It's a shame, but even old and reliable engines from M3 can be destroyed. So people are searching any solution how to back their M3 to the roads and avoid wasting of thousands of dollars or euros. That's why sometimes we can see such BMW M3 E30 with swapped M50 engine. Is it a fault or worthy solutions? Let's figure it out!

I may say about 2 important things you to got all needed information. About weight and power. In meaning of weight original BMW S14 and M50 are absolutely different. S14 is based on 4-cylinder M10 engine. M50 in could be with 2 or 2.5 liter of displacement, but it's larger and a more heavy 6-cylinder engine. Yes, BMW E30 had 325i and similar models with 6-cylinder M20 engines. But these models were not M3. Guys from BMW have used more compact ant lightweight engine. I guess they did it for better balance and handling. It had a sense because BMW had a plans to use M3 in sport. And, as all we remember, BMW M3 E30 was really successful in sport. Probably DTM and another racing series could have an own engine requirements. However, BMW made M3 so cool with that, 4-cylinder engine. And now about power. M50B25 has a power like original S14B20. But it's possible to increase power. Not significantly, if this engine will stay naturally aspirated. But in meaning of power it's really the similar replacement. So if you wouldn't take part in some serious races, if it's almost impossible or really expensive to restore original S14, it would better swap another engine and loos original look and specs. Because such awesome orange BMW M3 with swapped M50 on the road is better broken original M3 in garage or some barn. Especially if original S14 was disassembled.