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Got e from Zoche, near production

Garth

Member
I just got an e mail from Zoche diesel the other day, they are near production he said. I went to their site at http://www.zoche.de/zoche_brochure.pdf and it looks the same but a lot of the text has been changed.

Their 150 HP at 185 lbs with all acc burning 5.5 GPH and the 300 HP at 270 pounds and 11 GPH, and all this on road equipment and stove oil diesel? Man, thats less than $ 2 bucks a gal. I would (will anyway as auto gas is so much cheaper too) put a fuel tank in the truck bed to fill my plane myself.

If they come through (been gonna for years now) it will sure be a blessing. They say motor makes less noise than prop without a muffler, so you can never even hear the engine. Has a lot of new innovations and advanced features, one piece cylinder and head for no gasket to fail or bolts to tighten or leak, no hoses, belts, starter/generator one piece built in direct drive, no PSRU, etc etc. Their sites a nice read anyway. One clean neat little package for sure.
 
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When did you got this kind of report first time? Just wondering as they have been working with this engine ~15 years for now... And I've also heard couple comments about their engine design which are not encouraging, but I wish them luck and hope to see those engines in air soon.
 
When did you got this kind of report first time? Just wondering as they have been working with this engine ~15 years for now... And I've also heard couple comments about their engine design which are not encouraging, but I wish them luck and hope to see those engines in air soon.

It's longer than that, like approaching a quarter of a century. Zoche has an infinite supply of carrots (and money it seems) - they've been leading anyone who cares to be led for a long time.
 
Read my quote again. I said they been working on it for years, I know they are a joke in the industry, how long they take is not the issue, they can take as long as they want, it doesn't make the engine any less impressive. It will probably be several More, if at all before it is on the market, but did you look at all the fantastic innovations and revolutionary improvements to todays choices (or do you even care?)

I appreciate anyone who can bring something new to the marketplace, no matter when they come through. A lot of high timers would love to switch out to this from whatever (and whenever) they have now. The diesel offerings and wannabees out their now are not even in this league, they are just big balky boat anchors with so so performance at best. And they are not coming on line any faster. I will watch Zoche forever as a great alternative to the complex and heavy diesel monsters out there so far.

As I see it, diesel has no chance unless it is some new concept like a Zoche. Light, simple and strong. When you add belts, hoses, water cooling and weight it is fine for a boat, a car, but not an airplane.
 
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Aero Diesel Vs LOP Superior/GRT

According to the GAMI guys, we can run LOP at 0.40 SFC. My GRT says I can get that down to 0.38 pounds/HP/Hr. Zoche claims 0.346. That's a 9% gain over what I think I'm getting or 13.5% better than 0.40.

OK, that would be nice. The cheap fuel, lower weight and smaller frontal area would also be great. The tradeoffs include:
  • Untried Engine
  • Field Support
  • FWF resources
  • Full tanks weigh more for same gallons.
  • Vaporware vs. Hardware
 
I agree, a diesel at all is still questionable. The 300 HP Crossflow Suzuki http://www.crossflow.com/products/firewall_forward/powerplants/CF6-33.html claims 13 GPH at 75% and gas is a pound a gallon lighter, but it is also explosive and vapor locks etc. Diesel jells in the cold, who knows, but just as diesels go....

Also the rotary diesels when they come out. We will see, plenty of time yet as none are going to be real soon in the large engine categories.
 
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I agree, a diesel at all is still questionable. The 300 HP Crossflow Suzuki http://www.crossflow.com/products/firewall_forward/powerplants/CF6-33.html claims 13 GPH at 75% and gas is a pound a gallon lighter, but it is also explosive and vapor locks etc. Diesel jells in the cold, who knows, but just as diesels go....

Also the rotary diesels when they come out. We will see, plenty of time yet as none are going to be real soon in the large engine categories.

Crossflow used Subaru based engines, not Suzuki. Their SFC numbers are absurd. Taking their "350" hp engine at 75% power, they say cruise fuel consumption is 13.5 gal./hr. This equates to a SFC of .308, a figure never obtained by any gasoline engine ever- even turbocompound ones and better than most mobile diesel engines. Absolutely impossible.

Interesting how they would obtain this hp level with a mismatched OE turbo as well. My experience in helping ex clients is that they make nowhere close to this hp given the props they are turning. The compressors are frequently in the surge region as well.
 
My mistake, Subaru. You do sound like you know your stuff alright. (I will reserve my opinion of it on the Rotamax rotary for now though, Ha) I definitely won't defend Crossflow as I have two acquaintances that had bad dealings with them some years ago, real bad. And when I asked them about that (Crossflow) they got huffy with "we don't know what they are going to use them in and so many homebuilders try to modify the engine even before they mount it and void the warranty and ruin our factory dino settings and ..... on and on.

But like I say, Kirk Creelman says he has checked them out extensively and they are solid....HE says. But time for telling is very near. They have several flying now and more every week.
 
Never say never

This equates to a SFC of .308, a figure never obtained by any gasoline engine ever- even turbocompound ones and better than most mobile diesel engines. Absolutely impossible.

