost ~ $2500 to rebuild one with quality parts and workmanship.)

There you have it - My problem for the day.