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M20 Conversion - Auto To Manual


scabzzzz
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All,

 

Im preparing to drop an m20 with 265 transmission from a 90 325i into my car. I've been following this link for guidance, as well as comparing the 6 into 2 Does Go guide.

http://www.toyotadostlari.com/uploads/2002-6silindir.pdf

 

http://1971bmw2002.wordpress.com/m20-swap/

 

 

Ok, a couple of questions for those who have done it. I've read somewhere that the late model 02's with automatic trans have a larger trans tunnel. I know the Getrag 265 is the largest trans of all possible options, and the slave cylinder gets in the way (as well as the 325E bellhousing sensors). Ill be trimming off the ears for the non-existent sensors, but can I get away with heating up and beating the trans tunnel out to fit the trans? Or is there no way around cutting/extending the trans tunnel to accomodate the G265?

 

Another concern: The M20 I have was taken directly out of a running car with trans connected. I shuold be able to drop it in (given it fits the trans tunnel) and not have to worry about modifying anything with the clutch disk/flywheel right? 

 

I appreciate the responses guys and cant wait to start this swap!

-David 

 

PS - If anyone has a manual pedal box they are willing to part with, please let me know.

 

 

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first question, why are you using the early flywheels sensor? you should convert everything to a late model wiring, CPS, 173 ecu. much more efficient.

 

ive heard that alot of manipulation is need to fit the g265, plus its an electronic speed tranny, so you would need to convert to an electric tach.

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The G265 requires the 02 tunnel to be enlarged beyond what a hammer can do. I tried a few times on an auto tunneled 02 to make it fit with out cutting, it's just too tall.

 

PS, I've been doing other things the last 18+ months, but I will finish that damn guide one of these days(probably winter). I'm hoping to be back into making mounts later this year(just got a millermatic 220 and going to get a tig in a month or two), but I still have a lot of stuff to sort out and a job which require 50-60 hours a week.

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first question, why are you using the early flywheels sensor? you should convert everything to a late model wiring, CPS, 173 ecu. much more efficient.

 

ive heard that alot of manipulation is need to fit the g265, plus its an electronic speed tranny, so you would need to convert to an electric tach.

I'm not using the flywheel sensors. The cast of the trans has the "ears" for the sensors that need to be trimmed off on the G265 but they are not being used. I pulled this M20 from a 325i. Sorry for the confusion. But yeah, the electronic speedo is an issue. I'm considering buying a used cluster and just retrofitting a new age electronic speedo, perhaps from VDO. Apparently yuo can modify the original cluster by adding a potentiometer or something. 

 

i thought the 265 didn't fit without cutting up the tunnel to make more room...

Im definitely expecting this to be the case, but wanted to double check...

 

One thing's for sure... the A/T tunnel is WIDE, compared to an M/T, which is nice, but the 265 is a fairly tall tranny. Maybe somebody else will chime in. I'm actually curious about clearance myself.

THANK YOU. Confirmation that the automatic tunnel is different than the standard tunnel.

 

The G265 requires the 02 tunnel to be enlarged beyond what a hammer can do. I tried a few times on an auto tunneled 02 to make it fit with out cutting, it's just too tall.

 

PS, I've been doing other things the last 18+ months, but I will finish that damn guide one of these days(probably winter). I'm hoping to be back into making mounts later this year(just got a millermatic 220 and going to get a tig in a month or two), but I still have a lot of stuff to sort out and a job which require 50-60 hours a week.

Ok, with this being said, how should I approach it? Im planning on using the stock M20 and 02 mounts. I know others use custom mounts, but according to the source link I posted in my original post, custom mounts are not needed. 

 

So does this mean I need to cut into the firewall as well? Will the shifter linkage sit into the mount properly? Where exactly does the transmission hit at that I need to modify?

 

 

Sorry for the late replies guys. Didnt "Follow" the thread. 

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I have an M20 with a 265 tranny out of an 87 325is in my 69 2002 automatic.  No cutting of the tunnel.firewall was needed.  I used a sledge hammer.  I also had to hit the firewall to allow the valve cover to come off the head.  And I cut out an opening in the fire wall to access the coolant hose at the back of the head.  It's very tight back there.

You do not need custom motor mounts if you are talking about the "rubber" part.  But you do need to fab brackets that will bolt to the engine and adapt to the motor mount.

The shifter rod and shift platform will need to be cut, shortened and welded in order to line up with the hole in the tunnel.  That procedure should be done after the engine is in its final location.

