Ultimate inline-6 for an E28

E28 technical advice asked and given! Troubleshooting, modifications and more.
Post Reply
Ken NC
Posts: 83
Joined: Feb 12, 2006 12:00 PM
Location: Durham, NC

Ultimate inline-6 for an E28

Post by Ken NC »

I'm toying around with the idea of going big on an engine swap for my 87 535is, and I'm wondering if some of the folks who know their way around the E28 better than I do would mind pushing me in the right direction.

If you could put a newer and more powerful inline-6 BMW engine in your E28 (no LS V8s or other wildness), which engine would you go with, and why?

My top priorities are power, reliability, weight savings (would be nice), and ease of swap (something that's tried and true).
Thanks in advance for any suggestions or advice.
KM
MyE24
Posts: 94
Joined: Apr 16, 2021 10:43 AM
Location: California

Re: Ultimate inline-6 for an E28

Post by MyE24 »

My choice would be an S38B38!
Mike W.
Posts: 26872
Joined: Feb 12, 2006 12:00 PM
Location: California Whine Country

Re: Ultimate inline-6 for an E28

Post by Mike W. »

10:1 pistons and a B35 cam put you up close to 220. With what I think is a very easy and relatively inexpensive job. As long as you run premium reliability is the same as stock. Yeah, it's still a B34 engine, but the difference is jaw dropping.

Moderate complexity would be a M54B30, the 3.0 out of E39s etc. 225 rated HP, but double Vanos which gives a better torque curve/power feel. Bulletproof with a high quality swap.

Getting complicated, but it's been done, is a S54. ~330HP. Not what we consider BMW longevity, but I guess if you do rod bearings every 80K or something it's not bad. But 330HP? I can't imagine. :shock:
Nothintoseeere
Posts: 57
Joined: Apr 23, 2021 5:27 PM
Location: U.k

Re: Ultimate inline-6 for an E28

Post by Nothintoseeere »

Get some forged pistons for your engine with a b35 camshaft or after market camshaft and it wake up your engine.

Vac motorsport do pistons for the m30, not expensive either.

The other option is an m52b28 engine and fit a m50b25 inlet manifold. That will give you 220hp and its a lighter engine by alot.

Personally I'd rebuild your m30 as it's a great engine. You could also change you cylinder head to the b35 variant and fit an aftermarket camshaft. You might see 240hp that way. The more you want the more it will cost you. While the engine is open you might as well do the bearings and you might as well replace the valve guides and valve stem oil seals in the head.
Ken NC
Posts: 83
Joined: Feb 12, 2006 12:00 PM
Location: Durham, NC

Re: Ultimate inline-6 for an E28

Post by Ken NC »

Thanks to all the folks who have chimed in. I should have mentioned that I already have a b35 engine in the car, but I did the swap myself, and it's not the cleanest swap ever. It does have an extrude-honed Metric Mechanic intake, which helps.

If I do rebuild this engine, I'll go all the way with it, 10:1 pistons, forged rods, port match the heads, etc. But if I'm going to go to all that expense, I'm asking myself 'Why not just drop a (perhaps lighter and) stronger and newer engine in there that would only need a 'refresh' and not an entire new build?

From what I'm hearing, the s54 engine is a beast, but it requires an entirely different harness set - something about the something one not working with the older platforms). It sounds a little complicated, but doable, and would probably give 100 HP more than the other readily available options.

Keep the suggestions coming! I'm taking notes, and will stay in touch regarding where I go with the swap/build.
KM
tn535i
Posts: 5585
Joined: Jul 14, 2006 1:30 PM
Location: Middle Tennessee

Re: Ultimate inline-6 for an E28

Post by tn535i »

My opinion... not just the engine but the transmission and maybe final drive. While the S54 would be outrageous the N54 3.0 ZHP is superb and will take nicely to exhaust and other minor mods... and then if using either of those engines... the 6 speed is oh so sweet (replace the dual mass flywheel though). The final drive ratio would work anywhere from 3.25-3.91 depending on what you like to see on launch versus cruising.

The N54 3.0 ZHP 6 speed is perhaps my favorite BMW powertrain aside from an M car. It was still an honest NA 6 without too much complications. The e46 ZHP really only needed a little more free exhaust and LSD. Although... I'm sure an S38B38 with uber rare 6 speed would make for something beyond special in an e28.
Nothintoseeere
Posts: 57
Joined: Apr 23, 2021 5:27 PM
Location: U.k

Re: Ultimate inline-6 for an E28

Post by Nothintoseeere »

Personally I would put a m62b44 or b46 engine in there. More torque than you can shake a stick at in a car that not heavy. The m62 is probably lighter than the m30.

