New Hatz/Guzzi under construction.

[Stuart]

He's a few pictures of a bike under construction. They were passed on to me by Fletcher on the recommendation of Dusty (ecorider usa).

Fletchers uncle is building this diesel bike which consists of a Moto Guzzi frame complete with a Hatz motor. That's all I have.

[balboa_71]

That's a nice engine/tranny install, I like it!!!! Wish there was documentation on how and what is needed to mate the tranny/clutch to engine. This it still my biggest issue with this type of adaptation; if a "how to" book was written, it would sell.

Cris

[oilburner]

The Guzzi is like a BMW which is like any automobile with a standard gearbox. In order to adapt a diesel engine to a Guzzi or BMW, the engine needs (1) a flywheel with the Guzzi or BMW clutch assembly bolted to it and (2) an adapter plate (Guzzi) or custom fabricated bell housing (BMW) so that you can attach the motorcycle gearbox to the diesel engine. It's that simple. The *hard* part is determining the location of the bolt holes in the bell housing or adapter plate. The gearbox must line up with the engine crankshaft within a thousandth of an inch or so or you will experience rapid wear and failure of the clutch splines on the gearbox input shaft.

You can see the adapter on the Guzzi in picture mottohatz002rt4.jpg

The main difference between a BMW and a Guzzi is that the bellhousing is part of the gearbox on a Guzzi and part of the engine on a BMW. I suspect the Guzzi adapter is quite a bit easier to fabricate than a BMW. *However*, you are restricted to using the Guzzi flywheel or similar - it must fit inside the gearbox bellhousing. Installation of a starter and ring gear could be tricky on a non-Guzzi flywheel. None of this matters with a BMW gearbox.

Different engines will require slightly different approaches to fabrication but the bottom line is exactly the same - you must have a flywheel and an adapter. No more, no less. Some engines may not be well suited to attachment of a flywheel due to lack of a sufficiently sized bearing on the PTO end to support the weight of the flywheel and clutch assembly. And make sure the crankshaft turns the correct way!

In any case, this is not a job that can be done with a hacksaw and stick welder. Unless you have access to a lathe, milling machine, MIG welder etc. you will need to farm out the work to a machine shop. In my case, I fabricated a bell housing and entrusted the machining of the diesel flywheel and final surfacing of the bell housing to a machine shop. This is what I ended up with:


FYI

Avery

Daihatsu D950 / BMW 5-speed

[balboa_71]

Avery,
Thanks for the write up!! Nice piece of work in the photo.... I understand all the details regarding adaptation and am still amazed it can be done. I've used the famous Bridgeport series 1 knee type milling machine (in one form or another) for 30 years now and would not wish to build an adaptor with it due to lack of table travel and over all problems using that type of mill for precision work. It would (IMHO) take a vertical machining center to get the job done right the first time. Most small shops are limited to series 1 or 2 mills, so this kind of job would be expensive. If one had the blue prints for all stock assemblies (engine pto end, gear box/bellhousing data) it would be easy to layout the adaptor using a simple cad system on a pc (I do this type of work daily). There is still another dimension to all this besides alignment, and that's input spindle of gear box working with clutch friction plate splines and spindle lenghts, etc.. What would be better is using of the shelf items if possible???? Most automotive power plants use some SAE type bellhousing and clutch assembly, next would be finding an automotive gearbox (say off a small pickup or car) and using that instead. Adaptation would be only having to make custom motor mounts and a "U" joint to adapt output axle (where it mates to gear box) to bikes driveshaft. Only thing that comes to mind is needed offset for drive shaft to clear rear wheel. Don't know if this makes a lot of sence, but I'm wondering if parts are out there to reduce the gearbox to engine trickery???
I guess another approach would be to cannablize a diesel ATV for engine and gear box to put in a bike frame......

Cris

[oilburner]

Perhaps I should dispell any myths that some sort of magic is involved in making a bell housing. The diagrams below illustrate how easily I fabricated the bell housing for my Daihatsu D950 shown above. I have photographs of the fabrication process which I can scan and post sometime in the future if there is sufficient interest. This ain't rocket science!

The bell housing is made entirely from 6061 aluminum. An aluminum ring was made by cutting the centre from a solid aluminum billet 12 inches in diameter and 3 inches thick. I did this on my el cheapo Chinese lathe. Flat bars (plates) were cut from flat aluminum stock 3 inches wide X 1/2 inch thick:



1. The flat plates are to be welded onto the sides of the aluminum ring


2. The plates are then cut to shape on a metal bandsaw. The plates for the engine side must be wide enough to cover all the mounting holes on the engine block. The plates and ring are V-grooved prior to welding.


3. This is how the bell housing looked after the plates were welded on. The yellow circle indicates the inside section that will be removed in step 8 to make room for the gearbox. Also shown in yellow are the locations of the four gearbox mounting holes that will be located and drilled later on.


4. The next step was to make a bulge for the starter drive.

5. Next the outside edge of the plates welded to the engine side of the bell housing were trimmed to final dimensions.

6. The bell housing was then centered over the flywheel. The dowel (locating )pin holes and engine mounting holes were marked and drilled on a regular drill press.

7. The dowel (locating) pins were installed.

8. The hole for the gearbox was roughed out, slightly smaller that required.

9. Now comes the tricky part - centering the gearbox and locating the holes for mounting the gearbox. I did this by bolting a Daihatsu factory accessory stub shaft to the flywheel. An empty BMW gearbox was then positioned over the shaft. A push fit bushing was fabricated that slips through the bearing hole in the gearbox and over the stub shaft *if* the gearbox is in perfect alignment. The roughed out hole in the bell housing was carefully filed as required until the bushing pushed into the gearbox and onto the stub shaft without forcing it.

10. With the gearbox in place, the mounting holes were marked.

11. The gearbox mounting holes were drilled and steel thread inserts were installed in the holes.

12. Finally, the bell housing was taken to a machine shop where both sides were milled to the required engine side to gearbox side dimension, this ensuring the sides were parallel.

Final note: Lots of patience and time required - this isn't a one day project, but the result is worth the effort.

FYI

Avery

[balboa_71]

Avery,
Can't get better than this.....super nice work!!! I'd never try to build a bellhousing from any stock only because of of the welding and need to grind mating surfaces parallel after machining/welding. I agree, building up a housing is great, but you really have to trust the folks doing the work and for me, I'd have to indicate it all in afterwards. Anyways, it works, and I take my hat off to you for what you got done!!!!


Regards,
Cris