VB exhaust valve guides

[Pete.Silson]

I ordered a VB exhaust valve guide (460-29) from Draganfly and they sent an NH guide (480-33) which they say is an equivalent.

The NH guide is shorter and has an oil hole. The length is probably not an issue but, when fitted, the oil hole lines up with the gap between the valve chest and the exhaust port casting. This means that the oil hole is open to outside atmosphere potentially allowing ingress of water to the middle of the valve guide. This doesn't seem a good plan to me. Has anybody experience any issues using NH guides with oil holes in a VB?

Pete

[volker.halbach]

I think I have an NH exhaust guide without hole. Please PM me if you are interested.

[nevhunter]

Put a nipple in it and grease it and it will last forever. Nev

[Mike Nash]

Nev, that's brilliant! What grease would you recommend?
MikeN.

[nevhunter]

I ve used High temp WB grease BSA's did it in the 30's. . Don't need much grease. Do it each day. Nev

[Roger Gwynn]

Unfortunately not economic to make VB guides and NH will work but some cylinders have a gap. Grease nipple good idea. Dunno why Drags put a hole in guide, probably because Ariel did for to cover for the 2 years that there was an oil feed to the guide. I will talk to them and ask to drop the oil hole, which only increases the cost and the few people with such bikes can easily add the hole.

[nevhunter]

Where there's a gap in the casting it would be desired to machine a relief so the inevitable rust on the guide where exposed will not damage the casting when the old guide is removed .Nev