I know that not what your after but those m54, s54, n54 engines sound like way too much wiring work to be worth while for what you get.

The m62tub46 kicks out 347hp and they sound awesome.

The m62tub44 is found in oh so many x5's and range rovers and it makes a l322 range move well and that 2.5 tons. That's only 282ho but deliver 325 ft.lb of torque.

You could use a 3.07:1 final drive and still get some wheel spin.
Ken NC
Posts: 83
Joined: Feb 12, 2006 12:00 PM
Location: Durham, NC

Re: Ultimate inline-6 for an E28 - ISO more input

Post by Ken NC »

Thanks again to the folks who have already offered suggestions. At this point I've talked with one local source - a long time track buddy who I respect and trust - and I don't think I need to look any further. He has several motors sitting in storage, awaiting projects that may or may not ever materialize, and he's willing to part with one of them for my project. He felt that I should stay with an older, more traditional motor for my car, and avoid all the conversion logistics. Considering the two 'traditional' engines that he has available, he didn't have to twist my arm!

Here are the two engines, and - from my understanding - the advantages and drawbacks to each:

1) a Euro M6 engine that will need at least refreshing, probably a partial rebuild.
Advantages
- So, sooooo (!) pretty under the hood
- Easily recognizable as a primo set-up
- Lots of HP
- Music to our ears
- Relatively easy install
- Can use my current transmission (or source another).
Disadvantages
- $$$, plus more $$ for rebuild
- more $$ for maintenance parts, or any possible repairs that it might need
- somewhat like a high-strung horse: warm it up, cool it down; no short, repeated quick starts, or it can flood (= work)

2) a 'built', balanced, and tuned 3.8 crankshaft (special order) Euro M30b34 with 10:1 pistons, laptop tunable ECU, putting out 285 RWHP (on the pavement)
Advantages
- Monstrously strong engine (even moreso than the Euro M6 engine)
- Freshly built (a few years ago, but very few miles), by a local builder
- Ready to install, no refreshing or anything necessary
- Simple to maintain, easy to live with
- Will bolt right in, with no (or very few) mods necessary
- Less $$ to buy, less costly to maintain
Disadvantage
- Not as blingy (more of a sleeper)

Needless to say, either choice would make for a great transplant. My heart says 'take the beautiful DOHC Euro M6 engine (!!)', but my head says 'Nah, take the SOHC.... put a nice, pretty finned valve cover on it, and be practical'.

Question: are there considerations (present or future) that I'm not seeing? If you had your 'druthers', which would YOU choose?

BTW, this is for a weekend and 1-2 time a week 'driver' car (not a garage queen) that *might* do a track day now and again in the future; that would also get a good paint job, once the mechanicals are finished; and that then would do Cars and Coffee events or BMWCCA events here and there.
Thanks in advance for any insider suggestions!
Galahad
Posts: 495
Joined: Sep 06, 2016 9:08 PM
Location: Beverly/Worcester, MA
Contact:

Re: Ultimate inline-6 for an E28

Post by Galahad »

My opinion: You can get a drop in engine, with more power than the euro M6, for less money and lower running costs - Who cares if it's not as pretty? You could put the money you save into the paint job or other stuff you wanted instead and still have a faster car.
Ken NC
Posts: 83
Joined: Feb 12, 2006 12:00 PM
Location: Durham, NC

Re: Ultimate inline-6 for an E28

Post by Ken NC »

Galahad wrote: Oct 20, 2021 8:52 PM My opinion: You can get a drop in engine, with more power than the euro M6, for less money and lower running costs - Who cares if it's not as pretty? You could put the money you save into the paint job or other stuff you wanted instead and still have a faster car.
Where's the 'Like' button? Thanks, I think you're preaching to the choir ;)
austin8753
Posts: 1444
Joined: May 16, 2010 1:37 AM
Location: Portland, Oregon, USA

Re: Ultimate inline-6 for an E28

Post by austin8753 »

having just built a mild, but bitchin, 10:1 M30 for a client - go that route. you'll thank me later. :)
Mike W.
Posts: 26872
Joined: Feb 12, 2006 12:00 PM
Location: California Whine Country

Re: Ultimate inline-6 for an E28

Post by Mike W. »

Galahad wrote: Oct 20, 2021 8:52 PM My opinion: You can get a drop in engine, with more power than the euro M6...
Not an M30. 286 German HP? Or go crazy with a S38B38 and 340, but talk about expensive... I do think a built M30 is a good idea, but it's hard to get much more than 250 out of it.
Nothintoseeere
Posts: 57
Joined: Apr 23, 2021 5:27 PM
Location: U.k

