head in the stratosphere ?????????????????????????

[dwilfong]

OK its bin really mundane here lately and my brain is ready to go now after 2 1/2 years on the road.
I have a brain storm building and will let it loose here soon after my new shop is done next year.
I have a vision of two engines in one.
A piston ported one like the norm in gas eng with a completely different engine riding on top in the same jug.
May even inject it with a direct injection hole run buy a pump in the sleeve. Thank you Andy.........................
Babby steps.......LOL
Two carburetor's like the K eng...............................................
Two different intake tracks not connected at all.
The bottom side will be 4 small ports running threw the piston and at 4 corners of the cylinder like the NORMAL gas eng.
This will be the one run with oil to keep it all lubed up like a normal gas engine.
The top side will have its own carb and not need oil in the mix as the bottom side will do that.
Thy use this now to inject fresh air in-between the incoming charge and the ex charge to keep unburnt fuel from puking out the ex for emission in weed wackers and chain saws.
Now F the green weenies and stick a NITRO charge in it's place???????
O and a WT499 on the bottom side running 80/20 with the bag. Have to coddle the gas passers....LOL
Hard tank with pipe pressure , needle and NITRO on the top.
Glow plug to light it off and keep the ignition simple and light.
I will just leave this here......................................................................................................
Next year will be a good year for NITRO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
I am retired now and have all the time in the world.......................................
Lets get the party started...............................

 

[LohringMiller]

That's starting to sound like a version of an opposed piston engine I was working on. It fit the GX twin category with two crankcases each scavenging a pair of transfers. There would be a carb for each crankcase. Each crankshaft would drive a propeller and were counterrotating. The two exhaust ports were joined into a single pipe. I was using Quickdraw crankcases, but I would redesign it with the upper crankcases as part of the cylinder and everything 3D printed. I would still use off the shelf crankshafts and connecting rods. The pistons would need to be custom. Below are some pictures. The passage model gives a better idea of the design.

Lohring Miller

 

[RaceMechaniX]

Pretty cool Lohring, what crank phase offset are you planning?

 

[LohringMiller]

I "tested" (in a simulation) several leads. Below are the power curves. The number after the "us" is the lead. The lead mostly biases the curve to higher or lower rpm at similar powers.

I also simulated a lot of flows and pressures. I got another guy to simulate the flows through the engine at bottom dead center with the simulated flows and pressures. The big issue was scavenging the center of the bore, even though the long cylinder should scavenge well. The phasing from long and short transfers as well as various swirl and up angles didn't fix the problem. The guy got tired of running all the tests so I would need to learn how to use Fusion 360's pipe flow simulation. After all that it would still take a lot of development work. Below is a video from one of the flow tests for the twin pipe version.

Lohring Miller

 

[RaceMechaniX]

We were running quite a bit more asymmetry, 30Deg in the smaller 30CC, 10kRPM engine and between 15-18Deg in the larger 2.5L engine. We did a lot of work to create swirl on the intake ports to help scavenge the residuals in the center of the cylinder. In the 30cc engine we had a positive displacement piston compressor with roughly a 2.5:1 compression ratio and the large engine was mechanically supercharged plus turbochargered. Later it was driven by en eTurbo which is now entering production:

 

[dwilfong]

The idea I see in my head is the 4 small ports will be PUMPED in to the cylinder from the piston action like a normal gas eng.
Case volume will be minimized as much as it can.
This will be the jets to get the party going when the 3 separate ports boosts and transfers like a Nitro eng with there own carb will open up.
This top side section will have a strait shot to the ports.
This will look like two tea cup handles on the side of the eng and a strait shot boost port.
I am planning on trying my hand at casting my own jug and making a billet lower case with two end caps from round stock.
Will make the sleeve with some ductile iron stock this will give better control over the flow angles entering the cylinder.
Will use off the shelf parts for the crank, rods and pistons.
And of course I will build my own pipe for this eng.
The pipe will take control of the flow at speed and will be the key to making it work.
No valves in the way gust a piston. Strait shot thew the engine.