Question to people who have vapor honed their engine

[alexdecker]

Hey all

Getting my stuff vapor honed this week. All the engine parts. Can you guys help me with a list of all the oil passageways and other narrow places I have to pay special care to during the cleaning of the engine afterwards? I just wanna make sure I get all of them, and don't accidentally forget something.

Also, I considered if I could use plummer's putty to block all the passageways? Or what would people recommend for blocking them?

[Sesman]

I used wood pegs and hot wax. Block every oil way you can see.

[alexdecker]

Also, this might seem like a stupid question, but only the outside gets blasted, right?

[Laverda Dave]

Make sure you tell the person doing the work NOT to blast the inside of the engine especially the shell bearing surfaces otherwise you might have a pile of scrap on your hands. The bearings are measured to such fine tolerance limits blasting of the surface will make the tolerance bigger.
As has been said before, only use someone who a) knows what they are doing and b) is used to vapour blasting Japanese engines. If neither of the above walk away.

[Oddjob]

The powder coating people use silicon bungs which are left in when the engine is cured as they can withstand the heat.

You can buy them off Ebay in a variety of sizes.

[Sesman]

Bung the oil ways. I’d used Hilltops silicone bungs to good effect.

Blast the outsides only.

Dry thoughly and blast out with high pressure air line.

Wash and wash again.

Dry and blast with airline.

If in doubt, wash, dry and airline blast again .

Use pipe cleaners and small bottle brushes to clear the oilways.

Clean out all the threads. I used 6mm and 8 mm taps. Make sure you clear all debris from the bottom of the thread hole.

[Oddjob]

Or fit old bolts into the bolt holes first.

[royhall]

Or fit old bolts into the bolt holes first.

Ditto on this one, better to keep things out than try to remove them. This is especially important when powder coating. Also as an experienced toolmaker I cringe at people cleaning threads with taps. Taps are very sharp and hard and if started wrongly due to debris they will recut the thread again ruining the component. Threads should be cleaned with a new bolt with two flutes ground into it. A bolt is soft and will not damage the original thread but does take more time and effort than taps.

[Sesman]

Retapping clean holes worked just fine for me and has done for 45 years. The hole needs to be clean. I wouldn’t use a tap in all circumstances.

[alexdecker]

Ok, shot some pictures of the engine and marked all the oil passages I could find.

To me, it seems that all the passageways are through-holes, with the exception of the oil channel under the cam journals. So I will take extra care in covering that up. But the others, I can technically get some pipe cleaners and brushes through, right?

[alexdecker]

And the bottom end…

[alexdecker]

Oh, and a real quick one here. I cleaned all of it a few weeks back, and can see some very light surface rust has formed on the piston walls and the valve guides. Should I be worried about this? I am honing the cylinders, and when cleaning the combustion chambers, have a feeling that the valve guides will get cleaned as well. It is only three weeks since I cleaned it, and it has been stored in a dry place, so the surface rust must have formed from drying from the cleaning.

Also, its all getting vapor blasted on friday. But will take steps, if this is bad. Could put some oil on them or something like that?

[Bryanj]

Dont forget the holes at the oil filter and oil pump plus the gallery where the blanking plug does behind the generator cover

[Oddjob]

The 2 holes you've marked on the gearbox bearing areas are blank holes for the dowels which locate the bearings. A quick blow with an air gun will clear those I reckon, no need to blank them.

[alexdecker]

Dont forget the holes at the oil filter and oil pump plus the gallery where the blanking plug does behind the generator cover

I actually figured those passages were so big, that I could clean them rather easily, and maybe didn't need to cover them up at all. Shone a light through them, and they seem like there wouldn't be anything that would hide too well in there? Am I mistaken in that?