Another Internal Combustion Engine

[rdean]

The cylinder block was cut to size and trued up all sides.



Over to the lathe to drill and bore for the cylinder liner.



Thanks for looking
Ray

 

[rdean]

Now another cavity cut 2 1/2" deep.
These aren't really that bad to do but there is a lot of handle turning and swarf to contend with.


The finished product.
Now to clean up the shop again.


The cylinder liner will be next.

Thanks for looking
Ray

 

[rdean]

I thought I had a cast iron rod large enough to make the liner from but I was wrong.
I did have a piece of steel rod that will work just fine.
Turned down to size with a larger lip on one end to fit a groove in the cylinder.


Cut off the waste in the band saw and faced the end to length.
Using different size drills and a boring bar the inside is turned to size.


The finished liner and cylinder.
Note the groove in the end of the cylinder for the liner to rest against.


I use red form a gasket to seal the water jacket and around the liner.
The liners lip is longer than the groove in the cylinder is deep so I then place the liner and cylinder in the vise overnight to cure. I found out the hard way that when the form a gasket cures it will push the liner back out of the cylinder which doesn't show up until you try to start the engine.
When cured the liner and the cylinder face are surfaced in one operation.

Thanks for looking
Ray

 

[rdean]

Here it is after facing off the cylinder.


Thanks for looking
Ray

 

[rwm]

Beautiful. Why such a long throw on this one?

 

[rdean]

This project is definitely going to be an experimental model of hopefully a slow running hit miss engine.
3" stroke (never built one with that long a stroke)
1.250 Bore (I had to go that big to get the connecting rod in the cylinder)
8" diameter dual flywheels. (The 5" ones just aren't going to make it. I will use them for some other project)
Side shaft cam. (A new build experience for me)
5.5 to 1 compression (maybe even lower to start with)
19/64" valves (To limit the engines power)
Fly ball governor
Any of these items may change as the build progresses.

I cutout the connecting rod today.

Top

Right off the CNC machine.
This sucker is over 9" long.
I wonder if it will be strong enough for this engine.


Connecting rod with wrist pin ball bearing and 1.25 piston.


Well so far my measurements are working out and the crank shaft does turn.
I did have to taper the end of the liner for clearance.

The cylinder is not attached to the rails yet that's next.

Thanks for looking
Ray

 

[Chris Hamel]

Starting to look like an engine. I love that you are leaving things open to changes as you build.

 

[rdean]

Thanks Chris

I got the cylinder mounted on the side rails and the screw holes all lined up.
The cylinder is well aligned with the side rails and the crankshaft turns freely.


Made up a drawing for the side camshaft supports.
Will cut them out later.


There won't be much room left between the engine block and the flywheel with the side shaft gears in there but I think it will all fit.

Thanks for looking
Ray

 

[rdean]

Cutting out the cam shaft supports.


Hot off the mill.


The cam shaft drive gears can be either helical or bevel gears. The helical gears are more compact but much more expensive and a 2to1 ratio is also rare. I will be using the bevel gears but there are still problems with size. In order to get the pinion gear big enough so I could mount it on the crankshaft I had to go to Mod 1.5 which has good sized teeth on it and that makes the driven gear quite large.
Here is a shot of how I modified the pinion gear to fit a 12mm shaft and shorten it up as much as possible. There isn't much meat left on the inside hole. I was able to shorten the length of the gear considerably but that meant most of the original set screw holes were cut away. I pressed a brass collar over the gear and drilled and tapped through that for the set screw.


The driven gear was reduced in size by 1/2" which meant cutting away the outside of the teeth. I didn't need the full length teeth for this application anyway.


I mounted the cam supports on the engine and there was just enough room.


The driven gear is only about 0.050 away from the engine base and I now have 0.950 of shaft left for the flywheel.


Quite happy with how things turned out. (maybe I should make my crankshafts longer in the future)

I was turning the engine over with the drill when I realized I had another big problem. Even at 250 rpms the engine wants to leave the shop. I will work on that issue next.

Thanks for looking
Ray

 

[rdean]

I weighted the connecting rod, piston, and the rod journal bearing together and they came out to almost 5 oz. Now after much deliberation and concentrated thought using several data pages and checking the phase of the moon I came up with the size of the counter weights that I needed to make.
(Really I just guessed)
Cutting the counter weights from some 1/2" thick bronze.


As long as I had the material mounted on the mill I cut out the cam also.


The two weights together are 4.4ozs but they are mounted out further on the crank webbing so it should all even out.


A test at 1000 rpms proved to be very satisfactory.

Thanks for looking
Ray