Here is the set up for machining out the old valve guide. I dialed in the outside diameter of the o.g. guide and locked in my mill, then I machined it out and drilled and tapped the head for a 9-16 18 tap. After this set up, I had to flip the cylinder around and mill out the piece of metal that was still in the combustion chamber. I also spent an hour polishing the bases of the cylinders and the wall. They glow like diamonds and look amazing. It is pretty close to the o.g. plating on my original spacke cylinders.
HEre is a pic of the valve guide being threaded. We were able to modify big twin sidevalve valve guides from rowe. They are made out of cast iron which is ideal.
Here is a pic of the modified valve guide next to the donor one. This is a fix that my friend Steve recommended, and I think that it makes a lot of sense, The cylinder does not have very much meat to it after machining, so I would be a little apprehensive of a pressed in valve guide. I will give this a try and hopefully it will be a trouble free fix.
Hi Matt. Excelsior did a similar setup for guides. they are threaded with a hex head on top. But they also fit into a counterbore to locate them well and to transmit the heat well. I'll try to email you a photo.
ReplyDeleteOn your cylinder plating, did you use electroless plating, then follow it up with electro plating? that works really well, as the electroless will get down into the bottom of the fins, then the electro will give a better high gloss finish on the bigger surfaces.
ciao
pete
I pre polished the bases before having them electroless nickel plated. I did not send them to an electro plater. The way that it was explained to me by the plater is that the electroless is somewhat transparent and if the surface is shiny below the plating, you can polish the piece after plating and get a great shine. I was really nervous about some of my bronze repairs showing up through the plating, but they are undetectable which is good.
ReplyDeleteThe counter bore is a neat idea, but there isn't much room to spare on spacke cylinders for such a thing. Steve told me to use some super tough loctite when I install the guides for the final time, but I forgot which color he mentioned. I will have to ask him again.
that sounds great, and they sure do look good in the photos. I'm not sure which loctite will hold at high temps, maybe the green bearing locker? #609 I think.
ReplyDelete