Will 2.5 L components work on the 2.7L

[GarethE30]

Hey all, I have 2 E30s, one with the 2.5 L and one with the 2.7L. The 2.7 has 80,000 m on rebuilt and the 2.5 has 200,000 m and never been apart. The 2.7 L car is clean but needs fuel system, tank, pumps, etc. I plan on rebuilding the 2.5 L but for now wanted to swap the fuel tank, pumps, intake, injectors, air meter, ecu onto the 2.7 L. Are the heads different and will the fuel/air system work on the 2.7. Any help would be much appreciated. what would you do if you had these 2 complete motors? THANKS

[Wh33lhop]

If you've got an '88 super eta, the heads are the same (885) however the cam and valve springs are different. Otherwise, the heads are different. The rest of the "i" components will work on the eta block but if you're running the stock eta cam and valve springs but the "i" ecu, you'll get valve float before fuel cut and possibly damage your engine (alongside having the wrong cam). If you just want to bolt on a head to the pre-88 eta block you'll want a 731 head (from a 323i). Otherwise, if you have a super-eta you can either do the cam/valve spring swap or just swap over the "i" head.

[GarethE30]

2.5 head on 2.7

Thanks for the reply, does it make sense to stick a rebulit 2.5 head onto the stock 2.7 crank, rods and pistons. Will the 2.5 fuel system work on the 2.7. Is there any advantage using the 2.7 bottom half besides the higher tourque rating.