[SEL] Wierd Mechanics

[Elden DuRand]

Arnie:

I'm still working on an engine, although not too rare, can be called wierd.

It's an Edwards horizontal hopper cooled 2 cylinder.

Wierdnesses:
- The flywheel is between the crank throws.

- Both valves (for each cylinder) operate via one rocker arm.  The arm moves from "neutral" to open the exhaust, then swings through "neutral" to open the intake valve.  With such a system, there can never be any overlap.  (I know that this system was used on pre-1910 Stoddard-Dayton cars and was soon abandoned).

- Oilers (one per cylinder) oil the piston, wrist pin AND the big end bearing via a copper tube which ran between the little end and the big end bearing.

- All but the very first engines use a gravity fed float chamber with separate lines going to a mixer for each cylinder.  (Earliest engines used a suction system with check valve which was standard practice in that day.).  This is a really complicated way to do a simple job.

- There is no way to choke the engine to start it.  With the rocker arm cover on, there is a space between the inlet end of the mixer bores and the holes in the cover (for priming).  You can't just put a finger over the hole to suck up some gas.  You hve to "Prime" it by squirting a little gasoline into the inlet ports.

- The engine can be run on one cylinder or both depending on, according to the maker, how much power you need.  This is accomplished by simply turning the fuel off to one cylinder and letting it be cranked by the other.  Not very efficient.

- Starting is accomplished by wrapping a leather strap around the pulley and hauling on it.  The way the strap winds onto the pulley assured that you stand a really good chance of getting slapped in the face by the strap when it unwinds.

- At the top of the stroke, the pistons stick out enough to expose half the width of the 1/4" rings.  At least you don't have to worry about a top ridge!

- There is a separate exhaust pipe and muffler for each cylinder and a complicated bit of casting in the head for the leads to the pipes.  Why?

- On the ignitor version of the Edwards engine, piston strike ignitors are used.  I believe this method of tripping ignitors was abandoned long before the Edwards arrived on the scene.

I'm sure that right after I post this, I'll think of one or more additional wierdnesses.  Go to my webpage and click on the picture of the Edwards engine for the restoration narrative and photos.

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 Arnie Fero
> Sent: Friday, December 14, 2007 05:13 PM
> To: The SEL email discussion list
> Subject: [SEL] Was: Latest engine Now: Wierd Mechanics