8 replies to this topic

[Paul Menkens]

I vaguely remember an ad in Model Trains mag showing an HO 2 track (model train track) figure 8 with  propeller driven race things (for lack of a better name) by Atlas, does anybody else remember this, or am l losing my mind, l'd like to see the ad if it still exists.

[zipper]

Has anyone made an actual propeller-powered rail vehicle for O-gauge?

[blue&orange]

 

Atlas body, Athearn HO Hustler band-drive chassis. Yes, I have run it, and it does work – to a point.

 

P.S.  There is one on eBay for $49 as we speak.

[Paul Menkens]

Thanks, guys. l guess l'm not crazy after all!

[Dave Crevie]

There are several prop drive trains.

 

Triang made these.

 

 

 

 

This version from Marklin was pretty popular, and still made today

 

 

 

 

These were made by Lionel in the 1950s. You can find a ton of them on e-Bay;

 

 

 

I don't know of any specific prop drive trains from Atlas, but they imported a lot from Europe, and might have brought over a version from Triang or Hornsby.

[Dave Crevie]

You are hardly crazy, Paul. Here are some weird prop drive toy cars;

 

This Japanese kit could easily be made into a slot car. ( no brakes, though )

 

 

 

And Cox made these tether cars for a while;

 

 

 

Someone was not happy with just fast. He had to build a five cylinder motor from Cox parts to make it really FAST.

 

[Dave Crevie]

I've blown up the Atlas ad. Great to see some Slotbloggers also read the model railroad blogs. Especially the O-scale ones.

 

 

[NSwanberg]

And Cox made these tether cars for a while;

Someone was not happy with just fast. He had to build a five cylinder motor from Cox parts to make it really FAST.

 

Screenshot 2025-02-15 090748.png

 

 

.049 X 5 = ???

[Dave Crevie]

.049 x 5 = 2.45 total displacement. Simple, no? 

 

A little tougher is to calculate the horsepower output. I found an article in an old R/C plane magazine in which they were discussing building scaled down working models of full sized aircraft engine. In one part they discussed using the cylinders from the Black Widow series of Cox .049 glow engines. There was a chart listing the power output they achieved with their dyno. Here is the chart;  

 

 

Two sets of results are shown, one row for the Black Widow, and one row for their "Gold Series" version, which has bigger ports and higher compression. I believe the cylinders on that five cylinder radial are Black Widow. It looks like peak output for the Black Widow was 58.2 watts at 15000 rpm.

 

So, using that info, and the standard conversion formula for watts to horsepower, we can calculate the horsepower output of a Cox Black Widow.

 

                 1 watt equals .00134102 horsepower. 

 

That means that the Black Widow puts out, , 0780462 horsepower. So, theoretically, the five cylinder engine should be putting out, .390231 horsepower. Now one of the mitigating factors, is how the connecting rods are connected to the crankshaft. Seeing that the cylinders are laid out on the same plane, 90⁰ to the crankshaft centerline, I would guess that this motor has the usual arrangement of connecting rods, where there is one main rod that has a bearing for the crank throw, and the other rods connect to the big end of that rod. Like in the illustration below.

 

 

 

In this arrangement, you are not adding the large frictional loss of a rod bearing to all five cylinders. So the power output would be somewhat larger. If each cylinder had a rod bearing on the crank, the cylinders would be slightly skewed to keep each cylinder squared up with the crank.

 

What I found most interesting was that the builder went with an odd number of cylinders. Glow engines are two strokes, and have a power stroke on every crankshaft revolution. Four stroke engines need two crankshaft revolutions to complete all four strokes. That means that a five cylinder, four stroke engine firing order is 1-3-5-2-4. A two stroke engine doesn't care how the cylinders are arranged. 

 

Now if you really want to go nuts, try tuning this mutha. 

 

https://www.enginehi...60/r-4360.shtml

 

Well, Nelson. I hope this sates your curiosity. For everyone else, there's the bell. You can wake up now. Class is over.