Well, I must admit that I have been frustrated with the engine. I'm frustrated because every time I tried to do an atmospheric test on the combustion chamber, it failed miserably. The fuel injectors would blow too much fuel out and make a stream like a water gun, the ignition was giving me problems, and I couldn't get the fuel to ignite inside the combustion chamber. It was just one nightmare after another.

The really bad thing about my frustrations is that everything seemed to be right with both the design and construction of the engine! There was only one thing left I could do, and that was just bolt it all together and see if it would run. Having been a little upset with the engine at this point, I took a week away from it first to get my head straight and then (with the prodding of friends) I finally put the engine back together again.

Beginning of proper test stand

To get started, I took the simple test stand that I had in the garage and cut some plywood to fit the sides. The plywood would give me a nice solid mounting location for pumps and hoses. I wasn't really concerned with making the panels out of metal, since the location of parts would have to change with every engine I test. I have 4 more engines in the shop, so this will just make things easier on me.

Control panel

For the control panel I used a piece of sheet steel with the sides rolled down to form edges which would give it some support. All of my controls will mount right here for easy access to the power for all of the pumps and ignition.

Plenty of room

There is plenty of room underneath the cart for the oil cooler, oil tanks, fuel tanks, and whatever else I may need under there. I like that the stand is up higher. When you get a bit older, you don't want to have to bend down to reach all of the controls. I especially don't want to bend down to mess with an engine which up to this point has been very finicky and has done nothing but make me mad. It should bow down to me after all of the troubles I have been put through! Seriously, the engine is just much easier for me to access with it mounted up higher like this. The only concern is that if the engine makes too much thrust it can knock the stand over easier. That's a double edged sword, as I don't want the engine to fall over and get damaged, but I would like to see that much thrust! I guess I'll just test it out in the yard so "if" it falls over at least it will be a soft landing in the grass! Note the cinder block bricks at the back of the stand to help weight it down and avoid it tipping over.

The original small work stand

To get the turbo mounted on the test stand, I used the original small work stand which can be seen in previous sections. The little stand is just a handy way to hold the turbo while I am fabricating pieces for the combustor, but it seemed like a good ready made solution to mount the turbo. A few tacks with the welder and it was done.

Painting time

I wanted to get some color and a way to inhibit rust on the engine, so I went with a high temp paint. As my buddy will often say to me, "I put a coat of lipstick on that pig!" The combustor was first heated a bit in the oven, then it gets sprayed with the paint. Once the part has a good coat, it goes back in the oven to heat cure for a while. This sets the paint and makes sure that it will hold up. The color of the main CC is a nice gray which will go well with the contrasting end caps.

Painted end caps

Although I could have easily painted the end caps the same color as the rest of the combustor, I decided to get a bit artsy and try to make it look good. I was hoping that the contrasting colors would give it a more finished appearance. Sometimes the small details can really make a project look a million times better. The end caps were heated and painted just like the main combustion chamber housing.

Painted engine reassembled

With the parts were all dried, I reassembled the engine and mounted her up on the test stand. The contrasting paint scheme really does look nice, and I am proud of it. It certainly beats the heck out of my alternate colors of "Early American Rust", or "Krylon Leftover Surprise". You might have noticed by now that the new test stand also gives me some flexibility for the engine mounting. I can have the combustor straight up and down, or laid over on its side as can be seen here. For the tests, I'll keep it on the side to make plumbing the fuel easier, and it will also give me better access to the flame tube for tear down inspections.

Final plumbing of the test stand

Once the engine was mounted back up on the test stand, I could finish all of my plumbing. Things would have been a bit easier here had I remembered to buy enough "acorn" nuts for the flare fittings I was using. Just a hint to anyone doing this kind of plumbing. When you buy your flare fittings, lay them out with a nut near each one so you know that you have enough. If you try to keep a mental count in your head, you will always remember a few fittings you need at the last second and when you grab them you "will" forget to pick up the nuts from the store shelves. If your budget allows, always get 4 more nuts that you need, and at least 2 extra fittings of each size you are going to use. Trust me when I say that you will need them.

Fuel injector side

To make my testing even more simple, I am using a regular combustor cap with only one fuel injector and a propane pilot to start the diesel burning. I will put the cap with the manifold blocks on later. I just want to make sure she will run first. Now is a good time to admire that pretty paint job too.

The nozzle

Lastly, the nozzle was attached to the engine. Everything was there now, and theoretically the engine should run. I had no idea if she would actually spool up, or if I would just get a huge fireball out the rear. I had a fire extinguisher on hand just in case. OK, it was more like three of them..... plus a bucket of water. You know, just to be sure! It wasn't really that bad, I just was not encouraged about the previous tests with the 4 injectors in the end cap. On recommendation from a friend I have also used a smaller fuel nozzle in the engine. It does not stand to reason that the new engine will run on less fuel, but he assures me that it will. The idea is that the smaller nozzle will atomize the fuel more efficiently, getting a better burn inside the chamber and needing less fuel as a result. After seeing the "water gun" type streams of fuel from the last injectors I will at least give it a try. The tests on the engine will use a 10 gallon per hour nozzle instead of the 15 that I was thinking I would need.

HR-1A engine test - first firing

She works! I guess my buddy was right about the nozzle, as the engine runs great. Looking at the fuel pressure, I am not even close to using the capacity of the 10 gallon per hour nozzle, and may go even smaller on the next test run. The important thing is that the engine actually fires up and runs well. The exhaust gas temps were nice and low, and all of the gauges told me that everything looked great. Almost to good to be true. I double checked all of the gauges and everything is good, so I guess I just have a really nicely running engine on my hands. I will do a tear down inspection later to make sure that everything is OK after the tests. Right now, I am just excited to see everything going according to plan.

HR-1A engine test - The gauges in action

The video on this is not as clear as I would like it to be. You can see that the gauges are reading, but it isn't clear enough to make out what the readings are. The one important thing is to note the throttle response when I bring the engine speed up for a second or two. This thing is just really responsive. I am pleased with the outcome, and will do more tests soon.

Thanks for stopping by the site, and remember that there is much more to come. A few more engine tests and I will then be building an afterburner. And to think, this is just a test engine for much larger projects yet to come! Please remember to help support the site so that I can get more updates to you quicker. See you next time!

Gary Richards

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