www.brantly.info

Brantly is considering the possibility of a Diesel engine for the B-2B. Diesels should have a much lower operating cost due to longer time intervals before overhall, less expensive gas, and lower gas consumption. Moreover, no need to worry about spark plugs, magnetos, ignition systems, etc. They are also quieter. Below is a list of aviation Diesels; however, most have not yet been certified (only the SMA is currently certified).

Let's start a discussion about which Diesel might be best suited for the B-2B.

http://www.zoche.de./
http://www.thielert.com/en/index.html
http://www.smaengines.com/en/index_en.shtml
http://www.wilksch.com/
http://www.deltahawkengines.com

As a basis of comparison, here are the specs for the current Lycoming engine:

180HP @ 2900RPM
13.8 GPH @ 80%
11.1 GPH @ 70%
9.8 GPM @ 60%
8.5:1 compression ratio
Dry weight with starter & generator = 305 lbs
Height 22.95
Width 33.97
Length 30.00

Here is what I have found out so far:

The SMA appears to be too big and heavy (423lbs vs Lycoming 305lbs)

The Deltahawk 200 HP seems to be a very good candidate, as it is targeted toward replacement of the Lycoming IO-360. The Deltahawk weighs 295.

The Aero-Diesel from Zoche is only rated at 150 HP, but it is a full 120 lbs lighter than the Lycoming, and it just sips gas (5.6 gal/hr). Perhaps the lower weight more than compensates for the lower horsepower? It is also turbocharged so the output should be consistent regardless of altitude.

The Wilksch is 160 HP, but weighs almost as much as the Lycoming (253 vs. 305), so it is probably not a very good choice.

I assume this diesel would run Jet-A and not automotive diesel, right? The rumor mill is that Robinson is actively working to put a diesel helicopter on the market, but it is still a few years away. Although diesels are much heavier, you might recover some of the weight by removing magnetos and the like. Any updates on this?

Deltahawk has recently announced they will be producing a 180 hp diesel v4 (previously, they had announced a 160 and 200 HP version). There will be both upright and inverted forms, and it will run on both Jet-A and diesel fuel. The weight will be 327 lbs including starter, oil pump, fuel pump, water pump, turbocharger, all internal lines and internal exhaust system. It also runs in the same RPM range as the Brantly's Lycoming engine. So, it looks like this may be the best match yet when and if they get it certified.

Steve,
I was wondering about the 327 lbs. for the Deltahawk engine.

From Deltahawk web site:
currently about 327 lbs including starter, oil pump, fuel pump, water pump, turbocharger, all internal lines and internal exhaust system

Since this is liquid cooled. How much additional weight does the coolant add?

Deltahawk being 22 lbs heavier than Lycoming + coolant might not be effective.

Don

Don,

Deltahawk states that:

"The V-4 is at least 30 lbs lighter than the equivalent aviation engine (comparisons at fully installed weight).

I'm not exactly sure how they come up with this, but the 305 dry weight for the Lycoming only includes the engine and starter. I wonder too if they are really considering everything, including the radiator.

Steve

Even still, I imagine it will be some time before we see them in a Brantly. I really like the flying characteristics of the B2B, but a lot could be done to improve the performance. I'm not an engineer, but new composite materials, updated airfoils, and other industry proven technologies could really make this ship very competitive. I wonder why other aircraft manufacturer's aren't using multi-articulated blades... seems like a great idea.

Hi,
I was reading my AOPA email and it seems that American Flyers has opt'd to in stall the "CENTURION 1.7L" diesel engines on their C172's. Thielert Group claims to have 350 conversions flying now. It's getting interesting, I am a small gas/diesel mech myself, so I may have to get my "P" license yet.

