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LargePrime

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Originally posted by LargePrime:

I think the torque thing is leftover from cars.......

I wouldn't say that it's "left over" from cars - cars have a different operating environment than aircraft, and torque AND HP have more of an effect on the performance of automobiles.

 

Acceleration is a function of the torque output, and having lots of torque at low RPM (starting from a dead stop) is important to a car/truck. Aircraft engines do not operate at low RPM (relative to their max. RPM) - they're always at ~75% RPM or more when you're trying to get power out of them. Cars might easily be at ~15% or less of max RPM when you're accelerating away from a light.

 

Cars are also usually operating at much lower than maximum torque levels, so that when you want to pass on the highway and you step on the gas, the difference between the operating torque level and the maximum available torque level at the operating RPM is what will determine how quickly you can accelerate. Aircraft are almost alway operating near max. available torque and max. available HP.

 

The operating environment has a great deal to do with what's important to measure.

 

 

marbleturtle opined:

Thank GOD you took the time to wander over from your web site to straighten out all us ignorant bastards on this message Forum. I for one will sleep better at night.[/b]

Your turbodiesel putting out 178 HP at 2700 RPM would be completely appropriate for a COZY MKIV (assuming the weight was reasonable), if such an engine were ever to become available. My response was to the claim that torque was important, and HP not - it had nothing to do with whether the HP came from the Otto cycle, Diesel cycle, Rankine cycle, Sterling cycle, or hamsters in a wheel.

 

God had nothing to do with my post, nor with the relationship between HP and torque, and AFAICT from your response here (as well as your previous ones), there's only one ignorant bastard on this forum. As you can see from the followups to my original corrections to your misleading statements, many people do, in fact, appreciate having the theory and data explained to them so that they don't remain ignorant. Especially when the data comes from someone that's not hiding behind an anonymous moniker, and claiming omnicience.

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Marc,

Marbleturtle's signiture at the end of his posts speak for itself. I for one appreciate your posts, and all others as well. There is a lot of good info that can be passed around through this forum as well as your site. ;)

Dave Clifford

"The Metal Man" Musketeer

Vise grip hands and Micrometer eyes!!

 

Cozy MKIV Plans #656

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I need to get one of those new non-turbo Civic Si engines with the 182 HP MSL at 8600 RPM with a 3:1 PSRU thingys...

 

Sure..... if you want you're engine to last about three flights then fail at the worst possible moment. :D

 

While the little honda engine may be able to put out 180HP at 8600 I'd be willing to bet that it can't do it for long. Personally, since I only have one, I'd rather have my engine working at MUCH lower than its peak cabability most of the time, and I want it to be ROBUST (as in not blowing it's guts through the cowling on my forth flight. If you used something like honda I think you'd be better off with a 2:1 ratio and live (operative word) with the HP you can get at 5500.

I can be reached on the "other" forum http://canardaviationforum.dmt.net

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Marc

 

Keep the information flowing despite the uncalled for comments.

 

I have a question for you and other members, if you were to look ahead would you anticipate in 3 years there might be a suitable diesel in the 180-220Hp range for a Cozy.

 

There seems to be a lot of development work underway by quite a few reputable companies, the question is whether they will make it in the next little while. I anticipate needing an engine in three years or so and having grown up on a farm around diesels am quite comfortable with the concept and their simplicity and for my family anyway always seemed to be working fine. Some of our engines had 5000 hours with no problems and a lot of those hours were at or near maximum RPM. It would be so nice to ditch the mixture, spark plugs etc etc for a single lever diesel.

 

Enough rambling from me, comments from the crystal ball gazers is appreciated.

 

John

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>I think you'd be better off with a 2:1 ratio and live (operative word) with the HP you can get at 5500...

 

Thanks John. I agree with you completely when you point out that you would not be comfortable going with more HP at higher RPM. I think there is a balance between HP and RPMs that must be considered by all of us. There's add on weight for reduction, the issue of wear on all systems at higher RPM, as well as increased power loss with higher RPM engines at higher altitudes vs lower RPM engines.

 

When you weigh HP verses RPM... what do you get? Torque! Ta-da!

