Engine Swap Question...

[Boggie1688]

So tonite I was out...and my friend dropped by with his 330ci with a performance package....he just got a gruppe m carbon fiber intake installed and this baby sounded sick taking off.

That made me soo jealous...cuz my 525i is really harsh and slow. Now that I'm working and saving money...and investing...I was wondering how much a real engine swap would cost. I like the body style of the 525i, plus if I keep it...I'll look more unique than all the 3 series out there...and still be able to keep up. I don't want to get another 5 because I've already thrown money into the car with replacing stuff and I know its in good condition. So what do you guys think would be a good engine to throw in that will give me insane speed? So I can get a feel of what I need to save up for, that is if I decide to go for it.

[rickm]

Sell it and buy a 535 or a 540.

[1992 BMW 535i]

Go to Metric Mechanic and look at their 3.7 and 3.9s....sick speed there with no forced induction issues..

[bimmerd00d]

haha as much as this will piss people off, LS1 from a Camaro or Corvette and a 6-spd. LS-1 weighs less than the 540i motor, and has more hp. As much as i hate to say it, i think that motor in the E34 would annihilate anything.

[Boggie1688]

Where is metric mechanic?

So most engines can probably fit into the e34 engine bonnet then?
Sry rick I don't wanna sell the car...because I already tried...no 1 around her wants to buy an e34...the market just doesn't seem to like them. I think bmw has a reputation of having lots of problems after about 100k and ppl in cali know that.

[Brandon J]

Some questions,

What year 525i do you have?
How much money are you willing to spend?
How much power do you want ultimately?
Do you have another vehicle to drive for a month or so while a swap takes place?

[Boggie1688]

My 525i is a 1991,
How much I'm willing to spend....is anything...because if I like the idea ultimately I don't care how much I have to spend...
How much power? Enough to toast my friends 330ci, G35, and Accord v6 six speed. :D I probably want something that can do maybe 6.0 seconds realisticaly. As for another car...yup I have extra cars at home...a van and a benz...no 1 else drives except for me and my dad.

[1992 BMW 535i]

Go Here:

http://www.metricmechanic.com/

[Boggie1688]

Can all of those engines fit my engine bay? I want something that will make my car haul ass...I see a m5 engine in there...HEHEHE I want that...its 10k lol....Ok THATS IT I'm saving up....screw lights, body kits, .... already ordered my springs...but once I get those installed no more spending money on anything until I get my engine!

[632 Regal]

ummmm....i dont think any of the 8 cylinders will cause of the brake booster setup, do more research before you order one up.

[Mr Project]

I'd do some serious thinking about what you really want to end up with, and how much you want to spend. Adding a turbo to your current engine can yeild quite a bit more power than even an S38, and for less cost. Obviously that route would be more work and complexity than dropping in a stroked M30, but it depends on what your end goal will be. A 'normal' E34 M30 is a mid-15 second car, at best, so if you really have to 'beat' 330s and G35s, it's going to take some serious engine, or some serious FI.

I'd hate to see you drop $5-8k dropping in a stroked M30 and not be satisfied with it. If you know you want serious (S38 or greater) power, start planning for FI from the get-go, IMO.

And yeah, I wouldn't bother with the V8s, too much $$ and work to make it fit, and then the modification potential is even more limited and $$ than the 6s.

[Boggie1688]

What kinda of I6 or V6 would you guy recommend? I doubt I'll turbo my existing engine....if worst comes to worst and my dreams of swapping engines doesn't come true..I'll get a supercharger. But I really would like a new engine...and if I have to add some force induction to it to make it keep up with the 330s and G35s then I will. But for now...I'm trying to get a base price of what a new engine would cost...and what kind of performance increase I'll get. Any engine recommendations would be good. This is all reserach for now...too see if its actually worth it. If its not worth it...I'll add a few performance parts to my stock engine...then make it look nice. But I really really REALLY want to have a nice looking 525i 1991 that looks sick and can eat the latest cars for brunch. Wanna be damn unique...

[1992 BMW 535i]

These are stroked engines (you can send yours in too to be rebuilt and stroked). They will fit within the engine bay.

[Mr Project]

Well, part of the problem is that a mod that is good for a non-turbo engine might be bad for a turbo engine, so you end up having to start over when you go turbo/supercharged. Example: A stroker rebuild with higher compression would make more power, but would be much more difficult to to FI with.

This is why I suggest planning and deciding now, and then moving in that direction. Saves a lot of time and money.

Obviously the easiest way to go is to stick with the similar BMW I-6 engines. Your M50 (91 is an M50, right?) takes to turbocharging reasonably well, and can make around 400HP at the crank with a carefully-designed FI setup.

An S50 or S52 (US E36 M3 engine) will swap in relatively easily, and you start with about 50 more HP (240), and then it takes to FI pretty well too, with over 400HP being very possible. AFAIK, there are more turbo/supercharger options already set up for this motor than basically any other easy option.

An M30 (the 535 engine) can also be set up for FI, but there are not as many of them running around as the M50- and S50- based motors, so parts can be harder to find, plus it is a low-tech motor, so simple power potential might be a little limited. If you are willing to drop big $$, though, there is a guy in FL that has built at least a couple of 500+HP M30-based (or the alpina derivative) turbo engines.

