Water Cooled Webster

[Brian Rupnow]

You are going to have to bolt that thing down to run it, or it will walk all over the table on you. You should have left the baseplate 1/2" longer at each end for a pair of 3/16" holes at each end. I generally screw my engines down to the test bench.---Brian

 

[bmac2]

Hi Brian
Ya this is just to hold things in alignment so I can continue working. I have no illusions of my “balanced crank” will have it running smooth as silk. I was eye balling a rather nice 4 ½” wide length of 5/8 hot rolled I spotted in the garage yesterday. I’m thinking if it’s about an inch or so longer than the engine with its weight and a piece of tool box liner under its bum, it just might not go walkabout on me. Going to see if I can get the manifold knocked out today. When I don’t know what I’m doing its good to know I have a couple of guys looking over my shoulder that do.

 

[bmac2]

While the rest of the engine was making an oily mess of my bench I got to work on the manifold.

P.S. Special thank you to Brian. Can’t remember which engine it was but great tip not to stand in front of the open spark plug hole when running in an engine with a cylinder full of oil. Remembered this at the last minute and you saved my shirt.

 

[bmac2]

I started by laminated the 3 layers of ¼ in aluminum that make up the manifold and squared it up bringing it to the size shown in the Webster drawing. The thing at the other end of the vise jaws is a failed attempt at a step block. It just didn’t turn out the way I wanted but the darn thing comes in real handy some days.

 

[bmac2]

Laid out and drilled the 4 bolt holes tap size, and step drilled the center up to 9/32.

 

[bmac2]

Swapped the drill chuck for the EM holder and used a 3/8 end mill to do the 1/32 counterbore. Flipped it over and counterbored the other side.

 

[bmac2]

Numbered the 3 layers with a Sharpie and split them apart. By laminating the 3 pieces and drilling the holes to the smallest common size I can now move the top block to the bottom and the bottom block to the top so the 1/32 counterbore is on the inside and as long as none are flipped or rotated I know the holes will stay in alignment. Put some small witness marks on the pieces and opened the top and middle bolt holes #43. Reamed the centre hole of the middle block to 5/16 and tapped the 4 holes in the bottom block #2-56 Then bolted it together. At this point the intake and exhaust ports are 11/64, I’ll open them up to the full 3/16 once I have the valve guides ready.

 

[bmac2]

I generally don’t like to buy these things because I never use them. But some days I have weak moments and Princess Auto got my $3.95. But this time I’m sure my valve springs are in there somewhere.

 

[bmac2]

Was ready to start on the valves and couldn’t tighten the bolt on the tool holder. Stripped down the compound slide and saw that the shank was sheering up through the bolt head. I guess the 56 years of reefing on it took its toll.

Cleaned it up as best I could and took it out to the garage to braze it. The brazing looked great and it feels solid but Murphy’s Law dictates that if I make a replacement now the weld will hold forever, if I don’t it will fail catastrophically.

 

[bmac2]

Well it didn’t take long and it’s sort of the same shape as a valve. Into the spare parts bin.

 

[bmac2]

Ok, back to the valves. I remember making the valve rod on my Elmer's Oscillating Cylinder Engine. What a nightmare, 1.375” long and only .086 in diameter.

 

[bmac2]

After completely failing at 3 attempts to make it I found an article on step turning small parts.
http://modelenginenews.org/techniques/stepturn.html
I indicated the .25 tool steel in the 4 jaw chuck and took it down to about .1 in ¼ inch steps.

 

[bmac2]

When I was within a couple of thou I blued it and just rested the lathe file on it to find the high spots.

 

[bmac2]

Then I lightly honed the cutter in place and ran it back and forth just touching the surface until it was down to size. Cut the 45 deg. On the end and parted it off
To drill the #60 hole for the retainer spring I first put a small flat on the valve shaft with a 1/16 end mill. Wow, in that picture it looks like the bit is in the chuck half sideways.

 

[bmac2]

The valve guides are pretty straight forward just following the Webster plans. I must confess that for the taper on the guides I just used a file. I have to say that making the spring retainers was pure joy after doing those valves. If anyone knows of an easier / faster way of making valves please chime in.
Oh ya. In that bad “O” springs I found some with the correct wire gauge and the right length for the intake and exhaust. $3.95 well spent.Thm:

 

[bmac2]

Lapped the valves to the seats and got the valve block assembled.

It’s done and I'm pooped.

 

[bmac2]

In most every wright up I’ve read on a IC engine build it has poor compression due to the valves leaking so I made this quick little adapter so I can connect the valve block to my compressor.

 

[bmac2]

WOW! I can’t believe it! They leak. Ok, more fiddling and lapping seems to be in order. Sorry no picture. Just imagine the picture above, but connected to a compressor and air leaking out of the block.

 

[Brian Rupnow]

I found that I needed to add a thin gasket between all 3 blocks to stop leaking.--otherwise, you can not tell if the valve is leaking or if the air is blowing between the blocks.

 

[bmac2]

Good idea Brian.
I spent most of my allotted shop time lapping and retesting the valves and they seem good but yes the whole block is leaking.
I made up full set of gaskets for all the mating surfaces