The 101 Association, Inc.
For the preservation and enjoyment of 1928 to 1931 Indian Scout Motocycles
"You can't wear out an Indian Scout"

Front cylinder hotter then rear cylinder.

  • 28 Apr 2017 3:58 PM
    Message # 4790518

    Why is the front cylinder approximately 50 degrees hotter than the rear cylinder?
    Measured at 2 different 101 scouts.
    You would think the front cylinder is cooled more quickly by the wind.

  • 29 Apr 2017 6:40 AM
    Reply # 4791283 on 4790518

    There is many theories going around. Air flow around the cylinders, or more oil is spraying up the rear cylinder and cooling it, or uneven intake distribution because of fluid inertia of the air and the way the intake strokes are set-up. I don't know. Maybe a combination of all, but the most sensible explanation is that the front cylinder does more work than the rear. 

    The cause of this is due to the degrees at which the power stroke occurs for the front compared to the rear. Basically there is a longer lag time that the front needs to make up for.

    The crankshaft does not spin at an even speed during the revolution and the longer lag time for the front cylinder makes the crankshaft slow just a bit more than for the rear, thus the front has to work harder when accelerating the crankshaft. The cylinder pressure is what is doing the work, and when the piston has a higher resistance to do the stroke, the slightly higher average cylinder pressure that is produced is making a larger heat transfer to the cylinder material.

    Last modified: 29 Apr 2017 7:05 AM | Carl-Erik Renquist
 AMCA Chapter WebRing AMCA National 
Next >>       Random       Hub       << Prev
Classic Motorcycle Webring

Classic Motorcycle Webring

Join Now | Ring Hub | Random | << Prev | Next >>

Indian Motorcycles Webring
<< Prev | Hub | Rate | Next >>

Copyright © 2009 The 101 Association, Inc. All rights reserved. 

Powered by Wild Apricot Membership Software