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Possible NEW Engine

I don't get it

A lot of engine companies have come and gone, none with the reputation of either Lycoming or Continental and yet, when they release a new engine they all seem to say, "The engine cost will be competitive with a new Lycoming or Continental engine of similar power output."*

I would think they should sell a number of their new engines at 1/2 the cost of a competitive Lycoming or Continental until they build up a good reputation. Granted that is expensive but it should be figured into the R&D costs.

That might entice more people to try out their engines, give them feedback, and build up a good reputation. Otherwise, the for the money the builder invests, he/she might think, "I should have bought a Lycoming/Continental for the same money and had a lot less installation and operational hassles."

Thoughts?

*Quote from Adept Airmotive's web site.
 
I agree

Bill,
I agree with your thoughts on pricing structures of new engines. You state in your post a very important critical component of marketing a totally unproven product. That is, builders need to have a very good reason to "Go down the road less traveled".

If there is no motivation then we will not take the RISK. And the reality in the aviation world is that using a non-standard aviation engine for our experimental airplanes has a great amount of risk associated with that decision.
 
Its nice to see a liquid cooled v-style engine/psru specifically designed for aircraft, instead of just an automotive engine modified into an aviation setup. Although nothing can compare with the lycoming/continental reputation, it will be interesting to see if this company has any success when they install it on the SA Ravin 500.
 
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The 120 degree V angle is interesting having been used by some Italian racing engine manufacturers. I like the clean sheet design and integral gearbox with coupler. Looks like they've used RP to keep production costs down.

It seems they are competing with Lycoming 540s here as they mention "race engine"- probably a reference to Red Bull competition engines. Seems they have a ready proving ground there to really show what the design can do- 11Gs and running the snot out of it.

I wish them well but hope that they have deep pockets after mentioning certification. That usually makes the unit cost go through the roof or dooms the whole project to failure.
 
Good game..

"New" engine guys talk a better game than Texas high school football coaches in August.

Maybe one will get to December someday. MAYBE I will still be able to get a medical.

They are in South Africa--has to be an advantage: lots of innovation and not so many parasitic naysayers.
 
Ross, what is a CUSH drive?

....that I read about on their site. Looks like it might have something to do with TV problem solving.

Thanks,
 
Cush Drive

A cush (short for "cushion") drive is typically a coupling with several elastomeric inserts that engage protrusions between the drive and driven halves of the coupling. This is a common arrangement used in motor cycles and in diesel drive applications (amongst others). In the automobile world there is a similar system (comprised of springs and/or elastomeric inserts) used in the fact of the clutch disc on manual transmissions.

If you look at the top right side of their web page between the bull gear and the drive plate is a small cylinder. I believe that is one of the "cushions" that transmit power from the drive plate into the bull gear.
Regards,
Bill
 
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I read a little on the "Cush" drive and have a question about it. They say that this will protect the engine from a prop strike! How would this work? Our test engine here uses a soft coupling between the engine and the dyno, this absorbs the considerable vibration and power pulses from a single cylinder diesel engine but I do not see how such a coupling could save the crank from something like a prop strike. To do that would you not need a shear pin or clutch? I would think that the weight and dependability of such a system would not be worth it for a light aircraft.

This is an interesting engine but I agree that if it hits the market at the same price as a Lycoming or Continental it likely will not be a market success.

Bob Parry
 
Prop Strikes

Bob,
Definitely stepping out on a limb here - but the quote is "protect the rest of the engine from prop strikes. " . As they are using the plural form of strike, I think they mean prop vibrations resulting from unbalance or pulsation(language issue perhaps).
Don't forget - the above is a guess after years of association with a few people from the British Isles.

Vibration damping and shock absorbtion is what cush drives are designed to accomplish.

Regards,
Bill
 
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With a gearbox and coupler between the prop and crankshaft, the gears would take the brunt of the decel and bending forces during a prop strike. Easier and cheaper to change some gears/ nose case than taking the crank out although with the layout of this engine, crank removal would be easier than many split case designs.

I think they were referring mainly to keeping harmful TV out of the system.
 
I received a neat reply......

....from Richard Schulz at Adept this morning. I mentioned that there must be another 15,000 RV's under construction and that their engines fall right in the range we need and directed him to this site.

