Run vertical shaft on 2 stroke mix?

[robbie]

Remember the thread about weed whackers, where somebody mentioned a 4 stroke engine that runs on 2 stroke mix? I've been wondering if you could do the same thing with a vertical shaft Briggs 8 hp to mount it with the shaft horizontal. If you could mount the carb on the side of the case, then run a pipe from the other side of the case to the intake, and plug the breather, maybe it would lubricate the crank adequately. It's not like a car engine with oil pumped into the bearings. It's splash lubed under normal conditions, so maybe this would work.

I don't remember how the breather looks on these engines. I have one sitting outside so I ought to look at it. But I wonder if you could mount the carb there instead of the cover plate, to lube the valve gears directly.

I know it sounds like a crazy idea, but if you want to run a vertical engine horizontal you have to rework the carburetor mounting anyway....... but now that I'm thinking of it, it's probably a lot easier to just make an oil slinger and an intake adapter.

 

[crazycart]

I don't understand how you plan on getting air/fuel into the combustion chamber. The crank case and combustion chamber are separate, sealed off by the rings. There are no ports form the crank case to head.....You can make it work but it probably wouldn't last long or be good on a kart for that matter.

 

[oscaryu1]

Lol. Carburetor to the crankcase, and crankcase has a hose running to the intake port. When the intake port opens, it just so happens the piston is also going down.... pushing the 2 stroke mix into the combustion chamber...

Would want some reeds too.

 

[motor_head]

i suppose it could work don't know how long it would last
it would be much simper to make a dipper

 

[Doc Sprocket]

Adapting a Vertical in the "conventional" manner would probably be easier. More certain, anyhow. But- This would make an interesting experiment, and I'd sure like to see somebody take a shot at it...

 

[robbie]

Yeah, that's what I was thinking. It would be easier the normal way, but I'd be really curious to see how it turns out. I like the reed valve idea. Seems like it would create a slight supercharging effect.

 

[Doc Sprocket]

So... Go for it!

 

[Kenny_McCormic]

Why not, sounds like an experiment to me! You will want a pretty heavy mix for those plain bearings, 16:1 should do it. If I'm understanding correctly, cut a hole in the case somewhere for the carb to mount with reeds, then run a hose from another hole cut in the case to the intake port.

The only problem I see is you will lose some power compressing the charge on the power stroke. If you want to get really crazy, rig up a blower from an old smog pump or somehting, that will make up for it. Maybe use a 100ish CC 2 stroke in a draw through modified into a 2 stage pump(stage 1 being the case, 2 being the cylinder) running a 2:1 overdrive, it should hang on fine if you leave the briggs governed. If you are having trouble visualizing the pump, just block the exhaust port and enlarge the spark plug hole for a check valve.

It would still be a 4 stroke BTW, just with case induction.

 

[robbie]

Ever heard of an intake air chamber? It allows the air flowing through the intake manifold to pile up while the intake valve is closed rather than starting and stopping. If an air chamber at the intake port were combined with reed valves at the carb and at the crank case outlet, it might even have better performance than the regular configuration... maybe....

 

[sideways]

This would make an interesting experiment, and I'd sure like to see somebody take a shot at it...

I will, I'l get a Briggs mower from the tip next time I'm there, I like experimenting with these things.

Thanks

Hayden