Safe flights

Article from Centurions website:

"Frank Thielert, Managing Director of Thielert Aircraft Engines GmbH, presented the certificate in person on July 26, 2006 and symbolically a Centurion glass cube to American Flyers proprietors Clark McCormack, President and David Huser and Rick Freidinger, Vice-Presidents. "We are proud to have this opportunity to equip one of the best and largest flying schools in North America with our Centurion jet fuel engines", said Frank Thielert. "With the Centurion engines, American Flyers is deliberately opting for a fuel-efficient and easy-to-operate diesel engine that runs on jet fuel", continued Thielert.

American Flyers can lay claim to some 67 years of experience in the training of pilots. It employs 350 persons at 13 sites, who have more than 250,000 flying hours' experience. To date, over 100,000 pilots have been trained by American Flyers and have received their FAA certificate. American Flyer has 55 training aircraft of the type Cessna 172, which can be converted with the Centurion jet fuel engines. Epic Aviation, Inc., located in New Smyrna Beach, FL, a distributor for Thielert engines for Central and South America partnered with Thielert and American Flyers on the sale and installation of the first conversion displayed at Oshkosh. "

I would like to see Brantly do a turbo conversion first, the Carson conversion made a big difference on the Bell 47D1,G and the Hiller UH12C, like now with the heat here in Dallas.

Thanks,
Mark

The Centurion is turbocharged, so thats a plus. I don't think the Centurion 1.7L has enough ummphhh for the Brantly though, but maybe it would work with the Robbie?


From Wikipedia, the free encyclopedia:

"The Centurion 1.7 was the first product introduced by Thielert, a 1689 cm³ (103 in³) engine aimed directly at the 135 hp (101 kW) target that makes up the vast majority of the general aviation world. It is in this power range that the popular Cessna 172 fits, and its popularity drove the entire market into the same general size range.

Unlike older designs, the 1.7 is water cooled, turbocharged and includes a one-control digital fuel control system (FADEC), dramatically improving reliability (many engine problems are caused by improper operation and power settings) as well as making the engine considerably easier to operate. It runs on either Jet A or diesel fuel, or any mixture of the two, allowing the operator to choose whatever is available and least expensive. The high compression ratio of the engine combined with the digitally controlled fuel injection system dramatically reduces emmissions as well, putting it on par with modern automobile engines.

The recommended propeller is a three-bladed constant speed model. Much of the sound of a light aircraft is generated by the tips of the propeller, which can approach the speed of sound. By using a smaller propeller with more blades, the same amount of power can be dissipated at a slower RPM and smaller radius, dramatically lowering the speed of the tips.

Some indication of the improvement in engine design can be seen by comparing the 1.7 to the engines it is aimed to replace, notably the Lycoming O-320, and to a lesser degree the Lycoming IO-360 and Continental O-300. The O-320 delivers 150 hp (112 kW) from 320 in³ (5.2 L), while the 1.7 delivers 135 hp (101 kW) from 103 in³ (1.7 L). This represents a dramatic increase in specific power, from the O-320's 0.47 hp/in³ (21 kW/L) to the 1.7's 1.31 hp/in³ (60 kW/L). The 1.7 is slightly heavier however, 294 lb (133 kg) vs the O-320 at 278 lb (126 kg). As a result of the greatly increased compression ratio of the diesel cycle, fuel economy is likewise improved, the 1.7 has a specific fuel consumption of 0.36 lb/(hp·h) (0.22 kg/(kW·h)), while the O-320 gets only 0.42 lb/(hp·h) (0.26 kg/(kW·h)).

For a slight drop in takeoff power, the 1.7 will instead deliver considerably greater power at altitude due to the turbocharger. This allows the aircraft to fly at higher altitudes where the thinner air reduces drag and increases performance. Combining the better fuel economy, higher performance at altitude, and the somewhat greater energy density of diesel fuel, aircraft range is dramatically increased. For instance, replacing the O-320 with the 1.7 in a Cessna 172 drops the fuel consumption by half, increasing range from 575 to 900 nautical miles (1100 to 1700 km). Fuel costs fall dramatically as a result, notably in Europe where avgas is much more expensive than in North America.