Cheaper tows?

On Tuesday, October 16, 2018 at 2:36:58 PM UTC-5, Craig Funston wrote:

Hi Dan, I was asking about the LS1 powered Pawnee. That's a modern engine designed to run on unleaded fuel with or without ethanol.

I may have missed other parts of the discussion related to alternate fuels and certified aircraft engines. If not it would be nice to have discussions about the use of mogas in STC'd engines in another thread.

Thanks,
Craig

Craig just wants the LS1 powered Pawnee so he can run the airconditioner to keep cool while towing. Don't blame you one bit!

Steve Leonard

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.

I was flabbergasted when I saw the Corvette powered Pawnee at Narromine, and they didn't have air conditioning!

On Tuesday, October 16, 2018 at 2:42:22 PM UTC-7, Tony wrote:
I was flabbergasted when I saw the Corvette powered Pawnee at Narromine, and they didn't have air conditioning!

Hey, a two place V8 powered Pawnee with AC would be one sweet ride!

On Tue, 16 Oct 2018 13:13:58 -0700, 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.

Slightly off topic, but how do you guys like this engine conversion?

https://www.youtube.com/watch?v=loy2n8s_l00

The airframe is interesting: it was developed in California as a low-cost
counter-insurgency aircraft, but never caught on. The design was bought
by a NZ outfit and redeveloped as an agricultural plane in, I think, the
early '60s. It originally had 250hp, but was rapidly upgraded to a 400hp
Continental flat 6. Now they either have a 750 shp turbine or, line this
one a big block truck V8. I don't know if its burning petrol or diesel.

You see one or two 750hp turbine derivatives (the PAC750 bush plane)over
here in the hands of jump clubs. They like them because the carry a lot
of jumpers at a time and can manage 2500 fpm descent rates, so the turn-
round time is good.

Back on topic: I've not heard of them being used as tow planes, but I
reckon they'd be a match for the big turbine Zlins at that game.

Anyway, enjoy the video and its V8 sound track !


--
Martin | martin at
Gregorie | gregorie dot org

On Tuesday, October 16, 2018 at 4:20:17 PM UTC-7, Martin Gregorie wrote:
On Tue, 16 Oct 2018 13:13:58 -0700, 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.

Slightly off topic, but how do you guys like this engine conversion?

https://www.youtube.com/watch?v=loy2n8s_l00

The airframe is interesting: it was developed in California as a low-cost
counter-insurgency aircraft, but never caught on. The design was bought
by a NZ outfit and redeveloped as an agricultural plane in, I think, the
early '60s. It originally had 250hp, but was rapidly upgraded to a 400hp
Continental flat 6. Now they either have a 750 shp turbine or, line this
one a big block truck V8. I don't know if its burning petrol or diesel.

You see one or two 750hp turbine derivatives (the PAC750 bush plane)over
here in the hands of jump clubs. They like them because the carry a lot
of jumpers at a time and can manage 2500 fpm descent rates, so the turn-
round time is good.

Back on topic: I've not heard of them being used as tow planes, but I
reckon they'd be a match for the big turbine Zlins at that game.

Anyway, enjoy the video and its V8 sound track !


--
Martin | martin at
Gregorie | gregorie dot org

The E-Tug Pawnee VH-CUR with (backwards facing) LS1 V8 was great, but they had so many teething pains programming the chip that it didn't stick around at Keepit. Believe the E-Tug group have it all worked out now.
When I saw it, the E-Tug used a ground adjustable 4-blade prop on a PSRU made in Washington.
Climbed way too fast at first, got to 2000' before the end of the runway which is a concern at a competition.
During the period when the throttle would not go back to idle, it was shut down and landed dead stick with no shock cooling issues - but the water pump wasn't turning then either.
Believe there are newer LS- series V8s that are better.
Just found some photos from 2007.
https://www.dropbox.com/sh/0gh8y9b7p...ykXOTBjEa?dl=0
Jim

On Tuesday, October 16, 2018 at 4:20:17 PM UTC-7, Martin Gregorie wrote:
On Tue, 16 Oct 2018 13:13:58 -0700, 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.

Slightly off topic, but how do you guys like this engine conversion?

https://www.youtube.com/watch?v=loy2n8s_l00

The airframe is interesting: it was developed in California as a low-cost
counter-insurgency aircraft, but never caught on. The design was bought
by a NZ outfit and redeveloped as an agricultural plane in, I think, the
early '60s. It originally had 250hp, but was rapidly upgraded to a 400hp
Continental flat 6. Now they either have a 750 shp turbine or, line this
one a big block truck V8. I don't know if its burning petrol or diesel.

You see one or two 750hp turbine derivatives (the PAC750 bush plane)over
here in the hands of jump clubs. They like them because the carry a lot
of jumpers at a time and can manage 2500 fpm descent rates, so the turn-
round time is good.

Back on topic: I've not heard of them being used as tow planes, but I
reckon they'd be a match for the big turbine Zlins at that game.

Anyway, enjoy the video and its V8 sound track !

Yeah, that's video's been in my bookmarks for a few years.

It's hard to find newer footage and in decent quality :-(

Here's a newer model in 720p \o/ in a a two week old upload.

https://www.youtube.com/watch?v=YOTwJ1ASz1c


Oh, here's a two year old 1080p video of a classic 400 HP piston one. Looks like it's made by a model flyer who gets some stick for noise lol

https://www.youtube.com/watch?v=XSGYL3j5EXo

On Tue, 16 Oct 2018 21:40:33 -0700, Bruce Hoult wrote:

Here's a newer model in 720p \o/ in a a two week old upload.

https://www.youtube.com/watch?v=YOTwJ1ASz1c

Nice. Probably the best shot I've seen of a CRESCO doing its thing.

Oh, here's a two year old 1080p video of a classic 400 HP piston one.
Looks like it's made by a model flyer who gets some stick for noise lol

https://www.youtube.com/watch?v=XSGYL3j5EXo

Yep, sounds like an RC guy with noise problems. I didn't realise that
there were many straight 400hp Fletchers still flying.

Do you know who did the V-8 conversions?


--
Martin | martin at
Gregorie | gregorie dot org

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

Why are the wings bent?Â* Was the shop where it was built too small to
lay the wing flat?

On 10/16/2018 5:20 PM, Martin Gregorie wrote:
On Tue, 16 Oct 2018 13:13:58 -0700, 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.

Slightly off topic, but how do you guys like this engine conversion?

https://www.youtube.com/watch?v=loy2n8s_l00

The airframe is interesting: it was developed in California as a low-cost
counter-insurgency aircraft, but never caught on. The design was bought
by a NZ outfit and redeveloped as an agricultural plane in, I think, the
early '60s. It originally had 250hp, but was rapidly upgraded to a 400hp
Continental flat 6. Now they either have a 750 shp turbine or, line this
one a big block truck V8. I don't know if its burning petrol or diesel.

You see one or two 750hp turbine derivatives (the PAC750 bush plane)over
here in the hands of jump clubs. They like them because the carry a lot
of jumpers at a time and can manage 2500 fpm descent rates, so the turn-
round time is good.

Back on topic: I've not heard of them being used as tow planes, but I
reckon they'd be a match for the big turbine Zlins at that game.

Anyway, enjoy the video and its V8 sound track !



--
Dan, 5J