1990 - 24v swap

[mjweimer]

Aluminum block M52 is the best. You will love it. Im excited to see more people starting to swap these in. Im not sure why its taken so long. Its a wonderful setup, I love mine.

I think it should be a great combo for a nice driver that is quick, reliable and fun.

These alu M52's are harder to find but now that the Z3's are getting older they are more common in the yards. Most salvage places don't value them any different than a normal iron block engine.


MJ

[91tii]

That interior is awesome!

The light weight of the aluminum block should make for a super fun car, 318 balance with 24v power!

[mjweimer]

This car loves to challenge me. As I wrote above, I pulled the engine by lifting the car off of the whole front subframe assy in one piece. Straightforward.

However....when I attempted to put the subframe back into the chassis to make it a roller - it would not fit. The car had been wrecked so nothing is out of the question but there are no signs of damage or repair to either of the frame rails. Hmm...no matter what tricks I pulled, the dowels on the rear most mounting holes would not line up and slip into the chassis. Wonderful. I played around with it for a while making sure it was level, etc, etc no dice.

A couple of weeks ago I got my hands on a used subframe (Hi Bobbie!) to modify for the build so I checked it for fit - fit fine (thankfully...) so the grinder and drill came out to remove the dowels and enlarged all the holes to 13mm.

It fits now and will work fine for rolling the car around but this whole exercise ate through too many hours on Saturday. Too much fun. The subframe must have been slightly bent and "sprung" once removed from the chassis.

Other than that, torched out a broken stud in one of the the M52 exhaust manifolds and put together the latest of many parts lists.

BTW I can't recommend these guys enough for new hardware as well as metric coolant/fuel/vacuum hoses.

https://www.belmetric.com/

MJ

[2mAn]

I think it should be a great combo for a nice driver that is quick, reliable and fun.

These alu M52's are harder to find but now that the Z3's are getting older they are more common in the yards. Most salvage places don't value them any different than a normal iron block engine.


MJ

My previous E30 aka the aluminum monster was a '84 318 with a fully rebuilt aluM52 + S52 cams. It was a daily drive in Los Angeles and I put 36k in 18 months. Rock solid setup that made good MPG and 225whp. Eventually it became a racecar and then ultimately sold. I miss it all the time.

Im surprised the headbolts werent an issue, I had a headache in that arena even with the timeserts on the first go-around, but eventually when it was done it was "done"

I fight the urge to look for another 97-98 Z3, in fact I was looking at a few earlier. salvage titled Z3s with a little over 100k going for ~$3000. Tempting to buy and part, but Im really leaning towards either staying with the M20 or something a little wilder in the power/weight dept

[M-technik-3]

Great build shame you did not keep the rear subframe but assume it was because it was mangled beyond use.

[mjweimer]

My previous E30 aka the aluminum monster was a '84 318 with a fully rebuilt aluM52 + S52 cams. It was a daily drive in Los Angeles and I put 36k in 18 months. Rock solid setup that made good MPG and 225whp. Eventually it became a racecar and then ultimately sold. I miss it all the time.

Im surprised the headbolts werent an issue, I had a headache in that arena even with the timeserts on the first go-around, but eventually when it was done it was "done"

I fight the urge to look for another 97-98 Z3, in fact I was looking at a few earlier. salvage titled Z3s with a little over 100k going for ~$3000. Tempting to buy and part, but Im really leaning towards either staying with the M20 or something a little wilder in the power/weight dept

Very cool - that is a strong number from an M52. The fact that you put the miles on it with no issue just reinforces my thoughts.

I was worried about the headbolts too and was prepared for the worst but it worked out OK.

My Z3 had 114k and was purchased for the price of a Z3 steering rack. No one wanted the car for salvage because it was essentially worthless - everything a yard wants to sell was damaged. I hopefully got lucky but it has yet to run....

S54 swap is nice power to weight....

Great build shame you did not keep the rear subframe but assume it was because it was mangled beyond use.

Rear subframe was mangled. It looked like the car slid into a curb on the driverside rear and initiated the rollover. The RS trailing arm/wheel were one with the chassis and had to be cut out.


MJ

[2mAn]

S54 swap is nice power to weight....

MJ

Im more about weight & balance than all out power. Im actually not a fan of the S54 because of the huge weight penalty over the front wheels.

