Engines for Sale

Sunday, November 21, 2010

The Brown Junior 60 Ignition Engine

Above are the patent drawing issued for Bill Brown's Engine
The engine Bill constructed in his Dad's workshop for his school design project in 1930

Below: My Recent Ebay Purchase
Brown Junior D Model or B Model?
How do I tell the difference?
 Equipped with an adjustable choke

Displacement 0.601 Cubic Inches;
Bore 7/8 inches;
Stroke 1 inch;
Horse power 1/5;
Weight 8 ounces;
Propeller 14 inches;
Speed 6200 R.P.M.

Running my recent Ebay purchase:-
After taking the time to gather the pieces and wire up a power transistor ignition circuit, I was disappointed to discover that the sparkplug was smashed and a full ignition run was out of the question. I did have an old champion glow plug laying around so I installed it and gave the old girl a run anyway just to listen to that long stroke sound.

This summer (2015) I was able to locate another old spark plug and attempt to realize a lifelong quest, by running the Brown Jr. on full ignition.
The video below demonstrates how we made out.

The Brown "B" was produced by Junior Morors Corp in 1934 at Philadelpelphia, PA. and for years this engine captured many flying contests and held manyrecords for model airplanes.

One notable achievement is an award to "Wm. L. Brown Jr., for Gasoline Powered Flight, 2 Hrs. 35 Min., 35-1/5 sec., May 28, 1934." where a Junior powered model was tracked on a cross country flight and returned to the originating point by a full size chase plane. This unbelievable accomplishment captured the attention of the modeling world which assured the success of brand for many years.   

Click the Play Button of the object below to view a short video showing the original Model "B" engines being assembled and flown back in 1934 as well as a modern scaled down replica running on full ignition.

The following information is from Collect Air Vintage Model Engines.

This engine is the Brown D, manufactured by Junior Motors from 1938 through 1942. The configuration of this engine, along with the placement of the serial number, 15032 D, shown on top of the lug, suggests that it was built in 1939 which was the peak year for production of the "D" engine (16,600 built) although the "bump" timer arm presumably didn't come out until a year or two later. The "D" is equipped with piston rings.

So now it appears that my new purchase from an EBAY seller is actually a D model and not a B model as advertised. 

Latest Old Brown Junior

Factory Data Sheet.

The internal components of a disassembled engine

My new question is: how does one know how to locate the cam on the crankshaft when there are 4 different choices and only 1 is the correct one for running?

Ray's Engine Running Nicely (see comments below) 
We always welcome your comments on our posts and appreciate a thumbs-up.


  1. David, that last video is my Brown Junior Model D. I'm glad you choose to share it. To answer your question about how to position the drive washer/points cam, Turn the crankshaft until the piston in near top dead center. The washer needs to fit so that the points are closed when the piston in near TDC.


    1. Thanks for that tip and the great video Ray. I am about to run my engine and I will make sure to set the points per tip. I am looking forward to uploading my own video.

    2. David, Once you get it going you'll need a plane to put it in. I fly mine in a 72" Kloud Queen. The engine works amazingly well for such an old piece of machinery and competing with it in SAM contests is such a blast. Anyway, I'm here to help if you run into any problems. Just post them on your blog. :-)


    3. Thanks for the advice Ray. I ran my engine yesterday but only on glow ignition. I was disapointed that the plug was smashed and I didn't get a chance to try my ignition circuit. I have an ancient Red Zephyr which I fly on floats. Perhaps it could fly it?

    4. A Kloud Queen powered by a Brown Jr captures my imagition,.I bet it sounds great too.I just ran mine and I can't get enough of the sounds from her.

  2. David,

    So you need a spark plug? They are available new here:


    Is your Red Zephyr the full sized 73-1/2" wing span? How much does it weigh? My Kloud Queen is around 4lbs and climbs out well. These engines are not very powerful so much heavier than 4lbs and it will be a real dog. I run a 13x6 MAS wood prop. I know some guys like a 14x6.