Re: Ultimate inline-6 for an E28

Post by Nothintoseeere »

Go with the built m30. It will move well for less coin.
Ken NC
Posts: 83
Joined: Feb 12, 2006 12:00 PM
Location: Durham, NC

Re: Ultimate inline-6 for an E28

Post by Ken NC »

Mike W. wrote: Oct 21, 2021 3:27 PM
Galahad wrote: Oct 20, 2021 8:52 PM My opinion: You can get a drop in engine, with more power than the euro M6...
Not an M30. 286 German HP? Or go crazy with a S38B38 and 340, but talk about expensive... I do think a built M30 is a good idea, but it's hard to get much more than 250 out of it.
Yeah, it sounds almost too good to be true. But it's a 3.8 liter Euro M30. One good thing is the builder is local (well, not far away), and I should be able to get the build sheet from him, as well as have him set it up and re-tune it once it's installed and the exhaust is on. Apparently it dyno'd at 285 at the wheels. Even if not, and it's somewhere in the mid 200's, should be a kick-ass engine!
danielpouch
Posts: 64
Joined: Feb 27, 2018 12:41 PM
Location: Portland

Re: Ultimate inline-6 for an E28

Post by danielpouch »

austin8753 wrote: Oct 21, 2021 1:00 PM having just built a mild, but bitchin, 10:1 M30 for a client - go that route. you'll thank me later. :)
AINT SHIT MILD ABOUT IT BOY

+1 FOR 10:1 M30
Nothintoseeere
Posts: 57
Joined: Apr 23, 2021 5:27 PM
Location: U.k

Re: Ultimate inline-6 for an E28

Post by Nothintoseeere »

I'm still waiting for my pistons for 10.5:1 m30b35 engine. That will move when it's done. It might be 2022 before cp caprillo deliver them.

So if the engine is built go with that. Any other engine that may require work could be held up waiting for parts.
pavulon
Posts: 48
Joined: Mar 10, 2018 8:39 PM
Location: WI

Re: Ultimate inline-6 for an E28

Post by pavulon »

Putting some ITBs on an M30 would go a LONG way toward leveling the bling factor.
gwb72tii
Posts: 619
Joined: Sep 21, 2021 4:58 PM
Location: The Great Pacific Northwest

Re: Ultimate inline-6 for an E28

Post by gwb72tii »

I'm headed down the road of a metric mechanic 3700 motor. Their lead time is about 7 to 8 months right now.
Both kids are married, secure and out of dad's check book.
From what I can tell and read about, people that run their motors are pretty damn happy.
Personally I don't care about sheer horsepower/torque numbers as much as other's experiences and opinions.
Mike W.
Posts: 26872
Joined: Feb 12, 2006 12:00 PM
Location: California Whine Country

Re: Ultimate inline-6 for an E28

Post by Mike W. »

gwb72tii wrote: Oct 27, 2021 2:28 PM From what I can tell and read about, people that run their motors are pretty damn happy.
Personally I don't care about sheer horsepower/torque numbers as much as other's experiences and opinions.
Truth. Unless you're racing, the butt dyno is more important than actual numbers. Like many I'm skeptical about the numbers they claim, but if it feels right and like you got your moneys worth, that's all that counts.
MyE24
Posts: 94
Joined: Apr 16, 2021 10:43 AM
Location: California

Re: Ultimate inline-6 for an E28

Post by MyE24 »

gwb72tii wrote: Oct 27, 2021 2:28 PM I'm headed down the road of a metric mechanic 3700 motor. Their lead time is about 7 to 8 months right now.
Both kids are married, secure and out of dad's check book.
From what I can tell and read about, people that run their motors are pretty damn happy.
Personally I don't care about sheer horsepower/torque numbers as much as other's experiences and opinions.
Checked out their webpage, interesting.

What ECU, injectors and AFM do they use with that?
gwb72tii
Posts: 619
Joined: Sep 21, 2021 4:58 PM
Location: The Great Pacific Northwest

Re: Ultimate inline-6 for an E28

Post by gwb72tii »

An upgraded chip, recommended that I use SSquid, but stock ecu and injectors
But I’ll be having more conversations with them.
Mdreamer
Posts: 526
Joined: Feb 12, 2006 12:00 PM
Location: Atlanta, Georgia

Re: Ultimate inline-6 for an E28

Post by Mdreamer »

Of your two options, I'd go with the heated-up M30. A 3.8 with all of the other goodies sounds like a dream engine for an e28 that didn't start life as an M5 (to me).
Post Reply