starcain wrote:wz507, I've seen several variations of the K and KH valves through the years. I think the 18070-54 valve I have pictured may be the latest ones made? So your saying that one of your KHK cylinders was set up for a K intake valve and the other one for a KH intake valve? I wonder why someone would have done that? Interesting, It may have been a trick they used back in the day. I wonder what kind of running results you would have gotten from that? Which cylinder was the K valve in? BTW, nice background for your pic. I like yours better LOL
Stan
Yes each cylinder was different, one big valve and one little. The big valve is worn to the point of having no margin remaining and is sharp enough to shave with, so suspect it's partner was even worse off and no longer useable. Regarding why someone would do it, this is pure conjecture but....... they probably sunk the original valve so far it could no longer be used on the existing seat, didn't have any OS valve options, so opted for a new seat, and they just happened to have a new seat that matched the K valve in inventory, so problem solved with the seat installation. "Oh don't worry about how it runs, it will be perfect, these are strong engines and what difference would a minor detail like 0.100" in valve diameter make?"
Whoever performed the work did an atrocious job, leaving the lower edge of the seat hanging down in the port with no attempt whatsoever to blend it in anywhere - just a big blob hanging in the port. "Heh, but since 0.100" difference in valve dia doesn't make a difference in how it runs, why worry about a 1/4" protrusion sticking into the port. These ports are factory polished and have plenty of flow potential so it'll still get more air than it needs!"
I think the blacksmith that performed the engine work (apologies to blacksmiths, as they would likely be far more qualified than whoever did this work) actually did me a favor, as I'd rather have the port unmolested as it is with the seat hanging out, than have some other artist's interpretation of what the repaired port should look like permanently carved in it.
This seat installation was performed on the front cylinder. The rear cylinder had a hairline crack between the IN valve and bore. I Dremeled it out and brazed it in, so both cylinders will now receive new seats.