The comprehensive DOHC engine swap thread.

[Addissimo]

what is everybody doing for exhaust?


Anybody think these engines will pass emissions w/o a cat? (non cali of course)

[kylebes1]

I just took mine to a muffler shop, I did grab the e36 "mid pipe" (esction that bolts to the manifolds, but I cut it at the e36 collector before you get back to the CATS. The guy that did mine kinda crapped it out and made the bends to tight. I would suggest finding some with a mandrel bender.

I know in Georgia my car still has to have a cat because it had one originally, and you cannot get away with a "hollow cat" because they will test it at the tail pipe for NOx. The NOx will be higher, noticibally, without a cat. I know i did not smell any thing before i had the cat installed, but I am not sure if it would have passed the NOx test.

[grapedrink]

I just want to say this is a great thread. The best that i have ever seen on the conversion.
I currently have a 92 325i that needs a engine rebuild. It has been my daily driver before the engine finally went and i don't want to rebuild that motor and stick it back into an e36 just because the value of the car is not there. Soooo i picked up a perfect 325es for a really good price. I plan on useing as much stuff from the E36 as possible on this swap. Back at the begening of the year i did a manual trans swap on the e36 so i can understand the dificulty that this may take.
Here is what i have for the swap.

86 325es
92 M50
99 Mz3 trans
96-99 m3 drive shaft
3.91 open E36 dif (probably will change to something around the 3.15 area. With the current setup at 7k RPM my max speed in top gear was 128 :( It has some awsome ecceleration but not top end)
Wire harness etc from the E36

I saw the list of things needed at the begening of the post and i thank you very much. That is what Zio.. wants you to pay $100 for. Thats a rip off if you ask me.
But anyway since i will be useing E36 trans and engine i haven't seen anything about the correct drive shaft for that combo??
Do you know if i switch the engine from a non-vanos to a vanos engine that the wire harness will change?? I am pretty sure that the harness is the same but the ECUs are different. Correct me if i am wrong.
Shifter i can use everything from the E36 correct? Or E30 stuff?

Anyone have a list of the different gear ratios from the Mz3s trans, regular M50 trans, M20 trans etc?

Of course i will have more questions but that should do it for now.

thanks

[kylebes1]

first off congrats on the switch to e30, you will enjoy it!

Since you are starting with non vanos engine you could easily rebuild it as a s50, that is if you go to a VANOS head with s50 parts Talk to StuMc about that he knows the details). As far as I know you will have to change the wiringharness as well as the DME to go to VANOS.

As for the DS. If the transmission you are using is a e36 five speed you should be able to use the 1984-1985 automatic 318i one. You can messure for that later on and see if either of the three you have will work or what you need to do after that.

If you have the M roadster sixspeed and do not mind the added weight then you will have a .81 sixth gear. I do not remmebr what diff the 325es has, but if it is a 3.73 you would probably be happy with it.
your other option is to lighten it up and use the transmission already in the 325es. This way though you have to make a cutom transmission bracket and there are some problems with the shifter that others on this boiard could help you with.
At the moment I have the e36 five speed on my VANOS m50, it was a direct fit along with the shifter carrier and other parts, the only thing is a couple parts you will need to get to add some clearance for the guibo, I found that out the hard way. They are BMW pieces so there is no problem in getting them. I have ORCA so I can send you pictures of almost every part. BTW ORCA is a Rip!

Also you have most all the parts to go five lug, which is a plus and you should do. There is a lot of info on here about that, hell search LukasBMW and half the stuff you find will be about it! :D

good luck with the swap, I should be able to help you with the wiring stuff if you need it, that is if Brew's car turns out ok! :P

[grapedrink]

Kyle thanks for answering my questions and i will be hitting you up on some PMs for some specific info.

A little off topic but here is my BMW story. I used to have a 85 318i with a good motor but someone hit the car on prom night. I sold it to a guy in Utah and he put the engine and transmission in a 86 325es just to get the car going. that was over a year and a half ago. Turns out he was selling the car and the engine was haveing some problems by now so i picked it up for a fare price. I forget his name but he is on the bord somewhere. Anyway i am going to have some major projects with the car. Interior is nice for the swap of my dove gray vaders, 5 lug conversion half way there with my e36 front setup and drivetrane is going to go in the car first off. Enough E36s for me now. Those interiors are so crappy and they are going to be the next lost generation of BMWs (just like the old 320s).

back on topic now.

I also have access to a 94 M50 and still thinking about puting that in insted of the 92 with a fresh rebuild. I have everything for the non vanos swap and i would have to buy the motor and everything else for the vanos. Who knows what i will do??

being a BMW/ Porsche mechanic is nice :)

[Ryan Stewart]

noice!

grapedrink. Why are you installing the S52 tranny? Its heavier and requires the use of the M3 driveshaft.

If possible either use an M20 setup or the M50 driveshaft to save a good deal of weight on those peices and you could use your old shaft and sell the M3 one.

Unless you are planning on going farther. I stuck with the S50 tranny for my S50 because I intend on doing a camswap NEXT summer.

[Ryan Stewart]

The biggest issue so far has been the brake setup I chose. I went with a dual chamber 325ix booster with an E34 M4 25mm master cylinder. The problem is the MC goes a littler farther out into the engine bay (not a LOT because its recessed into the booster but the resevior is forced farther otu by the booster.

The only realistic solution is the E35 remote resevior which has two lines that relocate the resevior back above the booster. Ill get a pic up as soon as the res gets in.

