Moparman1
Posts: 68
Joined: 9/16/2005 From: Denver,
CO, USA Status: offline
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This post is going to be a long one, but let me clarify a few things here; first of all the 2 stroke engines used in most RC cars/planes/boats are self-charging, meaning that once air/fuel enters the crankcase it is trapped by the closing of the crank port and the already closed intake ports of the piston sleeve. As the piston travels down in the piston sleeve it compresses the fuel/air charge in the crankcase and pressurizes it. When the intake port(s) open on the piston sleeve the pressure in the crankcase and the downward travel of the piston force the air/fuel charge into the cylinder which inturn forces the exhaust gases out through the exhaust port. What most people don't understand about the combustion of nitromethane is that even after the exhaust port initially opens combustion is still taking place, which is why engines that run nitromethane have such a "cacling" exhaust note. The explosion that is taking place in the cylinder then travels into the exhaust pipe (tuned pipe) and is reflected back into the exhaust header where it is met by excess air/fuel escaping through the exhaust port. Some of the escaping air/fuel charge is forced back into the cylinder, but much of it is wasted as the exhaust port closes. The designers of modern 2 stroke RC engines were not fools, very precise timing of all components was needed to achieve the power levels of modern engines, so in response to the opinion that 2 stroke engines can't be turbocharged or supercharged, YES they can. Not only that, but super/turbocharging a 2 stroke engine could increase efficiency twofold. 1: more air/fuel would be combusted; 2: a more powerfull explosion would increase exhaust pressures forcing more air/fuel back into the cylinder. As for the value of RB innovation's "blower", it's hardly worth the aluminum it's machined from. It doesn't actually produce any boost, all it does is speed up the air entering the engine, similar to the way a roots blower operates. The rubber "belt" that connects the blower pulley to the flywheel is far too flimsy to hold any tension, causing the pulley to slip under any speed above idle. In most cases RB innovation's blower can actually be a hinderance to airflow. Lastly a turbocharger doesn't "pull" on the exhaust, it's driven by it. If you need proof look up any automotive design manual or talk to any competent (meaning not an import tuner) mechanic or proffesional engine builder. I'm not trying to be rude, I'm just trying to set things straight.
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