1/4 Scale Gade Build

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Thanks, Everyone for the encouragement. I may have something to show this year at Cabin Fever!
Thanks, Jared for putting on a great show every year. I haven't missed one yet!
cheepo45
 
I got some painting and assembly work done over the weekend.
The Gade is starting to look like something now!
cheepo45

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Looking good, what finish have you used on the cylinder & head?
 
That does look nice!

Good to see some more progress on the Gade

Dave
 
Thanks, everyone!
The cylinder and head are painted with krylon high heat aluminum. I like the flat finish. The base and flywheels are krylon antique red. I want the engine to look like an antique, so I may degloss the base and flywheels with some scotchbrite.
cheepo45
 
Hi Everyone,
I have been working on the small parts for the governor and cam systems. Things are coming along well, but not without some struggles. Several of the dimensions for the governor system are way off from what they should be. I'm glad I did a lot of dry fitting as I machined the parts, or I would have been making them over. I had to spot face the side of the base casting so the ignition trip would turn, and the dimensions for the cam roller pin and the hit and miss latch bar were off by a lot. I was kind of surprised because all of the rest of the drawings were spot on.
I did get everything working as it should, and I am looking forward to finishing this engine. I still have some springs and other small parts to make and assemble, and then the skids and display box to build. I'm not sure if it will be running at the Cabin Fever show, but it will be on display!
cheepo45

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Hi Again,
The cold weather has done wonders for my engine building.
I spent the day yesterday assembling and testing my ignition system. I am using a T.I.M. from Jerry Howell. I had purchased the kit several years ago for the Farm Boy that I haven't built yet. It looks like it should work fine for the Gade.
I haven't built any electronic circuits for quite a few years, but it all came back to me and the kit went together well. The only issue I had was that one of the resistors was missing from the kit, A quick trip to Radio Shack got me the part I needed and a nice battery holder. It puts out a nice blue spark when triggered.
I have also sanded, stained and assembled the wooden skids. Now the engine looks like it's supposed to!
I still need to build the carburetor, oiler and fuel tank, and make a wooden base for everything. It may be running for the Cabin Fever show!
cheepo45

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Please explain the advantages of the Gade exhaust system, and how it efficiently cools the engine cylinder to prevent overheating. I can't figure it out.

I see an auxiliary exhaust port, I see what looks like an atmospheric intake valve, and mechanically operated, in-head, conventional exhaust valve. Is it the secondary exhaust port that differentiates the Gade from any other air-cooled H&M engine? How/when is the secondary exhaust port opened? Does it continually open as the piston head clears the port hole that's drilled into the side of cylinder, when the piston reaches BDC? I'm missing something, as usual. Thanks for the explanations.

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A few other things to ask:
1- Do you think any scratch-built, air-cooled, H&M cylinder could be designed/converted to operate in this fashion?
2- Would gearing an air-cooled engine to operate on 6-strokes instead of 4-strokes effectively work in the same way as the Gade cylinder? The two extra pumping cycles would bring in more fresh air to cool off the cylinder walls. (Philip Duclos designed a 6-cycle, air-cooled, engine).

Opinions, thoughts, and speculations welcomed.


Frank
 
I was told the advantage of the second exhaust is so the hot gases can escape at the end of the power stroke and not heat up the cylinder on the exhaust stroke.

Aeromotor wind mill engine was a 8 cycle if I remember right (never really saw one that ran right).
 
Barnbikes-

Thanks. I'm starting to get the notion that the secondary exhaust acts almost like the exhaust ports for a Uni-flow steam engine. But, I could be wrong.
 
Hi Everyone,
I have some more pictures to post on my progress.
As far as the auxiliary port goes, a lot more exhaust comes out of it than comes out of the port from the exhaust valve. (which is why the muffler is on the auxiliary port) I'm not really sure of how this all works, but I would really like to know.
Here are some pictures of the carburetor machining. Drilling the angled hole through the casting to connect the internal passages was interesting, to say the least! It looks like it came out ok-we will see how it runs!
cheepo45

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In reply to BronxFigs and Barnbikes about the Gade cooling, I append a cut and paste article from Farm Collector magazine from December 2013:

Cooling problems?

The Gade engine was touted as being air-cooled without a fan. “It breathes air,” company literature said. “This engine is cooled without fans and water.” The theory may have sounded good at the time but Dave has doubts as to how well it worked in practice.