I installed a VDO speedo and pulse sensor to read from the allen bolt heads on the diff axle output side.  While the speedo face does not match the rest of the cluster, it works and I don't really mind.  There are other options to make your original speedo work which would take the pulse signal and convert it to a cable drive.  The cost is similar.  Or you can try to find an E21 323i tranny with a cable drive.  They are very expensive if you can find one and in most cases, it does not read correctly unless you have the same diff ratio and tire size as the 323i it came out of.  The pulse sensor method is adjustable.

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I have an M20 with a 265 tranny out of an 87 325is in my 69 2002 automatic.  No cutting of the tunnel.firewall was needed.  I used a sledge hammer.  I also had to hit the firewall to allow the valve cover to come off the head.  And I cut out an opening in the fire wall to access the coolant hose at the back of the head.  It's very tight back there.

You do not need custom motor mounts if you are talking about the "rubber" part.  But you do need to fab brackets that will bolt to the engine and adapt to the motor mount.

The shifter rod and shift platform will need to be cut, shortened and welded in order to line up with the hole in the tunnel.  That procedure should be done after the engine is in its final location.

I installed a VDO speedo and pulse sensor to read from the allen bolt heads on the diff axle output side.  While the speedo face does not match the rest of the cluster, it works and I don't really mind.  There are other options to make your original speedo work which would take the pulse signal and convert it to a cable drive.  The cost is similar.  Or you can try to find an E21 323i tranny with a cable drive.  They are very expensive if you can find one and in most cases, it does not read correctly unless you have the same diff ratio and tire size as the 323i it came out of.  The pulse sensor method is adjustable.

Interesting.... I've not heard or read any of what you're saying about the mounting situation or the tunnel. 

According to this guys experiences ( http://1971bmw2002.wordpress.com/m20-swap/ ), you need "the passenger side 02 mount and the m20 driver side mount". Because of this, it puts the M20 in at a fairly native angle (aside from the fact that the motor sits further back into the tunnel) in comparison to the m10 and allows the use of the original 325i driveshaft without shortening the 2002 unit. At this point, since everything is mating up, I was assuming that the linkage would bolt to the chassis properly. 

 

Why am i getting so much conflicting information on this swap?

 

The speedo is the least of my concerns. This is a toy, not a DD.

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I can only tell you about what I did with my swap.  I will not argue/comment on how others did theirs.

I can not see how the engine brackets from a 2002 would bolt up to an M20 motor or how how an M20 bracket will line up with a 2002 mount and still maintain the native angle of the engine?  If it was that easy and straightforward, why is anyone fabricating mounts for the conversion?

If the M20 driveshaft fits perfectly between the output flange of the transmission and the input flange of the diff, and if the tail end of the shaft actually matches the bolt pattern of the 2002 (or E21) diff, (I think not) I can guarantee you the the center bearing location WILL NOT MATCH.  You will need to weld mounts on the body for your center bearing to attach to.  And if the assumption is that the front half of the 325i shaft can be mated to the rear half of a 2002 shaft... all I can say is, try it and let us know how it turns out.  The reality is that you will need a 325i and a 2002 driveshaft. They will both need to  be cut, welded and balanced to make a hybrid that will fit in your car.

Your assumptions of the shift linkage are incorrect.  The native angle is referring to the rotation of the engine in the car, not it's position forward and back.  The native rotation means that the shift linkage will end up under the shift lever hole, as opposed to being on the left or right of it.  But it ends up being further back and need to be shortened.

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I can only tell you about what I did with my swap.  I will not argue/comment on how others did theirs.

I can not see how the engine brackets from a 2002 would bolt up to an M20 motor or how how an M20 bracket will line up with a 2002 mount and still maintain the native angle of the engine?  If it was that easy and straightforward, why is anyone fabricating mounts for the conversion?

If the M20 driveshaft fits perfectly between the output flange of the transmission and the input flange of the diff, and if the tail end of the shaft actually matches the bolt pattern of the 2002 (or E21) diff, (I think not) I can guarantee you the the center bearing location WILL NOT MATCH.  You will need to weld mounts on the body for your center bearing to attach to.  And if the assumption is that the front half of the 325i shaft can be mated to the rear half of a 2002 shaft... all I can say is, try it and let us know how it turns out.  The reality is that you will need a 325i and a 2002 driveshaft. They will both need to  be cut, welded and balanced to make a hybrid that will fit in your car.