 

:D

This ain't rocket surgery!

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Originally posted by jw25wg

Keep the information flowing despite the uncalled for comments.

That's the plan, thanks.

 

 

Originally posted by jw25wg

.....if you were to look ahead would you anticipate in 3 years there might be a suitable diesel in the 180-220Hp range for a Cozy.[/b]

Geez, you know, if you had asked me this in 1995, when I started building, I would have said "you bet" - I saw two likely contenders at OSH that year. Now I can think of Deltahawk, Zoche, Continental, and SMA - I'm sure there are others, too. However, the Deltahawk is, AFAICT, a shoestring operation that has made almost no progress in the intervening 8 years. Zoche has likewise made little progress, and the price is out of sight anyway. IIRC, continental's entry is now on the back burner, and I don't know what SMA's status is.

 

So, is it possible? Sure. Would I hold my breath?.........

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When a tractorsalesman tries to make me buy one of his fantastic mashines.He is able to document how many gram of diesel the engine consumes to produce 1KWh.This information is hard to get on both aircraft and automotive engines.

Expirience shows that where my wifes Volvo V 70 (170 hp)drives 25,8 mpg gasoline,

a similar car used as taxi (163 hp) drives 44,6 mpg Diesel.

Now I do believe the auto engine to be more economical than a lycoming.But if the figures from theese engines are to be used,then the range of the Cozy could increase from 1000 miles to 1728 plus the increase of reserve fuel.So you might say that the range has doubled.

In denmark the price of jetfuel, wich will work with the diesel engine,is about 1/2 of the 100LL. These are the only fuels aviable at our airfields.

The Subaru solution might not be bad.But they are rare in these parts.

With a diesel you will never have carburettor ice or malfunctional ignition.

You might suffer from injection or computer errors,and it might be difficult to add a backup

Plane will be called `Hugin`

After Odins raven

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Hi mark

allways nice and educational to follow your paths on the net.Like your Cozy to.

Maybe because english is a foreign language to me I could still be a little confused about this hp thing.

When my son pops the same question I try to explain it this way:

If the engine was a hard working man shovelling sand, the torque would be the size of the shovel (lbs/ft) and the hp would be the amount of sand moved within a certain time (work produced).Please correct me if I am wrong.

In terms of an aircraft engine maybe the thrust would be a better measurement to use allthough now also the reduction unit and the prop gets involved.

In a european magazine "aeromarkt.com"there was an article claiming the Thielert TEA 125 to have a " Standshub "German for standing push mounted in a warrier III of 265 KG = 583 pounds. Compared to the original O-320 of 210 KG = 462 pounds.I dont know the figures for a O-360.

HM

Plane will be called `Hugin`

After Odins raven

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Diesels, due to the chemical nature of the fuel, will produce more power per gallon than a gasoline motor. As a general figure, an efficient diesel engine will use about 200 grammes per kilowatt, or about 0.33 lb per hp.

A Piper Cherokee Archer (180hp) running at 75% (135hp) uses 37 litres per hour, or about 10 gallons. A diesel at an equivalent hp setting should use 28 litres per hour, or about 7.5 gallons.

The Volvo D5 is regarded as the best diesel auto motor on the market, so it should meet those expectations. The same motor with a petrol head produces 300 hp out of the box.

Heico Sportiv of Germany sell upgrade ECU chips which give 190 hp and 282 lb/ft @ 4000rpm.

http://www.heicosportiv.de/images-produkte/bilder-produkte/p26-d5-190-ps.pdf

The Coconut King

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the engine was a hard working man shovelling sand, the torque would be the size of the shovel (lbs/ft) and the hp would be the amount of sand moved within a certain time (work produced)

Makes sense. And the speed of shovelling would be the RPM - right?

I can be reached on the "other" forum http://canardaviationforum.dmt.net

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Originally posted by HM Andersen

....the torque would be the size of the shovel (lbs/ft) and the hp would be the amount of sand moved within a certain time (work produced).

This is not an unreasonable analogy - as John Slade said, the rate of shoveling would be equivalent to the RPM.

