IC 2 Cylinder Horizontal Engine

[Brian Rupnow]

Chuck--what's happening with this build? I'm still waiting for the video of the engine running on two cylinders.---Brian

[cfellows]

Chuck--what's happening with this build? I'm still waiting for the video of the engine running on two cylinders.---Brian

Hi Brian, I haven't abandoned the engine, just shelved it for a while.  I've been dabbling in other areas for the past couple of months.  Thanks for your interest.

Chuck

[cfellows]

So, here I am, jumping around on projects again.  Seems like I get bored with any one project so I've set the solenoid engine aside for now.  Not really on topic, but this is what I've been working on for the past Month or so...





It's a 3d Printer I started on well over a year ago and am now nearing completion on it.  Just have to add the print bed and the electronics.

But, to the topic at hand, I've pulled the horizontal twin off the shelf and am determined to get it running to my satisfaction.  The original intake manifold was leaking air around the base so I made a new one that seems to have fixed that problem.  I've also shaved 1/8" off the base of the cylinder block to raise the compression ratio from around 4.25:1 to about 6:1.  And finally, I'm making two new pistons.  The originals were kind of a sloppy fit and the o-rings just couldn't quite take up the slack, so I'm hoping to improve the compression quite a bit.



So stay tuned and I'll try to take this thing to completion before I jump back to something else!   

Chuck

[NickG]

Sounds like that should do the trick Chuck, will be interesting to see the results from your 3D printer. We are trying to convince the powers that be at work that one would be really useful to properly visualise concepts by printing scale models of things we design! They aren't buying it though ha!

[cfellows]

Thanks, Nick.  I got the engine back together now and I've learned a few things.  First, good, reliable compression makes a world of difference.  I now have wrist-breaking compression and it starts and runs way better.  I bumped the compression ratio up to something over 6:1.  The new pistons are very close fitting but do slide freely in the cylinder.  Here's a short video of the results so far.

<a href="https://www.youtube.com/watch?v=_W9aBWE4REg" target="_blank">http://www.youtube.com/watch?v=_W9aBWE4REg</a>

The other thing I learned is fitting the o-ring.  I'm using .0625 thick o-rings and I made the groove depth about .004" less than the thickness of the o-ring.  This compresses the o-ring somewhat against the cylinder wall.  I also made the width of the groove about .006" wider than the o-ring thickness.  This gives the o-ring plenty of lateral room to expand due to the compression against the cylinder wall.  It also allows a small amount of lateral movement which seems to help it seal.  At any rate. the compression is rock solid.

I still need to fiddle with the carburetion as it's way too sensitive at the moment.  After I get the carburetion sorted, I'll get the generator and light mounted to put a load on the motor.  I'm also probably going to need a cooling fan as the engine get's hot pretty quickly...

Chuck

[b.lindsey]

Fantastic Chuck, it is most definitely a runner and a good one at that. I was wondering as I watched the video as to the heat build up with both cylinders firing, then saw your comment as to the need for adding some kind of cooling. In any event, congratulations on getting it going!!

Bill

[gbritnell]

Hi Chuck,
It's great when you at least get to that point, it gives you something to work with. It's really frustrating when you're trying to start one and you don't know which one of the three, spark, fuel or compression is the problem. You are definitely correct about the compression making a world of difference.
gbritnell

[Brian Rupnow]

Chuck--Great to see it firing on both cylinders and running so well.---Brian

[NickG]

Runs superbly. I heard once that a groove for an o ring should be wider than the ring anyway to allow it to roll slightly to either side on each stroke.

Sent from my E380 using Tapatalk

[cfellows]

Thanks, Nick, I agree... somewhere in my past I've read that the groove needs to be wider than the o-ring to allow compression and slight movement to improve the seal.

Thanks, Brian, still got some work to do on the carburetion.  The engine is just to sensitive at low idle.

Thanks, George, I've always kind of known that good compression was critical, but have been in denial about how good my compression actually was.  It's not always apparent when the compression is less than stellar, but it is blatantly obvious when it's really good.

So, I think the tuning still requires some carburetor work.  Today I'm going to experiment with rotating the the venturi tube to see how pointing the fuel aperture more toward or away from the intake affects things.

I'm also wondering what affect a small groove in the venturi tube would have, either across the fuel aperture like this...



which would seem to make the mixture richer as the throttle was closed, or above the fuel aperture like this...



which should make the mixture leaner as the throttle was closed.  I'm leaning toward the latter since everything I've read says you need to lean down the mixture as the throtte is closed.  Any thoughts?

Chuck

[Tennessee Whiskey]

Chuck, she sounds great  . While you are playing with the carb think about some type of exhaust that would accentuate it's already great sound.  Maybe something like the old gutted tractor mufflers  .

Cletus

[Don1966]

Chuck you the man buddy, that engine sounds and runs a treat. Great work as usual and very educational as well. From an old coonass neighbor of yours, your the tops.........

Don

[Roger B]

That sounds good    I will be following your carb developments with interest  What electrical load are you planning to put on the engine?

[gldavison]

Sounds like a 2 cylinder John Deere. Love it.   

[cfellows]

Thanks, Cletus.  I'll definitely want to fiddle with the exhaust to get some good sound and something that looks reasonably authentic.

Thanks, Don, I do love Cajun music from down your way.   Some years ago, when I was still a working stiff, I used to travel on business to New Orleans pretty regularly.  Don't remember much of it though since I spent a fair amount of time (and money) imbibing the local spirits!

Thanks, Roger.  The DC generator will put out 50 - 90 volts depending on RPM.  I will power a 60 watt incandescent bulb with it since that combination worked well for me on one of my other engines...

Thanks, GL.  The John Deere sound is exactly what I was aiming for!

Fiddling with the carburetor today yielded varying results.  Turning the venturi tube to change the orientation of the fuel aperture definitely affected RPM, but I think 90 degrees to the venturi is the best position.  I now think my fuel tank arrangement isn't working well.  The engine will run like heck for 15 or 20 seconds then just dies.  When I disconnect the fuel line from the carburetor, there is no fuel in the line, so I either have an air leak or the vertical distance from the top of the fuel level to the carburetor is too great.  I think moving the fuel line outlet to the bottom of the tank and raising the tank level would improve things.

I figured as long as I had some momentum, I might as well get started on the generator.  Here's a picture of the DC motor I'm using and the block of aluminum from which I'll fashion the case.  The motor is 2" diameter by about 3" long, not counting the shaft. 



The first operation was to bore a 2" hole though the block to accept the motor...





Tomorrow I start shaping the outside of the case.

Chuck