I am converting a 42cc Poulan:

Installing a CH Ignition with syncro spark.

I have got a crazy idea and I wanted to run it by you all to see what you all think?

Anywho... I thought it might be an interesting idea to add a blower to my engine (rear shaft) to force air into the intake of the carb...

Does anyone think this will work?

No, it wont work , two strokes on the whole (with one or two notable exceptions in some large industrial diesels) do not gain from aforced induction, mainley due too port overlap, all you will do is blow the extra charge out the exhaust port

Hi,
Crusty is right. Super charged two strokes like the detroit desiel don't use the case to pump the charge. They force the charge into the chamber through a valve like a four stroke. This allows many cylinders to fire at different times. When I was a kid we mounted a dental drill onto a Fox 15 to supercharge it. The pressure in the case got so high that the combustion migrated to the crank case. A Day Cycle two stroke like we use doesn't seal the combustion chamber completly during combustion like a four stroke. It is more of a continous flow through the engine. Needless to say the bottom of the case blew off. We were lucky that we didn't get hurt. It all happened very quickly. This was almost fifty years ago. We did a lot of wild experiments. We had crank shafts fly apart inflight long before DA thought of it. LOL It is good to see that you are using your imagination. Thats were great things come from.

Enjoy, Dave

First off, a Detroit has exhaust valves and intake ports in the liner, and a Detroit is not super charged, it has a blower on it. And yes, you can super charge, or turbocharge a 2 stroke, going to have to make changes to make it perform like its suposed to, and I don't think your going to do it with a squirlle cage blower, they dont' make pressure like a roots blower. I do know someone who made a turbo for a two stroke once, greatly increased the power, and instead of loading the motor more with more prop, they let it rev up much higher, and ripped the rod out of it at 22K rpm, and it was always very touchy, and never realiable. SS

Hi Steve,
I guess the Detroit deisel was a bad example, but many deisel engines use valve and port combinations. My point was that I don't think that pressurzing the crankcase through the carb is a good idea with a conventional stock two stroke. I have been there and tried that. How would you accomplish this?

Regards, Dave

Steve, this "someone you knew", did you get any of the details of the engine, I would be interested to hear how it worked

maybe get a b&s 4stroke trimmer engine and try the blower on that, if you are prepared to tinker you could get good results, just remember if you boost the input pressure without increasing the fuel supplied you could do some damage. Have fun and good luck

I think it was a YS61, and it had trouble ideling, and only screamed for about 3 minutes, and surprisingly quite! There was also a guy who made one and it was in an artical in a hobby mag some years ago, 80-87, this is what gave him the idea. I am sure it would work, esp with a gas engine, or on alky with ign, may have to have different port timing, just like a turbo detroit, for optimal performance. I am sure that just a couple of pounds of boost would make a big difference. As far as how to do it, ????. I don't need one on mine,LOL. When I need speed I use the dragster, and its got one of those fans on top, I know how to do those, LOL.

a lot of my two-strokes have superchargers...but i prefer to call them tuned pipes




dave

Carb would have to be mounted on the inlet side of the squirrel cage too. They don't like to be blown into.

a unit is currently made for model car 2 strokes , it was tested by some heli guys, it dont work its just b.s. hype, but people hear supercharger and think wow must be awesome.
Every time someone has told me they made one that works and provides a performance gain, they could only offer anecdotal evidence, Not enough to convince an old cogger like me
I remain open to enlightenment tho, I have a hat ready for eating

hi
I say just go 4 it man would be cool[sm=thumbup.gif]. If you feel like making it just go ahead.
Don’t let any1 change Ur mind or ideas[sm=sunsmiley.gif]. I made a turbo 4 my (2 STROKE) whipper snipper and it has made a significant improvement in the performance and the power output. I agree that a 2 stroke is not the best 2 be turbocharged or supercharged cause of the fact of having no valves and the whole 2-stroke cycle thingy. But I have proven that it can work and gains that little bit extra power where you need it.[>:]

1 tip I give U is to make sure to balance the blower well. Any vibrations could generate wear and tear on your piston and main bearings. Resulting in bad luck [&o]

good luck