The new engine ready for testing

First we have to get the engine mounted to the test cart and make a few changes to accommodate today's testing. Everything came off of the cart, and we started from scratch to get it ready.

Turbo reoriented

The VT-50 had to be removed from the test stand and reoriented with the turbine and compressor outlets facing up. Although the engine can fit in the stand sitting in the normal turbo on top combustor on bottom way, it makes access to the flame tube and end caps difficult. To make tuning easier, we just have it flipped upside down for today's tests.

Sealant applied

Once installed upside down, the turbine flange was given a nice coating of high temp sealant. The sealant will probably burn away pretty quickly, but should help a little. For the most part, the turbine flange is so flat to the new exhaust manifold flange, that no sealant should be required at all.

Exhaust manifold bolted on

The exhaust manifold assembly was bolted to the turbine inlet, but the bolts were kept finger tight at this point. The bolts would be fully tightened after the entire combustor was mounted so that adjustments to the compressor to combustor fit could be made.

Installing studs

Since the bolt holes located on the combustor will not be accessible behind the exhaust bend on the manifold, studs were screwed into place which will have nuts attached to them later. High temp sealant was then applied to the ring on the combustor.

Combustor mounted

The combustor was firmly bolted to the exhaust manifold, and then excess sealant was cleaned from inside the combustor. This sealant could cause the flame tube to not be able to expand, or worse yet could be ingested by the turbine. Better to be safe than sorry on your first engine test. John was kind enough to clean the sticky sealant out of the engine.

Completed engine

With the combustor attached to the turbo, the flame tube went in and was followed by the paper gasket and end cap. Everything bolted together nicely, and looks really good. Of course the engine will look much better after it is sand blasted and given a dip in our magic black solution provided by our sponsor Caswell Plating.

Almost ready to roar!

This beast is almost ready to roar, and reminds me of commercially available turbines when looking at it like this. And before you ask, the picture is angled a bit, there is only a slight bit of angle actually in the engine. Doesn't she look mean! You can see the temperature probe mounted for recording EGT at the turbine exhaust.

Yes, I am lazy

When the engine is done running, it will be cooled by blowing air through it with the leaf blower. We are all just too lazy to stand there for 5 minutes with a leaf blower, so we set up this stand to hold it for us. This picture was taken right after the first successful run, and you can see that the exhaust manifold has turned a nice pretty blue color. Compare it to the picture above to see the difference.

John with the engine

This is John, the owner of the Chevy Nova project. John has been helping with the engine, and is now officially part of the Bad Brothers Team here at the shop. To initiate him, we had him present when we fired the engine. Although he was warned about the scariness of these engines, he still backed away really quickly when it first started. I can't say as I blame him. My hands were shaking a bit too! This thing is a beast!

Oil cooler

The following pictures are just some shots of the ancillary equipment we added and changed on the test stand for the tests. The oil cooler was not present during the short engine tests on the original combustor, but after some thought I put it on real quick. Turbos are expensive to replace!

ShurFlo pump

This is the famous ShurFlo pump, model number 8000-643-236. It is a rock solid little pump with the seals needed to run high temp oil for this application. It kept the pressure up at at least 50 PSI while running the engine, and only draws a max of 7 amps. Great little pumps!

Battery bank

The batteries used for the test were sealed gel cell batteries such as are used in computer uninteruptable power supplies and burglar alarms. The two batteries near the back were used to run the pump for over 2 hours straight on the day of testing. They are each rated for 7 amp hours. The pump never lost flow or pressure. I will be using these batteries on the bike. The larger battery is a 12 amp hour unit, and the bike will have some of them as well.

Fuel injectors

The fuel injectors on the combustion chamber are arranged so that there are 5 in a circular pattern. The central injector is for a propane pilot light while the outside injectors are for liquid fuel such as diesel or jet-a. We were only using propane for the tests, so the remaining injectors were blocked off. Also visible is the emergency shutoff butterfly valve.

Ignition unit

This little gem of a black box is the ignition unit. It provides a hot enough spark to light this engine up every time and is only 3 x 4 x 1.5 inches in size. It also has a nice feature of being able to be hooked up to an output pin of a basic stamp for control of the spark. A special thanks goes out to William of Aautomation for building us this little unit!

Oil tank

This is the oil tank for the test stand. Yes, I am aware that it is a paint can. It was purchased new for this very purpose from a large home improvement store. I like using it because it allows me to see the oil inside to check viscosity as it heats up, as well as aeration.

Temperature meter

The temperature meter was another of the many great gifts my wife has given me through the years. It was purchased at a Harbor Freight store for about $27 on sale. The probe that came with it is a bit wimpy, so I upgraded that. The meter itself is rock solid, and has a nice yellow rubber protective housing, as well as a threaded hole (1/4-20 threads) on the back for mounting.

Thermocouple

The thermocouples we use for the engines are available from tsitoday.com and are among the nicest I have seen. The price is right too. They are rated up to 2200 degrees F, which should be plenty for use on this engine, unless I plan on doing some turbo repair later.

Bluing

You can make out here a little of the bluing that happened to the exhaust manifold from the heat. The color is actually very nice and if I didn't have to be concerned with rust I would leave it like this.

Tank adapter

This is our custom tank adapter for the propane testing tank. There is no regulator at all, as it has been removed to allow for the highest possible flow of fuel to the engine.

Tank adapter

The internal anti flowback mechanism has been removed from the tank adapter as well. The propane has a nice 5/16th inch passage to flow through all the way to the engine this way. By having the pipe a larger diameter, and enlarging the openings here it reduces sweating of the bottle. There was very little condensation on the outside of the propane bottle, and no icing at all.

Tank magnet

This is just a little trick I though I might share. If you build one of these engines and are worried about particles in your oil, simply place a high power magnet near the bottom of the tank like this. It will capture larger ferrous metal particles before they even get to your filter system. Sorry, won't work for aluminum!

Small bottle adapter

This is the bottle adapter for the small propane bottles that will be used to pilot the burner when the bike is finished. Sorry the picture is a bit blurry, my camera got cranky!

End cap and flame tube

After the test runs, the end cap turned blue on a few areas. I don't think this will be much of a problem once we switch the bike over to diesel or jet-a, since they will burn further down the flame tube.

More bluing

The bluing is more apparent inside of the cap near the spark plug locations and injector tubes. It seems to be localized in those areas though.

Flame tube after tests

This is what the flame tube looks like after testing. I can't see any bluing at all on the tube. It appears to be the same color as it was before the testing started. Could it be that there is a perfect air curtain created by the hole pattern that is keeping the flame tube walls cool? This was suggested to me by another builder, but I am not sure yet. I will test further to see if a longer run will make the color change.

Well, it is time to show you what you have all been waiting for. The video of the first test run on the new engine. The following video is only a short run and the video is about 1 minute in total length. More video will come with more testing. Numerous tests were carried out through the day, and about 5 minutes total run time was accumulated on the engine. We are looking forward to further testing and to switching over to the liquid fuel.

The first test run of the new combustor. Push play to watch

Thanks for following along with the site so far. As you know by now, we are trying to play catch up from the lost time waiting on parts that never showed from a previous supplier. More updates to come soon, and please remember to support the site!

Russ W. Moore
and
The Bad Brothers Racing Build Team

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