    It does sound great. In fact I flew her yesterday for a test-n-tune session in preparation for the SAM12 August contest. They are doing something special for the Brown Junior LER class. Here's what the CD, Roy Wilson, has to say in the newsletter:

    "27th Annual Oldtimer Meet

    This is the big one! Format will be the same as the Spring Meet except for Brown Jr LER:

    Through the efforts of Charles Thuet he has procured and secured a Trophy of May 9,
    1936 from a Model Meet at Hadley Field. Steve Kowalik had won the award, donated by Junior Motors, with his orginal design “Miss Delaware” The large and very original trophy will be inscribed with the winner’s name and aircraft as the winner of our event and then donated to the AMA museum. It is already inscribed with “Bob Peru, Walt Geary, John Delegrange” all well known to us. In addition to the trophy, the original Brown Jr engine that Steve Kowalik flew to win will go to our winner. A never flown ”Miss Delaware” will also be yours with a set of Steve Kowalik plans. Crank up those Brown Jrs. This should be a great event and well worth winning. We will serve lunch at noon and start “talking up” next year’s events. Some surprise awards will also be awarded at the event."

    I'm really looking forward to August 2. :-)

    1. I am hoping that you had a great Oldtimer Meet back in August, I wish I was there too.
      My Red Zephre is the full size version, built many years ago from a short kit that I located on the Internet. Actually its thae second one I built, the first one I built in the early 1950's from a kit;never flown, but hung from my bedroom cieling for years. I fly the current one nowdays exclusively at the lake. https://youtu.be/3FN0OTvi4DY

    2. David,

      I did have a great time. Managed to get first in Brown Junior LER and 1/2A Texaco. Took second place in Electric LMR. There's plenty of pictures here:


      Your video of the Red Zephre is great! That thing makes for a really nice float plane, oh and you live in a really beautiful area. What engine are you running in that video? I don't think a Brown Junior would have enough power to get the plane off of the water like that.

      I looked at some of your engine run videos. I especially enjoyed the diesel engine. Been wanting to get my hands on one to play with and maybe even power some sort of old timer. Mike Salvador runs a diesel in the Glow LER class and I love the exotic smell that thing produces.

      Here's a couple of cautionary notes for running Brown Juniors. You probably should avoid using an electric starter on them. The starter is hard on the bushing and will eventually wear to the point that the crankshaft's rod pin is carving into the rear crankcase cover. I like to hand flip my antique engines or use a chicken stick. The electric starter is the last resort and is usually not needed anyway.

      Do not run nitro fuel in a Brown Junior. It was never designed for the cylinder pressure that burning nitro creates. Also note that alcohol based fuels will melt the stock plastic fuel tank. Aluminum replacement tanks are available if you want to run alcohol based fuels. Whichever fuel you choose be sure to run the correct 4:1 fuel/oil ratio. This is called for in the Brown Junior manual so I stick with it. I blend my own fuel which consists of methanol and Klotz Benol racing castor oil. The advantage of using methanol is that it creates a little more power than gasoline and the engine tends to run a little cooler, which allows you to bump the timing up a little more. The castor oil also assists in cooling the engine as it takes some heat with it when it's blown out with exhaust. Oh, and it produces a lovely exhaust aroma.


    3. I am glad to hear that you had a great time at the SAM meet and that you were so successful in the classes. I am looking forward to viewing the site link pictures. I always love looking to SAM pictures and vids.
      Thank you so much for sharing those helpful tips for running antique ignition engines.
      The Zephyr has been around a long time and is getting heaver with age. It has been flown with many power sources, even witha clapped out O and R 60 with full ignition with a rc kill switch. Currently I am flying it with a Webra 61 Blackhead and it seems to require all the power it can put out especially on calm water.

  3. It's a wonder that engine didn't destroy itself. It was never made to run on glo or nitro. Just simple 3 to 1 gas and oil mix. 70 weight oil. 14-6 wood prop. I have several and I run them like they should be run and never start them with a electric starter. Tsk Tsk

  4. running your brown junior engine on a 3 parts 70-90 weight oil to 1 part gas would be much kinder to them and is as i understand it the mix used on the original engine. I also would never use an electric starter but i guess your glow fuel was to thin and there was not enough compression to start it by hand and i would guess that if you ran it for longer than a few seconds its probably used half its life