 

Originally posted by HM Andersen

....In a european magazine "aeromarkt.com"there was an article claiming the Thielert TEA 125 to have a " Standshub "German for standing push mounted in a warrier III of 265 KG = 583 pounds. Compared to the original O-320 of 210 KG = 462 pounds.

The "static" thrust is a combination measurement of the engine power and propeller blade size/pitch settings. "Climb" props will have a much larger static thrust than "cruise" props on exactly the same engine, but will obviously not obtain the higher cruise speeds. The Thielert engine/propellor combination runs at lower RPM with a very different propeller than the O-320 setup. In order to fully compare the two installations, you'd need to see the full graph of climb vs. weight data as well as the top speed vs. weight data.

 

It's very possible that with the current Thielert setup that the performance of the plane with the Thielert engine will be as good (or even better) than the O-320 for the following reasons; even with 15 HP lower THEORETICAL, the Thielert is turbo-charged, meaning that it will put out it's maximum power all the time, while the O-320 will be density altitude limited. If they've tuned the prop for climb (or even used a CS prop), the Thielert will have a better climb rate and roughly equivalent cruise speeds due to the better ACTUAL power output from the turbo-chargine. If you turbo'd the O-320, you'd get better performance than from the Thielert.

 

 

Originally posted by No4

The Volvo D5 is regarded as the best diesel auto motor on the market, so it should meet those expectations.....

That certainly looks like a good diesel candidate, but it weights 185 kg dry, or 407 lb. This is more than 100 lb. MORE than an O-360, and that's without the radiator/coolant/PSRU. You'll need the PSRU to get the speed down from the 4000 RPM to 2700 RPM or so. If you say that the fuel burn is 12 - 15 lb/hr. less than the gasoline engine, you could claim that you could reduce the size of the fuel tanks by 75 lb. or so, and get back most of the difference (not counting radiator/coolant/PSRU etc. weight). You might have a difficult time doing the W&B, with the extra 100-140 lb. so far back, however.

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The weight of the Volvo was told me from the factory to be 182 KG.

This weight was without any declaration of accessories and I kind of doubt it.The Volvo being a 5 cylinder inline should be leighter than the Audi V6 ,which was offered to me by a swedish used carparts dealer,or whatever that trade is called in proper english. He claimed he could send it for the price of a 134KG package.But also told me that it was extremely easy for him to sell ,because they tend to break down.I am very interrested in the accurate weight of the Volvo.

The length was 70cm

Plane will be called `Hugin`

After Odins raven

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To mr Slade

By mistake I started a new Thread look at "torque"

 

I finally managed to get in touch with the sweede flying PA 25 with a Volvo conversion.It showed to be a gasoline 6 cylinder in line out of a Volvo S80.He has clocked over 800hours mainly towing gliders without sirius problems.He uses a98,4 inches prop turning 1700 RPM and a cogged belt reduction 3: 1.

He also told that there is a C 172 with a 2,5 liter volvo gas engine flying in sweden.But untill now no diesels.Nevertheless he has two brandnew 2,4 diesels laying around and is willing to sell one for svkr 35000 =us$ 7084.He sees no problem in increasing the power to 200hp

He will now put an engine on the weight and return to me with the answer.

As for the comparison of the O-320 and the thielert.Thielert claims:

PA 28 O-320 118 KTAS FL 60 requires 115hp and 8,7 gph

PA 28 Thielert 118 KTAS FL 60 requires 97 hp and 4,6 gph

The Thielert using a CS prop

HM

Plane will be called `Hugin`

After Odins raven

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He will now put an engine on the weight and return to me with the answer.

 

Interesting. Please let us know the weights when you get them. Of course we need to know what is included. (bare engine, intake, radiator etrc.) I'm committed to installing a rotary in my Cozy IV, but many builders are tempted by the diesel option -if we can just find one that's viable.

 

One additional thought - The cost of a CS prop would pay for a lot of petrol when spread over the years.

I can be reached on the "other" forum http://canardaviationforum.dmt.net

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Well mr Slade don´t let yuor mind change because of the diesel talk .

