Bellerophon
XS400 Member
Okay, so I am going to start this post by mentioning that everything was done in good faith - I know there are a limited number of these engines so I want to apologise in advance if what I have done is the equivalent to motorcycle heresy.
I won't bore you with the details of how I came to the decision of wanting to getting the casings blasted but they were in pretty rough condition and speaking to two local blasters they said it would be fine as I plan to have the engine painted after, and that sand blasting was correct, not vapour or soda. Needless to say, I could have done more research.
Here are the results.
The medium must have been pretty coarse as the surface is very rough. Areas like the mating and running surfaces that the blaster assured me he would avoid, weren't (they're not as blasted as the outside of the casing, but still affected. He did not blast inside the cylinders thank goodness). And, finally, everything is covered in a fine film of sand!
So, my concerns are:
I won't bore you with the details of how I came to the decision of wanting to getting the casings blasted but they were in pretty rough condition and speaking to two local blasters they said it would be fine as I plan to have the engine painted after, and that sand blasting was correct, not vapour or soda. Needless to say, I could have done more research.
Here are the results.


The medium must have been pretty coarse as the surface is very rough. Areas like the mating and running surfaces that the blaster assured me he would avoid, weren't (they're not as blasted as the outside of the casing, but still affected. He did not blast inside the cylinders thank goodness). And, finally, everything is covered in a fine film of sand!
So, my concerns are:
- Mating surfaces - What should I do here? Gently wet and dry the rough surface back or leave it and just let the gasket do its job?
- Embedded Grit - I've read that the aluminium can retain some of the grit that will then be expelled when the engine gets hot - can I do anything to prevent this?
- Cleaning (for paint) - I want to clean these parts to take to the painters. When I asked the blaster how to clean the parts he said not to do it until after it had been painted as the rough surface would absorb the water and make it harder to paint. The surfaces are so dusty however that I doubt the paint would stick anyhow and the masked areas would likely peel away. Do any painters here have any advice?
- Cleaning (grinding paste) - My cleaning apparatus consists of a tub and hot soapy water. With all the will in the world, can I realistically expect to be able to get all the grit removed and prevent any damage to the engine further down the line?
- Other - What other horrible pitfall have I fallen into and haven't realised yet?