[SEL] TWO THREADS

[Elden DuRand]

Bill:

First, just a little reminder to not use all capital letters.  No biggie but it's too much like shouting and hurts our eyes.

Anyway, per the valve timing, I assume you are talking about a low speed flywheel engine with atmospheric ("automatic" or "suction") intake valve.  If that's the case, the exhaust should open around 40 degrees before bottom dead center and close just a little past top dead center.  I find that most engines like to have the exhaust just closed just a few degrees past TDC.  A little fiddling with that may optomize performance a little.

As far as boiling of a hopper cooled engine is concerned, if it is throttle governed, it will eventually come to a boil even at no load, no matter how the ignition is timed.  The heat is dissipated via the boiling process, not by radiation so boiling is the normal running temperature.  If the engine is hit and miss and is running right and not pulling a load, it may never reach boiling.

As far as magnet charging is concerned, you need a very strong field in order to properly charge any truly magnetic material.  That means LOTS of ampere-turns.  The charging field needs to be several times stronger than the magnetized strength of the material being charged to overcome hysteresis in the individual poles and turn them far enough in the same direction that they stay there.  Having said that, I've just exhausted my knowledge of magnet charging and defer to the superior knowledge of others.   :-)

Take care - Elden
http://www.oldengine.org/members/durand


Take care - Elden
http://www.oldengine.org/members/durand 

> -----Original Message-----
> From: sel-bounces at lists.stationary-engine.com
> [mailto:sel-bounces at lists.stationary-engine.com]On
>  Behalf Of William
> Young
> Sent: Monday, October 19, 2009 05:54 AM
> To: SEL at lists.stationary-engine.com
> Subject: [SEL] TWO THREADS
> 
> 
> HI, GUYS   I'D LIKE TO GET SOME FEED BACK ON TWO 
> TOPICS, VALVE TIMING AND MAGNET CHARGING. 

.......................snip......................................

  BILL
> wmyoung at juno.ocn.ne.jp