Schlauncha
12-18-2009, 07:53 PM
It's just so tempting to look at what it would take to turbocharge or supercharge these little engines we have, since it could potentially double the power of a motor with only a simple bolt-on.
But if it only were that easy...
There are very few turbochargers meant for engines anywhere near this small, I think the smallest being of the Smart ForTwo and is rated for 240cc to 660cc engines. These turbochargers seem to be bought up as fast as they become available, because of the popularity of upgrading those Rhino's and other side-by-side atv's (Whatever the evolution of a JD Gator, that looks somewhat like a monster Golf Cart, is called). Their larger motors are the perfect size for those turbos I guess.
Thinking about small devices that convert between air pressure and mechanical motion, my mind comes to things like air powered tools, such as die grinders. I took one apart, the actual "motor" in it is only about the size of a C battery. That would be about perfect for these small motors! But when I back-drive it in my drill press at 3500 rpm, I could only get as much air to come backwards out of it, as about what comes from your nose during casual breathing. But I read online they're rated to go 25000 rpm, so maybe it's just a matter of needing to backdrive it faster. Installed, that would probably look like a 4'' diameter pulley coming off the camshaft, with a small toothed belt (like a miniature timing belt) driving like a 1" diameter pulley on the die grinder motor. It would be set up as a simple draw-through, so as to not mess up the carburetor. The housing I would machine for the die grinder motor to mount into, would take care of mounting to the intake flange on the head, and the carb would mount directly to it. This should keep things from changing position too much, for room considerations.
Well, if that can't displace enough, then what I've found through google is many people try to make these out of smog pumps from cars. These usually are a vane-style rotary mechanism that displaces air pretty decently, used I guess to cheat the emissions tests by diluting the exhaust fumes... strange that this was acceptable, but there's plenty of them out there. I dug one out of the back yard (literally) off an old rotary mazda, but it was rusted solid, and the thing was huge. Maybe on larger engines this would be okay, but there's just NO room on my atc70 for this. But IF one were in good shape, maybe a little smaller, and you had a larger vehicle it was going on, I could see using one of these.
Well right now I'm stumped. I will try running that die grinder the other direction in my lathe (my drill press could only turn it backwards) since maybe the motor only really works one way. I couldn't get it open to see what was going on inside, but it appears to be another vane-style motor like in the smog pumps.
Another option would be to make my own roots-style blower from aluminum. EDM could make some very precise profiles for the lobes, but I will have to check and see how thick the machines at school can cut. I would need to get a pair of gears first, to measure the distance between their centers at ideal mesh, so I could scale the lobes for ideal clearance. If material thickness is limited to about .5", it might be possible to make many pieces, and stack them on the same axle, and rely on the extreme precision of the EDM to make the parts all line up right. A person might even be able to add rubber inserts (made from automotive wiper blades) to work as apex seals on the lobes, if it becomes necessary to have a more airtight seal between things, and it is too tough to machine those clearances.
For the really small motors, like my ATC70, maybe an electric ducted fan would be a possible solution. A housing would have to be machined, but they could be the most bolt-on of all options, if bolted in-line between the carb and intake manifold (so long as it's okay to move the carb rearward by about 2"). Then just run power to the fan motor (which takes up to 14v) coming from that wire you can run a headlight off of. You could even put an adjustable resistor on there to control the boost pressure, but in reality I doubt you could barely get close to achieving a positive pressure in the manifold. But that might be enough to be a kick in the pants on one of these low-power motors. I mean, a new spark plug and a better air cleaner sure were noticeable. Plus the ducted fans I'm looking at, if you google GWS Ducted Fan, or look on eBay for them, are only in the price range of $15 shipped. Of course, it will take some machining to make a housing for them to bolt inline with the intake, but nothing too fancy at all.
Anyways just thought I'd start a discussion about this stuff, in case anyone else here has been thinking about, or made attempts at, making some forced induction system for their trike.
But if it only were that easy...
There are very few turbochargers meant for engines anywhere near this small, I think the smallest being of the Smart ForTwo and is rated for 240cc to 660cc engines. These turbochargers seem to be bought up as fast as they become available, because of the popularity of upgrading those Rhino's and other side-by-side atv's (Whatever the evolution of a JD Gator, that looks somewhat like a monster Golf Cart, is called). Their larger motors are the perfect size for those turbos I guess.
Thinking about small devices that convert between air pressure and mechanical motion, my mind comes to things like air powered tools, such as die grinders. I took one apart, the actual "motor" in it is only about the size of a C battery. That would be about perfect for these small motors! But when I back-drive it in my drill press at 3500 rpm, I could only get as much air to come backwards out of it, as about what comes from your nose during casual breathing. But I read online they're rated to go 25000 rpm, so maybe it's just a matter of needing to backdrive it faster. Installed, that would probably look like a 4'' diameter pulley coming off the camshaft, with a small toothed belt (like a miniature timing belt) driving like a 1" diameter pulley on the die grinder motor. It would be set up as a simple draw-through, so as to not mess up the carburetor. The housing I would machine for the die grinder motor to mount into, would take care of mounting to the intake flange on the head, and the carb would mount directly to it. This should keep things from changing position too much, for room considerations.
Well, if that can't displace enough, then what I've found through google is many people try to make these out of smog pumps from cars. These usually are a vane-style rotary mechanism that displaces air pretty decently, used I guess to cheat the emissions tests by diluting the exhaust fumes... strange that this was acceptable, but there's plenty of them out there. I dug one out of the back yard (literally) off an old rotary mazda, but it was rusted solid, and the thing was huge. Maybe on larger engines this would be okay, but there's just NO room on my atc70 for this. But IF one were in good shape, maybe a little smaller, and you had a larger vehicle it was going on, I could see using one of these.
Well right now I'm stumped. I will try running that die grinder the other direction in my lathe (my drill press could only turn it backwards) since maybe the motor only really works one way. I couldn't get it open to see what was going on inside, but it appears to be another vane-style motor like in the smog pumps.
Another option would be to make my own roots-style blower from aluminum. EDM could make some very precise profiles for the lobes, but I will have to check and see how thick the machines at school can cut. I would need to get a pair of gears first, to measure the distance between their centers at ideal mesh, so I could scale the lobes for ideal clearance. If material thickness is limited to about .5", it might be possible to make many pieces, and stack them on the same axle, and rely on the extreme precision of the EDM to make the parts all line up right. A person might even be able to add rubber inserts (made from automotive wiper blades) to work as apex seals on the lobes, if it becomes necessary to have a more airtight seal between things, and it is too tough to machine those clearances.
For the really small motors, like my ATC70, maybe an electric ducted fan would be a possible solution. A housing would have to be machined, but they could be the most bolt-on of all options, if bolted in-line between the carb and intake manifold (so long as it's okay to move the carb rearward by about 2"). Then just run power to the fan motor (which takes up to 14v) coming from that wire you can run a headlight off of. You could even put an adjustable resistor on there to control the boost pressure, but in reality I doubt you could barely get close to achieving a positive pressure in the manifold. But that might be enough to be a kick in the pants on one of these low-power motors. I mean, a new spark plug and a better air cleaner sure were noticeable. Plus the ducted fans I'm looking at, if you google GWS Ducted Fan, or look on eBay for them, are only in the price range of $15 shipped. Of course, it will take some machining to make a housing for them to bolt inline with the intake, but nothing too fancy at all.
Anyways just thought I'd start a discussion about this stuff, in case anyone else here has been thinking about, or made attempts at, making some forced induction system for their trike.