M30 vs. S50

[slammin.e28]

M30....because E30 has to have a SOHC and valve tick to be E30.

[e30polak]

The m30 isn't all that much heavier than an any of the 24v m/s5X engines; I believe it's about 13 lbs heavier. It does however sit even further forward over the nose of the car, which you may or may not feel in hadnling and braking compared to a 24v.

The only NA M30 worth swapping in is an m30b35. If you do a Miller MAF kit, a proper cam, Lightweight flywheel, IE headers and exhaust, it will be a real torque monster. If you plan to boost an m30, any version will be a good choice in a light little e30.


I've always preferred the linear powerband of the VANOS motors. The VANOS motors are faster revving and more responsive than an M30. Also in NA form with the right set of cams and Euro headers, the s50/2 can safely reach 270+whp!

The 24v heads are MUCH more effiecient, which is another reason why I prefer them. :up:

[Wanganstyle]

OR buying a complete running m30+5 speed car :) This is the best way IMO and can lead to very very good results.

Jean has a M30 e30 autoX car and is quite fast!!!!!

in regards to engine position, I wish this was an option on E30 M50 family swaps- I wonder if there is any interest in this.....

[Bearmw]

I can see a good M30 swap running anywhere from under 2 grand complete if you are a decent mechanic with patience to hunt out deals and to be able to check condition of parts before buying to it running over 6 grand for everything if you are paying top dollar, getting top of the line, and having others do your work and so on.

Ideally if you have the patience (to get good deals on parts and to put things together the right way the first time) and desire to learn to do things yourself it can be a big bang for the buck to do a swap. The more you know the less money you will waste on parts that won't really do what you want or live up to the cars potential.

If you have knowledgeable people nearby who can lend advice and maybe even help with the swap you are golden.

A good basic freshened B35 swap with 3.25 or 3.46 diff, light weight flywheel, E28 radiator and Ford Taurus or similar radiator, 179 ECU and Mark D chip, stock manifolds with 2 1/2" exhaust is a big improvement over stock and doesn't have to cost too much except for your labor. Key is finding a good used B35 (preferably from an auto) that you can run leak down and other tests on.

[Wanganstyle]

Lets remember there are so many variables from build to build for instance what type of headers vs. cast iron manifolds, what type of air cleaner/intake is used, is AC being retained, what position is the motor mounted in, what other weight adjustments are made to the car. You get the picture.

It is hard to make blanket statements about handling and performance without getting into the exact details of a build including suspension. A supposed weak point may be offset by a change in another area. I made an effort to retain and even improve the balance of the car but it does take work and planning and of course some sacrifices including $.

yes, most swapping a M30 cannot afford a nice built motor like you have done- owners madness determines the machine :)

[Bearmw]

Lets remember there are so many variables from build to build for instance what type of headers vs. cast iron manifolds, what type of air cleaner/intake is used, is AC being retained, what position is the motor mounted in, what other weight adjustments are made to the car. You get the picture.

It is hard to make blanket statements about handling and performance without getting into the exact details of a build including suspension. A supposed weak point may be offset by a change in another area. I made an effort to retain and even improve the balance of the car but it does take work and planning and of course some sacrifices including $.

[Wanganstyle]

Do some more research Wangan, M30 is lighter than all iron block twin cam M50/S50 BMW engines. Both of the engines are heavy for their stock output.

incorrect on weight according to some internet research, but I'm talking about the Deck HEIGHT.

I have even driven both engines in the SAME BODY:

E34 with m30+5 speed
E34 + s52+ 5 speed.

The turn in front grip of the M30 block big SENIOR SIX is WORSE than the small 6 in dohc form. Comparing similar prepped cars in identical, native OEM BMW e34 chassis.

you can drive E34 in:

small 6 sohc (m20)
small 6 dohc (mine was s52)
big 6 sohc (m30)
big 6 dohc (s38 )

as far as handling is concerned the M20 will be the nicest balanced vehicle. M20 is lighter than all other 6's


I have also driven M30 engine in E28 chassis, and S38 engine in e28 chassis. M30 engine handles better, but it cannot do 170mph OVER
S38b35 will do 170mph :P

overall weight can be juggled, I did like to be proven wrong if you feel M30 weighs LESS than M52/s52 in similar dress form.

m30 has lighter cylinder head, but metal intake and its TALLER, longer crank, heavier crank.
M52/s52 has plastic intake, plastic shit everywhere and is shorter, shorter lighter crankshaft. only the cylinder head is heavier, but cylinder heads don't weigh more than 60 lbs, the M30 aluminum intake manifold and cast iron headers should negate this advantage.

longmotor vs longmotor, the M30 is TALLER, and longer ==== handles WORSE.

http://www.bimmerforums.com/engine_faq.php

m30: 315 lbs
M50/52 24v family: 299 or 308 lbs.

