bead blasting pistons?

[dmaxvaz]

i had a friend of mine that builds vw engines for a living( lots of them featured in hot vw magazine), bead blasted my used lb7 pistons and to me everything seemed fine and cleaned up nice. anyways the guy i took my rotating assy to balance, says that they are junk and will cause the piston rings in the ring lands to seize because of the bead blasted finish. any truth to that? or should i worry about it?

 

[mytmousemalibu]

I would be concerned personally. I have no data to back this up, however, if you think about it, bead blasting creates a tiny surface of peaks/valleys where bead impingment overlaps. That "satin" finish would make an ideal surface for carbon/deposits to adhere and build on, possibly causing problems. And the machined surface has been changed. It wouldnt bother me to do the tops but im not sure the ring lands/skirts/wristpin bores would be safe to blast. Just IMO

If someone else has experiance with this, I for one would like to know!

 

[Turbo Buick 6]

I would be concerned personally. I have no data to back this up, however, if you think about it, bead blasting creates a tiny surface of peaks/valleys where bead impingment overlaps. That "satin" finish would make an ideal surface for carbon/deposits to adhere and build on, possibly causing problems. And the machined surface has been changed. It wouldnt bother me to do the tops but im not sure the ring lands/skirts/wristpin bores would be safe to blast. Just IMO

If someone else has experiance with this, I for one would like to know!

I tend to agree, I use crushed wallnut shells to clean pistons

 

[Stingpuller]

Pistons

"IF" there clean it will be fine. Double/Triple clean them. Jeff

 

[Dzlnut]

I have bead blasted gas pistons...all except the skirt and have not had a issue....not sure what shape yours are in.

 

[super diesel]

ideal surface for carbon/deposits to adhere and build on,

This is my experience in the past with gassers. This was on the top of the pistons. You want as smooth of a surface as possible for nothing to stick to.

 

[dmaxvaz]

Thanks guys, what do you guys think about micro polishing them if possible?

 

[Cougar281]

I tend to agree, I use crushed wallnut shells to clean pistons

Backing soda would probably be even gentler than walut shells. It works quite well to get paint off AL without marking up the surface.

 

[paint94979]

i had a friend of mine that builds vw engines for a living( lots of them featured in hot vw magazine), bead blasted my used lb7 pistons and to me everything seemed fine and cleaned up nice. anyways the guy i took my rotating assy to balance, says that they are junk and will cause the piston rings in the ring lands to seize because of the bead blasted finish. any truth to that? or should i worry about it?

Just curious why would you allow your pistons to be bead blasted? I have never heard of any Duramax build where a guy bead blasted their pistons

 

[S Phinney]

Just curious why would you allow your pistons to be bead blasted? I have never heard of any Duramax build where a guy bead blasted their pistons

Mine wear blasted but you have to do that for coating purposes. You don't want to blast the ring lands though. It is possible to cause the rings to stick with carbon deposits that would build up easier now.

 

[dmaxvaz]

just curious why would you allow your pistons to be bead blasted? I have never heard of any duramax build where a guy bead blasted their pistons

what is the answer you want me to give you? You are pretty hostile towards me and i dont know what to say without being called all kinds of names. Move on

 

[Ben46a]

I honestly see no problem with it as long as there thoughoughly cleaned, although soda or shells would be better choice. If beading i would clean the lands with a fine emery or wet dry paper first.

 

[Turbo Buick 6]

When ever I blast pistons I always tape off the ring lands and skirts. Then I usually hit the tops on the buffer till they shine like a mirror. Blasting has a tendency to pean the metal and work it around. This can alter the geometry of the ring grooves if they aren't protected.

 

[super diesel]

Thanks guys, what do you guys think about micro polishing them if possible?

I would just use some 600 grit paper with some WD-40 and do some figure 8s with the top of the piston on it. Then do the entrant dome with the same paper but by hand to polish the tops up.

 

[Leadfoot]

The engine builder I use bead blasts the tops (not the skirt or the ring lands) of brand new pistons before installation. I not sure how/what it does but he has enough dyno testing to know what works and what doesn't. I'm assuming it must promote a better burn/swirl. I never really asked him why, but I guess I will now. As far as if it's different for turbo diesels, I'll have to ask that too. I wouldn't worry about the tops, but the rings lands would bother me....

i had a friend of mine that builds vw engines for a living( lots of them featured in hot vw magazine), bead blasted my used lb7 pistons and to me everything seemed fine and cleaned up nice. anyways the guy i took my rotating assy to balance, says that they are junk and will cause the piston rings in the ring lands to seize because of the bead blasted finish. any truth to that? or should i worry about it?