can you sand blast valves and piston tops?

E

eightsevenzero

Been Around the Block
i have some heavy buildup on my valves from them sitting in a dead engine for 30 years, is it ok to blast them with silica sand? also have the same problem on a piston thats stuck in a cylinder, if i get it out ever is it ok to blast just the top?
 
Answer would be yes. BUT, as with all blasting done to motorcycle parts the masking and cleanup are very important. Pieces of abrasive sand in an oil way? Or worse still blocking a small drilling? Is it really worth it?
 
point taken but i dont see another way to get the valves clean, any ideas? thought about chucking them in my dril and using sandpaper also but figured blaster would be faster...
 
Get a container of parts cleaner and let them soak overnight then scrub with a brush. Any auto parts store has just what you need. But yes, it is okay to blast just the top, do make sure to mask well and clean well.
 
+1 to parts cleaner, carb cleaner and wire brush. One single grain of blast media will score your piston and cylinder.
 
let me ask you if you have looked into media blasting with Dry ice. I have heard many people having it done with success I don't know who specifically or how much but could be worth looking into. nothing left behind at that point.
 
media or walnut only!!!!!!!!! carb cleaner, stool, beer, music works the best.
messed around one day with a sand blaster and a piston, took 22 seconds to go through it.
 
It's all media.... Sand, silica, walnut shells, dry ice etc. And very true, sand will eat that piston for lunch. Good ol' fashioned elbow grease is the best way.

reelinfeele said:
media or walnut only!!!!!!!!! carb cleaner, stool, beer, music works the best.
messed around one day with a sand blaster and a piston, took 22 seconds to go through it.
Click to expand...
 
if you blast the sealing surface on the valves your gonna need to have the seats and margins recut. pistons should be ok but dont blast the skirt! and clean the hell outa them after, sand+engine=bad! I think i would go the part cleaner method suggested
 
I use a bench grinder mounted wire wheel for cleaning up valves. Quick, simple, effective, no chemicals, no mess (well, not much ::) ).

As for pistons, I've blasted the tops of them before with glass beads without issues, but don't do the ring grooves because the beads will "flare" the piston material and the ring grooves will close / tighten.
 
I use the grinder with a wire brush attachment for my piston tops and valves also. You can finish them off by polishing with metal polish and "00" steel wool.
 
I use the wire brush wheel also. It is possible to buy a wire brush cup for a 4" angle head grinder but you will need to be careful and use a light touch. It goes without saying, anytime you use a wire brush wheel, use eye protection. The wire strands come loose.
 
+1 wire wheel on bench grinder. Doubly so after letting stuff soak. The wheel will take all that baked on carbon right off. There are lots of theories about smooth vs textured intakes, exhausts, pistons, combustion chambers, etc. However, I would suggest simply cleaning everything, and then putting a light polish on the piston tops -- the smoother they are, the less likely they will build up carbon.

I would not just casually sand blast valves and pistons.

-fang
 
Also, the smoother your pistons and combustion chambers are...... the less likely it is to get detonation. Those small irregularities get hot and ignite the air/fuel mixture before the plugs do their job..... especially in higher compression engines or those running on marginal fuel.....
 
parts cleaner for sure and scrub with a BRASS brush....when cleaning metals, especially metals that are important internally you never want to use a metal brush that is harder then the metal your cleaning (ie a steel brush) it can scratch it to shit and really leaving you sceptical as to did i just F that up?




so spend the 2$ get a brass brush a gallon of parts cleaner or carb cleaner from autozone and let soak.....will do the trick
 
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