My BMW engine weights guide

[VinniE30]

Direct Injection. Turbo. Valvetronic.

I just can't see that thing running right without the stock ECU. That said, anything is possible...

Figured as much that it would be best getting it working with the stock ecu. Do you have any plans for another swap project in the future?

[hoveringuy]

Figured as much that it would be best getting it working with the stock ecu. Do you have any plans for another swap project in the future?

Yes, maybe N52, possibly S54. Or ??

The M54 is just running so sweet I'm not in much of a hurry.

[SeatTime]

I have actual hands-on experience with the N20 motor and can tell you more about the internals of this motor than most at this point in time.

It is the ultimate 4 cylinder motor. No ifs, buts or ands about it.

You could definitely get an ecu to control everything on the motor (if you were very clever) but you wouldn't know why you're controlling it without a dyno setup you won't see outside of OEMs. We're talking stuff like fully controllable electric water pumps.

Running the factory ecu would be a chore to sever it from it's happy CAN network, but if there's someone out there who wants to give it a shot, this would be the best thing going for an E30 or really any small car. Or large car or small truck. Really anything.

[mulletman]

This is a great thread and deserves a bump.

Now I need to start researching an M54.

[2mAn]

personally, Im just excited to have an aluminum M52 going into my 84 318. final curb weight should be ~2350. M52 + S52 cams in a car that light is going to be something

[mulletman]

personally, Im just excited to have an aluminum M52 going into my 84 318. final curb weight should be ~2350. M52 + S52 cams in a car that light is going to be something

Yeah. Doing some reading... The M54 swap looks harder than my level of expertise would handle. I'll probably just end up going with an S5x. Pull A/C to save what weight I can, and deal with it.

[moatilliatta]

N20's at the moment dont seem to be holding up well. A lot of issues going on. I was surprised that the m54 is about 50lbs heavier than the m44. Thats not including upgrading radiator, more oil, more coolant, weight further forward and a bigger driveline.

Some mini's have that n20 motor. not sure how different?

[stanhayward]

Does anyone know what an M30 would weigh without PS or AC? Probably close to an M20, am I right?

[AndrewBird]

Unless you are going from a 4 cylinder to a 6 cylinder, the weight change will not be noticeable with any swap. Less than 100lbs is really not much.

Think about it this way, do you notice a difference in performance with a trunk full of groceries? Because that's about all the difference there would be.

And yes, I realize that the location of the weight has a lot to do with things, but still, less than 100lbs is nothing.

[atmobenzin]

Going flat out trough a corner I go trough every morning there was a considerable difference in turn-in today when having two 15" wheels with tires and some tools in the trunk.

So yes, I would say that in an E30 100lbs really is something to consider when choosing a swap.

[whitebulat22]

Wanted to bump this thread after my extensive journey searching the internet for engine weights. My finding is that engines weighed independently as they would've gone in the car are the only worthwhile sources to base any conclusions on.

S52 weighed this way is 406 lbs w/o tranny and 512 with.
Makes a lot of sense that an S52 minus only AC and PS is about 10 lbs over the M20 weighed in this thread given that people gain nothing or about that much after swapping in M50s and doing their AC deletes.
Also, the S54 cannot possibly actually be 478 lbs without a very pessimistic weighing method. It's missing 3 mm of iron cylinder bore in the block compared to an M50 (this amount of iron is more than 15 lbs), and probably has a lighter rotating assembly as well. This means this S65 would actually be under 400 lbs if it is lighter as BMW claims, which is about 100 lbs off of what the internet normally gets weighing an LS engine.


I also believe Jean weighed in his M62TU at 450 lbs with all fluids and everything down to motor mounts scaled. Couldn't find the post itself just people mentioning it.

[nando]

I'm pretty sure the S54 weight listed is accurate. it's no lightweight.

it might have a larger bore but I don't think that adds up to much. the deck is also taller, there are way more parts in the head, and it has a huge stroke.

[328ijunkie]

S54 Forged crank vs M50 cast as well. DVanos is heavy as well... ITBs are heavy vs 1tb and plastic intake manifold. dual pickup oil pump, etc.

[nando]

yep. the block is probably thicker/reinforced due to the extremely high piston speeds.

[whitebulat22]

For curiosity I did some fact checking on bmwfans.info and 478 lbs with all accessories does sound reasonable. Between Crank (2-4 lbs) / Block+ piston (~10 lbs) / Head (~5 lbs) there is 15-20 lbs over an M50 or S52. I don't know how much the throttles / oil system / airbox add exactly and I don't know if 10 lbs from the site is per vanos system or including both, but going from 427 for an M50 to 478 for S54 sounds about right considering there's probably more little things not worth listing that I'm not including.

So dressed the same way as the 406 lb S52 w/o PS and AC we can call it 440 ish, or 35-45 lbs for the factory race preps.

On a separate note to get the 15 lb discount from boring I just used the density of iron and multiplied it through a volume of deck height x circumference using avg bore (~85 mm x 2 x 3.14) x thickness removed (3 mm). Aka rolling it into a rectangle length x width x height. It was a touch over 5 lbs for mm of bore you take out of small six iron engines. This is at least slightly nifty for M20 builds and worth accounting for when comparing weight with aluminum block engines.