Another R80gls build, just slower

[Ghilli]

Originally Posted by goatroper

You know about the thrust washers on the crank, yes?

Aah yes, thanks, but I almost just took it apart before I accidentally read about it.

I took a few spacers the same thickness as the ring gear and screwed back the original bolts, this keeps the front and back clear without the worries of the thrust washers slipping out. But to put the spacers in, I had to block the crank from the front.

[Ghilli]

Now for the some cool stuff, or not, can't decide.

I took my valve heads to an engineering workshop where they told me all four my valves needs to be replaced, that hurts allot. I did some research and it turned out that the custom stainless steel valves the engineering shop makes would cost the same as ordering new ones online, and the BMW dealer was just too expensive. So I thought the stainless valves would be a nice thing to do.







If you cant tell that the outside fins are ceramic coated, its a good thing, trying to keep the look original. The coating is a ceramic heat dissipating one and helps with increase heat transfer and corrosion.

[Clay Spinner]

Originally Posted by Ghilli

In the back of the manual it says that the max permitted wear on the drum is 201.5mm, that is the inner diameter of the hub which I measured with a large vernier. If you look closely you can see its a steel band that is cast inside the aluminium hub.

Only problem is, this is the data for a 4 bolt hub and not the older 3 bolt, not sure if it is the same for both models.

Ah.. i'll have a look in my clymer... I bought it and haven't even opened it yet! My rear hub on the g/s is rubbish... no real rear brake though the ST feels very good.

[Ghilli]

Here are some photos of the three stages of piston, they are on the lower side of their wear limit with the barrels, but if it took 30 years to get to that point I am more than happy to put them back in. If they reach the point where they need to be replaced, I would definitely not go stock, I would upgrade to the 1000cc conversion. But that's a lot of maaanie.

[Ghilli]

The barrels and tubes are both coated with a ceramic coating. These parts take a beating from the road, so putting something durable on them makes sense to me.







These are the coated and finished barrels ready for assembly.



Two of the tubes has a lot of pitting I presume from sand and stuff from the front wheel, they seem to be steel so not coating them was not an option.

[Ghilli]

The disc is a bit of an experiment, I got the front hub ceramic coated and coated the disc with VHT engine enamel. The idea is to see how they handle all that brake dust, some brake fluid and road conditions and compare the coatings next to each other.

This is the renevation and DIY spraying of the disc.



Just cleaned



And the painted hub



Ceramic coated hub.



And here are some more parts I got coated.

[Ghilli]

Painting the engine scared me a bit, but living near the coast and seeing how things corrode as you wach made me do it with a smile.

I masked off the areas not to be painted and prepped the parts for painting, it looks pretty nice, I hope I did the curing process properly.



I baked it a few times, in a box, and it seemed to be working.



Most of the painted parts were only on the outside surface.



And this is where I am now, a lot of work and really not much to show for it.

[Rucksta]

What is the heat disapating ceramic coating?
The only ceramics I have any experience with are in exhaust coating and increase the exhaust velocity by retaining the heat.
Is that the bake temperature showing on the dial thermometer?

[Ghilli]

Originally Posted by Rucksta

What is the heat disapating ceramic coating?
The only ceramics I have any experience with are in exhaust coating and increase the exhaust velocity by retaining the heat.
Is that the bake temperature showing on the dial thermometer?

It is a coating that helps with heat transfer where the other type ceramic coating reduces heat transfer, I made pretty sure of this because I don't want to trap heat in the barrel and "lock" the heat inside. That is the bake temperature I baked at when I was curing the engine enamel. The instructions on the can said 93C, but I made it a little more to be safe.

[Ghilli]

Soooo, I realized that there's a difference between the stud bolts that goes into the engine for the barrels. 6 of them are the same and then there is two odd ones.



I did not pay attention at all when I was taking it apart and did not see where they came out off. If I had to guess, they fit into the two rear holes on the right hand side of the engine, that's the two in the left of the picture with the deep thread?

[Airhead Wrangler]

Originally Posted by Ghilli

If I had to guess, they fit into the two rear holes on the right hand side of the engine, that's the two in the left of the picture with the deep thread?

"You are correct, sir!"

[Ghilli]

These came out of the engine and are going straight back in, they look fine? Measured it and got 21.955mm, should be 22.025ish. But I seriously doubt my measured accuracy.

[Ghilli]

Used some general purpose gasket loctite for these, I want to seal them as good as possible. They were quite dirty when I took them off and its really difficult to clean there.





Using an oven, mallet and freezer for building a bike is definitely a first.

[Ghilli]

I took the forks apart and the oil in the left tube looked like, uhm....



This cant be good, I guess there was a fair amount of water in that tube. Everything is stripped now, but I can figure out if the bottom of the slider that is kept in place with a cir-clip can or should come out.

[SOLO LOBO]

Originally Posted by Ghilli

but I can figure out if the bottom of the slider that is kept in place with a cir-clip can or should come out.

Yes, early 81's internals look like this: