The comprehensive DOHC engine swap thread.

[87-325ic]

Finally.. i finished reading this...

a few questions now.. and many more will come. dont worry about that.


1.) Using an 95 s50b30, with the ZF tranny, and stock e30 325i transmission crossbrace-mount.. Which tranny mounts do i use?
2.) ill have to use the e30m3 driveshaft, is there another option, and which models can i use the Diff's from.. im looking for a 3.25 i guess.

3.) for all the c101 diagram stuff... Which side are the colors referenced to?
e30 chassis side and the e36 engine side?
i plan to make an "adapter" for this, from the 325es engine harness side and the e36 chassis side of the connection.. so i dont have to cut either of the important harnesses.

last. 4.) I plan to use the porsche 924/944 booster to avoid fabrication/ welding/ rethreading.. do i re-use teh stock MC with this?
i know the 320i uses the stock cylinder right? is this the 4-cylinder m10 or 6 cylinder m20b20 cars? my local junkyards have Tons of 320s.. just all m10'd


thanks for all this help..
and yes. this post should be summarized.

[bimerok]

Finally.. i finished reading this...

a few questions now.. and many more will come. dont worry about that.


1.) Using an 95 s50b30, with the ZF tranny, and stock e30 325i transmission crossbrace-mount.. Which tranny mounts do i use?
2.) ill have to use the e30m3 driveshaft, is there another option, and which models can i use the Diff's from.. im looking for a 3.25 i guess.

3.) for all the c101 diagram stuff... Which side are the colors referenced to?
e30 chassis side and the e36 engine side?
i plan to make an "adapter" for this, from the 325es engine harness side and the e36 chassis side of the connection.. so i dont have to cut either of the important harnesses.

last. 4.) I plan to use the porsche 924/944 booster to avoid fabrication/ welding/ rethreading.. do i re-use teh stock MC with this?
i know the 320i uses the stock cylinder right? is this the 4-cylinder m10 or 6 cylinder m20b20 cars? my local junkyards have Tons of 320s.. just all m10'd


thanks for all this help..
and yes. this post should be summarized.

1.) Use the stock e36 M3 tranny mounts P/N: 22-31-6-771-219 ~$10 each.

2.) 96 328 manual drive shaft (models that are without CV Join) 3 bolts on front flange and 4 bolts on the back. Not 100% sure but I think P/N is: 26-11-1-227-283. You are better off getting e36 Driveshaft as e30 drive shaft bolt holes are smaller in diameter then Flex Disk and transmission output shaft holes and trust me you don't want that. (Not sure about the Diff. I'm using my stock diff. I have 91 325i with LSD)

3.) Yes C101 Chasis side and x20 Engine side. (I was looking through a lot of charts on this and other forums and none matched 100% to my colors, so I ended up spending about 3-4 hours reading through e30 and e36 diagrams to figure out for my self. What I found out is that a lot of times people were right on the wire, they just took the color from the other side of the connection. I recommend you reading through these diagrams and figuring it our for your self. It is actually not difficult. Trust me, I have never done it before and it only took me 3-4 hours for both sides)

Very smart Idea to make an adapter. I did the same thing so I didn't have to cut either harness.

4.) I used 320 booster. Had a friend do the welding though. I cut the extra length off a 320 booster then cut the thread part from the stock 325 booster and he welded it together - no rethreading! Oh and yes, stock 325 MC.


btw if you are on the junck yard - make sure you get couple of extra c101 and x20 connector as some models don't always have the pins you need (some are blanks). I found one from 90 525 and every single pin in c101 was used so I took that for my adapter.

[87-325ic]

the "wedophones" link to the very helpful ETMs seems to not have the 95 m3 engine wiring diagram..

if anyone cares to help with the wiring of the 95 s50b30 into an 86/87 Eta.. that is the only thing im worried about holding things up..

[bimerok]

the "wedophones" link to the very helpful ETMs seems to not have the 95 m3 engine wiring diagram..

if anyone cares to help with the wiring of the 95 s50b30 into an 86/87 Eta.. that is the only thing im worried about holding things up..

Its there. Look for 1995 BMW 318i-s-c - 320i - 325i-s-c Electrical Troubleshooting Manual.pdf It has M3 info inside.

You're welcome!;)

[nholm325e]

I used the 320 brake booster, but i couldnt "dye" down the brake booster shaft thin enough to match the same size/pitch as the stock E30 brake fork, so i just tapped the brake fork out a little and meet "half way"

[87-325ic]

Thanks above, i didnt open the file, just saw no specific M3 one for 95.

For the 320 booster, it seems the best thing to do is to cut off the rod, and weld on the e30 one at the right length.

[nholm325e]

i didnt want to take the risk of having all that heat that close to the brake booster

[bimerok]

i didnt want to take the risk of having all that heat that close to the brake booster

water is your friend.

[Mike B.]

4.) I plan to use the porsche 924/944 booster to avoid fabrication/ welding/ rethreading.. do i re-use teh stock MC with this?
i know the 320i uses the stock cylinder right? is this the 4-cylinder m10 or 6 cylinder m20b20 cars? my local junkyards have Tons of 320s.. just all m10'd


thanks for all this help..
and yes. this post should be summarized.

Yes, you can use the stock M/C with the 924/944 boosters.

[87-325ic]

Yes, you can use the stock M/C with the 924/944 boosters.

perfect. you are the only one who consistently pushed this idea.

why is everyone else still recommending the 320i booster? even though this porsche one is "Completely" bolt-in.

is there a difference in braking feel?


thanks for the help.

[mattdk318i]

now that ive actually dove into this swap fully. Ive realized everything is pretty easy. We were able to make a trans mount within 15 minutes. Having a welder and the skill is something i take for granted, But nonetheless it was pretty straight foward.
Now that everything has been given a priority level, Im onto the shifter.
Im using a 260 on a M50 engine. So i have the 10 degree issue.

Can someone post pictures of their actual selector rod modification and shifting linkage?

[FredK]

Well the 944 booster still needs to be threaded around 3/4" or so. I used a 944 booster in a swap that I just sold. The braking feel was pretty good, just a little more effort than usual, but a hard stab at the brakes and you could lock the brakes up. I just reused my stock Girling MC.

[mattdk318i]

Shift assembly modification went smoothly with the help of Swapjunkie(jeff). He engineered and i welded. Beats the hell of out simply bending the shifting linkage. The shifter feels like it did when the M20 was in there.

Ill post pics for people that are interested, Can possibly fab one too if you pay accordingly

[87-325ic]

did you cut twist and re-weld the shifting selector rod? seems like the most logical.

[windsor318is]

i have a question, can i swap in a 3.2 and keep it running obdII in my e30? and without having the key and ews from a donor car??