Bead blasted head

[Guest]

I had a shop do a valve job on my 1978 gs750. They bead blasted the head and ground and reinstalled the valves. The head is still off the bike. I was reading the thread about start up after new piston rings and now I am worried about beads in the oil passages of my head. Is there a thread with some pics on cleaning a head after bead blasting? If drilling and tapping the plugs is the best way, I will do that. Should I pull the valves back out? Are the passages easy to find?

[OldVet66]

I think I would talk to the shop that did the work. If they are any good at all, they would have cleaned it thoroughly after bead blasting, and may have blocked the oil galleries before blasting.

[snyderman]

Thanks for the reply.

I talked to the shop this morning and they assured me that it is clean. I will probably run some compressed air through it before I put everything back together.

[OldVet66]

I would worry about carbs and things with tiny passages, but I don't think a stray bead in the oil gallery would pose much of a problem, supposing one did get in there.

[Nessism]

I would NOT trust the shop, and strongly recommend that you remove the valves and clean the head yourself.

The oil galley transfer passages are plugged from the ends of the head so it's not easy to clean them out. The galleys run crossways with interconnection passages up to each cam bearing saddle and valve pocket. When cleaning out my own bead blasted head I first made sure it was fully degreased, since grit loves to cling because of the oil, followed by repeated water flush rinsing. I used copious amounts of Simple Green forced down the galley passages, valve guides, etc, followed by more rinsing. You can also use a small diameter bottle brush down the oil passages visible from the top of the head, followed by scrubbing down the entire head with brushes. When rinsing, pushing water up the outer stud passages is useful since this is where the oil flows up. You will have to cork the stud hole at the top other wise the water won't flow though the galley. I flushed and degreased the head at least three times before I called it good since even a small amount of grit in the galley passages will be tragic to the engine.

Good luck and hope this helps.

[Agemax]

agreed, flush it, flush it again, then keep flushing it a gain with whatever you like until you are happy. they shouldnt have bead blasted it, should have been vapor blasted

[hampshirehog]

I would NOT trust the shop, and strongly recommend that you remove the valves and clean the head yourself.

The oil galley transfer passages are plugged from the ends of the head so it's not easy to clean them out. The galleys run crossways with interconnection passages up to each cam bearing saddle and valve pocket. When cleaning out my own bead blasted head I first made sure it was fully degreased, since grit loves to cling because of the oil, followed by repeated water flush rinsing. I used copious amounts of Simple Green forced down the galley passages, valve guides, etc, followed by more rinsing. You can also use a small diameter bottle brush down the oil passages visible from the top of the head, followed by scrubbing down the entire head with brushes When rinsing, pushing water up the outer stud passages is useful since this is where the oil flows up. You will have to cork the stud hole at the top other wise the water won't flow though the galley. I flushed and degreased the head at least three times before I called it good since even a small amount of grit in the galley passages will be tragic to the engine.

Good luck and hope this helps.

I disagree with Ed. I would do everything above but flush and degrease at least 4 times (and probably a few more times for good measure).

I've seen too many cream crackered engines because the blast shop cleaned the head properly.

[Agemax]

I disagree with Ed. I would do everything above but flush and degrease at least 4 times (and probably a few more times for good measure).

I've seen too many cream crackered engines because the blast shop cleaned the head properly.

dont you mean "they SAY they have cleaned it properly" wheras they probably havent!

[hampshirehog]

dont you mean "they SAY they have cleaned it properly" wheras they probably havent!

I was attempting irony. They definitely cleaned that engine properly....

The lads who blast my stuff will not bead blast heads - they know what's what.

[Agemax]

I was attempting irony. They definitely cleaned that engine properly....

The lads who blast my stuff will not bead blast heads - they know what's what.

vapour blasting is perfectly ok, lots of engine builders do it

[Nessism]

I'll use soda blasting the next time I'm doing a cylinder head. I'll also spend more time sealing all the openings so grit can't get inside the internal passages. Vapor blasting sounds good, only I'd rather do things myself.

[hikermikem]

Random thought I had while reading this thread...

I would also heli-coil or twinsert the spark plug holes while the head is off. I didn't think to do mine when I had the head off, but now the plugs are starting to bind & the threads are getting quite worn in the head. I've had to pull the plugs a lot to dial in the jetting & if I had to do it again, I would have installed heli-coils in those threads.

just a thought...

[tatu]

I spent most of an afternoon pressure washing, air and rinsing a head and it still didn't get it all out.
I got a bag of this for my next job but the compressor I have doesn't have very much puff. so can only be used in short bursts, it is effective though.

http://www.ebay.co.uk/itm/ECOSTRIP-SODIUM-BICARBONATE-25KG-BICARBONATE-SODA-/360302919418?pt=LH_DefaultDomain_3&hash=item53e3ba3efa

[hampshirehog]

I spent most of an afternoon pressure washing, air and rinsing a head and it still didn't get it all out.
I got a bag of this for my next job but the compressor I have doesn't have very much puff. so can only be used in short bursts, it is effective though.
http://www.ebay.co.uk/itm/ECOSTRIP-S...item53e3ba3efa

That's the stuff. You're right about it using a lot of air though - you need big compressor to do it quickly. Just rinse after use and it all just 'magically disappears'.

I thought of using crushed walnut shells as well - anyone used that?

[Agemax]

a vapor blasted head soaked in a ultrasonic bath for a while will be like brand new