Need blue print for valve guide.

[AdminGuy]

Need blue print for valve guide. Has anyone done this. Must make over sized 660.

Would help. Pls email or post. Thanks.

[Carl N. Olsen]

Paul,
Just get me a good measurement of the hole, an old guide, or a repro guide and I can make you one out of a chunk of cast iron or another larger guide. Piece of cake. Also I have contacted manufacturers of valve guides and purchased unmachined blanks for difficult situations. Just don't weld another one back in. We are still working on the web site info. and disk.
Carl

[AdminGuy]

Thanks Carl,
Standard new guide inserted wiggles. Looks like the hole is a slideing fit at base. Maybe a 1/4". Then the guide hole expands upwards. Maybe this was a casting flaw? I kinda think it was, as the hole is not gauled or stepped.

So I figure the guide hole should be milled to increase to full inner diameter. Then I can measure new hole for oversized guide.

If I get oversized guides made. (Figure I may as well get three made up at same time, keep with barrel). Why not go to a better material like 660 bronze? Also I could easily identify in the future which one is oversized. Well I guess it would be pretty self-evident upon insertion of standard guide. But wouldn't it make sense to use a better material? I don't know - you tell me.

*General; my guide was tacked welded into place. A quick fix maybe 40years ago. Something that a good janitor (hopefully me - with guidance) should take the time and expense to fix properly now. Also considering that I plan to accually ride the bike a fair bit. If the guide fails the valve head will most likely snap off. Probably in 100 degree heat, in the middle of a barren wasteland. Upon which occurance, my rideing buddies will surely leave me for dead - due to my lack of foresight and thrifty ways. Well, maybe not dead. But a sure fire way to make the **** list for a while. Sooo... I'm doing it properly.

Well I guess the other thing that has me a little concerned is that the seats are pitted and may be close to wear limit before pocketing occures. Still need to be cut again. So I may have to re-seat (inserts). But don't want to because of Stainless valves. Too hard? May have to cast weld around seats and re-cut 35 degree. Turning into a big operation here. Ohhh... what to do?

Oh YA! There's more. Same barrel requiring over sized guide on exhaust valve. Intake valve seat has 1/4" hairline fracture to bore. Possibly (my guess) due to previous owner reving the pee-pee out of it with double springs trying to keep up to some British bike. This I figure, I can live with - due to being on the cooler intake side, and using single new springs.

Welcome to my misery!

[Carl N. Olsen]

Paul,
Use cast iron for self lubricity, the bronze material is prone to valve seizure. Not good on an overhead and worse on a flathead. As a matter of fact, why do'nt you get rid of that old warhorse and move up to a Harley (hehehe). Had to throw that little jab in you know. New seats can be installed in both the sunken exhaust and the cracked intake, use a cast alloy seat that has a matched coefficient of heat expansion to the parent metal and you will maintain the interferience fit. The cracked seat should be welded up before counterboring though. With this old iron we sometimes must be creative in order to put these machines back into service, but just about anything is possible.
Carl

[AdminGuy]

Wow! I thought you were going to suggest finding another barrel. I've hear that a few times. But they ain't growin on trees around here.

Yes - Cast iron (grey cast), high carbon content 4.5% = natural lube.

Yes my friend - jab away... Looking forward to putting the "old war horse" up against multiple 1940 wldrs (W.orthless L.ame D.itch R.iders) hee-heeee... opps! just heard a few family members spin in grave. Oh well, looking forward to some old time brand battles. This engine is pretty much stock. But still should be great fun! I've never put a hard tail into a powerslide, so I'm real curious to see how that all feels.

I'll have to get my valves in hand and see how things shape up. So you say it's all good with stainless valves and seat inserts? Not to hard? Hummm... OK. I'd still like to avoid seat inserts if possible. I'll lug my junk over to my Jack of old flats and see what he thinks about cast welding and my existing pitted seats.

I have to look at the least invasive proceedure first. But it sure is comforting to know that proven options are available.

[AdminGuy]

Carl couldn't I just make a bronze sleeve for the guide? Fit the sleeve to guide. Then cool, and fit that into barrel.

[AdminGuy]

Bronze has different contraction expansion values in comparison to grey cast. They make oversized guides for Chiefs - but not for Scouts which are different. Hummm..... comments anyone?