Chris, Alex, Bill, Brian, Kirk; thanks for your kind comments.
Brian- your comments on the spacer are spot on. I’ve always used a spacer. I can imagine the disappointment if you didn’t.
Kirk- saw the Volstros at Cabin Fever. They were priced at the top of the going rate so I suspect that’s why they didn’t sell. I got mine in an eBay auction for under half those prices, I guess I lucked out.
I never tried pressing a thinner liner; I’ve always done it this way. My Bridgeport bores a concentric hole if you don’t push the boring head with a heavy cut. I follow this up with a hone (just a spring brake hone) but if there was any taper I suspect I could work it out with the hone.
I’ve been working toward the time I need to fabricate the helical gears that drive the camshaft. This project is dead if I can’t make acceptable gears.
Up thread I talk about the process (thanks again George and Chuck).
I was so engrossed in making the crankshaft that my single train of thought didn’t move on to think too much about the gears
. Now that I’m there, I thought I would get some leaded steel that’s supposed to be very machine able: I’m thinking I’ll need all the help I can get. With that in mind I ordered a bar of 11L17 steel. It is supposed to machine “like butter” and is a stock used for gearing-
so the literature says. While I’m waiting for delivery, I thought I’d look into the valves.
I took lots of pictures, some aren’t that clear. Looks like I’ll need to start using a REAL camera, as opposed to my phone.
I’m using stainless steel for the valves. Don’t know what type it is; it was a gift from a friend who was closing down his shop. Here I’ve just started working the piece down to the largest OD.
Once this was accomplished, I needed to center drill the end. No way can I machine the slender valve stem and expect it to be uniform in width without some support on the end.
Now that the end is supported, I’m working the shaft down to the next diameter step.
Finally, I’m working on the valve stem itself. One of the things about your own design is that you can change the design as you go. I had originally specified these valve stems to be .094 dia.
This is ridiculously small for this size of valve. I changed it to .156 (also re-reamed the valve guides in the block).
Here I’m just finishing up a valve stem. They’re still pretty slender.
This is the setup I used to cut the valve lip. It’s a 60 degree angle and I used the compound on the lathe to facilitate this.
And a closer view.
After that I cut the valve off the stock and faced it. (Jo- you following?). In another thread Jo showed leaving a stub on the top of the valve to facilitate valve grinding.
I commented that this was a GERAT idea and I would certainly be using it on this engine, so of course I forgot all about it till I had faced the top of the valves.
Well, there’s always the NEXT engine.
All the Lauson engines use a pin, captured in a keeper to retain the valve spring. If it’s good enough for the full size, it’s good enough for the model.
Here I’m drilling the hole through the valve stem for the pin.
Since I’m NOT
using Jo’s method for valve grinding, I’ll cut a slot in the valve top and use the traditional screwdriver method. A woodruff keyway cutter works great for this.
Finally the completed valves.
While I was at it I lapped them to the valve seats. One valve needed very little lapping and the other; well, it took a while. Some keepers and springs and I’ll need to find something else to work on till the gear material arrives.