Well.... In the normal range of experience, quite true. Hard to get under .4 really. However, just for entertainment and education, one should look up the Wartsila engines. Super massive diesel 2-strokes (2300 hp per cylinder, 112 rpm, etc). The pictures are stunning. Their documents show less than .30 lb/hp*hr. I am inclined to believe them since the uses these are put to are frequently monitored by CFO's. I had one of their tiny V-16s as a power regeneration facility at a previous employer. Only way to get one of these flying is a project of Howard Hughes scale! :D

http://www.gizmag.com/go/3263/
 
Well.... In the normal range of experience, quite true. Hard to get under .4 really. However, just for entertainment and education, one should look up the Wartsila engines. Super massive diesel 2-strokes (2300 hp per cylinder, 112 rpm, etc). The pictures are stunning. Their documents show less than .30 lb/hp*hr. I am inclined to believe them since the uses these are put to are frequently monitored by CFO's. I had one of their tiny V-16s as a power regeneration facility at a previous employer. Only way to get one of these flying is a project of Howard Hughes scale! :D

http://www.gizmag.com/go/3263/

I'm talking gasoline engines here. There are many stationary diesels well under .30.
 
But like I say, Kirk Creelman says he has checked them out extensively and they are solid....HE says. But time for telling is very near. They have several flying now and more every week.

We supplied Kirk with some EFI systems for Jabirus many years ago now if my memory serves me. These were a disaster at the time with multiple short term valve and head failures. He ditched these pretty quickly. I hope the Crossflow engines do the job for him and he gets good service from them. The Subaru EG33 base is a wonderful piece of engineering IMO if you don't screw with the thing very much.
 
...... The Subaru EG33 base is a wonderful piece of engineering IMO if you don't screw with the thing very much.

I have been wondering since day one about the efforts of Jan Eggenfellner and Robert Paisley to reduce fuel consumption with the 3.0 H6 by reducing fuel pressure. I am running at about 32 psi as per the recommendation but no one has ever answered the question, why was the engine designed to run at 43.5 psi by Subaru and why is the mixture so rich at high power settings at this pressure?

A/F flow ratios have been confirmed at the lower pressure but is the assumption, that 12:1 to 15:1 is normal for a gasoline engine, valid with this engine? Only time will tell.

The ECU your company has developed obviously controls fuel flow differently than by reducing pressure. My engine has three O2 sensors, at least one of which does measure A/F ratio but this information is only used at low power, like going down the highway at 55 mph. Why does the ECU insist on running the engine so rich at high power? It reverts to computer tables (open loop) for fuel flow ignoring the sensors at relatively low power going up. Could it mean the engine needs a ratio of 11 or 10:1 to develop rated power or to protect it from excessive combustion heat? The compression ratio of this beast is 10.7:1 and perhaps the internal dynamics are quite different than running at say, 8:1, with older technology.

 
I have been wondering since day one about the efforts of Jan Eggenfellner and Robert Paisley to reduce fuel consumption with the 3.0 H6 by reducing fuel pressure. I am running at about 32 psi as per the recommendation but no one has ever answered the question, why was the engine designed to run at 43.5 psi by Subaru and why is the mixture so rich at high power settings at this pressure?

A/F flow ratios have been confirmed at the lower pressure but is the assumption, that 12:1 to 15:1 is normal for a gasoline engine, valid with this engine? Only time will tell.

The ECU your company has developed obviously controls fuel flow differently than by reducing pressure. My engine has three O2 sensors, at least one of which does measure A/F ratio but this information is only used at low power, like going down the highway at 55 mph. Why does the ECU insist on running the engine so rich at high power? It reverts to computer tables (open loop) for fuel flow ignoring the sensors at relatively low power going up. Could it mean the engine needs a ratio of 11 or 10:1 to develop rated power or to protect it from excessive combustion heat? The compression ratio of this beast is 10.7:1 and perhaps the internal dynamics are quite different than running at say, 8:1, with older technology.


The issue with the OE ECU is that to protect the engine at high power settings and make max power, the ECU does not operate in closed loop (around 14.7 AFR) under these conditions, generally defaulting to open loop tables and an AFR of around 12.8 to 13.1 to 1. Because aircraft applications generally operate above this rpm and load point, they are almost always in open loop.

In order to reduce fuel flow then, the easiest way is to reduce fuel pressure. Closed loop is not affected by this change as the ECU re-trims injector pulse width to compensate. The question is, what is a safe AFR to run at high power settings? That can really only be answered by getting a lot of flight time on engines running leaner than what the factory did and seeing how long they last.

With a programmable ECU many more possibilities are open for AFR vs. HP including targeted AFRs vs. HP using a wideband O2 sensor.

In my view, there is rarely if ever a need to be richer than 13 to 1 AFR.

I lean my turbo EJ22 out to around 13.8 to 1 in cruise and use about 13 to 1 for takeoff and climb. This results in an EGT of around 1400F.
 
why was the engine designed to run at 43.5 psi by Subaru and why is the mixture so rich at high power settings at this pressure?

Probably because in a car, high-power operation is usually brief. Nobody cares what mileage a car gets during highway overtaking or climbing a hill because those operations don't last long enough to notice at the pump.

Therefore, it's safest to operate very rich during those brief periods to avoid knocking. It probably also makes the engine control system more tolerant of faulty sensors.

Airplanes engines, of course, spend most of their lives operating at those high power settings, so we care very much how close to stoichiometric mixture they operate. Conversely, the fuel economy at 20-30 HP (typical highway load in a Subaru car) is much less important in an airplane...that's descent power.
 
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