Getting top end vapor blasted. Leave valve guides in?

[alexdecker]

Hey all

I have my bottom end completely split apart for vapor blasting soon. I wanted to have the top end vapor blasted as well, so I am taking out valves etc. I heard the valve guides are quite troublesome to remove yourself.

Can I leave them in when getting in vapor blasted? To my knowledge, that should be the only thing that could cause trouble?

[Oddjob]

Leave them in. Just blow them clear afterwards.

[alexdecker]

Good man. Just the kinda answer I was hoping for 

[Trigger]

The head has to be stripped completely apart from the guides as it is glass bead and one bit of bead will destroy your engine. The blaster should have rubber bungs to put in to protect the inside of the guide. Also on the 500/550 head there is a main oil channel that runs under the cam journals, the plugs on each side of the head need to be removed so, this channel can be cleaned after wards. New plugs can be easy made on a lathe out of alloy and pressed in 

[Oddjob]

If you remove the guides Alex your going to need to recut the valve seats, whilst it's true you need to remove everything the exception is the guides. Be sure though that the small metal spring seats at the bottom of the valves has been removed, use a magnet to suck them out.

[Sesman]

Hi, Alex.

I stripped the head except for the guides. Plus one on removing the valve spring seating rings. I used wooden dowels and wax to block all channels inside the head and instructed the blaster to treat the outside only. I then dried the head for several days in the airing cupboard and cleaned the head with a high pressure air line. I then socked the head in very hot soapy water, jet washed and repeated the drying and blasting routine.

Plus one on Tiggers advice on the oil channel if the ownership of the head is in question or if you suspect blast media may have entered the gallery.

Just saying what worked for me. If in doubt, clean  and clean again.

[alexdecker]

I will give it a couple of thorough cleanings when getting the parts back. I don't have a compressor, so using nylon wire brushes through the oil channels and other places. For drying, I was actually planning throwing it on the oven on low temp and just let it dry that why. Shouldn't be anything wrong with that, right?

Do people usually vapor clean their carburettors? On many pics I've noticed that the usually don't get blasted. Is that not good practice?

[Sesman]

Yes, oven is fine. I doubt you will be able to pass fine brushes through the cam bearing oil galleries?

Vapour blasting carbs seems to be trendy, but I prefer to chemically clean using ultrasonics. I guess it depends what state they are in to start with.

Again, it’s all personal preference.

[alexdecker]

Mmh. The more I read about vapor blasting, the more hassle it seems to be. I can see how nice everything comes out, but the chance of ruining the engine but not cleaning properly has me a little worried I must admit.

What are the options for going the paint route? I degreased the bottom end recently, and this is what I'm left with. Quite a lot of corrosion, and in those hard to reach places under the oil filter and between fins. Scotch brite and a Dremel? Or is there some more clever solution to it?

[murdock]

en vez de perlas de vidrio utiliza  bicarbonato de sodio luego solo agua y jabon , no hace falta secar el bloque en un horno , al fin y al cabo es solo un poco de aluminio , tambien suele usarse creolina para limpiar carburadores y bloques de aluminio


instead of glass beads use baking soda then just soap and water, there is no need to dry the block in an oven, after all it is just a bit of aluminium, creolin is also often used to clean carburettors and aluminium blocks.

[Sesman]

The oven drying was in expectation of vapour blasting. Drying the media and blasting with air is more effective than washing.

I agree, baking powder can be effective, but I’ve never rated it for paint prep.

Personally I’d bead blast, but only external surfaces and not before taking great care to exclude media from galleries I’d sill wash, dry, blast a couple of cycles on the assumption media has got into the oil ways.

[Spitfire]

I did mine old school, I did not strip the bottom end just cleaned it, I used Dremel, Brillo pads, Lolly sticks, McDonalds wooden stirrers, wet and dry, the result was  lots of bashed and bruised fingers and nice clean components.
Then paint and popped the head, barrels, oil filter cover in the oven, the crankcases cured themselves when I ran the motor.



Cheers

Dennis

[murdock]

en las fotos no se ve tan mal , se ve pintura vieja , si vas a pintar  y no tienes compresor de aire podrias utilizar un decapante , un removedor de pintura y luego si un buen labado , ademas de lana de acero y cepillos , aqui podran indicarte que pintura anticalorica utilizar , creo que la marca es silominz o algo asi


in the photos it doesn't look too bad, it looks like old paint, if you are going to paint and you don't have an air compressor you could use a paint stripper, a paint remover and then a good scrubbing, plus steel wool and brushes, here they can tell you which anti-corrosion paint to use, I think the brand is silominz or something like that.
the oil passages can be cleaned with thinner or some other solvent.

[alexdecker]

I did mine old school, I did not strip the bottom end just cleaned it, I used Dremel, Brillo pads, Lolly sticks, McDonalds wooden stirrers, wet and dry, the result was  lots of bashed and bruised fingers and nice clean components.
Then paint and popped the head, barrels, oil filter cover in the oven, the crankcases cured themselves when I ran the motor.



Cheers

Dennis

End result looks good, but I didn't think you could use Brillo pads on aluminum? I have some 0000 grade steel wool, and was thinking about trying that, but afraid of using it an aluminum…

[Spitfire]

I've used Brillo pads since the 1970's, wet and dry, sometimes in conjuction with Solvol, I should imagine some of the coarser grades of steel wool would not be good with Alloy though.
I used to use this method to polish casings when the clear laquer failed.

Cheers

Dennis