Cheaper tows?

On Tuesday, October 16, 2018 at 3:14:01 PM UTC-5, Charlie M. (UH & 002 owner/pilot) wrote:
To sorta answer this, there is an ongoing push by AOPA and other groups along with the FAA (in the US) for a suitable unleaded fuel for use in the older "leaded fuel" engines.
I know we added a supplement to our low lead fuel for our towplanes. Don't remember the name of it.

As to using auto derived engines for aircraft duty, sheesh, other than endurance racing (likely max runtime until rebuild, maybe 25hrs?), auto engines were not designed to run near full power for about 2000hrs before rebuild.
While most piston aircraft engine are rather archaic compared to modern auto engines, they are rather dirt simple and last for a long time at high power loads.
Yes, a better ignition system can help, although try getting that certified.
Yes, in the US, and other countries, there is a push to find a suitable unleaded fuel.
Aviation is still a small niche market (a bit larger than sailplanes, but still small for Shell, BP, Exxon, etc.), so what do they care about losing us due to environmental concerns?

There have been discussions on Subaru forums about peeps wanting 300hp+ from a 2.5L NA Subaru engine for aero use.
Yes, can be done, but at what cost?
Most is in the experimental arena.

As to going LPG, it usually is a big drop in power due to the lower power density of the fuel compared to gasoline, leaded or unleaded.

Really hard to beat gasoline for now. Anywhere close is big money to get there.

Hey, I am all for innovation, yes, we need to move from leaded fuel, but there are tradeoffs.
Just ask the peeps that get ethanol blends for cars based on season. There is a MPG drop because of it. The little performance gain due to ethanol cooling is more than offset (thus far) by the lower power density of the fuel.
This is more common in northern bits of the US, especially in metro areas (I am in the NY metro area).
I log my fuel mileage, I can tell when fuel stations go from summer blend to winter blend. It averages 15% drop in mileage.

Wrong again, Charlie.
In the era of smallish 50-100HP auto engines in Germany in the 70's we used to flog them for many hours at full throttle on the Autobahn. They were made for this abuse and lasted just as long as those in a taxi.
Herb

Wrong?

Answer this, did you/others run small engines for close to 2000hrs at full throttle with no rebuilds?
Frankly, not likely.

While most IC aircraft engines are archaic, they spend most time at close to full power for close to 2000 hours.

Herb, while I know you (and you know me, but maybe not remember me), I have to say most automotive engines trying to do what a "lump of an archaic engine" is normally used in US GA gas piston engines,

Rough guess........would you run a car engine at full power for 2000hrs? Quick numbers, 45MPH for 2000 hours, say about 90,000 miles.
Me, no Frikkin way.
You, I have no clue, go for it, not my wallet.

Herb, go rush against other issues, I think you lose on this one.......OK?

At 20:52 17 October 2018, Charlie M. UH & 002 owner/pilot wrote:
Wrong?

Answer this, did you/others run small engines for close to 2000hrs
at full
throttle with no rebuilds?
Frankly, not likely.

While most IC aircraft engines are archaic, they spend most time
at close
to full power for close to 2000 hours.

Herb, while I know you (and you know me, but maybe not
remember me), I have
to say most automotive engines trying to do what a "lump of an
archaic
engine" is normally used in US GA gas piston engines,

Rough guess........would you run a car engine at full power for
2000hrs?
Quick numbers, 45MPH for 2000 hours, say about 90,000 miles.
Me, no Frikkin way.
You, I have no clue, go for it, not my wallet.

Herb, go rush against other issues, I think you lose on this
one.......OK?


You can't compare aero engines with car engines,They are nearer to
boat engines in their usage .And tugs are worse.
To red line ,full throttle, a car you would need to tow a heavy load
up a very long hill for 2000hrs.
A sensible engineer would want to size the engine to run at max for
20 or 30seconds then throttle back to 50%.

Modern Motors are much more robust, but the way we are using
Rotax engines in modern tugs is going to lead to a lot of scared
tuggies making dead stick off field landings.
With a slippy tug like the Dianamic (probably spelled that wrong)
which I saw for the first time last month, with a blown Rotax and a
variable pitch prop you might have a chance .

I spent much of last year in a Duo Discus xlt behind a eurofox tug.
I am not sure who was most scared me or the Tug pilot, but it was
my syndicate partner that decided to give the sport up.

