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Old 10-15-2016, 08:09 AM
Johnincali Johnincali is offline
Motorized Bicycle Newbie
Join Date: Oct 2016
Posts: 8
Default Re: Dolphin powered bike... a different kind of 2 stroke

Hi MT, Those engines are typical 2 stroke boat engines manufactured by a company called Dolphin in the 1950's and 60's ... They are not the same as the original dolphin type engine that uses a piston to charge the cylinder...

Also I think most of the reason the Dolphin runs smooth is because it uses top / down uniflow scavenging... this causes the fuel / air near the spark plug to be in an ideal state for combustion. Ricardo also used a narrow passage to ensure the engine idled smoothly but IMO a narrow passage is also wasteful and not the best answer. I developed a different combustion chamber design which also allows for smooth running.

Most small carbureted 2 strokes use ether cross or loop scavenging which tends to not idle smooth... they also loose a portion of the unburned fuel out the exhaust which makes them not good from an emissions standpoint.

Modern low emission engines like the E tech and Orbital use a system that injects the fuel after the exhaust port is covered.

Last edited by Johnincali; 10-15-2016 at 07:41 PM.
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