Your assumptions of the shift linkage are incorrect.  The native angle is referring to the rotation of the engine in the car, not it's position forward and back.  The native rotation means that the shift linkage will end up under the shift lever hole, as opposed to being on the left or right of it.  But it ends up being further back and need to be shortened.

Okay. I see what you're saying. The two links I originally posted have 2 different takes on how to get it done. The kid that did the hybrid 02/m20 mount solution and used the stock driveshaft appears to be right in a number of cases. I've seen others confirm that it works. Now, if you make custom mounts and move the engine forward to get it out of the firewall, then I totally agree wtih what you're saying in that the driveshaft will no longer mate up and everything will fall forward a few inches thusly changing the entire scenerio. 

 

I really dont know how this will play out. I'm reading everyones opinions and how they did it and finding the common points and going about this THE CHEAPEST WAY I CAN TO GET A RUNNING AND RELIABLE CAR with the stuff I have at my disposal. Which is basically a running and driving 1990 325i. As far as the driveshaft bolting up the output flange on the trans and the diff; if thats the case, I'll go ahead and swap the E30 diff over too if its possible.

 

And now I will comment on the link you referred to.

 

In the first paragraph, <snip> I also supply conversion parts like motor mounts(currently) and hopefully soon a tranny mount <snip>

Yeah, that guy seems to have all the answers and wants to sell his custom stuff. Some good information in there, but the other resource I posted appears to be a WHOLE LOT easier and simpler.I must say, you are the ONLY person I have read about not needing to cut and modify the transmission tunnel to fit a G265 in there. Literally, the only person.. 

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I cannot explain why it worked for me and not for others.  I just think that there aren't that many auto 2002 that were converted to M20s with a 265..

I suggest you try it yourself.  It's a tedious job to get the drivetrain under the car and seeing where you have contact, then move it out of the way, hammer away and try again.  If you were closer by, I would have you take a look at mine, or I can take close up pictures underneath and send them to you lf that would help.

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Pierre, could you repost this pic with some MS paint circles areound where you banged the tunnel out? I still haven't fully cut my auto tunnel out and would love to simplify the step for those who can't weld and want to do the swap. I made a ~1ft long slit cut on either side of the trans tunnel in the circled red area. It only opened up about an inch on each side,
 
You can use the M20 rubber driver's side mount in the 02, but you need a passenger rubber rectangular mount. The metal portion of the motor mount is custom, the e30 metal mounts mount entirely different.
 
As for the driveshaft. The centerbearing mount on the 02 body needs to be relocated, but the m20 driveshaft is the correct length and has a slip coupling in the middle so it's much easier to remove.
 
Cheapest way possible is how I was going about it, but you need to be able to weld. WIth a donor 325i, you have almost everything you need.
 
E30 diff will not fit. There are many threads on that. You can make it work though,
1. Clean/simple = Buy an 02haus modified subframe/stubshaft axle kit and it will bolt on under the car
2. Cheap/effort = Modify your own subframe and put the inner tripods off e30 stub shafts onto your 02 stub shafts. Get an e36 twin ear diff cover, then cut/fab a diff mount for the body(you'll have to raise the trunk floor about 1.5")
 
I'm also the guy in the 1971 link. For a while I was jobless, so the parts were some income. I don't really care anymore, between work and wanting to have time for my car/home projects/bike riding it's really not worth my time(hence why I haven't made any in long time). No one had made the mounts in a long time and I think it's an awesome swap, so decided to do it. I'm planning on making them again eventually.

 

I'll have to figure out how to upload pics later.

1969_BMW_2002_Race_Car_Interior_1.jpg

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I cannot explain why it worked for me and not for others.  I just think that there aren't that many auto 2002 that were converted to M20s with a 265..

I suggest you try it yourself.  It's a tedious job to get the drivetrain under the car and seeing where you have contact, then move it out of the way, hammer away and try again.  If you were closer by, I would have you take a look at mine, or I can take close up pictures underneath and send them to you lf that would help.

Yeah man, that would be great! Anything to elaborate on this issue would be good on this forum considering this board is really the only place to find this type of information documented. You could be right though, I'd love to see some pictures. Any pictures to elaborate on your mounts, angle it sits in the car, just anything would be extremely helpful in planning. I'll be using my brother in laws shop on Sunday's so anything I can do to prepare now will be saved time later. 

 

Thanks Pierre!

 

Also, thanks for the reply Manimal! 

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