Throttle valve -again

[southwestern737]

OK here we go again, after burning out the last throttle valve ( ball valve with graphite seats ), on my oil fired 1.6 Mikado, I rebuilt my super heater to reduce the amount of superheat, and replaced the ball valve with a fast opening gate valve. I just fired it for the first time after the change two days ago, could not run because the valve leaked so badly, shut down took the valve out and opened it up, cleaned up the seals to make it operate smother and get it to seal. Just fired it up again with very similar results, the valve gets so tight that it is near impossible close completely, also not happy with the amount of lost motion in the handle which my throttle linkage magnifies. I know many who use them and have good results but it is not gonna work for this engine. Now for the question, I have ordered another graphite seated ball valve, should I try that again now that the superheat has been reduced, or should I just build a Little Engines throttle. If I go with the Little Engines type it is a Stainless disk running on brass, heat will not be an issue and I can pack the stem with graphite string. The Little Engines throttle drawing has the cylinder lubricator line injecting oil into the throttle so it is constantly lubricated, I would delete the lubricator line for a couple of reasons but mainly because I already have lines running directly to the cylinders. I am sure that oil running through the valve is helpful but I don’t think it is required, what do y’all think. As I write this I am leaning toward building the throttle but still not 100% about removing the lubricator. Would like to hear from anyone that has experience with the Little Engines valve.
Brent

[Fred_V]

Are you actually getting real superheat? I get a small blast after the engine sits for awhile but otherwise it just drys the steam.
That is a smokebox throttle as I remember it. You may have too much smokebox heat for a ball valve. Maybe too much draft.

[southwestern737]

No clue as to how much if any superheat, but I am getting dry steam. No doubt about the smoke box temp being high, but I see guys firing as hard or harder and they don’t seam to have any trouble with valves. I think i am just going to build a new throttle, it should handle the heat better.