How Satisfied are you with your S/M5x Swap?

[Stephen]

I think people are also swapping from B25s and expecting a big difference because others are happy with their swaps.

Do not be under the impression that an M50 is going to make your car balls-out quick. It'll make it respectable, but it's only a modest increase from an M20. It will have a better powerband (depending on if you went with the NV or TU) and a bit more power (25hp, maybe 30 if your M20 is tired out and M50 is new, that's about a 15-20% peak power increase), as well as get better mileage and get rid of the sewing-machine mechanical lifters of the M20. It'll be on the quick side for an E30, probably a tiny bit quicker than an E30 M3, but in today's world E30 M3s are not fast in any sense of the word.

The best way to do an M50 swap is scavenging for good deals for a few months. Spend wisely, check/loctite the oil pump nut, maybe replace a gasket or two, maybe the water pump and a few other minor things "while it's out." Don't go balls-out spending money left and right because the M50 will make it scoot in relative terms but it is not going to make the car FAST.

My 2 cents. Never forget the law of diminishing returns.

i agree. Exactly how i picture mine being done

But also, people talk about not being much hp from an m20, but not all m20s are b25s. While m50 isnt a huge jump from the b25, it hopefully will be a big step from the eta. :D

[e30polak]

Wasnt even a bad failure, just a weak spot on a high compression motor.

Curt did you bump up the compression ratio on your motor? Are you running different pistons?

I know you've had the Schricks for a while, but i didn't think you had any other internal stuff done.

[91 318is]

Nice man, glad to see a thread like this. Been thinking of a 24v swap, although an S5x would be nice, I feel like a M5x would be a good enough for me. Not looking for something lightning fast, but something strong and fun!

[D-rock]

What trannys are you guys running? I herd for e36 3.5 is the way to go!?

I have an m50 i was considering either turbo or SC or swap for s52. Its all around the same price.

[C-T]

I couldn't be happier with the car.

[M-technik-3]

Liked having mine, need to finish the current two projects before winter sets in. Seems this summer was way to short and cool.

Kinda miss my old rat thou.

[shiboujin]

What trannys are you guys running? I herd for e36 3.5 is the way to go!?

3.5 what? I use a ZF310D which is basically the same as the M3 ZF (ZF320D).

I think I'd be very unhappy with an NA M50. maybe 2.8 liter M52 would be nice. But eh. It's moderate power. I'm used to boost. I picked the M50 because the same boost gives you more power.

[jrdeamicis]

Either a 2.8 or 3.0/3.2 is the way to go with these things. With the m50s though they are a nice upgrade for someone with a 4 cylinder they lack the grunt.

My 3L w/ a 6 Speed and a 3.73 has some serious oomph.

[D-rock]

Opps 3.25 in a e36zf

[E30 Wagen]

does anybody have some insight on a "built" m20 versus an m50 or m52?

I have a 731 head from an e30 323i that i have been thinking about rebuilding my 125k eta with. The problem is that it will get expensive rebuilding the head (possibly a new 325i cam, seals, guides, maybe even new springs and valves, and new manifold studs). I also aim to have the intake ports enlarged to match a 325i intake manifold. I estimate that with new parts and labor i'll have over $600 into it, not including what i paid for the head itself. I also debate about rebuilding the bottom end, which will only drive the price higher, but might be worth it because i want a "new" engine, not to mention the fact that it will be something rather unique and robust. I also have an exhaust ready to go on, a getrag 260, and a s2.93, and various other parts ready for the swap.

I read about people buying m50's for $600 but i'm having a hard time believing that because every reputable place i look these engines are going for like $1000 minimum, over $3000 for a remanufactured one. I'm really interested in doing the swap but the numbers start to rocket upwards fast.

So, does my proposed 327i seem like a m50 contender? My mom drives a 328is so i know what a m52 feels like (awesome) and want one but i think it will be too expensive. I'd like to stay under $1000.

[SamE30e]

I have a M50NV swap and it's alright, but it's nothing to gloat about. It needs boost or something.

[rThor432]

So, does my proposed 327i seem like a m50 contender?

It depends on how deep you get into the head. If you stop at the ports and use a stock B25i cam, you will not have the top end power of the M50, although you might have the torque. If you run stock B25i valves or slightly oversized (especially with a bit beefier cam, think... 288 Schrick) that will help a lot.

Edit to add-- For comparison, a friend of mine is running the B25i 885 head with the eta bottom end. Did 152 whp/164 lb/ft on the dyno. The head lost .020 iirc, so it bumped the compression up a good bit (similar to the 731 on the standard eta block). If you get the head to flow like an "i" head and have it tuned right you should see similar numbers.

I ran a bunch of numbers on different combos using the 731 head (I had a 323i at the time and an eta with a spare 731). I was dead-set on seeing what numbers you could achieve from that head/block combo. In the end a customer decided to install an M54B30 in his car instead of the S52 our shop had ordered for him, so the S52 naturally ended up in my car instead.

[So Live]

NV m50 isnt worth 2k but the turbo (NV) m52 is well worth all the money. Even though i want more...