Author Topic: Turbo M42 Club Racer Hits a Snag... (Read 5782 times)

rob_e30 · « **on:** March 08, 2007, 07:33:55 PM »

Well as some of you are aware, a friend and I are in the process of building a turbo M42 for BMW Club Racing. We started with an 89 325i chassis and have poured a ton of work into the engine development. I looked around for information on dropping an M42 into a 325 body and had trouble finding details.

We'll I've identified a major issue... Although the M42 will bolt to the Getrag 260 it fails to line up properly with the tranny mounts, the tranny appears skewed left to right and rotated slightly, and it sits a few inches short of both the prop shaft as well as the opening for the shifter to pass into the cockpit.

I'm trying to figure out what my options are. I'm kicking myself because I had the tranny that came with the car which I sold for $100. I figured I didn't need it and I paid only $200 for the engine so I was feeling generous.

I'm open to suggestions... if I have to swap in a different tranny which one will bolt up and fit the easiest? Will I have to replace the prop shaft as well?

For some reason, this board NEVER notifies me of subsrcibed threads even though I subscribe and my e-mail is correct. I do get PM's but I'll be checking in as well. If anyone in SoCal would like to see the work so far, I'd love to have you stop by so that I can check out your car and make some measurements! Heck, I'll even provide the beer.

fabe · « **Reply #1 on:** March 09, 2007, 12:22:52 AM »

yes, the gearbox would be moved slightly to the front. That's why the front portion of the propshaft is different for the 4 and 6 cylinder with manual engine..

you would need to source for a correct lenght for the front propshaft. But that's only one of the issue. the shifter linkage would be another issue. Not too sure if you can use the link rods from the M42 gearbox..

Gunni · « **Reply #2 on:** March 09, 2007, 05:05:29 AM »

Can you measure the distance from the middle of the CSB to the back end of the Guibo bushing?
I have alot of driveshafts in my garage and I could check wich one you need.

I wouldn�t mind running a 325i trans in my 318is turbo either.

rob_e30 · « **Reply #3 on:** March 09, 2007, 08:39:24 AM »

Yes, the shift linkage does not work either

and we just installed a brand new UUC race SSK.

Regarding the measurement... by CSB do you mean the Center Shaft Bearing?

Does anyone have a M42 transmission (Getrag 240?) that they could measure from the front edge of the bell housing to the back of the output shaft?

Alpine003 · « **Reply #4 on:** March 09, 2007, 09:12:15 AM »

Quote from: rob_e30;20898

Does anyone have a M42 transmission (Getrag 240?) that they could measure from the front edge of the bell housing to the back of the output shaft?

I might be able to do it this weekend if time permits.

1991 E30 M42 · « **Reply #5 on:** March 09, 2007, 07:10:43 PM »

19 1/16"

rob_e30 · « **Reply #6 on:** March 09, 2007, 07:41:59 PM »

Thanks all. So it looks like the Getrag 260 will work, but I needed the E30 318iS prop shaft and shift linkage. The standard tranny mounts won't work either so I may just shim it with washers and bolt it together. It's a dedicated racing application so noise or vibration are not issues.

nickmpower · « **Reply #7 on:** March 11, 2007, 02:01:52 PM »

have you found out if the m20 starter will work? you FW is not using a spacer right? as soon as you are sure the pinion clears, let me know

nickmpower · « **Reply #8 on:** March 12, 2007, 11:06:39 PM »

rob_e30 · « **Reply #9 on:** March 14, 2007, 11:56:12 AM »

Sorry, like I said, this board NEVER e-mails me threads I'm supposed to be subscribed to. The starter bolted up and I'm wrapping up the plumbing for the oil cooler, turbo oil supply, and coolant lines before I try to crank it.

I also need to wrap up the prop shaft and I expect the center bearing today. I MIGHT be able to try and crank it later tonight.

PM or e-mail me might be more consistent.

rob_e30 · « **Reply #10 on:** March 14, 2007, 09:06:10 PM »

So there appears to be no problem with the pinion. I measured and it looks like there is 1-2mm clearance between the retracted pinion and the flywheel/ring gear. The problem I do have is that the starter, when engaged, spins but does not extend the bendix. This is a very simple install as it's a race dedicated application. Power to the starter from the battery and +12V via a momentary switch to the solenoid. The starter spins (not that fast) but no engagement of the flywheel.

Is there something I'm missing about the starter?

nickmpower · « **Reply #11 on:** March 14, 2007, 09:13:46 PM »

I think there are 3 total wires that need to be connected

rob_e30 · « **Reply #12 on:** March 15, 2007, 11:03:44 AM »

I'm pretty sure that the 3rd wire is the load reduction relay to cut off power to the AC, lights, etc. while you crank the starter. I may try jumpering them to be sure.

rob_e30 · « **Reply #13 on:** March 15, 2007, 12:15:41 PM »

Looks like I have it figured out. I was using the wrong post on the starter.

I have not cranked it, but just bumped the starter a few times and there appear to be no problems with the pinion or ring gear. An M20 starter with an M20 lightened flywheel and no spacers, and a Getrag 260 seem like a good combination (once you get the prop shaft and shifter linkage figured out).

I still have to bolt up the prop shaft, but everything looks good so far (not the first time I've said that though either).

nickmpower · « **Reply #14 on:** March 18, 2007, 02:44:11 PM »

any updates? running yet?