In this photo here you can see the chamber for the gas is all completely closed off
now. There are a few more parts to weld onto the main housing assembly like the valve
guide and a tube where the gas will actually go into the chamber, but I need to do a little
more turning in the lathe first...
Here you can see the main housing assembly in the lathe with the mounting face all trued
up and also the end of the large tube all squared up. I need to weld a plate on the end
of the tube to capture the gas valve assembly. I also cut a large chamfer on the tube for
welding the plate onto the tube...
In the first photo here you can see a 1/4" thick plate I have welded onto the main housing
assembly that will form a large ridge or shelf for the gas valve barrel to locate and be
clamped against. The second photo shows the original part, and if you look close at the bore
you can see the ridge or shelf I need to make on the main housing assembly I am
My youngest son Christopher is helping out on the restoration. In this photo he is doing
some clean up on the valve chest with the wire brush...
The main housing assembly is put back into the lathe so the plate can be machined. In photo
#1 you can see the corners of the plate disappearing. Photo #2 shows the corners all gone and
just a few more passes needed to get the plate and tube O.D. to size. This is the part of the
main housing assembly that will mount into the valve chest. Photo #3 shows the plate, tube O.D.,
and mounting face all complete...
Before setting up the boring bar, I drilled a hole in the 1/4" thick plate. In photo #1 a 3/4"
diameter hole has been drilled. Photo #2 is of a 2" diameter hole in the plate. I wish I had
some bigger drills. This really saves a lot of boring time in the lathe, roughing the hole in
with the drills...
Here in the first photo you can see the boring bar all setup and the hole now getting larger.
The second photo shows the hole bored with about .50 of material left so when the I.D. of the
tube is bored I can finish bore this I.D. That way both diameters will be concentric. The outside
face of the main housing assembly was trued up also...
Now its time to bore the I.D. of the tube. I had to remove the main housing assembly from the lathe, so
I couldn't pass the opportunity up to try the main housing assembly on the valve chest. This
photo shows how it fits on the valve chest...
In the first photo you can see the bore is starting to get cleaned up. There was quite a bit
of distortion from all the welding on the main housing assembly but doing the final machining
after the welding I was able to true everything up. Photo #2 shows the bore all finished. Also
you can see the (3) holes that the gas comes through to get into the combustion chamber...
The intake valve assembly is held into the main housing assembly with the air intake pipe which
screws into the end of the main housing assembly. I needed to cut some threads on the I.D. of the
tube. I used 16 TPI and in the first photo you can see the threads starting to take shape. Its
tough to see with all the cutting oil and chips in the photo. The second photo shows the threads
all cut and deburred. This main housing assembly has come a long way but believe it or not there
is still quite a ways to go...
The intake valve assembly can be machined to its finished size now that the I.D. of the
tube in the main housing assembly is completed. I setup the intake valve assembly in the lathe,
ready for more machining...
These next (3) photos show some of the machining on the intake valve assembly. Photo #1 shows
the barrel and ring all faced off. Photo #2 shows the front face of the intake valve assembly
all faced off. This is the end that the valve will seat against. The intake valve assembly is
now to the correct length too. Photo #3 shows turning the O.D. to make it fit into the bore of
the main housing assembly...
Photo #1 shows the stepped surface all turned that will seal the intake valve assembly to the
main housing assembly and also to the combustion chamber. I have left about .025 material on the
O.D. of the rings for final fitting to the bore of the main housing assembly. The next (2)
photos show drilling the hole in the guide for the intake valve. Photo #4 shows a piece of
3/4 diameter round stock in the guide that I am going to use to make the valve stem...
The bore of the tube in the main housing assembly still needed some work before I could fit
the intake valve assembly to it. The next (2) photos are a before and after view of the bore.
When I cut the 16 TPI, the I.D. raised up about .002 per side just in the area of the threads.
To remove the .002 I used a flapper type sanding disk in a drill. This worked real good and
it also worked for polishing up the rest of the bore. In the second photo you can see how
smooth it came out. I will measure the I.D. now, and then finish turn the O.D. of the intake
valve assembly rings...
With all the fitting done you can see the intake valve assembly going into the main housing
assembly bore in these next (3) photos. Photo #1 shows the step of the intake valve assembly
going up and mating with the shelf on the main assembly housing. Photo #2 shows the (2) pieces
all together. Photo #3 shows the other end of the assemblies. What will hold this all together
will be the air intake pipe that will screw into the 16 TPI on this end of the tube...
There is still a lot of work to do on the intake valve chest assembly but I am going to shift
gears here and make the intake valve. I started by making the stem first. In photo #1 you can
see the threads (3/4-10) are starting to take shape. In photo #2 I tried to take an action photo of
cutting the threads but the focus of the photo wasn't to good. Photo #3 shows the thread all completed
with a 3/4-10 nut on it. Photo #4 shows the stem in the intake valve guide...