1913 Evinrude Row Boat motor back in service.

[Pappy!]

I bought this engine a while back and it ran only one time and was a bear to start. Lots of blow-by which on a 2-stroke is a killer. It sat for a while,  then I disassembled it, then it sat for a while longer, then I diagnosed what had to be done. A friend of mine has access to a shop that can true and hone blind cylinders. He took the cylinder up to Tennessee and had that done. Brought it back a few months later.
Then I measured the cylinder, then it sat for a while longer.
Next step was getting a piston ring made for it. Not an easy venture however I have the luxury of being close to a great machine shop with an older master machinist that is tired of the same old stuff. When I brought him the old ring and told him what it was for his eyes lit up. A few weeks later I had a completed ring.
From this point it was a simple task of making gaskets and assembling the rotating assembly again. Not much to one.
It's not often a person gets the honors of bringing back a 107 year old piece of mechanical history.
Anyway....if you are interested this is part of what I have been doing with our stay in place time.

https://www.youtube.com/watch?v=3kVFGwRMBQs

[BCoy]

  Very cool, love to see the older engines with their simpler engineering. Even better when someone knows what they are doing and returns it to its former glory.  Great job!

[Challenger]

Love it! Good job, I was a tech for 44 years, rebuilt hundreds of small engines but never worked on a blind cylinder bore motor. Are you planning on puttering around on the lake with it, or just got it running because you could?

[_Sheffjs_]

 Very cool and sorry I still do not understand the eccentric ring. My p brain struggles, the ring is placed in one spot only and will not move or spin on the piston?  

[Pappy!]

The ring is built thinner on the ring end gap side on this engine due to the overall mass of the ring.
If you have ever had a typical 4-stroke ring in your hand you can bend it and twist it and close it pretty easily. Not much tension on them in comparison to what this ring can produce.
So....to reduce the ring tension at the open gap side the ring was built off center which gave the end gap side an overall reduction of .040 in material. This reduced the ring tension at the gap.
I knew about the off-center machining on it but for the Hell of it i assembled the engine with this ring prior to having the material removed. The amount of rotational friction was amazing compared to the finished ring.
In the ring groove on the piston there is a solid dowel pin. The small hole in the ring had to be located exactly in order to put the gap in the right place in the cylinder and to keep the piston ring from being able to rotate freely while the engine is running.
Should the ring rotate the ends of the ring will eventually enter an intake or exhaust port and catch in the opening. When the piston goes up or down with the end of the ring in the port it will clip the ring and destroy the engine.
How'zat?

[Pappy!]

I will be running this engine fairly often now. I really like how well they run and there are quite a few folks that seem to want to know about them and enjoy watching them or experiencing a ride in a boat with one on it.
I have 4 of these engines. I have not tackled the 1914 yet but it should be an easy one to get going compared to this one.
Two are gorgeous restorations that can run but the 1913 and the 1914 will be left with their 106 and 107 year old patina and history on their finishes and will be run pretty often.

[_Sheffjs_]

Ok but is the grove in the piston the same depth or mated to the ring. If the same it would not have the best seal on the cylinder in the area that is - .40?   This is completely new to me.

[Pappy!]

Good question! The piston groove is concentric and is the same depth all the way around.
Remember the stepped ring gap?
That pretty much seals the ring up tight. Not easy to build but it works. Also had the ring built with only a .006" gap. There is very little clearance at the top and bottom of the ring in the groove. The engine only turns around 900 RPM at WOT.
Secondly the gap on the ring faces straight down, where most of the fuel/oil accumulates. With the rich oil mix it has a bit better seal in that area.

[_Sheffjs_]

Pretty cool Pappy.  If school had subject matter like this when I was young I would have paid attention. 

[_Sheffjs_]

And I suppose you will keep us hanging on the cost of the custom ring? 

[Pappy!]

And I suppose you will keep us hanging on the cost of the custom ring? 

um......yes.

[flsix]

Very cool Pappy. It's good to bring something back from the dust bin to workable condition
I try to do that with older Marlins.

[ridingron]

I try to do that with older Marlins.   

AMC Marlins?

Marlin rifles?

Marlin birds?

Marlin boat motors?


eschew obfuscation.