My Flat Head Hit Miss Engine

[SteamChEng]

Nice work, Ray. I really like the way this is going!

 

[Rdean33422]

Thanks SteamChEng glad to have you along.

Short day today but I got the timing gears mounted.





Next will be the lifter and push rod for the exhaust.

Ray

 

[Rdean33422]

Today I made the valve lifter or I made two of them. I forgot to leave material for the roller bearing on the first try and then I thought maybe I might be able to salvage it but I knew it would never be right so I made a second one.



Things went well after that and I have the exhaust valve train completed.





Will work on the governor next.

Ray

 

[Rdean33422]

I was able to get the governor gear box completed today. It runs off the cam shaft so there is some speed increase to the fly balls. I have made this governor type on two other hit miss engines but they ran with a gear reduction and powered from the crank shaft. Nothing real scientific here I will try this setup and see how it works.







Thank you everyone for the "Likes" it lets me know how I am doing.
Ray

 

[Rdean33422]

In the past I have always made the fly balls separately and drilled and taped them for the arms.
I thought I would try making them all in one piece on the lathe.


This worked out very well and a lot less work. I also made the spool and cross brace.


And a couple of pictures of the completed governor.
I still have to cut some off the shaft.




Next will be the hit miss mechanism.

Thanks for looking
Ray

 

[Rdean33422]

Lots of fiddly little things to get sorted out but I have the Hit-Miss mechanism completed.
Spinning the crank shaft with a cordless drill confirms it does work as designed. There will still be changes to the spring tension and other adjustments after the engine is running but it is working as I hoped.




I had one oops today in that I broke a 6-32 tap in a deep blind hole. I was able to eat the tap out a little piece at a time using an 1/8" end mill and then taped for a larger size screw.

Thanks for looking
Ray

 

[Gedeon Spilett]

Always a great pleasure to see a well thought-out personal design taking shape, thanks to share the build !

 

[Steamchick]

Remember, bob-weights do not need to be spherical. Just tradition made them that shape. Cylinders and cones can put mass where you want it (c of g distance from the fulcrum) if you want to make bobs from found stock in the lathe. You can also be creative with artistic shapes... which is really what you have done. Whatever you fancy? Don't limit your designs to the traditional, if it works?
K2

 

[Rdean33422]

Always a great pleasure to see a well thought-out personal design taking shape, thanks to share the build !

Thank you for the kind words

Steamchick you are right and I have used other shapes before but for this engine I wanted the traditional design.

Thanks for looking
Ray

 

[Rdean33422]

I finished up the piston and connecting rod today. Since I had moved the crank shaft and the cylinder block an inch further apart than I had originally planed I was hoping the connecting rod would not hit on the piston liner. Well it still did so you can see how I narrowed the rod to compensate.






My connecting rod length came out right, almost flush with the cylinder face.


I will finish work on the flywheels next.

Thanks for looking
Ray

 

[Rdean33422]

I made and polished the flywheel taper locks and mounted the flywheels on the engine. Everything fit and lined up correctly.


It was time to make a wood base for the engine and I had a piece of poplar that would work fine. Before applying the finish to the box I drilled holes for the wiring and made a cutout for the switch.



This is what it looks like with a spray finish and the motor mounted.


I polished up the cylinder head and drilled and taped for the spark plug.


A view from underside showing the electrical components and the rubber feet.


Thanks for looking
Ray

 

[Rdean33422]

Lets make a gas tank.
I started with a 1 1/2" diameter piece of aluminum that I turned down to 1.200.


I cut it off at 3" and bored out the inside to leave me a nice wall thickness. (I didn't measure it)
Then bored an inside lip for the tank ends to sit in.


I like to have a tank I can see the fuel level in so I cut a couple of 1/4" plexiglass squares larger than the size I needed. I put some masking tape on both sides of the squares to protect them from scratches. I put one steel slug in the three jaw chuck and then squeezed the plexiglass with another slug in the live center of the tail stock. This really works well and I was able to turn the square into the correct size round to fit the ends of the tank.


Here are the completed ends and the two slugs I used plus I turned and pressed in a brass nipple for the gas line.


These are the parts for the tank with a filler bung and a brass gas cap.


I used 5 minute epoxy to seal the ends of the tank and the filler bung.
A couple of aluminum stands and copper straps finishes off the gas tank.


Please let me know what you think.

Thanks for looking
Ray

 

[minh-thanh]

Nice engine.

 

[Steamchick]

I like the technique for holding the plexiglass while turning. Is it petrol resistant stuff? How about the epoxy?
K2

 

[Steamchick]

I might have used Viton o-rings to seal the ends - clamped into the tank body?
K2

 

[Rdean33422]

Nice engine.

Thank you Sir much appreciated

Steamchick I have used this method on several models and have had no problems to date. The plexiglass and the epoxy are not special just over the counter.
Ray

 

[rickhann]

I made and polished the flywheel taper locks and mounted the flywheels on the engine. Everything fit and lined up correctly.

View attachment 145251
It was time to make a wood base for the engine and I had a piece of poplar that would work fine. Before applying the finish to the box I drilled holes for the wiring and made a cutout for the switch.

View attachment 145252

This is what it looks like with a spray finish and the motor mounted.
View attachment 145253

I polished up the cylinder head and drilled and taped for the spark plug.
View attachment 145254

A view from underside showing the electrical components and the rubber feet.
View attachment 145255

Thanks for looking
Ray

 

[rickhann]

Ray, I noticed that you have four holes in your taper lock. I I suggest you tap an additional 2 holes on opposite sides to use for jacking screws to remove the taper lock. I have made several of these taper locks and have found that they can be a bit of a challenge to remove once tightened. I hightly recommend taper locks for flywheels as they practically eliminate any perceptible wobble. Sorry for my accidental previous post. Rick

 

[Rdean33422]

Rick you are so right I always tap two holes for jacking it is probably hard to see them from the pictures.
Thanks for the reply.

Today saw a lot of progress as I got a couple of 1/8" brass 90s in the mail. I turned one of the male ends down to 0.312 and threaded it 5/16-24 to fit in the cylinder head. The other street 90 threaded into the first one and things lined up as planned. (hoped)
I found a chromed lamp tube that threaded right into the 90 so the exhaust is done.


Since I was on a roll I made the carburetor and it fit too.
Also checked the gas tank for leaks and none found.


I glued a hall sensor on to a piece of wood and mounted it on the side of the frame.


Turned an aluminum disk for the magnet and set the timing.


There isn't much left to do but I ran out of time for today.

Thanks for looking
Ray

 

[Rdean33422]

Yes it runs

Issues that had to be fixed.
I had to move the gas tank up 1" as the fuel level would drop in the fuel line and there wasn't enough time left for the engine to pick it up and fire after it had coasted. I tried to make an inline check valve but that didn't work out so just move the tank.


The governor drive o-ring was slipping so I cut a new one from some larger diameter stock and super glued the ends. Works fine now.
Other than what I mentioned there were no other problems just the usual adjustments and tweaking of a new build.

OK here's the video


Some of the things I have learned is this style of head arrangement seems to require a richer mixture than other overhead valve engines I have built. She wants to have a little choke to start even if the engine is warmed up. There are more intake strokes needed before the engine fires again after the coasting cycle. I suppose all of these things are because the fuel air mixture has further to go to get to the spark.

I ran the engine straight for over 15 minutes with water in the hopper and the temperature was 120 degrees.
The engine low speed was 540 rpms with a high around 800 which is a respectable range but not as good as some of my other engines.
I may in the future plane some off the head to increase the compression ratio and see how that works but for now it is complete and a success.

Thanks to everyone for following along with comments and likes.
Ray