RD350 returning to the road!

[sprouty115]

Lasse, what did you do to the crankcases? De-grease and clean? Polish? Bead-blast? Trying to figure out how to attack mine. Also trying to find something less than poisonous to use.

This (second picture in the link) looks good, just not sure of what "the process" means.
http://www.aircooledrdclub.com/smf/i...?topic=25398.0

[welshracing_752]

[LasseNC]

Originally Posted by sp115

Lasse, what did you do to the crankcases? De-grease and clean? Polish? Bead-blast? Trying to figure out how to attack mine. Also trying to find something less than poisonous to use.

This (second picture in the link) looks good, just not sure of what "the process" means.
http://www.aircooledrdclub.com/smf/i...?topic=25398.0

I vapourblasted them, without any media. Which is then just hot, highpowered water/solvent :)

[Leo.G]

Well Lasse, something similar to your problem with the cylinders happened to me today, but with the rear rack I'm making for my bike..
Had to sand everything again, with the grinder and also with "elbow grease", and paint it again...

Lets hope this paint to be better..

Any updates in your build?

[LasseNC]

Originally Posted by Leo.G

Well Lasse, something similar to your problem with the cylinders happened to me today, but with the rear rack I'm making for my bike..
Had to sand everything again, with the grinder and also with "elbow grease", and paint it again...

Lets hope this paint to be better..

Any updates in your build?

I took an anglegrinder with a worn "flap" disc to my fins, very lightly, but still a bit deeper than I wanted. Finishing with grit 120, then scotchbrite pads. Will happen tomorrow :)

[Leo.G]

Originally Posted by LasseNC

I took an anglegrinder with a worn "flap" disc to my fins, very lightly, but still a bit deeper than I wanted. Finishing with grit 120, then scotchbrite pads. Will happen tomorrow :)

Good luck with that, for today's job I used a flap disc grit 120 and also a grit 120 sandpaper..

I'll be waiting to see some more progress on that little beast, since I'm bored on holidays..

[LasseNC]

This is how far I got with grit 120. I might "water grinding paper", lost the word for it, and then call it a job done.

There are however some gouges in the fins, but polishing those up will simply be too much.

[Leo.G]

It's a really nice job that way..

Polishing would be too much for a bike that is gonna be used and not just stay in a showroom for the end of its life..

Actually, if I were you, I wouldn't even thought of sanding the edges of the fins..

A little question..
What did you paint the cases and the cylinders/heads with?

A mechanic I know told me that if you have a primer, or just the old paint of the cases, you can use normal synthetic enamel for the outside of the motor..

[sprouty115]

Originally Posted by LasseNC

This is how far I got with grit 120. I might "water grinding paper", lost the word for it, and then call it a job done.

There are however some gouges in the fins, but polishing those up will simply be too much.

Looks good. You might have been thinking of "wet sanding"? Anyway, just blasted the heads on my rebuild may follow your approach, may leave it blasted.

[LasseNC]

Cases I've left unpainted.

Heat resistant paint, made by a company called "Presto" its around 16$ for a can. In Denmark that is.

[sprouty115]

Lasse, you may already know this, but in case you don't...I started in on my oil pump today and I remembered reading a "trick" about disassemble. Check the link below when you get to that point (starts with reply #36):

http://www.aircooledrdclub.com/smf/i...topic=25398.30

[LasseNC]

That is a good thread, noted :)

Today I put on the pistons and NOS needlebearings.



Then I saw the rings, a setup that I have never seen, so I don't know how it goes in. Anyone?

[JonnyCash]

That kinky ring is made to go in behind the lower ring, and is meant to keep the piston centered in the bore. They're rubbish, and every time I've taken apart an engine that was fitted, they were broken in several places. Thinking of what a mess it would make if one of those pieces got loose, I can't bring myself to put the new ones in. I'm not alone in this, lots of people that know a lot more than I do omit them.

[LasseNC]

Originally Posted by JonnyCash

That kinky ring is made to go in behind the lower ring, and is meant to keep the piston centered in the bore. They're rubbish, and every time I've taken apart an engine that was fitted, they were broken in several places. Thinking of what a mess it would make if one of those pieces got loose, I can't bring myself to put the new ones in. I'm not alone in this, lots of people that know a lot more than I do omit them.

Great info! Cylinders will go on in a few days then :)

[sprouty115]

Originally Posted by LasseNC

Great info! Cylinders will go on in a few days then :)

JC is correct. That ring often gets called an "expander ring". Lots more info if you search using that phrase - almost all of it will tell you to leave it out.