Possible Engine Swap?

[canada karl]

Would a 76 530i motor and Getrag 5 speed fit into a 1974 Bavaria or would there not be enough room for the M30 motor?

[528i-1981]

Hi Karl -

this sounds like a fun winter project - perfect for scraping frozen knuckles. You have a Bav in your sights? I've obviously never done such a swap, so take these comments for what they're worth.

As you may already know, the Bav was one of the New Sixes, which came originally with an M30B30V I believe. There should be no problem with having the physical space for the motor and tranny, and I don't think you'd have hood interference switching between the Bav's carbs and the L-jet. E3 3.0 CSi's had (i think) a variant of the same M30B30 motor with injection, so there should be space for the 530i's Jetronic stuff. The earlier injected E3s may have had D-Jet, and I'm not sure when L-Jet was introduced but I'm pretty sure it made its way into the e3.

TLake would know these ins and outs, I'm certain.

I believe all of the Bav manuals were Getrags. Some of the earlier 3.0s had ZF gearboxes, but I think the switch was before '74 and didn't affect the Bav. I think the gearboxes were swappable anyway.

Mike would definitely know if there are any odd features on the 530i M30B30/Getrag combo you have that might require some accommodation in a Bav.

[canada karl]

Thanks for the info. I know where there is a Bavaria that has a cracked block but the bodywork and paint has been done. A possible candidate for my wrecked 530i parts. So L jet may have been fitted to some versions of E3?

[Mike W.]

Absolutely it will fit. Both M30 engines, in the 75-76 model years the engines were identical, with L jet on both. My fondness for the original dual Zeniths was such that I put fuel injection on a '69 Bavaria. Huge improvement in drivability. There's a lot of stuff that interchanges between the two even though the Bav was technically a larger car, and it was inside, it was very roomy, but about the same size outside.

[canada karl]

So on a "74" Bavaria would have had the Zenith carbs and not the L jet and a 75/76 would have had the ECUs and electronics similar to a 530i in them?

[Mike W.]

So on a "74" Bavaria would have had the Zenith carbs and not the L jet and a 75/76 would have had the ECUs and electronics similar to a 530i in them?

Correct.

[canada karl]

That's unfortunate as the Bavaria I was thinking about is a 74. A potential swap would have been a lot less hassle in terms of wiring had it been a 75/76 but I suppose it is still doable but a lot more work.

[Mike W.]

You could always put the carbs on your engine, you'd probably have to rig up an electric fuel pump, but that's easy.

But FI is just so much better, IMO. It's some work, but not that much. Biggest part was running a return line for the fuel and mounting the fuel pump. Only thing I did wrong was hooked up the FI to the wrong terminal on the starter and it ran crazy rich until I figured out what I did. The FI thought it was always in start mode and was providing starting enrichement. But it was no big deal to fix.