Sunday 7 March 2021

Vapour Blasting Horror

Having let the project slip for a few years, I picked up on the engine to start the process of preparing it for paint. A lot of people had warned me that I needed to check all the oil passageways for the ingress of vapour blasting media.

This is a very fine sand like substance and because of the high pressures used in vapour blasting, it gets into all the small oil passageways in the head, and other parts of the engine that were blasted.

I bought one of those cheap iPhone endoscopes and I was horrified at what I saw.

And what came out

There are a whole load of passageways that need to be cleaned. Some of them are dead ends where this media will be hard to get out.

There was only one way to get the job done completely. The plugs in the cylinder head that were created when the passageways were drilled into the head during manufacture, will need to be pulled out.  There are 10 of these plugs on the cylinder head. They are soft aluminium. I drilled them, tapped them and made a puller from a socket and bolt.

And just look at the horrible build up of media that been trapped in these places.

ANY amount of this stuff in your oil and goodness only knows how any of the bearings would have survived.

Saturday 29 December 2018

Clutch Selector Bearing Stuffed

I didn't notice this for a while but it looks like the guys who vapour blasted my cases, saw that there was a bearing still in there and attempted to get it out.

Well they botched that pretty bad. Gouging out the inner part of the bearing and leaving the outer shell in place after marking up the cases pretty badly.

With the help of some technically adept motorbike mates, we got the shell out and smoothed off the damage.

This is how it looked when it was sent for blasting (OK I should have got it out myself):

and this is what came back from the blasters:

so we took the Dremel to it:

and out it came:

New bearing had a lot more rollers on it and will go back in after the painting has been done.

Monday 17 April 2017

Vapour Blasted Engine Comes Home

Got the cases back now. They did an aggressive blasting to try and eliminate all the corrosion. Mostly this has worked well but still a few places where I'm going to have to wet and dry.

In any case (get it?) it's a good finish for painting. The cam cover I have painted as my test piece using VHT paints; Engine Enamel Primer, Barrel Paint and Satin Clear Clear. Comes up good.

And a reminder of what I started with:

Saturday 5 November 2016

Head Comes Apart

All the valves need taking out and clearances checked.

Gear Box Components Out

For vapour blasting all the internals need to come out.

Including this roller bearing that supports the gear selector drum.

And How Are Things Inside?

Quick look at the pistons: they have very few marks on their side but are quite sooty. I guess they were quite carbonned up, even though the mileage wasn't high. I sprayed WD40 into the barrels several times over the years to stop any corrosion and that's a good way to loosen up the deposits. They are very soft now.

To get the crank out it was necessary to take off pistons 1 and 4.