Now if you want to be really unique, and you're willing to go to great lengths and expense, a LS1 or some other compact and powerful non-BMW engine would be really cool, I think. But you'd be pretty much on your own as far as figuring out how to make that work!

IMO, your best bet might be to do a US E36 M3 engine and tranny, and start looking at FI options for that. Figure $4500-6000 for the engine and tranny, and then getting it installed and blown would be on top of that. 'Cacatfish' on this board just parted out his FI M3-engined E34. Maybe he would have some input on that project.

[bjl4776]

Im thinking of a similar project and was wondering which of these options would be the best choice and provide the most power. The metric mechanic M30 3.9, M5 I6 3.8 (euro version), S50 M3, or a rebuild one my M50. I would plan a turbo for all of these, i am looking to achieve 450 hp, even 500hp if possible. Cost is a concern but i know it can't be too much to get that kind of power. Is this project reasonable and what would be my best choice on a setup. All of this talk got me think of this earlier than i thought. Im workin a replaving my interior and then was goin onto exterior before doin the suspension and finally the power as my current M50 still runs strong, but i keep on gettin that itch for power, hehe.

[Boggie1688]

Well, part of the problem is that a mod that is good for a non-turbo engine might be bad for a turbo engine, so you end up having to start over when you go turbo/supercharged. Example: A stroker rebuild with higher compression would make more power, but would be much more difficult to to FI with.

This is why I suggest planning and deciding now, and then moving in that direction. Saves a lot of time and money.

Obviously the easiest way to go is to stick with the similar BMW I-6 engines. Your M50 (91 is an M50, right?) takes to turbocharging reasonably well, and can make around 400HP at the crank with a carefully-designed FI setup.

An S50 or S52 (US E36 M3 engine) will swap in relatively easily, and you start with about 50 more HP (240), and then it takes to FI pretty well too, with over 400HP being very possible. AFAIK, there are more turbo/supercharger options already set up for this motor than basically any other easy option.

An M30 (the 535 engine) can also be set up for FI, but there are not as many of them running around as the M50- and S50- based motors, so parts can be harder to find, plus it is a low-tech motor, so simple power potential might be a little limited. If you are willing to drop big $$, though, there is a guy in FL that has built at least a couple of 500+HP M30-based (or the alpina derivative) turbo engines.

Now if you want to be really unique, and you're willing to go to great lengths and expense, a LS1 or some other compact and powerful non-BMW engine would be really cool, I think. But you'd be pretty much on your own as far as figuring out how to make that work!

IMO, your best bet might be to do a US E36 M3 engine and tranny, and start looking at FI options for that. Figure $4500-6000 for the engine and tranny, and then getting it installed and blown would be on top of that. 'Cacatfish' on this board just parted out his FI M3-engined E34. Maybe he would have some input on that project.


Thanks for all the info....seems like dropping a S50 motor might be costly...near 8K....if I can drop a turbo into my engine and make near 400 hp I'd be pretty happy....but I can't seem to find any kits out there...Do you happen to know where to get one?

[Brandon J]

The S50 or S52 is the best option. The engine can drop right in. You will need your oil pump and pan. Assuming you want OBDI, you will need the right chip (for S52), computer, MAF, and a few other things. If you have the 5sd manual ('91-'92 525i only), that tranny is the same one used in the e36 M3. No need to swap there. The S52 OBDI should pull around 275hp .

If you are looking into tuning the engine, afterwards, then I would look into Eurosports twin screw supercharger. It yields a flat torque curve and power off idle. No jumpy boost or lag.

I would continue with the mods, as long as they are for the suspension and brakes. Plus, change all the rubber and balljoints that need to be changed. It is always a good idea to make sure the car is up to the task of the new power.


Obviously the easiest way to go is to stick with the similar BMW I-6 engines. Your M50 (91 is an M50, right?) takes to turbocharging reasonably well, and can make around 400HP at the crank with a carefully-designed FI setup.

An S50 or S52 (US E36 M3 engine) will swap in relatively easily, and you start with about 50 more HP (240), and then it takes to FI pretty well too, with over 400HP being very possible. AFAIK, there are more turbo/supercharger options already set up for this motor than basically any other easy option.

IMO, your best bet might be to do a US E36 M3 engine and tranny, and start looking at FI options for that. Figure $4500-6000 for the engine and tranny, and then getting it installed and blown would be on top of that. 'Cacatfish' on this board just parted out his FI M3-engined E34. Maybe he would have some input on that project.

[Boggie1688]

Can you vaguely give e a price on all of that stuff? Just and estimate of the top of your head soo I can get a ballpark figure...Thanks

[Jon K]

haha as much as this will piss people off, LS1 from a Camaro or Corvette and a 6-spd. LS-1 weighs less than the 540i motor, and has more hp. As much as i hate to say it, i think that motor in the E34 would annihilate anything.


sigh, give it up brandon, no one likes chevys ;)

[Jon K]

Can you vaguely give e a price on all of that stuff? Just and estimate of the top of your head soo I can get a ballpark figure...Thanks


$10k...

$5k for the motor and harness (dme, etc)

and another $5k for the labor and parts of all the sh*t that is broken that you don't know about yet ;)