He told me that they're working hard with Coss Aviation of South Africa to build a FF package for the RV's.

Regards,
 
It looks nice: A real clean sheet design for an avgas/mogas piston aircraft engine, and the 280N is probably ideal for the -10. Lots of nice details in the design too, if you read this (pdf).
 
What's so good about it?

I fail to see its merits, apart from the downsizing/re-drive attempt at weight reduction, which at first glance looks reasonably successful. I'll bet the claimed weight doesn't include that very heavy looking exhaust system though...

Where are the fuel consumption benefits coming from though?

It's really oversquare which is bad for thermal efficiency.

It's making rated power at 6000rpm so why the need for DOHC? There's at least twice as much cam friction as necessary.

Not an optimal solution to the piston aero engine problem IMO.

A
 
Andy_RR said:
I fail to see its merits, apart from the downsizing/re-drive attempt at weight reduction, which at first glance looks reasonably successful. I'll bet the claimed weight doesn't include that very heavy looking exhaust system though...

Where are the fuel consumption benefits coming from though?

It's really oversquare which is bad for thermal efficiency.

It's making rated power at 6000rpm so why the need for DOHC? There's at least twice as much cam friction as necessary.

Not an optimal solution to the piston aero engine problem IMO.

A
Click to expand...

It's just different, another possible choice. I agree, the bore/ stroke ratio is not the best choice for an engine like this nor is the quad cam setup. It is very unlikely that it would match the fuel efficiency of an atmo Lycoming 540. Weightwise, probably would be close. Wonder why they have a muffler on a turbo engine though, just dead weight unless they are trying to meet European noise standards.

Got to give them credit for the drive to design and build it. A breath of fresh air so to speak.:)
 
From the last paragraph of the PDF posted above:
"320 hp, 120 kg engine that has a fuel burn of around 30 litres per hour at 65% cruise power"

Check my math here:
30L/hr = 7.9 gal/hr = 47.5 lbs/hr
65% * 320hp = 208hp

BSFC (lbs/hp/hr) = 47.5lbs/208hp = .23 lbs/hp/hr !?!

I must be misunderstanding something...
-DC
 
digidocs said:
BSFC (lbs/hp/hr) = 47.5lbs/208hp = .23 lbs/hp/hr !?!

I must be misunderstanding something...
Click to expand...
I get the same result, so your math is OK. That article dated from 2004, but it seems that the engine first ran in 2007. So, those numbers appear to be predicted values. My bet is that the marketing guy(s) had more to do with those predictions than the engineering guy(s).

I'll be very, very impressed if it does better than 0.35 lb/hp/hr. 0.23 seems extremely unlikely, unless these guys are a whole lot smarter than anyone else who has ever designed a gasoline fueled internal combustion engine.
 
We know that this engine is not going to do anywhere close to that and the company would do themselves a favor by not publishing stuff like this.

Knowledgeable eyes are watching this project. If they can match fuel flows, hp, weight, cost, reliability and customer support with the current offerings, they will do ok in the market. If they can exceed current performance, they will do even better.

I think many details still need to be fleshed out compared to what we see on the website. The radiator setup will almost certainly not cool well in hot climates, especially in extended ground running IMO.
 
They are a South African company right? If there's one thing they'll get sorted in testing it'll be the cooling...
 
RichB said:
They are a South African company right? If there's one thing they'll get sorted in testing it'll be the cooling...
Click to expand...

Don't be too sure they will fix all the problems. The SMA diesel, won't run at high alt and during winter due to cooling problems - too much cooling.
 
Cooling Issues

I hope that they do come up with a complete cooling package in a firewall forward kit that includes everything in a properly engineered package.

It surprises me that Lycoming an Continental do not do this as most of the problems that result in shortened engine life are due to overheating. Large trucks have similarities to the aircraft manufacturers in that they make the chassis and purchase the powertrain. The diesel engine manufacturers supply the cooling systems and have very specific requirements on air flow and other things important to the engine in order to meet warranty.

If I was Lycoming I would sell the engine with the baffles and cooling system mounted and tested and specify inlet/outlet conditions to the airframe manufacturers who are then responsible for the cowl design to meet these conditions.

Bob Parry
 
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