I understand that Greg Richter is happy with his rotary equipped Cozy.And it is actually flying.To my knowledge no diesel canard is in the air yet.

As for the propeller, my mind is set on an Ivoprop magnum in-flight adjustabel, NOT with the constant speed option.I was thinking of taking advantage of the diesel torque to use the adjustment as kind of an overdrive,with reduced RPM.

HM

Plane will be called `Hugin`

After Odins raven

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>Well mr Slade don´t let yuor mind change because of the diesel talk .

I'm way too deep change my mind now

 

> understand that Greg Richter is happy with his rotary equipped Cozy.And it is actually flying.

Well, yes and no. It ran well, but he's replacing it with a turbine.

 

>my mind is set on an Ivoprop magnum in-flight adjustabel

Really? Are you sure? While the concept is nice, I've heard bad stories about that prop. Issues with the blade attach method and the potential for catastrophic failure due to engine pulses. I believe at least two IVOs have thrown blades. I also recall that it's a bit inefficient at the high end, and doesn't provide a good top speed especially for fast airplanes. All this information is third hand. You might want to search the archives or ask on the Rotary Newsletter and the flyrotary mail list. I think thats where I've read about the failures and problems.

I can be reached on the "other" forum http://canardaviationforum.dmt.net

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This really proves the value of a forum like this.

Here I am 5000 miles away from where a lot of interesting things happen.This is not meant ironically.

I have seen only one Ivoprop ,it was placed on a norvegian Sky Arrow that along with two others visited my home airfield.The owner was happy with it,but the Sky Arrow which I tested was more of a STOL than a of fast plane

Plane will be called `Hugin`

After Odins raven

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>This really proves the value of a forum like this.

 

But keep in mind - what I gave you wasn't solid information. The failures may have been due to installer error. IVO may have fixed the problem.

 

Better to check it out than be swayed by unsubstanciated third hand rumor.

I can be reached on the "other" forum http://canardaviationforum.dmt.net

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An ignorant has no doubts and ask no questions.Everything is bound to be a success

Every doubt or question makes the decision more reliable,allthough it consumes time and effort.There were a danish philosoper Piet Hein,him with the super ellipse,who said that experts are put on earth to tell why nothing is possible.Now it is up to us preferrably former ignorants,to show that if you put in the effort needed, everything can be accomplished.

Still waiting for the weights from Sweden

HM

Plane will be called `Hugin`

After Odins raven

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Here is a little less ignorant Dane

Answers has arrived from Sweden.The Volvo diesel 5244T(5 cylinder-2,4 liter-4 valves per cylinder,Turbo)was put on the weight including exhaust manifold and turbo.The standard weight is 352 pounds.

This is without engine mount,starter ,alternator (toothwheel for the starter-dont know the proper name,not in the dictionary)reduction divice,radiator and water.Theese were the words.

I assume a few pounds could be peeled off. Maybe by building the valve cover and the oil pan in kevlar.

The length of the engine is 70cm-27,559 in.

Couldnt this engine have a chance for a flight?I think I will go for it.

HM

Plane will be called `Hugin`

After Odins raven

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The specifications I saw for the D5 mentioned that it has water cooled exhaust gas recirculation, I wonder if this can be disconnected/removed? This may add around 5 hp and save some weight.

A lot has been discussed about engine weight, horsepower, and torque.

The D5 should be capable of 200 hp for take off, which I think will be enough. I think lower rev torque is important for cruising at lower rpm settings, especialy with a CSU, but horsepower is ultimately the important number.

If you changed the standard turbo set up to one tuned for altitude compensation, and used a tricky intercooler, the charge air temp can be cooled to well below zero. 29 inches manifold pressure at -20'C gives a density altitude of minus 4200 ft or equivalent 4 inches of boost. This means the motor has lower rpm, lower pressures and lower temperatures throughout (but more torque). But of course you'll need oxygen, a CSU, and be happy cruising at FL180. This altitude also gives a 215 KTAS cruise at 160 KIAS.

I've just received plans 1124, and am provisionaly going for the D5, and then if not the motor out of my Nissan Skyline, but I'd hate to lose her.

The Coconut King

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