M42 Touring or M20/M50/2 Touring?

[JGTI]

Lads, i am in a bit of a confusion here.

Right now, i am driving an M42 316i Touring, running on LPG, white with no sunroof. The engine is in need of serious attention in the chain,sprockets and such. At around 150k miles, nothing that i would not expect! Rebuilding it would be a 1000 quid job. The tailgate is rusting to hell, and, sincerely, i do not want to repair it, since it has got no sunroof, and it's only a 316i, so, it's pretty "normal", and in case of a sale, i would not recover a fair percentage of the investment.

Accidentally, i bought an 84000 mile black, sunroofed,M-Tec leathered 320i Touring with the engine off. Why, i don't know, but it comes in the trunk! Once i had a pre facelift 320i 2 door, and it was a bit dull in the performance stakes, so it might be even worse in a touring with 90kg extra.
Measures eventually would be taken, and this would allow for a m20b25 or a 24 valve m5x to be in the engine pit. I can get hold of an m50b25 with around 50k miles, for 250quid, and with the IS drivetrain, it would get easier to snug it in the engine bay.

The m42 touring is, as some of you have said in other posts, the best car that BMW never built, but really, mine needs a lot of money put into it, and the LPG does not make too much of a difference, since i use it only on weekends and in short runs.

The m42 touring has IS drivetrain, LSD, z3 steering rack.

What would be the best bet? Keep the m42 touring or make it a parts donor for the 320, and sell it on a profit??

Would the m50 be worth it?

[town325i]

Well im doing myself an m50 touring and many on here have done m50 conversions and they seem like a good way to go if you are looking for an engine upgrade as for the m20 engines its getting harder every year to find a good due to there age

[Jozi]

I have an m42 touring but not really any thing to compare it to except for my parents shopping trolley car. I'm also going to fit a m52 once I have all the pits gathered.

I like it the way it is, put a smile on my face anyway. I can only imagine the m52 will put an even bigger one on my face

[Brianmoooore]

As above, really! M42 touring = good, M50/52 touring = a lot better, M50/52 touring, running on multipoint LPG = as good as it gets!

[Morat]

Aren't non-sunroof touring shells useful for racers? You might be able to get a reasonable price for it if it isn't too rusty (apart from the tailgate)

[djk]

Aren't non-sunroof touring shells useful for racers? You might be able to get a reasonable price for it if it isn't too rusty (apart from the tailgate)

Can't believe they are - I've only seen about 4 or 5 e30 touring race cars, so they're hardly popular, and the non-sunroofness is only really handy in the sense that it's one less thing to prep on the shell. Tourings are heavier and less stiff, hence they are only really raced by folk looking to be different - the ones I've seen have had monster cages in them compared to 2-doors to stiffen them up, so adding more weight.

[JGTI]

As above, really! M42 touring = good, M50/52 touring = a lot better, M50/52 touring, running on multipoint LPG = as good as it gets!

That just gave me the itch! Fast and gnarly enough but with diesel mpg!

The 316i is going to be sold as a normal 316i with LPG, as the kit is a Prins multipoint one for 4 cyl.


I have a question! How will behave my large case 3:91 LSD with the IS box? I have a 3:46 one that came out of a south african 325i Auto, so it must not have had much abuse. I really don't have a clue which one to fit.

Is it worth it to go around and find a proper m52, having a nice and tight m50 secured?

I wonder if there is space left for the A/C compressor, LPG Vapouriser, and all things alike?

Hummm questions, questions.


Thanks in advance! You lot sure know how to keep a petrolhead busy.

[Brianmoooore]

You'll lose money by selling the 316i with a Prins kit fitted.
Earlier this year I bought a M3 lookalike E36 325i with an immaculate leather interior and Prins VSI LPG of off ebay for £600. A few weeks ago an identical Prins VSI LPG front end kit only sold on ebay for £610!
It's a strange fact, but a car fitted with a good LPG system is worth little if any more than the same car without a LPG system.
Nothing wrong with a good M50 vanos. A M52 has the potential to be better, but don't forget that as they come they have the same max. bhp.

[JGTI]

Well, i think i might study that route, if the LPG kit sells for good money!

As for the m50, it's an early one, non-vanos, out of a 325i. Good unit, i think.
Due to the m52's weight and "stock" modifications possible, i believe it might be a better proposition altogether, am i wrong? Today i've been ringing around to try and get some ideas on its prices. No luck though, as here in Portugal they are a bit scarce, and fetch good money.