Main difference: Weight BALANCE!!!!!!

[Good & Tight]

With a 5k budget go with the S50, if you plan to turbo it add another 5k. That's a rough estimate, could be a lot less if the engine has low mileage and in excellent shape. When you start to rebuild that's were the $$ will start to add up.

[The Humjet]

Lots of E34 535i M30s in my neck of the woods have 5spds according to Craigslist.

Humjet you've got some misinformation there. Some of the s50s/s52's DID come with auto's, though are less prevalent than the manual transmissioned cars. Also, while the m30's did largely come in automatic form, the manual transmissions aren't hard to come by. Even so, you can match the m10's manual transmission up, the s14's and I believe the s38's, so if your not able to find a transmission that spent it's life hooked up to an m30, you've got other options.

Whichever one you choose, Dom (suicide109), I already know where to find transmissions and other swap parts locally.

Sorry for the misinformation I gave I guess its different being on the other side of the pond. I have had experience with the m30 swap since I helped my mate convert it into his car where I did all the research and he played with the spanners.
We used the m10 gearbox since the g260/6 is so hard to find here. The g265 you have no chance of finding your probably better off importing it in.
We both happen to be close friends with the owners of a large BMW wrecker down here and it took us 8 months to find a g260/6.
He bought it for $800 which is a bargain since they cost $1200 to the regular customer. We're still using the m10 with a spec stage 3 clutch. We just got the g260/6 now all we need to get a tail shaft made up to fit.
But for a turbo which the OP looks to do especially with his budget an m10 gearbox and hd clutch isn't enough. The clutch still slips a tiny bit even with a bone stock m30b35.
But since its much easier to swap an m30 just go for it. And boost it. It'll be way more fun that an NA s50/52

[Jean]

M30b35 over M50NV or VANOS OR do the S50/S52 if the main goal is most hp/tq per $ spent.

MPG on M30 sucks, but usually you don't care about mpg when you go for performance so who cares.

m50/s50 swaps are EASIER than the m30b35 from the machical stand point, but m30 is almost plug and plug from the electrical side.

If you dont want to deal with custom engine mounts and having to find an M30 SPECIFIC 5speed (m20 g260 will not work as you may already know), then M50/S50 is easier to swap.

Skip the M50NV at least, almost not worth the hassle of swapping into m20b25 car UNLESS there is something wrong with your m20b25. You will get smoked by M30b35 swap car all day everyday, just way more torque and even more hp vs M50NV. M50 is not exactly lightweight, so it doesn't win in that area either. It wins in MPG, and being a newer engine = not as loud running, no valve adjustments needed.

Just not a big net gain vs B35 or S50 for example. Of course if you are starting with a 318i/s then any of these would be a big upgrade .

24v m/s50 are not much lighter than the m30b35, the DOHC heads are quite heavy and the block is still iron... unless you find the rare aliminum blocks as used in the m52s?

If you want light, stay with 4cyl.

[mr2peak]

With $5k you should an S50. People also seem more willing to buy S50 E30's should that ever come up.

[dannyyisntt]

Comparing the two is hard. What it all really boils down to is what you want out of the car.

M30: Takes boost like a champ, is torquey and has that old school burn 'em up charm, is the cheaper of the two, parts are in an abundance around here, is basically bullet proof and isn't as heavy (in comparison to 24v swaps) as people like to claim

S50/s52: Better gas mileage, much better top end, is less boost friendly to start, will probably get increased hp numbers easier, more aftermarket support, will make you giggle like the man child you are, but will come at a much higher price $$

[Brian D]

I just saw a post titled "my project" by TodB on mye28.com about his recent M30 build. It was detailed and very interesting. And he used a B34 head.

Thanks for pointing that out!

[LJ851]

M30 is HEAVY and TALL. BUT is BIG...

M30 problems ? heavy, turn in suffers, weight bias shift.

S50/52 family is shorter in length, lighter weight than m30

Do some more research Wangan, M30 is lighter than all iron block twin cam M50/S50 BMW engines. Both of the engines are heavy for their stock output.

[LowR3V'in]

Get the s50 no question.
Is 5k a good price? I'm kinda outdated last time I looked 5k was just for the engine.

M30 you'll spend 1/16 of the s50.
Anything less then a b35 is not worth the swap.

Most people here I'm guessing went m30 because s50 is far out of price range
and m50 is just too weak. Best bang for the buck is m30 but since you can afford the s50 do it is my opinion.