[SEL] two questions about hit n miss engines

Orrin B Iseminger obise at moscow.com
Wed Sep 10 15:11:50 PDT 2008


My guesses are embedded within the original text.  

Orrin Iseminger
Colton, Washington, USA
http://users.moscow.com/oiseming/lc_ant_p/menu.htm
So many projects.  So little time.   

-----Original Message-----
From: sel-bounces at lists.stationary-engine.com
[mailto:sel-bounces at lists.stationary-engine.com] On Behalf Of Kangas, James
G.
Sent: Wednesday, September 10, 2008 12:23 PM
To: sel at lists.stationary-engine.com
Subject: [SEL] two questions about hit n miss engines

Why were so many of the early gas engines' speed governed by hit n' miss
rather then regulating the fuel/air volume? 

* Perhaps hit and miss were simpler to design.  Right off the top of my
head, besides throttle mechanisms it seems as though the early throttle
governed engines required air valves, such as those found on F-M and IHC
engines and Schebler carbs.  Then came venturi carbs and the gradual scaling
down of engines.

* In my experience hit and miss run cooler and the hoppers don't boil dry
nearly as fast as throttle-governed.  

Why  do these same early engines have such a poor power to weight ratio?
    Jim kangas

* I suspect that precedent played a large role in the mind-set.  First came
slow RPM steam engines with large bores.  The next step in the evolution of
engines was to make them internal combustion.  Of course, slow RPM demands
the use of large flywheels, something that doesn't help the power-to-weight
ratio one bit.  What inventor would have thought of a building small bore,
high RPM engine?  It certainly wouldn't have occurred to me.  

* The same thing happened with traction engines.  Steamers were monsters.
So were the first ones of the IC-engine powered variety.  The eventual
development of small gas tractors was somewhat revolutionary.  





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