SAITO's new engine
#1

Thread Starter
#6

Tried that.... Does not work nearly as well as anyone thinks. Scratch that: It does not work AT ALL! It will in fact have a negative effect on cooling.
At 50 mph, the pressure at the intake of that ram air duct is a maximum of a whopping 3 mBar, and that value is only achieved with a fully closed exit.
That kind of weak pressures is NOT going to compress air into that converging exit. It simply is not. All it will achieve is a reduction of air velocity in the wide "ram air intake".
So there will be less air flowing between those rockerboxes, and at a lower velocity, resulting in less heat dissipation.
I can assure anyone from experience, that a diverging duct will have a better effect, and in fact will result in an improvement of airflow. A slight bit of divergence will go a long way, too much and the effect will be cancelled.
At 50 mph, the pressure at the intake of that ram air duct is a maximum of a whopping 3 mBar, and that value is only achieved with a fully closed exit.
That kind of weak pressures is NOT going to compress air into that converging exit. It simply is not. All it will achieve is a reduction of air velocity in the wide "ram air intake".
So there will be less air flowing between those rockerboxes, and at a lower velocity, resulting in less heat dissipation.
I can assure anyone from experience, that a diverging duct will have a better effect, and in fact will result in an improvement of airflow. A slight bit of divergence will go a long way, too much and the effect will be cancelled.
#7
Member

#8


I ran mine on the stand yesterday with the HS needle way out for the break in setting recommended in the manual. . The right cylinder seen from the front of engine was cold while the left was significantly hotter. I am not sure if the fuel going into the right cylinder is much richer, but find it hard to believe that there would be so much temperature difference. This is my first twin four stroke gas and am wondering if I should expect this