DKW vintage 250cc motorcycle - Shortblock dismantling

[FrankenMech]

Just like the foil and vinegar must have a complete circuit, metal to metal contact, the foil headwrap must be grounded also.

[motu]

No indicators and stop lights on the 850 ?

[Lucass2T]

This cilinder has a strange port layout, its kinda rotated or something. Theres not much room for extra ports either, the studs are very close to the bore. The exhaust port is small and completely square which i hope i can do something about without uncovering it at TDC.

But first im gonna give it along with some other parts and electrolysis treatment to remove the rust. Then i´ll drop it off at a machine shop to have it bored to spec to the oversized piston that came with the bike.

[jackrides]

That port in the 5th pic is really strange. If the dip doesn't take the outside down to bare metal, Protect the gasket surfaces and have the head and cyl sand or bead blasted. Can't wait to see progress!

[Lucass2T]

Today i bought a used shortblock. It has yet to come in the mail so no pics yet. Last week a friend bored and honed the jug to accept the oversized piston that came in the box of parts.

Im only gonna use the crankshaft from the shortblock since thats the last important part im missing...apart from gaskets, cables, tires and all that sort of generic stuff.

I need to check port timings and see where some upgrades can be made. Maybe build a pipe to suit higher rpms?

[Lucass2T]

Not too much talk, mostly pictures. Nothing too exciting, just dismantling an old engine.

Bought a shortblock from a guy from the other side of the country. It weighed 60lbs (even without the massive cast iron lump of a cylinder), heavy AF! I only need the crank but I already noticed I also needs a bunch of bits and pieces I forgot about but this motor luckily has! I made a deal with the guy to include a front axle, didn't have that yet.







So yeah, nothing really interesting there, just an old engine.
The next day I went to the friend who keeps my bike and helps me restoring it. His dad bored and honed the jug and that revealed a nice susprise...not!


I want to keep this cylinder. I don't want to buy another one and I think this one is salvageable. The crack is in the bottom part of the skirt which kinda is a bummer. On the power stroke the bottom part is stressed most by the piston. I think I'll just drill a small hole at the end of the crack to prevent it from going any further. I pretty sure it won't do too much harm after thats done.

[Lucass2T]

Did some work today on the motor. Drilled a hole in the skirt to prevent it from cracking any further, removed the rotor from the crank and removed the clutch basket.



I'll have to bevel the edges though








Next up is to take the cases apart. I'll have to buy a gasket set and bearings and seals. Luckily Auto Union did an excellent job in documenting EVERYTHING back in the days. Every part is documented, identifyable and even still in production in Germany. I don't live that far from the border and I know this DKW specialist about 2 hrs drive from my house who has like EVERY single part from this bike still new in stock!

[milly]

Nice build thread and great that you can get all the parts still

[Lucass2T]

Ordered €300 worth of parts today, all kinds of bits and pieces which i know i'll need. Probably need to do a second parts run afterwards for stuff imissed.

Ordered from Germany since theres a huge constant supply of newly produced parts. Literally everything is still available and produced new, apart from frames, tanks and fenders. Thats the stuff i already have and is still in reasonable shape.

Aparently theres also a very big parts storage in holland somewhere in the north. But to be able to make use of that i'll have to subscribe to the Dutch DKW club which costs me about €50 yearly. Don't really feel like paying that money just for subscribing. Dont really need anything else but parts since DKW did a really good job in putting every bit of info and data in catalogs, registers and what not. And everything is available online for free if you do some research.

Anyway, Germany is great place to order parts and shipping from any part of Germany is €25, thats still reasonable i think.