Resurrection of a Deutz MAH 914, 1952? Lets see!

[cobbadog]

I just used some red oxide primer onthe tray of our beaver tail truck. Fantastic paint then got most of the tray coated in red high gloss epoxy paint  but  ran out of time before going to this weekends rally.

[sirpedrosa]

Gentles

An afternoon kicking the Deutz, and I could manage to take off limescale with descaling chemical.

Use some straps of rubber to buffer the passage to head, and put head buffering block.

A few pics of the mess. Not all clean but bottom fair clean to remove liner.

After another task.

[sirpedrosa]

Gentles

Finally camshaft came off (SOB). And so has the IP tappet and its guide.

The camshaft has a design flaw. The stud could been conic, or have a dowel or other thing to make solid.

Was a nightmare to withdraw it, because it turned, and the narrow single flat on shaft it's not enough to hold it with a wrench. Just my frustration.

IP tappet and guide came off smodly. Last time stupidity striked, and guide won a dent!!!!!

A few pics with explanation of measures of 'this' camshaft and how to time this engine - IT DOESNT HAS ANY TIMING MARKS.

And the crank handle won a primary coat! Hua!

stay tuned for more updates!

Cheers
VP

[ajaffa1]

Hi VP, looks like you are making good progress. The camshaft is in very good condition for a 70 year old item, I`m guessing the lift on the inlet and exhaust lobes would have been the same so there is 0.1 mm (less than 4 thou) of wear on the exhaust lobe. Not too surprising given that the exhaust valve gets bound up with carbon soot from combustion, it could also be as a result of poor spray lubrication caused by the engine geometry.
The limescale build up does not look to be too bad, they probably used rainwater rather than tap/well water.
Are you going to replace the sleeve or just clean it and reuse it?

Bob

[sirpedrosa]

Bob, Gentles

I think cam is in very good condition.

They used creek water as cooling, therefore there is decades of limescale.

Just clean sleave and see oring condition or replace it to new.

Cheers
VP

[ajaffa1]

Hi VP, if the sleeve is in good condition I would just be replacing the O-ring seal, I would be replacing the seal regardless of it`s condition. When reinstalling the sleeve it can be much easier if you leave it in the deep freeze overnight. You might want to put a couple of witness marks on the block and sleeve before pulling it out, that way if there is wear in the bore it will all be reassembled as it was.

Bob

[cobbadog]

I find it odd that there are no timing marks on the cam or gears. I would hyave marked them myself before disassembly just to make sure all went back together again timed. Good idea for marking the liner before removal,

[sirpedrosa]

Cobba, Bob, Gentles

Yes, liner will have witness mark, and follwing the book timing this engine will be like you can see at pic.

Just a few cents for the rant.

Cheers
VP

[ajaffa1]

Hi VP,  So the two bolt holes need to be vertical with the piston at TDC, be careful not to get it reassembled a tooth out either way, it will be a bugger to start and run like a dog.

Bob

[sirpedrosa]

Bob, Gentles

When you say vertical, you mean those 'screws' have to be parallel to liner (camshaft is perpendicular to piston).

AND DOWEL (my scientific research) MUST BE (because after assembly you canot see intake top lobe) oriented to crankshaft.

And yes, one tooth out of timing can also make piston colide with valve. IM AWARE OF THAT, but nothing like to have gurus nearby. 

German company can made (they have in stock for mah711: https://www.enginedynamics.de/traktoren-ersatzteile/deutz-khd/mah-711/248/ventilfuehrung-deutz-mah711?c=53) valve guides for me... if I order up to 50 pieces. 

But thy can sell blancks too... for customization: https://www.enginedynamics.de/shop/en/blanks/fuehrungsrohlinge-guss/; and I think it will be the best solution. Take a look!

Later I'll put another pic for LEF members comprehend the axles plan of the main and cam.

I'm watching that shed. Nice work.

Cheers
VP

[sirpedrosa]

Gentles,

As promised 2 more pics of timing scheme, and...

The assembly of the camshaft.

Cheers
VP

[sirpedrosa]

a few more pics...

[ajaffa1]

Hi VP, I love that governor mechanism, the Germans have some very skilled engineers and designers, that is a beauty.
A bit worried about the valve guides, 9 euros each as long as you buy 50 is a bit rich. My offer to do the machining stands but you will have to wait till my shed is finished and fully equipped.

Bob

[sirpedrosa]

Bob, Gentles

This mechanism is tricky. There are too many pieces that can fly away inside crankcase.

I like more Lister mechanism, more simple and effective.

The valve guide blanks are 9€ each, and I can buy just one. I SAID, they tell me IF I want they can make the model for this engine, as long as I order at least 50.

But Im going order just blanks.

I need 22*95mm round, and they say it only be available in November, and not centrer drilled. CAPISCI?

To send to you the blanks they will be at the end at gold price. Your offer is priceless but you are around the corner only here! 

Cheers
VP

[cobbadog]

I hjad to make new guides for my McDonald engine and bought a 300mm length of 25mm diameter cast iron. Machined it roughly to OD and then drilled the bore undersize. Gave that to the engine rebuilder who made a final cut on the OD then pressed it into the head then reamed the bore to suit the new valves.
I must say that cast iron is a dream to machine.