M52b28tu or m50b25 in swap e28

[Ian 422]

Hey everyone im doing a swap in my e28 but don't know what engine to use. I have a m52b28tu from a 1999 528i and I have a m50b25 from a 1995 525i. Which one is better? Which one is cooler? Also think im going to turbo one but which one is more reliable? I'm thinking about 400whp. I have both engines in my garage rn. I need to pick one.

[Mike W.]

Stock they have almost the same HP rating, but the B28TU is underrated, much quicker in a car, and has a better torque curve. No question, use the B28.

[Ian 422]

Thanks Mike W. that was my plan in the first place but then I just bought a whole e34 525i that was running and driving for 300 bucks just to take off the the oil pan to put on the m52b28 to then put that I'm my car.

[ElGuappo]

The M52 will be 'better' overall, but there is more at play than just power and oil pans.
Does the E39 have EWS? that will have to be deleted or mock installed in the E28 column.
Vanos rebuild...fun.
Much more complicated harness to convert.
I'm not saying not to do it, but it will be more work.
You'll also want to think about your diff with either swap, the 5spd for the M50 at least has a 1:1 5th gear, making the 3.25 in the E28 535 a bit tall at freeway speeds. A 2.93 mates up quite well given the 4.21:1 first gear.

[Ian 422]

Ok I know about the ews delete. But would I be able to swap the whole engine harness from the m50 onto my m52? I'm doing intake manifold swap and exhaust manifold swap because my m52 has catalytic converters in the exhaust manifold. Ya I was thinking about swapping the whole wiring harness because of the ews, exhaust manifold o2sensors, sap pump, and intake manifold would plug right in and other stuff. If I could swap it I would but want to make sure it's possible first so I don't waste my time.

[Preacher's 5]

Just completed the M52b28 swap in my e28. Engine came out of 98 328i. Loving it!

[Mike W.]

Ok I know about the ews delete. But would I be able to swap the whole engine harness from the m50 onto my m52?

No. A 99 is a M52TU which is double vanos, M50 is single vanos. I suspect more reasons than that, but that's for starters.

I'm doing intake manifold swap and exhaust manifold swap because my m52 has catalytic converters in the exhaust manifold. Ya I was thinking about swapping the whole wiring harness because of the ews, exhaust manifold o2sensors, sap pump, and intake manifold would plug right in and other stuff. If I could swap it I would but want to make sure it's possible first so I don't waste my time.

M50 intake is an upgrade which supposedly can get you 20 HP on a stock engine. It's extra plumbing, more than just the intake, but HP usually doesn't come that cheap.

[Ian 422]

Nice job preachers 5 any tips I should know before I start?

[Preacher's 5]

You will need the e34 oil pan w/pump and dip stick. I found mine on Ebay for about $300. Here is the link for one...https://www.ebay.com/itm/BMW-E30-E34-M5 ... 4d806e76e4
You need to find motor mounts and tranny mounts.
Wayne Lins (Lins Specialty Automotive, Lawrenceville, GA) did all the work for me. He ordered the motor from England and custom made the tranny mount. I have the 4 speed auto tranny from the same 98 328i. Check out my thread on the Eye Candy index.

[Ian 422]

Ya thanks, I have the oil pan because I just bought a whole running driving e34 for $300. That's why I was debating whether I should put the m50 or m52 in. But I'm putting the m52b28tu in. And I'm doing the intake manifold swap sense I have the engine in my garage rn.

[Ian 422]

Also I am doing a auto to manual swap so does anyone know where I could get swap parts in Seattle/Tacoma wa for cheap? Pedals etc.

[Mike W.]

But I'm putting the m52b28tu in. And I'm doing the intake manifold swap sense I have the engine in my garage rn.

I would hold off until it's in and running well. If you do it now before it's installed and there's an issue you'll be wondering if it's the manifold or something else.

[Ian 422]

Thanks Mike W. Good idea. I just didn't want to go through the hassle to do the intake manifold swap in the car but you have a good point.

[Ian 422]

I will swap the fuel rail before I put it in because the m52's have all that extra fuel return junk that is unneeded and harder to hook up.

[RondoAcapriccio]

Just completed the M52b28 swap in my e28. Engine came out of 98 328i. Loving it!

How does your brake booster fit? I have an S52 in my e28 and I shaved the ribs off the intake manifold. Although it fits, it is touching and I haven't tried yet but I dont think I can pull off the manifold or the brake booster, I am going to have to relocate the booster an inch over or go with a smaller diameter booster.

[Ian 422]

What year is your e28? Mine is 84 and it doesn't have a brake booster.

[RondoAcapriccio]

mine was orignially an 82 528e, im not familiar with the 535i system but I think it is different.

[Preacher's 5]

Just completed the M52b28 swap in my e28. Engine came out of 98 328i. Loving it!

How does your brake booster fit? I have an S52 in my e28 and I shaved the ribs off the intake manifold. Although it fits, it is touching and I haven't tried yet but I dont think I can pull off the manifold or the brake booster, I am going to have to relocate the booster an inch over or go with a smaller diameter booster.

With the M52, we did not have to make any adjustments for the brake booster. It fits like a glove.