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Old 09-18-2011, 05:28 PM   #98
bmwhacker OP
Still on 3 wheels
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Joined: May 2009
Oddometer: 4,460
Since today is my only day off I decided to make another attempt to turn the Zundapp engine again. I removed the cylinder heads and drained the Marvel Oil which has been sitting for a couple of weeks.
I raised the rear wheel off the ground, shifted the transmission into high gear and attempted to turn the engine but to no avail. She is still stuck tight. I made a few pretty brutal attempts at the rear wheel and tapped the piston head with a hardwood dowel hoping to break something loose, but nada.
Wondering if a rod was fouled in the engine I decided to inspect a little deeper.

I decided to drain the crankcase and pull the oil pan to see if any debris was present.
I had visions equivelant to a surgeon opening a terminal cancer patient and immediately closing them back as nothing can be done for them.
I removed the drain plug and a combination of Marvel Oil and ancient motor oil gushed forth.
Removing the pan took some time. There are 14 bolts and some felt a little tight so took my time working them out. All came out OK and threads looked good. The pan lowered itself as the long winded bolts came down. The pan probably weighs 5 lbs. all by itself. The pan had about 1/2 inch of coagulated "spooge" in the bottom which, I guess were the elemental compounds of the broken down oil.

I have seen some nasty oil in my years but never have seen crap like was sitting in the bottom of the oil pan. Not a liquid and not a solid....kind of a "plasma grunge". I should have photographed it before scooping it out but was so covered in the crap I couldn't touch a camera. A couple drops below:

Rumaging through the goo I didn't find anything resembling metal which is good. The oil filter/pickup was coated in the crud so cleaned it somewhat. I doubt if it can ever be used again and will need to be replaced.

I stuck my camera under the open engine a took a couple photos....looks like this rod is where it is supposed to way of knowing if it is welded to the crankshaft.

I cleaned up all the removed parts, carefully cleaned each oil pan bolt and plate which goes with each one, then reinstalled the filter and oil pan. Replaced the cylinder heads and filled each cylinder with Marvel Oil.
So no real progress today in the "free the pistons" department. At least I was able to do an in depth study in the elemental compounds contained in 50 year old motor oil.
I'll continue the soaking process and hope for the best.
From what I saw today, I'm pretty sure the engine will need a complete tear down to inspect everything before it could ever run. If I could only get the damned pistons to move I'd clear the road block in tearing the engine down.

I also possess 3 BMW motorcycles and each one needs attention in some way or another. I picked up a R60/5 last weekend so maybe the BMW motor could get shoe horned into the Zundapp frame (?) if the Zundapp engine is toasted.
I figured that the cost of a total Zundapp rebuild could be a financial catastrophe but I already have a complete gasket set and NOS rings are less than a $100.00.
If I was lucky, all I'd need is a valve grind and a cylinder hone job. I will definately want to remove the rods to check the bearings, which are a roller / cage variety. Those roller bearings are a weak point in the motor. These engines also use a fiber material cam gear but from what I've read, they are pretty tough. Hopefully mine is in one piece.
So again the pistons.....soak....soak.....soak.....
If anyone has any better ideas, I'm all ears.

Living proof you shouldn't play with matches
ABC# 1992

bmwhacker screwed with this post 09-18-2011 at 09:32 PM
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