Trying to find answers on which swap to go with

[Helltime]

My e30 leaks everything from everywhere (engine and trans), 201k miles (when the odometer broke years ago) and I am wanting to get it ready for full size road course. I bought this car a couple years ago, suspension is good, brakes are good and body is 100% rust free. I have been researching and going over this in my head off and on since the bought the car almost 2 years ago. Which swap is right for me?
I have a pretty good mechanical background. However I do not have access to a welder nor do I feel my welding skills are all that great. With that being said,
What engine swaps can you do on an e30 325i that require NO welding or fabrication (as in any "special" part can be bought online and bolted on, I would not be required to weld or fabricate anything other than exhaust).
The swaps I have read into
M30B35 (been looking for one of those locally for a while)
M50
5.0 V8 ford engine (which I am sure is out, looks like some fabrication and welding is required).
Any others I should consider? Any of the ones listed require fabrication/welding? I am not looking for insane power, but I want more than my N/A M20b25 has to offer.

[wildstoats]

I think it depends on what you want to do with the car. You said road course but do you mean just HPDE / open track days or eventually getting into competitive stuff? That could help narrow your decision down somewhat.

[Helltime]

I think it depends on what you want to do with the car. You said road course but do you mean just HPDE / open track days or eventually getting into competitive stuff? That could help narrow your decision down somewhat.

HPDE/open track days. I have never been on a Fullsize road course but I really don't care about being competitive to the point of having to class the car. Even the auto-x events I go to are just for fun (usually on a smaller road course,less than a mile, no cones), no real classifications and you are just out having fun trying to best your own time each run. I don't do SCCA or anything.

[wildstoats]

I don't think you can go wrong then. Whatever puts the biggest smile on your face :). I don't have any experience with 24v swaps but I really enjoy my m30. Most US spec m30s aren't anything hair-raising, 180-200hp crank with beefy torque curves. You could always build a euro-spec HC engine if that tickles your fancy but if you are looking for cost effective power turbo is the way to go. I would assume the 24v engines would have the advantage if you want to stay NA.

[CorvallisBMW]

If you're really in to HPDE/Track days, 24V is your best bet. M30s are great for street cruising because of the big midrange torque, but they really run out of breath at high RPMs.... unless you go turbo ;)

[Helltime]

If you're really in to HPDE/Track days, 24V is your best bet. M30s are great for street cruising because of the big midrange torque, but they really run out of breath at high RPMs.... unless you go turbo ;)

I make it to 3 or 4 small auto-x track events a year and want to make it to atleast 1 or 2 full size track events a year. Other than that my 135i and e30 split the summer time driving duties. I enjoy engines that pull to red line, but also really wish I had something with low end grunt too.
I am looking for something fun with no fabrication/welding required that is an improvement in power to my m20b25. wiring doesn't bother me. Also i want to keep A/C and power steering (if that makes a difference on which swap to go with).

[CorvallisBMW]

m30 drops straight in, you can keep the wiring harness, A/C, and PS from your m20b25. But it's heavy and has very little top end. 24V is a lot more fun on the track, but slightly more difficult to swap in and has less low-end pull.

[marshallnoise]

I would vote for m30 with a smallish, quick spooling turbo. A 5.0 is the same issue. Gobs of torque but runs out of gas before 6K unless you slap some nice heads on it with a good cam. I will eventually do HDPE/open track stuff too.

[Helltime]

I would vote for m30 with a smallish, quick spooling turbo. A 5.0 is the same issue. Gobs of torque but runs out of gas before 6K unless you slap some nice heads on it with a good cam. I will eventually do HDPE/open track stuff too.

before I went euro, I played with foxbody mustangs, which is why the 5.0 ford has some appeal to me, i know those engines and T-5 transmissions like the back of my hand.
Not looking to do turbo, actually wanting a NA build (been playing with turbo cars non-stop since i graduated highschool in 2009).

[PiercedE30]

I've had a 24v and I'm currently building an M30. M30's will make gobs of power and torque, even naturally aspirated. Head over to mye28.com and check out some of the builds over there and look at the dyno sheets. Fully built, high compression M30's will usually range from 250 - 325, on average..... But with torque out the ass.

[totheredline]

The whole M30 "running out of breath" at higher RPM can be remedied with a cam. Theres no getting away from the 2v head but a cam with some overlap and duration will help stretch the powerband out to the upper RPM ranges. Im hoping to make peak power around 6500rpm and rev it out to 7k with my build. Should be fun with a 3.73.

[Doughnut]

It's pretty biased towards the m30 in this section, and I'm no different.

Dropping the clutch in an m30 powered e30 is something special. M30's are a cost effective solution if you want more horsepower and are one or the cheapest "bang for your buck" swaps!

Just like the 24v swaps there is plenty of write ups and support if you want to swap the m30 in, you can buy brackets for either the b34 or b35 and no welding required.

[marshallnoise]

If money was no object, I would do LSx in a heart beat. But as stated in the great post above, m30 is hard to beat.