M30 vs. S50

[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]

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.....

[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:

[slammin.e28]

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

[Danny]

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

I get plenty of ticking from my VANOS.

[SUICIDE109]

I've got some of the best ppl around to help out, I'm not exactilly as e30 savy as I was before the army because of going through basic training and 3 months after being deployed to afghanistan... well now I'm almost half way though my deployment and my R@R is coming up soon so I can read up and go through my car. I know my car has a 2inch drop and has f/r tie bars, a 4 point cage will be in the works and a modest interior strip will be also aswell as 3.46-3.64 gears. High dollar parts and quality are mandatory and when I build something nice, I am determined to build it nice! I will be mounting the engine as far back as possible to get the balance. The reason for the swap is that the current 2.5 is running around 250k and when I get back to Ft.Drum (I'm not worried on passing emissions in NY)I'll have some rivals like my Lt. who's going to purchase a new boss 302 with track keys. I'm liking the idea about that lighter flywheel to get quicker revs out. The car might be N/A for while and the turbo is not included in the 5k limit...

[VinniE30]

If I can make as much peak power from an m30 as a stock s50 then all the better. Same power from a 12v head without VANOS and better reliability and less complexity is a great thing.(Isin't less complexity what the e30 is all about?) Not to mention it's a period correct swap if you care about that for the cool factor.

And i'm not sure what you guys are talking about as far as the 24v having a more linear powerband. The m30 torque curve is very flat, and since HP is a function of torque, a flat torque curve results in a linear increase in HP with increase in RPM. The extra displacement of the m30 helps it match the VANOS's linear power band.

Lots of misleading statements here about torque. The M30 has around the same peak torque as the s50. The reason it feels different is that it get it's peak torque at a lower RPM than the s50.

I have an m30 e30 and just drove an s52 e30m3 last week. The s52 was very smooth and fast but wasn't that impressive compared to an M30. I thought the joy of the e30 for a lot of people was it's raw, old school feeling right? M30 can give you s50 power with that old school feeling and reliability and less complexity.
Everyone and their mother has a 24v swap, M30 is less common.:D

BTW i'll have a dyno of my very lightly modded m30 within a week or 2.

[Wanganstyle]

I've got some of the best ppl around to help out, I'm not exactilly as e30 savy as I was before the army because of going through basic training and 3 months after being deployed to afghanistan... well now I'm almost half way though my deployment and my R@R is coming up soon so I can read up and go through my car. I know my car has a 2inch drop and has f/r tie bars, a 4 point cage will be in the works and a modest interior strip will be also aswell as 3.46-3.64 gears. High dollar parts and quality are mandatory and when I build something nice, I am determined to build it nice! I will be mounting the engine as far back as possible to get the balance. The reason for the swap is that the current 2.5 is running around 250k and when I get back to Ft.Drum (I'm not worried on passing emissions in NY)I'll have some rivals like my Lt. who's going to purchase a new boss 302 with track keys. I'm liking the idea about that lighter flywheel to get quicker revs out. The car might be N/A for while and the turbo is not included in the 5k limit...

if you want to mess up your Lt; why not a S38 swap? same thing as m30 and you could buy a running e34M for close to your budget and break it if you are so inclined. S38 is a marvelous engine; 3600cc :D

[Danny]

S38 is a much more difficult swap, friend.

[kronus]

eh, you just need one more custom thing, subframe spacers. Everything else is purchasable. the real issue is the cost, S38s are expensive to buy and expensive to maintain.

[slammin.e28]

I get plenty of ticking from my VANOS.

...but that ticking isn't supposed to happen. M30/20 ticking is.... ;)

Also, that's probably the e30 trying to puke out that 24v engine. It's like giving my grandfather a Mac and taking away his abacus. Something will be thrown out the window....then we just have and angry old dude and a broken computer.

[InuFaye]

but 24v is what god intended to happen you heathen.

[Wanganstyle]

S38 is a much more difficult swap, friend.

its been done so many many many times in europe -

I'm sure if given a running E34M you would do it...... :P

[slammin.e28]

but 24v is what god intended to happen you heathen.

If ?god? intended 24 valve....M20 wouldn't exist....and thus the would would be a better place.

M30 still would though....it's what ?god? intended before 24v, then we fucked it up...(M20...)

[stinkydriverx]

This is the one time I feel like a faahhgett(spelled that way on purpose). I chose the m30 for its period correct look. And that wonderful sohc noise maker. I'm gonna be in my m30 swap for about 2k when its done. I'm in it that much and I payed 300 for the running engine. I didn't spend this much money for a stock for stock swap. I chose it because for 300 dollars, Its a great base to start with. I chose it because an m30 can make 400hp without breaking a sweat. Now, so can an s52. However 9/10 times. the m30 is going to make that power for alot less money. Its all up to your budget. whats important to you.

Chris brings up a good point that i'm a little scared of. The handling. I guess we will see how that goes.