New Engine Experiment - Rudy Kouhoupt Pioneer

[cfellows]

I always liked the way Rudy Kouhoupt's Pioneer engine runs, but never cared much for the design.  I think he built it as a prototype to see if it would work and didn't give a lot of thought to design. 

Rudy's Pioneer Engine:  <a href="https://www.youtube.com/watch?v=4cotsoGhJp8" target="_blank">http://www.youtube.com/watch?v=4cotsoGhJp8</a>

So, I've decided to disassemble my big, horizontal 4 stroke and see if I can make it into a 2 stroke like the Pioneer.  Today I made a new head for it.





The bore and stroke on my engine are about 10% bigger than the pioneer, but the bore to stroke ratio is about the same.  I already have the hall effect sensor mount and magnet carrier that attaches to the crankshaft from my previous 2 stroke adventure with this engine.  So, all I need to do is finish the new head, make new exhaust and intake valve assemblies, the cam and the pushrod.  Instead of a cam actuated intake valve, I'm using an atmospheric valve to simplify the design.  I'm thinking the intake valve will stay open until the spark plug fires.  The combustion should snap the intake valve closed, hopefully before the flame goes back into the carburetor... 

So, stay tuned and we'll see it works.

Chuck

[cfellows]

The Pioneer engine, as designed by Rudy Kouhoupt, appears to work like the Lenoir cycle engine.  It is a non-compression engine and fires on every revolution.  The operation in Rudy's engine is as follows:  The intake valve is opened by a cam at 6 degrees after TDC.  The intake valve remains open and the piston draws in the fuel/air mixture until 76 degrees after TDC where the intake valve is closed.  At 77 degrees after TDC, the spark plug fires and the burning mixture drives the piston the rest of the way to BDC.  A separate cam opens the exhaust valve at BDC and the exhaust gases are driven out as the piston returns to TDC.  The cycle repeats itself on the next revolution.

My engine won't have an intake cam.  Rather, the vacuum created by the piston as it travels downward from TDC will overcome the rather weak intake valve spring causing it to open slightly and allow the fuel/air mixture to be drawn into the cylinder.  When the piston reaches 77 degrees after TDC, the spark plug will fire, creating positive pressure from the expanding gases which in turn will close the intake valve and push the piston the rest of the way to BDC.  The exhaust cycle will work the same as the Lenoir cycle engine.

Chuck

[b.lindsey]

Interesting Chuck!  This is not one of Rudy's engines that I am familiar with at all but as his video shows, having the cams on the crankshaft should really simplify things while still making for a nice running IC engine. Good luck with the experiment

Bill

[gbritnell]

Hi Chuck,
I'll be following along to see how this turns out. I had heard of non-compression engines but I guess I was never curious enough to investigate further. From your explanation it now makes a little more sense but I'm still baffled by the fact that any power can be developed by the burning fuel, that is without compression. No doubt Rudy's runs so the proof is there. I'm wondering why normal internal combustion engines that don't have good compression won't run by this same principal.
gbritnell

[Roger B]

Yet another interesting concept to follow along  Thanks Chuck 

[cfellows]

Today I worked on the valve cage assemblies.  I needed 3/4" x 3/4" pieces but didn't have any so I started by whacking a couple of pieces off a cast iron bar.



Had a fair amount of shaping to do on the mill and lathe.  Here's what I wound up with.



I drilled and tapped 4-40 mounting holes in the head.



Here are the valve assemblies attached to the head...









Next I'll work on the valves.  Also have to plug up that hole on the outside of the head where the valve cages are attached.

Chuck

[cfellows]

Thanks for the interest, everybody.  George, I don't know why this engine runs and engines with low compression don't.  Good question.

Chuck

[cfellows]

No pictures today, but I did get the exhaust valve made and installed with the spring and keeper.  I also got the intake valve made but need to wind a spring for it.

Chuck

[smfr]

Following along with interest, Chuck. This will be, what, the third incarnation of this engine?

Simon

[cfellows]

Following along with interest, Chuck. This will be, what, the third incarnation of this engine?

Simon

Yep.  It started out as a model of a large 2-stroke like those that were converted from steam back in the early days of gasoline engines.  Couldn't really get it to run reliably, so I converted it to a 4-stroke side shaft engine.  Now I'm converting it over to a Lenoir Cycle engine.  I'm not materially changing anything, just replacing a few parts.   I can change it back to the 4-stroke any time.  However, I did modify and use some of the original 2-stroke parts, so I can't go back to that version with remaking some parts.

I have several reasons for converting rather than building from scratch.  Part of it is laziness, but I also have run out of room for all my engines.  If this latest version works out well, I will probably rebuild it from scratch.  Either way I'll most likely revert it back to the 4 stroke side shaft version eventually.

Chuck

[cfellows]

So, here's the intake valve assembly.  Still have to drill the intake hole for the carburetor.



I wound the intake spring on a 12-24 screw, using the threads as a guide for the wire.  Made a perfect spring.  The spring wire is about .009". 

And here's the exhaust valve assembly...



Still have to patch the hole on the outboard side of head where the valve cages attach.  I had to drill that hole to form the passage that goes into the head and leads to the cylinder.

Chuck

[AussieJimG]

Interesting engine Chuck, I have not previously heard of the Lenoir engine so you are again adding to my education. I will be following.

Jim

[cfellows]

Thanks, Jim, adding to my education as well! 

I'm getting pretty close...





I tapped and installed a 1/4-28 setscrew in the extra hole in the side of the head.  Then I drilled and tapped the hole in the intake valve assembly, 1/4" model pipe taper, so I could install the carburetor, one of several extras I had laying around.  Finally, I tapped the spark plug hole and installed the CM-6 spark plug. 

I think all I have left is re-installing the hall affect sensor & magnet disk and making the cam and push rod assembly.  Will hopefully have this thing ready for a trial run this weekend.

One thing I wanted to add is that if I do decide to build a second version of this engine, it will be pretty easy to just transfer the head and valve assemblies as one unit to another engine.

Chuck

[cfellows]

I'm in the home stretch but I've run out of steam for this evening.  Got the cam made as well as most of the push rod.



Tomorrow I'll finish up the push rod, remount the hall effect sensor and magnet disk, and install a longer length of fuel line.  That should make it ready for a test run... stand by!

Chuck

[cfellows]

Ugh... .  First test is disappointing.  Haven't been able to get a single pop from it so far.  I think the problem is the location of the spark plug.  On Rudy's engine, the spark plug is located in the intake manifold, directly opposite the intake valve.  I'm guessing the intake fuel mixture is passing directly over the plug and will ignite when it fires.  On my engine, the hole leading into the cylinder is directing the fuel mixture away from the plug so it won't fire.  A buzz coil which fires multiple times might cure the problem.  Not having one of those, I'm going to try modifying the head so the fuel mixture passes over the end of the plug.  Stay tuned...

Chuck