Max power is at max revs, so the prop needs to be set so that you
can reach max revs by lift off, but if that is only 65Kts you have no
choice but to tow at max revs if the glider is heavy like mine (2 fat
men a tank of gas and a fin full of water) ,and that is at a low
British pressure altitude.
I asked the salesman for a rough price for his as yet uncertified
dianamic with a vp prop ,,,about £160,000+tax,
At that price you can put a lot of gas in Pawnees

On Wednesday, October 17, 2018 at 6:00:07 PM UTC-4, Jonathon May wrote:
I spent much of last year in a Duo Discus xlt behind a eurofox tug.

And that was during just one tow!

"I spent much of last year in a Duo Discus xlt behind a eurofox tug.
I am not sure who was most scared me or the Tug pilot, but it was
my syndicate partner that decided to give the sport up. "

Move to a club with more powerful tugs! Or buy an Arcus M.

On Wednesday, October 17, 2018 at 3:52:56 PM UTC-5, Charlie M. (UH & 002 owner/pilot) wrote:
Wrong?

Answer this, did you/others run small engines for close to 2000hrs at full throttle with no rebuilds?
Frankly, not likely.

While most IC aircraft engines are archaic, they spend most time at close to full power for close to 2000 hours.

Herb, while I know you (and you know me, but maybe not remember me), I have to say most automotive engines trying to do what a "lump of an archaic engine" is normally used in US GA gas piston engines,

Rough guess........would you run a car engine at full power for 2000hrs? Quick numbers, 45MPH for 2000 hours, say about 90,000 miles.
Me, no Frikkin way.
You, I have no clue, go for it, not my wallet.

Herb, go rush against other issues, I think you lose on this one.......OK?

Can't wait to see you cruising, descending and landing for 2,000 h on full power, Charlie. All engines have significant partial power time. I'm just fighting that old myth about GA aircraft engines (the dinosaurs of American technology) being "made" for constant max power.

Fred Drift:
I've towed behind a 400HP Brave, and don't recall the owner claiming it being inexpensive to operate. How does the FU-24 with IO-720 provide cheaper tows?
Chevy LS series crate engines ~400HP are 7 to 8000 dollars. How does that compare to IO-720 top and major overhauls?
Jim

On Thursday, October 18, 2018 at 8:05:44 AM UTC-7, JS wrote:
Fred Drift:
I've towed behind a 400HP Brave, and don't recall the owner claiming it being inexpensive to operate. How does the FU-24 with IO-720 provide cheaper tows?
Chevy LS series crate engines ~400HP are 7 to 8000 dollars. How does that compare to IO-720 top and major overhauls?
Jim

There's a popular and successful LS conversion for the Repbublic Seabee. It's also offered for other aircraft. Some versions can accommodate a reversing prop. Drop the glider and put the prop in beta to descend. Yee ha!

Here's their take on operating costs for the various engine types (including aircraft engines).

https://www.v8seabee.com/conversion-...ing-costs.html

Craig

On Thursday, October 18, 2018 at 7:44:18 AM UTC-7, wrote:
On Wednesday, October 17, 2018 at 3:52:56 PM UTC-5, Charlie M. (UH & 002 owner/pilot) wrote:
Wrong?

Answer this, did you/others run small engines for close to 2000hrs at full throttle with no rebuilds?
Frankly, not likely.

While most IC aircraft engines are archaic, they spend most time at close to full power for close to 2000 hours.

Herb, while I know you (and you know me, but maybe not remember me), I have to say most automotive engines trying to do what a "lump of an archaic engine" is normally used in US GA gas piston engines,

Rough guess........would you run a car engine at full power for 2000hrs? Quick numbers, 45MPH for 2000 hours, say about 90,000 miles.
Me, no Frikkin way.
You, I have no clue, go for it, not my wallet.

Herb, go rush against other issues, I think you lose on this one.......OK?

Can't wait to see you cruising, descending and landing for 2,000 h on full power, Charlie. All engines have significant partial power time. I'm just fighting that old myth about GA aircraft engines (the dinosaurs of American technology) being "made" for constant max power.

Not max, but 75%.

Tons of people are cruising around with 200 to 300 HP engines in their cars.. They occasionally use full power for five to ten seconds and then cruise along using something like 15 to 20 HP continuous.