OBD1 M54/M52TU swap as a M50b25

[CMBusch]

We had a m52b28 in there prior and the m54b28 makes a little more midrange power, little less top end.... likely from the slightly different head ports.

The cams, manifolds, electronics were all re-used; mainly because of lack of time —>using easiest available resources (this m54b28)

Gotcha, makes sense. For some reason I think frankenmotors are super cool since the combinations never came from the factory.

[Wanganstyle]

Gotcha, makes sense. For some reason I think frankenmotors are super cool since the combinations never came from the factory.

Need is the best forced innovation; it s a great combo for someone looking for a replacement engine as the older m52/m50 engines are quite often tired. Much easier to come across a complete good running e46 for cheap nowadays or at least the m54

Frankie is headed to Sonoma Friday!

[CMBusch]

Need is the best forced innovation; it s a great combo for someone looking for a replacement engine as the older m52/m50 engines are quite often tired. Much easier to come across a complete good running e46 for cheap nowadays or at least the m54

Frankie is headed to Sonoma Friday!

Agreed. My points exactly. Thankfully 2 out of my 3 M50's that I have are in decent shape. This also gives M54s a future purpose, rather than being turned into a wine bottle holder.

Let us know how it goes!

[Wanganstyle]

Agreed. My points exactly. Thankfully 2 out of my 3 M50's that I have are in decent shape. This also gives M54s a future purpose, rather than being turned into a wine bottle holder.



Let us know how it goes!

Frankie did 2:07 at thill east in testing..... Sonoma should be great.

[BudTendy]

Picked up an M52TU, with an interest in trying out this swap. I was curious on how you closed the gap near the exhaust side of the vanos cover?

Sorry to bring up an old thread

[Wanganstyle]

You can do whatever you want. It’s your car

[hoveringuy]

I loved my M54. Megasquirt3, M50 intake, Schrick cams and headers, it put down 250whp and was an incredibly easy swap compared to the N52.

[moatilliatta]

Old thread bump FTW. It means you’re actually reading and searching.

[Lithium]

Thanks for the writeup - I upgraded from M50 swap to M54B30 based on this thread - Wired the two Vanos solenoids together and running off 513 Red label (Chipped to 7000k) - Its super fun & no issues = Thanks for the inspiration

[OddBallNo3]

also giving this post a bump. going to do a m54b30 in my z3 because f-u im not paying $1500 for a damn 180hp engine with 300k on it its half the price and more power. thanks for the tips!

[Northern]

So you are removing everything that makes m54 great engine and making it worse. Why? To make it fit that power/weight ratio, just de-tune using the stock m54 ms43 control unit, and the engine would have been drop in replacement. The -413 bosch is ancient technology compared to the ms43 you would had.

But now when you are doing that, remember to block those idle air holes in the head, or you are going to have massive vacuum leak.

I think this made sense in 2015, but in the context of 2024 I don't see it. It's so much less effort to just stay on MS42/MS43 and keep the benefits of an easily tunable ECU.

Also being a racecar and getting some top-end out of the cams/intake combo, with likely a decent loss in midrange between all the VANOS variability/travel/lack of exhaust half of the system. I think it's a reasonable tradeoff for this specific application, but for me not worth the effort.

Maybe I missed what H did with the VANOS gap. I know the same sort of issue exists when adding dual VANOS to the iron block, and that basically needs the weld/machine flat treatment...

[OddBallNo3]

So I was noticing that there is quite a bit of port mismatch from the D shaped m54 head, to the m52 oval shape.. I'm thinking im glad that I used the B30 engine, as the extra displacement will hopefully make up for the power loss the intake mismatch will cause. also to note, no one has mentioned the little tiny holes below the main intake ports that also lead to the intake valves. they are just the right size to tap with a 1/8 npt thread and plug with a plug. I'm betting that JB weld / right stuff gasket maker would also work too.