Have any ideas on the A/C? Isn't space going to be tight?

[Boyraceruk]

I always wanted an M30 over an M50 for my Touring, I think the extra grunt would suit the car better. Let the coupe boys have their revs.

[daimlerman]

Bore centres are the same on M50/52 as M20,it's the cylinder head that is somewhat wider.
So no reason why an a/c compressor will not fit.
What's the ball park price for petrol in Portugal/Spain this summer,please?

[Simon13]

M50 is a waste of time if your going to that effort, the 2.8 has a massive torque increase throughout the rev range for a start. I've yet to see one that doesn't make over sotck power on the dyno either!

[JGTI]

Bore centres are the same on M50/52 as M20,it's the cylinder head that is somewhat wider.
So no reason why an a/c compressor will not fit.
What's the ball park price for petrol in Portugal/Spain this summer,please?

That is quite a relief. I only think about A/C in the summer, sometimes it can get a bit hot inside. Oh leather seats, burn, burn. Fuel prices for 95 unleaded are around 1.39€ per litre, maybe a few cents more on motorways! In Spain i suppose the price per litre is around 1€. I have a friend who went to Tenerife and he called me saying he was going to bring a few litres in the airplane, since it was so cheap, at 0.87€ a litre.

Boyraceruk, i think an m30 would be a bit "lazy" for me. Not that it wouldn't be fast enough, i know it would, but it wouldn't appear to be! Engine noise also speeds your senses. And the fuel consumption scares the hell out of me! Isn't it still a more involved swap, mechanically speaking? It has a plus, its sheer rude beauty when the bonnet is popped.

Simon13, i'm still weighing options, i want to do it right first time, but the m52's aluminium block makes me wonder how strong and durable it would be, compared to the simplicity of the early m50..! And with the advantage of having a good m50 unit by my doorstep, i think that on a later date it could receive 2.8 guts.

I really want to make the best e30 touring possible! By road car standards, of course!

[Bob_S]

simon is right. It's an m52 or nothing. they are a far better engine than the m50 and will pull all day long. by far the best motor I have had in an e30!

[Simon13]

the dramas abouyt M52's are over hyped on here, you wouldn't believe how much lighter that ali block is.

My m52 is going very strong 158k up they can do monster mileges. Its a nikasil engine also, uses about half a litre of oil between changes. theres plenty about slike this still

[JGTI]

So, following your precious feedback, how am i sure to find the proper m52? Out of a 328i e36 or 528 e39? Any exterior visual indicators, such as little tabs, numbers engraved and such?

220 bhp, is it really possible? With a 3:91 LSD, and IS box, should fly? Or should it fly more than desired? Still, from reading engine weight charts, a m52 is 1 or 2 kgs more than an m20, which would work better than a m50 in the dynamics department, correct? Tell me your tales!

It still would be a road legal comfortable cruiser, as well as a nutter in the bends? We have lovely mountain roads over here!

I hope i got the skills to drive the thing.

[Dave_M3]

I agree. The day for M50s is gone. The M52 is infinitely better in every way. Drive a good 328 and 325 back to back and you'll notice there's slot more of a difference Thant just 192 and 193bhp!
The issues with the Nikasil bores is over-hyped too as any that did have trouble would be long dead at this stage.

Don't worry about it being too fast. BMW straight sixes deliver their power very smoothly and are very controllable unless your an idiot altogether. Even an S50ed E30 has pretty decent road manners

[Droog]

Sorry to add my confusion, to the confusion!
The engine codes on the BMW range always confuse me!
So the M50 is the 325i from the E30, and the M52 is 328i from the E36?
I am following this thread with interest as I am in a similar position! I own a '93, 316i touring lux. I have sorted all the bodywork corrosion and painted both sides. The car looks good and is solid. My only gripe is it is woefully underpowered and has the common fault of a horrid rattle on startup, quietening down to a persistent, annoying rattle on driving. To be fair to it, it uses no oil or water and starts and runs perfectly (if rattly). It has done 150k and therefore has no shame!
As I stare now from the window of my workshop I see a Red 328i coupe, with M-tech body kit and interior! The car has had a bang on it's passenger side rear 3/4 and has the wheel knocked right under the body as he lost it, span and hit the kerb and a wall! I know the owner and could buy the whole car for Scrap money cost!
The question is!
As a comparison to having an E30 325i engine (M50?) and all it's associated running gear such as the gearbox and differential etc fitted! How much extra work, parts and modification would it be to fit the E36 (M52?) engine and running gear into an E30 touring? Would the entire wiring loom and ancillaries from the E36 need to be swapped or spliced? Does it need major modifications to the shell in the way of engine mounts, can I use the gearbox, diff and other mechanicals off the donor car? Is the extra work involved with 328i E36 engine worth it, versus the relative simplicity of the e30 swap? of which I have also had offered to me?
Sorry for the extra confusion!

