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Old 12-21-2011, 12:13 PM
OM616 OM616 is offline
10mm MW
Join Date: Sep 2008
Location: Michigan
Posts: 711
Originally Posted by GGR View Post
According to EPC, that bell housing will fit both M112 V6 and M113 V8. It will bolt on the transmission housing p/n 140 271 26 01 found on various transmissions mated among others to the M112 V6, M113 and M119 V8s and M120 V12 with same or different bell housings.

The conclusion is that the same adaptor plate between the manual trans and the auto bell housing will work for the M112, M113, M119 and M120 engines, and even for the M117 engine by modifying one hole of the M119 bellhousing found on the W210 E420.

If on top of that the same plate can be made to accomodate both the Getrag and the Tremec manual transmissions, the same plate design will open the door to quite a number of interesting combinations and will target a rather large market.

I have also noted the following:

the washer bolting on the follower and the crankshaft p/n is 116 032 05 76 and is common to the M116, M117 M119 and M120 engines. I also noted that the follower is common the the M117, M119 and M120 engines. Ring gears are different, but as they bolt on the same follower their bolt pattern is the same.

I know for a fact that the M116 manual flywheel and 240mm clutch assy bolt on the M117, but its outer diameter is bigger than the alloy blocks. One solution , as mentioned by Pagodino here: is to machine down the diameter of the M116 flywheel until it matches the diameter of the required ring gear. This machined flywheel would fit the M117, 119 and 120 engines. It can also accomodate a BMW M3/M5 240mm clutch disk which would in turn accept the Getrag trans input shaft.

Let's sum up:
- One common adaptor plate and throwout mechanism for M117 119 and 120 engines do adapt a Getrag 265 to their respective bell housings;
- One machined M116 manual flywheel to accomodate the M117 119 and 120 ring gears;
- one BMW M5 clutch disc

and we shouldn't be too far form a nice conversion kit.

For the M112 and M113 engines, I noted that one version of the M112 came with a manual transmission. But the ref of the crankshaft washer is different, do I don't know if the crankshafts share the same bolt pattern with M117 119 120 engines.
I wanted to condense these two posts and bring them up again as this is the best way to go.

After thinking about using a housing from a one piece auto trans, I have put that into the last resort file as the housing is not designed to transfer the loads via the pump bolts like the two piece auto housings are. It sounds line the M119 converter housing can be moded to fit on the M117 block, and the M116 manual flywheel can be modded to fit on all the engines of interest. If the M116 flywheel is not available for less than it can be made on a "as needed" volume, than they can be reproduced, which would allow for some fine tuning distance fitment.

Regarding transmissions, manual transmissions with a removable bell housing is first choose and almost a must, an adaptor plate can be made to bolt the trans to a modded converter housing in a very clean manner. The Getrag 265 is an overdrive trans, and it has a long, 10 spline input shaft, which makes it a very good candidate for a transplant, as it is easer to space the trans back, than to try to stretch the input shaft, or move the flywheel back. Also the T-5 and possibly T-56 would be options, given the input shaft is long enough.

Manual Transmissions with one piece bell housings are not a good choice for an engine that does not have a trans adaptor plate like the inline engines use. When a plate is used, a custom one can be made that sets the trans set back to accommodate the flywheel and clutch depth. If the block is flush with the clutch surface of the flywheel, then a spacer plate will most likely space the trans back too far so the input shaft does not engage the clutch and pilot bearing.

One method to over come this problem is to cut down the trans bell housing and weld on an adaptor plate that will bolt to a moded converter housing. A second way to address the problem is to make a custom flywheel that sticks out farther, but this moves the rotating mass farther out on the crankshaft and that can cause problems at high RPMs, and adds weight farther out, putting additional loads on the crank.

I have not seen the M116 Flywheel, nor any engine blocks or trans plates, other than the OM61X and OM60X plates. I have an OM617 auto flywheel that I can measure the dia and get a quote on the material to make a manual one. My machines will handle the gob, it will come down to price. There will not be enough volume to warrant having a CNC machine program and tooling generated.

I have a M112/113 converter housing, witch is perfect for a manual bell housing as it is very strong an has lots of room for a yoke, the depth matched the 265 housings depth as well.

I have a BMW 6-speed, (has a one piece housing) and the end of input shaft is flush with the mounting face of the trans which means the flywheel of the engine will need to stick out of the block quite a bit to allow for a spacer plate to be used, other wise, the trans will have to be cut down and an adaptor plate welded to it. I am good with that, lots of surface area to weld, but it is not as clean as a bolt on bell housing trans would be.

There are now two members who are putting in on different projects that share some commonalities, so lets get a plan of attack that addresses the common aspects first and progress from there.

The Flywheel and clutch set seems to be a common and very important part for all as the crank bolt pattern seems to be the same for the engines. I need to get a material quote, and either measure up a M116 Manual flywheel, or if someone as a print of it that would work too, as I want to be able to intelligently quote the job, I do not like surprises.

What does every one think?


I just measured the OM617 auto flywheel I have and it is about 11 3/4 inches in dia. I got a price on some 4140-HT, 12 inch dia X 2 inches thick. To make a traditional manual flywheel like a SBC uses, with in the 12" OD X 2" thickness, would quote in around $1100.00 (Note: this does not include the ring gear, however one could be robbed from an auto wheel), (would set up to use a BMW M5 Disk and Pressure Plate)

I had them quote three pieces, and the price per piece did drop a touch, and if I could spread the time cost to make the tooling and the set up for each process over at least three wheels, that would help the cost per piece as well.

If the M117, 119, 120 flywheels are less than 12" dia, and I had orders for at least three, and there was nothing special about the design of the wheel, I could make them for the general public at $950.00 ea. This is without a starter Ring Gear, however, if I was sent an auto flywheel, I would remove the rear and install it on the new flywheel at no charge.

I will make a private arrangement with the gentleman that has the original M116 flywheel to use as a model, as they are rare, he would be risking it in the shipping process, and he is being generous with his contribution.

I have a part number for a converter housing for the M119, it is: A 210 271 11 01 I have a price of $400.00 ea written down, but not sure where I got it from.

After seeing how beefy the M112/113 converter housing is, I am confident that I can mod the M119 converter housing to mate to the M117 block.

Last edited by OM616; 12-21-2011 at 02:10 PM.
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