Slowest RestoMod Ever

Don't remove guides yourself , let a shop do it.

The head's finally stripped of everything bar the valve guides now. Having never done it before, it was a bit daunting, but I enjoyed it . I can recommend Sealey valve spring compressors - a bit pricey compared to some of the cheap stuff on ebay, but excellent quality (Model No. VS1814). My wife wasn't too impressed with the acrid smell it left in the oven, but it's finally cleared (lemon and baking powder )! I've cleaned the head as far as I can and boiled it to remove as much oil as possible from the metal. Next stage is to blast it before getting welding. One of the local bike shops do vapour blasting, which is what I was planning to use. However, the welding company that I'm using suggested that they could shot blast it with nickel beads . My concern is that this will be too aggressive and potentially damage the aluminium .

My preference is the vapour option...advice please!

Absolutely vapor. I wouldn't shot peen Britbike engine part castings.

I agree with vapour too.

Bear in mind though that you’ll need it blasting again after the repair works so it all blends in as much as possible.

Cheers guys. I thought as much...and for the further blasting after the repair.

I had a friend who had a speed shop back in the 80-&-90's and he used ground up walnut shells for all the blasting he did to his customer's bikes heads. He said that no matter how good you clean it, when it was put back together and brought up to operating temperature, the aluminum would expand and any blast media that was embedded would be released feom the heat.

We used ground up walnut shells to clean our Huey and Cobra engines in Nam, worked great. Later years they decided it was to abrasive so we had to buy something artificial, not biodegradable and made someone a lot of money.

Years ago, I sandblasted the crankcases and gearbox shell that are now in the SS clone. I have to say, it's remarkable they've never oxidized despite having no protective coating. the finish has weathered somewhat, but no oxidation. I'm assuming the blasting peened down and closed the pores of the alloy otherwise the parts would have turned chalk white from oxidation.

That being said, when I needed to clean up the head of the Titanic, I had it vapor blasted. Cleans without altering the surface finish. A slight lapping of the valves was all that was necessary, mostly to check the contact areas.

I have stopped having cases vapour or plain blasted, instead I now use a Ultrasonic bath with a dilute citric acid solution, the citric acid attacks the aluminium oxide freeing it up for the ultrasonic waves to remove it and any dirt. The finished cases are not as uniform as vapour blasted but more natural looking IMHO.

2 Rockerboxes, one Vapour and one Ultrasonic



and a case partially submerged to show difference

Thanks for the helpful responses all .

Have a good Easter.