Crazy to do the M54 as my first ever build/swap? (87 325es)

[TobyB]

Not sure what numbers you're comparing to m20b27 either way numbers seem a extremely suss.

...because I was pulling them out of my butt. They don't matter, tho, y'know, because butts aren't very well calibrated.
In this case. Where a first- time owner is starting with a tired car and going to put a different used engine in. There are
just too many variables.

My only slightly calibrated butt says an eta has darn near as much torque as an M52, but it lasts almost as long
as a teenage boy in heat. The M20B25 in the i pulls longer- but also runs out far too early (I race an M10 more often than an M20)
Spinning the M52 higher is totally a winning proposition, but one would want a freshened and slightly uprated version for that.

The M54B25 pulls solidly, and for a little longer than the M20, but the B30 adds even more torque for almost as long, if you're a bit brave.

A turbo on anything makes you not want to go back... until it goes >pop< and you're back to the garage.

t
Yes, the numbers vary. Even in my head!

[nando]

Curious as to why you say the M52 is a waste of time?
I was pleased with my M52B28 even naturally aspirated. It made my E30 feel like a different car compared to the M20B25.
It was a great match with the stock 14" wheels/tires and a riot to drive (aka tail happy) with a mildly-upgraded suspension setup.


It's a well-documented swap and able to make good power as an unopened stock unit when boost is added.

It was also the first engine I opened up to refresh, and it was simple enough. Even the single vanos wasn't too difficult to rebuild. It all went back together without issue and runs strong.


All that said, I do have a spare M52 waiting in the wings that I pulled from a parts car. They are becoming harder to find in my area. And that's a big point for the M54/newer engines.

they're old, they're heavy, they are getting harder to find and they really don't make a huge amount more power over an M20B25.

The appeal back in the day was you could pick up one for a song at a local junkyard and swap it in over a weekend. That really isn't the case anymore - and there are now better options, including better builds for the M20 itself.

[e30strokr]

Overall, would I do it again? Absolutely! I'd definitely recommend it, just be sure to go through the engine before dropping it in (and change to a better oil ring design... they're good at using oil with stock style rings)

I believe youre suppose to use the N52 oil control rings instead of the stock M54 to get rid of the oil consumption problem/issue

[TobyB]

M52TU rings. but yearp, m54s do have a history of oil issues, from about day 15.

t