Gades are 4-cycle hit-and-miss engines. They operate on the same 4-stroke principle as your car engine or other 4-cycle engines, that is, intake, compression, power and exhaust strokes. The Gade difference is that it does not have a traditional exhaust stroke where, after traveling to bottom dead center on the power stroke, the piston pushes the hot burned gases up out of the top of the cylinder on the exhaust stroke.

Rather, when the piston in a Gade engine travels to bottom dead center on the power stroke, it uncovers a port (a hole) in the cylinder wall near the bottom of the cylinder in the same manner as a 2-cycle engine. The hot exhaust gases immediately rush out of that port, relieving the piston from pushing gases back up out of the top of the cylinder. That reduces the engine’s total time exposure to the hot exhaust gases and theoretically should result in a cooler running engine.

Additionally, since the Gade is a hit-and-miss engine, the power stroke (especially when the engine is not carrying a load or doing any work) results in a significant rpm increase. The governor then holds open, for several revolutions, what other engines would call an exhaust valve, preventing more gas-air mixture into the cylinder.

Thus no more firing takes place, but the piston continues to move up and down, and since both the upper and lower ports are held open, fresh cool air is pumped back and forth through the cylinders, cooling the cylinder without water or a fan.

So far so good. But under a significant load, the engine slows down and fires more often, without many (or even any) missed strokes. The cool air coming in the ports is limited and can’t keep up with the heat created by the engine. “The cylinder fins aren’t enough help, so after a while the engine just seizes up,” Dave says. “Probably doesn’t damage anything, but it gets pretty frustrating for a farmer.

“Now you have a 4-cycle engine without water cooling and fan cooling whose only advantage is ridding itself of hot exhaust gases faster than traditional engines,” Dave adds. “I would think, but don’t really know, that this was not enough of an advantage to forgo a cooling fan or a water hopper. I think the Gades likely couldn’t keep themselves cool enough to compete with other engine manufacturers of the same horsepower rating — which is why I think these engines might not have been used very much and those at shows don’t show much wear.”


Makes sense to me.

Dave
The Emerald Isle
 
Thanks, Dave for posting this article. It sounds like this was another great idea on paper that didn't work out so well in reality. Very interesting!
I did actually get the engine running for a little while today!
I still have a lot of fine tuning to do. The carburetor adjustment is way too sensitive. It's about 1/100 of a turn from no gas to flooded!
I also think I cracked the spark plug, because it will only fire occasionally now. Once I get it running right, I will post a video.
cheepo45
 
deverett-

Thanks so much for taking the time to find and post an explanation-clarification of the theory behind the Gade engine's operation....especially, the cooling. I does sound good on paper. Reality and theory oftentimes differs quite a bit. My guess, after reading your article, is that the only thing that made the Gade different than any other air-cooled H&M engine of the time, was the secondary exhaust port.

Many thanks, again. Now, I know. Quite interesting stuff....


Frank
 
Here are some photos of the fuel tank construction.
I used 2 3/4 copper pipe caps to make the tank.
I first cut mating 45 Degree angles on the open ends so the halves would mate together well. Then I drilled the outlet hole in one cap so pressure wouldn't build up during soldering. I clamped the halves together and soldered the seam. Next I made an outlet fitting out of 3/16 brass tubing
(I cut a 45 degree notch in the tubing so I could make it a right angle fitting)
I soldered in the outlet and filler tubes, and made a cap for the tank.
I think it came out well.
cheepo45

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After almost 5 years of on and off (mostly off!) building, the Gade motor is complete!
Here are some pictures.
I still have to build the oiler, and then the fun starts - getting it to run reliably!
Thanks for following the build!
cheepo45

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Good Luck! Thanks for sharing the build with us.

Frank


 
Looks good

I see from your other post you are having a job getting it to run consistantly. It may be the fuel tank is too low and you are having to open the valve too much to get it to suck up and then it floods. The full size and the 1/2 scale model have the tank sitting on the bearers rather than under them.

J
 
Thanks for the compliments!
I did have the fuel tank mounted on top for the first test run, but I couldn't put hardly any fuel in it without it running out the carb. intake. Once I get it running right, I may make a new flatter tank for a more scale appearance.
My main priority is getting it running for the Cabin Fever show.
cheepo45
 
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