Tbirdsteve 0 Report post Posted May 8, 2004 Boiled up the engine in traffic recently and need another. I've pulled the head and the middle 4 pistons have scored the bores. Can I fit any old M20B25 from 3 or 5 series into my car? I'd hate to pay $2000 for another E34 motor but it seems possible I could get an old one from the seventies or eighties for just a few hundred. I'd like to be able to bolt my old head on (it is warped .5mm - is that too much?) along with the fuel injection so I can get back on the road again. Will my motronic fuel injection bolt straight onto an older head? I have a mongrel 3 series also and in comparing the blocks it is obvious that the distributor location is different but it would appear interchangeable - am I right? My 3 series is highly modified so I could be wrong. Will the engine mounts for a 3 series engine interchange easily with 5 series mounts - ie same engine, just different mounts? Any advice or offers of engines for sale much appreciated. Steve Quote Share this post Link to post Share on other sites
Guest Andrew Report post Posted May 8, 2004 Hi - The e34 525i came with the m20b25 and if I remember correctly an M50B25 in some later model ones. The e30 motor from the 88+ 325 will bolt straight into your car. The pre 88 m20b25s won't, they come with an early primitive version of motronic (like Tim's (bumpstop325s) car). I'm doing a m20 b25 build up now and just figured i'd shell out the coin to do a motor rebuild. Worth it in the end. I'm pretty sure the engine mounts will differ from 3 to 5 series. Quote Share this post Link to post Share on other sites