[mjweimer]

Im more about weight & balance than all out power. Im actually not a fan of the S54 because of the huge weight penalty over the front wheels.

That's a fair statement. Nothing wrong with an M20 and quite frankly the cars are plenty fun stock with a few light suspension mods. Back in 2004 I owned a gray market '86 325i with the higher compression engine and the factory tune for high octane fuel It was noticeably stronger than a US car. It also helped that it weighed less due to less options (crank windows but power sunroof, and very little sound deadening among other weirdness).

Here's a pic:




The all around best E30 daily I have owned was an '88 325iS - stock with the exception of a Dinan chip and stock M3 springs/bars, Bilstein sports and Euroweaves. Put a lot of miles on that one.


MJ

[2mAn]

Here's a pic:



The all around best E30 daily I have owned was an '88 325iS - stock with the exception of a Dinan chip and stock M3 springs/bars, Bilstein sports and Euroweaves. Put a lot of miles on that one.


MJ

Thats a good looking car!

My 84 was also very base, essentially manual everything (windows, sunroof, door locks, etc) It weighed in at 2450 as a full loaded 24v daily driver with a 12" lukebox in it. Got it down to 2300 as a half stripped, roll bar equipped car. Still had a lot of weight to drop.

Im back to a 88 325i that will be the daily so even though its simply a chipped M20, I still added j-stock suspension just because haha

Im excited to see this wreck get completed, keep at it. Are you keeping power steering, and A/C?

[mjweimer]

Thats a good looking car!

My 84 was also very base, essentially manual everything (windows, sunroof, door locks, etc) It weighed in at 2450 as a full loaded 24v daily driver with a 12" lukebox in it. Got it down to 2300 as a half stripped, roll bar equipped car. Still had a lot of weight to drop.

Im back to a 88 325i that will be the daily so even though its simply a chipped M20, I still added j-stock suspension just because haha

Im excited to see this wreck get completed, keep at it. Are you keeping power steering, and A/C?

I probably should have never sold that Euro car but no regrets. I do wonder where it is today and if it is still in great shape.

I've never run a true J-stock suspension but I do plan to run Billie Sports and H&R sports on the wreck along with E30 M3 bars (properly mounted to the strut housings in front). I have not run a set-up like this since my '87 iS years ago and it will be interesting to see how it feels compared to how I remember it.

Yes the plan is to keep power steering and run A/C. Will be using the Z3 2.8 rack and converting to R134A with parallel flow condenser and associated parts. I kept the compressor and lines from the M52 so hopefully the local hose shop can merge the lines when the time comes.


MJ

[wworm]

These alu M52's are harder to find but now that the Z3's are getting older they are more common in the yards. Most salvage places don't value them any different than a normal iron block engine.


MJ

I’m jealous of your junkyards! I have yet to see a shred of an alu block m52 existing around my area.



Sent from my iPhone using Tapatalk

[kid325e]

Cool build! Are you doing all of this in your garage or work? Your workplace looks like a cool place to build!

[mjweimer]

Cool build! Are you doing all of this in your garage or work? Your workplace looks like a cool place to build!

I am doing all of this in my garage. Saved up for years to finally build a shop worthy of doing real work. I spent many years working out on the driveway and now am lucky and spoiled.


MJ

[mjweimer]

Got the used spare front subframe blasted in preparation for welding in reinforcements and got to work.



My plan is to use the stock M52 exhaust manifolds as well as the stock Z3 2.8 downpipes/center section (which is a 2 into 1 merge prior to the converter).

Most folks mod the front bank downpipe to go around the subframe but I decided to go a different route and modify the subframe. Since the engine is on a stand I mocked up the exhaust to the engine.

Here is a shot of how far away the flanges are from mating up with no mods.




I took several measurements and notched the subframe for clearance.




Obviously the notch needed to be filled...so took some 14ga sheet and bent it up on the "beater bag". This was my first time using a bag to form sheet metal and it was pretty interesting - you can do a lot with simple tools.




Also made a plate to reinforce the the area below the notch as well as front swaybar tab reinforcement plates.




Welded up the swaybar and engine mount reinforcements






Then the notch filler and extra reinforcement.




I am a fairly inexperienced welder and had a few minor problems but overall it turned out pretty good. Need to get it out to powdercoat after the holidays and then this piece of the build will be done.

[ZekeTheSneak]

I wish I did this to my subframe. It's so trivial but would help immensely.