[trent]

Unless you are planning on going farther. I stuck with the S50 tranny for my S50 because I intend on doing a camswap NEXT summer.

A cam swap has nothing to do with transmissions :!:

[kylebes1]

You will have to get the codes Cleared for the DME, I had mine checked because it was funning like crap, and he said there were a bunch of faults and that the DME was running on a default setting.

Also the guy said that any oil off the filter can ruin your AFM! costly to replace.

[kylebes1]

What parts do you need? I'm putting in a BMA order soon, so it'd be nice to get everything at once!

Thanks

Hey, I if I were you I would go with the s50, but that is up to you.

either way here is a breif breakdown:

engine- including wiring harness and intake, ect. ( if the engine came form an automatic car all you have to do is cut the transmission controller plug off, PM on this before you break out the wire cutters)
IF your engine did come from an auto car you will need a Pilot bearing, DO NOT go to Autozone or Advance for this though! The ones they have are the wrong size and they are adimate that they are the correct ones, F them!

Transmission-
e36 five speed, most easiy to use for the swap since the e30 transbracket bolts right up. And you can use most of the shifter parts ( I have a llist of these parts as well). You get a 1:1 fitth, this is good in that you can run a slightly taller diff and actually put about 4 or 5% more power to the road since no gears are involved. (these came in e36 318i and 325 cars 92-95 for sure and the ones after may also be the same up to 99)

e30 m20 Getrag 260, many like this due to its strength, but I don't think anyone is gonna be making 1000hp so it is up to you. Use of this trans requires a custom bracket for the transmission, I am not sure what that intails. Nor do I know anything abou the shifter setup. You get a ~.81 fifth gear.

e36 six speed, if you want the extra strength of the getrag 260, a closer range, other than 6th which is .81 as well. This also requires a custom bracket since the trans extends toward the rear more. As well as adding weight you will have to come up with a custom shifter setup, though the m3 it came from may have a usable setup.

A good step up could be going directly to the e46 transmission if you come across one, I do not know anyhting about using it in the m50 swap though.

Driveshaft-

in my tow door car I am using the m50 engine and the e36 five speed. form the Center support bearing mounting hole to the front edge of the diff flange the distance was 33 inches. fromt he same hole to the rear edge fo the transmission was 26.25 inches. The rear section should be the same for all e30s, I think. The front section measurement includes the Guibo. I used the driveshaft of a 85 318i with an automatic, I was looking at ETK and it shows this car to have a CV jount, not a UV jount, you need the one with a UV jount.

I will be back later

[kylebes1]

getting the e34 oil pan and dipstick are necessary, as well as the sump tube. IF you do use an m50 from the e36 you have to remove the oil baffle as the e34 oil pan has it built in. there is a support for the e36 oil tube that is attached to one of the main bearings. If you opt to remove the bolts and the main cap you have to get new bolts and be sure to get the cap back on the same way it came off. or you can di it the easy way and bend the bracket until it breaks off, I would not attempt to cut it because where do the shavings go?

While you have the pan off make sure you oil pump nut is VERY tight!

To digress a little, what ever flywheel you use you have to match it to the starter.

you need e28 535 engine mounts, the green rubber ones. e36 engine brackets. You can use the e36 power steering pump and all. My e30 hose had a bango fitting on the rack side and a sort of nut typ fitting on the pump side, well the e36 pump requires a bango type. I looked over to my m10 power steering pump and it already had the adapter I needed so I could use the e30 hose I had recently replaced.

IF you have a 89+ car your cooling system will work, if not get a e36 radiator and 89+ surge tank and hook it up.

If you want to stay with a clutch fan you have to use the e30 one, it goes right where the e36 one comes off.

When you buy the engine, make sure they are sending you a complete running engine, includign the AFM as well.

Cannot think of anything else right now, but I do remeber The Euro Depot sells a e30 "kit" for like 2800. They also have low mileage engines.

[blunttech]

Dunno. That IS what I was thinking of doing though. Just a coin sized peice to seal the back off. I cant imagine the groove allowing a slight connection between the two ports causing any troubles.

you shouldnt do it this way. the ports between the cylinders may induce a lean condition in 1 cylinder. machine small cylindrical pieces the same size as the holes and weld them in from the outside so the cylindrical pieces lye flush with the gasket surface. this seals the hole and the passage at the same time and no grinding.
before i did my cams i ran the obd2 headers with the ports open as i didnt know any better. turner instructed me to seal them up when i questioned them on it.

[Ryan Stewart]

Trent I meant going with the slightly beefier tranny since I dont intend to leave the engine anywhere near stock. Even though its heavier it saves me hunting down another on later if I decide to up the juice.

I didnt do the backseal on the manifolds, went ahead and piled a lot on the groove and ground it smooth.

[kylebes1]

anyone using Euro s50 manifolds? They list for like a million new but i would think they are even a step above the already great s/m52 manifolds.

are there any headers out there that would work in the e30?

[Ryan Stewart]

Well I just installed some S52 shorty headers into a 97 SC M3. They would most definately fit in my car. I have more room to the bodywork on the exhaust side than this guy did. There is plenty of clearance to the subframe for the headers but you would still have to modify the downpipes because these bolted up in the exact same place as the stock ones.

The shorties would get you equal lenths but not a whole lot more flow. Straighter ones would be better but we wouldnt have much room to the subframe. Although its not all that bad because they are far more cramped under there than our cars.