[Brianmoooore]

No M50 engine was ever fitted to a E30 by BMW. The 325 E30 engine is a M20B25, and is an easy swap into your shell, requiring just the engine complete with all electrics, gearbox, prop and radiator.
The engines under discussion in this thread are the M50B25 engine with an iron block and 24 valve head, as fitted to the 325 E36 and later 525 E34's, and BMW's first alloy blocked engine, the 24 valve M52B28 (which also comes as a 2.5).
I disagree with the above posts that say a M50 conversion isn't worth doing, as it will be a spectacular improvement over a 316i, but if you have a M52B28 available, then it's a no brainer! The dimensions of the M50 and M52 engine are the same, and the work involved in the conversion is the same, apart from the minor complication that all M52 engines have the EWS immobiliser as an integrated part of the ECU, while only some M50 engines have it.

[Dave_M3]

I know the M50 will be better than most engines fitted to E30s but we mean its a little bit of a waste in that for only a fraction more in price you could have an M52 and both are exactly the same work to fit. Ok, some M50s don't have EWS but if somebody can modify the C101/X20 plug right, re-wiring the EWS back in shouldn't be that difficult.


An M50 is great in cases where you have an engine for nothing or almost nothing or one just sitting there going spare but if you have to go out and start from scratch in buying an engine or donor I don't think there is much point settling for an M50 as oppose to an M52.

Thats kind of what we are getting at Brian... or at least the point I'm getting at anyway :p

[Droog]

Thanks for helping me out on this!
I have found that the E36 that I can buy is an E36 328is! If it is pretty much the same job, I guess it is indeed a 'no brainer'. The engine is only a 70k low mileage example as well!
Is the immobiliser the reason that the clocks are transferred along with the engine?
I have transplanted an Audi S3 20v turbo into a MK1 Golf and found that the main hassle is that they integrate the immobiliser as part of the clocks unit! as well as the ECU. (some kind of anti mileage altering measure, as It Keeps the clocks and engine 'tied' together.) I managed to eventually find a guy who plugged into the ECU and he sorted out all the sensor and ABS etc warning problems in the end!
I would love to fit the E36 328is engine and think it will make my old touring very interesting to drive!
As an interest, mechanically can the E36 drive train etc be fitted onto the E30 chassis, without major mods? Or do you have to find and fit different parts to mate them up? Or is it a case of finding 325 E30 drive train parts married to the engine/ gearbox?
This, of course would mean I have to find more parts?
As I love the old 'bus', and I am determined to keep it, the extra work would mean I get a damn good engine!
Thanks for your invaluable help and opinions! Your knowledge in these matters is helping me to judge what direction to take and weigh up the possibilities! It would be such a shame to see the E36 turned in for scrap, without maybe giving at least some of it a useful life!

[Dave_M3]

No, clocks don't need to be swapped over. Just the ECU and EWS parts.
There isn't anything near as complicated as the 20v swap in the Golf in terms of wiring the M50 or M52 engines.

For fitting the engine, you need a sump from a M50 engined E34 such as a 24v 520 or 525.

Other little bits like electric fan, rubber engine mounts, smaller brake servo such as a Clio unit, manifold needs alittle tweaking etc.

nothing has to be done to the E30 chassis itself.

You can use the 316 box if you like, the 328 box or use a 325 box and whichever diff is suitable.
Easiest is a E30 318iS box with a 3.64/3.91 diff, strongest is a 328 box and maybe a 3.15/3.25/3.46 diff


There is numerous threads on here and project builds of putting M50 or M52s into E30s.
Have a look in the "engine swaps and Forced induction section" and then in the "M50/M52 conversion" sub-section and put the kettle on for a nights reading and you'll have everything you need to know

[Droog]

Cheers!
Having found and looked at the great guides on here, I see nothing is left to guess work! I shall have a good think on my options! Thank you all again, sorry for hijacking the thread! I shall get the kettle on!