Design and build side shaft hit and miss engine from bar stock

[Brian Rupnow]

I have thought long and hard about how happy I am with this engine, and I'm not terribly impressed---yet. I am going to make a few changes. The engine and the governor remain essentially unchanged, however the face cam and the cylinder head are going to change radically. Craig Deshong would quickly recognize what's going on here.---

[Craig DeShong]

Running great now Brian, you must be very happy   


From up above, yes I do.  And you've also designed a way to get to the valves without a design that requires you make them in parts and assemble them in the head.

[Art K]

I don't get it, I think I'll wait for the movie.
Art

[Brian Rupnow]

Art--You will like it. I have designed a new and different cylinder head to allow use of a more conventional cam set up.---Brian

[Brian Rupnow]

I am going to change directions now. Although the engine ran, and ran very well after I muddled through the carburetor and anti backflow valve issues, I'm simply not satisfied with the hit and miss action from the engine in its current state. I am going back to a much more conventional cam shape which will act on the exhaust valve thru the rocker arm.  The basic engine remains unchanged, and 95% of the governor remains the same. The changes will mainly be in the cylinder head, and the fact that the valve stems now set vertically and extend thru the underside of the cylinder head. I have seen this set-up on another hit and miss engine where it worked very well.

[Craig DeShong]

Art

Go back to the thread on my Myers build and look at the crazy  way they did the valves and you will.

[Brian Rupnow]

I've even been able to find a spot for the carburetor. The carburetor sets much lower than it did on the first go-round, but it is still above the top of the gas tank. I might have to put an extension on the carburetor needle valve to keep my fingers away from the revolving cam. Tomorrow I will make the new cylinder head. I can re-use the valves, valve cages, valve springs, spring retainers, and exhaust pipe and carburetor.

[Brian Rupnow]

So--If you were wondering what I'm doing today---this is it.

[Brian Rupnow]

People always like to see "in process" shots. I checked my stock this morning and all of my 1" aluminum was about 0.015" undersize, but I did find a bar of 3 x 1 1/4" stock. I cut out a piece on my bandsaw, then squared it up and milled it to 1" thick. The bolt pattern was laid out, drilled, and counterbored for #6 SHCS. Since I had set the part up in my mill vice and zeroed on the sparkplug (which is also the center of the cylinder)I drilled the hole for an M10 sparkplug. I then flipped the part over and plunged 0.7" with a 1" diameter endmill, then set up my boring head to put in the 1.181" diameter counterbore.

[gbritnell]

HI Brian,
I guess I'm kind of at a loss here! After all the work you put in on the first side shaft version, design, drawings and experimentation and then ultimately getting it to run well, what is the reason for almost a complete redesign of the engine?
gbritnell

[Brian Rupnow]

George--Part of it is that I don't really have a lot else to do. I don't have much "real work" right now, I'm not a television person, and I've read books until I'm all read out. I did confirm that I can successfully build a face cam. That was a first for me. Even with all the dialing and tuning and adjusting I did to that engine, it wasn't consistent enough for me.  There is actually very little that changes on the engine.  Most of the changes will effect only the cylinder head and rocker arm. I haven't lost anything. I will save that cylinder head for some future project. I enjoy doing this, and pushing my limits out a little farther in terms of what I can do.---Brian

[Art K]

George,
I think what he's saying is that he's bored and can't sit still. 
Art

[Brian Rupnow]

I love my rotary table. It lets me do things that none of my other machines can do.

[crueby]

Oh yes, the rotary table makes SO many jobs possible!

 

[Brian Rupnow]

Progress today on the new cylinder head design. It bolts on where it is supposed to. After mounting it I seen that there was potential for interference between the governor weights and the corner. Fortunately there is a lot of material in the corners, so I was able to remove some material. I may have to take a bit out of the water reservoir for clearance as well, but I will take a "wait and see" attitude with that.