LHL-14: A horizontal long-stroke

[MuellerNick]

Hi!


As a side-project, I have been dreaming about a super-longstroke engine for long. So I finally designed it.
Bore is 45 mm, stroke is 90 mm, 143 ccm 4-stroke. Plan is to have a real slow-runner. Castings are made from my own patterns.
Will be water-cooled. I wanted something long and slender. The base-plate will be about 700 mm long, flywheel-diameter 350 mm. I'll have to recycle the flywheel of an other engine, because I'm not sure wether I can cast cast iron now or not (modified my furnace).




The last pattern (the base) is still in the mill and be ready in about an hour. Tomorrow, I'll do some finishing on the patterns and maybe cast on Sunday. I'll see…


Picture #1:  The cylinder. Left and right are sticking out the core prints. I'll cast it around a precision-drawn tube.
Picture #2: Core box for the water-jacket (that goes around the cylinder-barrel.
Picture #3: Bearing covers for the crankshaft bearing and the camshaft.
Picture #5: Core box for the channels in the cylinder head.
Picture #6: Mounting bracket for the camshaft.
Picture #7: Cylinder head, core prints for the channels sticking out.
Picture #8: The base still in the mill.


Nick

[steamer]

Nice stuff Nick!

Dave

[MuellerNick]

Last pattern is off the mill.


The cylinder,
All main parts "assembled"
And a detail with the bracket for the camshaft.




Nick

[MuellerNick]

And a top-view from the CAD:




Nick

[ths]

Very, very nice indeed, Nick. What is the pattern material?

Hugh.

[MuellerNick]

Pattern material is block material  from Renshape with a density of 0.7 kg/l.
They don't suggest it as pattern material, but I had good experience. The real stuff would cost about 4 times more and would last hundreds of castings. Easy to mill and good for final sanding. But it needs a layer of paint, can't be polished and the sand sticks a bit to it.


Nick

[steamer]

Gas or Diesel?

Dave

[Maryak]

Nice Patterns Nick 

Best Regards
Bob

[MuellerNick]

Thanks for the nice comments, ladies!


In the first posting, I forgot the description for picture #4: Pattern and core box for the piston.


Engine won't run on Diesel. Gas or gasoline, I haven't decided yet.


Nick

[ths]

Ladies? I thought that was only one of us.

[steamer]

OK so the valve gear is ohV....gear reduced on the side...and then a rocker shaft  mid engine.

What's that rocker shaft look like...seems unusual....?

Dave

[MuellerNick]

What's that rocker shaft look like...seems unusual....?

Well, unusual. I didn't want to follow too much conventional patterns how things look(ed) like. So the cam went to the base of the cylinder, driven by spur gears (are they called that way?). From there short rockers right in front of the camshaft. They only help to keep the pushrods in place. Pushrods go to conventional rockers. The rocker shaft is on two turned poles.
All this setup to keep the engine slim. Also, I wanted it to be as low as possible, just with the flywheel as the big part. So part of the counterweights of the crankshaft go through the engine's base and the base-plate. And obviously the flywheel. Slightly inspired by the Mery engine, but all shifted down as much as possible.


OHV to keep it narrow and to make it longer. This engine will be very long (if you look at the top view). I also tried to add as many features to the cylinder to avoid having to add external features. -> Few castings, exploiting the fact that I can cast. The head is not water cooled. I could cast that, but it wasn't worth the effort to me. This engine is not a power plant, it's a display engine that runs slow, hopefully very slow. I'd like it to run below 50 RPM.


The camshaft also has an excentric that drives the coolant pump. That pump also is a bit odd, as the pump itself doesn't have any valves. The valves sit in the water inlet and outlet to the water jacket.


Attached, a picture of rocker arms with the shaft on poles.




Nick

[steamer]

OK....understand it now....I couldn't tell if it was a rocker shaft or rotating cam.....clearly it is a rotating cam....though a rocking cam with big mushroom tappets would be interesting to watch.

Watching along Nick!

Dave

[MuellerNick]

though a rocking cam

A rocking cam? No, I never had the idea. But I'll try to remember it!
The gearing would be a bit odd, but interesting to watch.
Also the fact that the cam accelerates when it is lifting and decelerates when it is closing the valve.
Does that setup exist somewhere? Never seen that.


Or maybe, I imagine something different than you do?


Nick

[steamer]

Nope....but that's what struck me with the picture of your engine....and I agree...it would be interesting!

Still watching....

Dave