"How it's Made" coming to Lycoming (work)
04-16-2008, 09:57 AM
#1
Team Owner
Thread Starter
Member Since: Mar 2001
Location: Boston, Dallas, Detroit, SoCal, back to Boston MA
Posts: 30,607
Received 239 Likes
on
167 Posts
"How it's Made" coming to Lycoming (work)
If your curious how airplane engines are made, they'll be filming here tomorrow. It should air in a few months.
http://science.discovery.com/fansite...owitsmade.html
Feature engine is our Thunderbolt series
http://www.lycoming.textron.com/thunderbolt/index.jsp
750hp @ 3,000rpm
http://science.discovery.com/fansite...owitsmade.html
Feature engine is our Thunderbolt series
http://www.lycoming.textron.com/thunderbolt/index.jsp
750hp @ 3,000rpm
04-16-2008, 04:48 PM
#7
Le Mans Master
Brian, I didn't know you worked on tractor engines.
I thought you worked for GM. Anyway, that is pretty cool and I look forward to seeing the show. So is this 750 hp engine a TIO-720 or a 540? Are the Thunderbolt engines all 6 cylinders? I'm not that familiar with the lyc. product line. I never look to buy one and I fly them when I have to. I would be interested to gab with you about what you are up to there especially with your automotive experience/interest in contrast to the certified aviation mindset.
I thought you worked for GM. Anyway, that is pretty cool and I look forward to seeing the show. So is this 750 hp engine a TIO-720 or a 540? Are the Thunderbolt engines all 6 cylinders? I'm not that familiar with the lyc. product line. I never look to buy one and I fly them when I have to. I would be interested to gab with you about what you are up to there especially with your automotive experience/interest in contrast to the certified aviation mindset.
04-16-2008, 07:33 PM
#11
Former Vendor
Sweet looking aircraft and engine both
Looking forward to the show, thanks for the heads up!
Aircraft engines, got to love those massive twisted piston engines from the big WW2 bombers and outboard engies, small craft airplanes, etc
Rick
Looking forward to the show, thanks for the heads up!
Aircraft engines, got to love those massive twisted piston engines from the big WW2 bombers and outboard engies, small craft airplanes, etc
Rick
04-16-2008, 07:46 PM
#12
Le Mans Master
I sure agree with you on that! A few years back I was part of a WWII Army Air Corps reinactment group. I spent a bunch of time working on (and riding in) the various planes with their Pratt and Whitney R-985, R-1340, and R-2800 radial engines.
04-16-2008, 08:15 PM
#13
"AlohaC5" Senior Member
Thanks for the "heads up" - I look forward to recording that episode. As an active private pilot flying a Cessna 172 with a Lycoming engine, I always find these "Hot it's Made" series very interesting. Brian, I'll be calling you for an "overhaul discount" when I reach TBO in two years. 
Mike
Mike
Last edited by Gray Ghost GS; 04-16-2008 at 08:20 PM.
04-17-2008, 12:10 AM
#15
Race Director
Member Since: Oct 2000
Location: Deal's Gap 2004 NCM Motorsports track supporter
Posts: 13,915
Received 1,103 Likes
on
717 Posts
post , "If your curious how airplane engines are made, they'll be filming here tomorrow. It should air in a few months."
Yeah, but most of us need to know how to do other stuff to afford the engine, though
(remind me to tell you sometime about the difference in the use of 5/32 SS cotter pins in connecting rod bolts as opposed to 1/8" NAPA, national airplane parts association, cotter pins.....
)
Yeah, but most of us need to know how to do other stuff to afford the engine, though
(remind me to tell you sometime about the difference in the use of 5/32 SS cotter pins in connecting rod bolts as opposed to 1/8" NAPA, national airplane parts association, cotter pins.....
)
04-17-2008, 02:36 PM
#16
Team Owner
Thread Starter
Member Since: Mar 2001
Location: Boston, Dallas, Detroit, SoCal, back to Boston MA
Posts: 30,607
Received 239 Likes
on
167 Posts
Brian, I didn't know you worked on tractor engines. I thought you worked for GM. Anyway, that is pretty cool and I look forward to seeing the show. So is this 750 hp engine a TIO-720 or a 540? Are the Thunderbolt engines all 6 cylinders? I'm not that familiar with the lyc. product line. I never look to buy one and I fly them when I have to. I would be interested to gab with you about what you are up to there especially with your automotive experience/interest in contrast to the certified aviation mindset.
I thought you worked for GM. Anyway, that is pretty cool and I look forward to seeing the show. So is this 750 hp engine a TIO-720 or a 540? Are the Thunderbolt engines all 6 cylinders? I'm not that familiar with the lyc. product line. I never look to buy one and I fly them when I have to. I would be interested to gab with you about what you are up to there especially with your automotive experience/interest in contrast to the certified aviation mindset.On the street, you rev out you engine, and then get into high gear to cruise, dropping the rpm substantially. Aircraft engines get up to cruise speed, but only back the rpm down about 200rpm. It's left like that until you reach your destination.
The props can only spin about 3,000rpm otherwise the tips of the props go sonic.
If you build an engine that can run direct, w/o reduction gearing, you can eliminate it's weight.
Also, reduction gears on airplanes have been tried. They work great on turbines, but a turbine doesn't have to deal with pistons firing.
The race plane has the boost cranked up.
It runs 50ft off the ground @ 386.9mph!
Most of our production engines are "turbo normalized", in other words the turbo is there just to make up for the altitude.
They run on 110 low lead, not for the power, but to keep it from detonating at altitude.
The engine pictured is a 540ci flat six.
We have some of the old WWII radials down in the museum.
Real nice looking engines.
As well as some Dusenburg engines, Lycoming also built those.
04-17-2008, 10:14 PM
#17
Le Mans Master
I chose those words more for describing the "state of the art" in recip aircraft engine design coming from Lycoming. It is essentially 1930's tech with a few things from the '50's included. I am very familiar with the operating regime of an aircraft engine as I have a commercial pilots license with a multi-engine rating and my background and degree are in aeronautics. I mention my qualifications merely to let you know where I'm coming from and not to take an "I know more than you" attitude. I have my opinions but I still wouldn't mind learning more things as I have never worked for an engine manufacturer.
I take exception about reduction gears. Nearly every radial engine ever built had a reduction unit on it. Additionally, one of the best piston engines ever (Rolls Royce Merlin) had a reduction gear in it. If you are talking under 200hp then, maybe, the trade off isn't worth it but over that it is definitely a strong favorite. Consider that power boats have a similar operating regime to aircraft with similar requirements (i.e. torque is were it's at, not hp). They run reliably with reduction units. More power pulses per minute means more output and gearing down means more torque output. So running higher rpm yields more power and doing a 2:1 reduction doubles your torque. That is a pretty strong case. That's how turbines make so much torque. They spin the suckers at 45,000 rpm or more and gear it down to 2500. You don't have to make a hole lot of torque when you can multiply it by 18.
Anyway, I'm curious to know what kind of work you are doing there and what is going on that is of interest to an engine geek like me.
I take exception about reduction gears. Nearly every radial engine ever built had a reduction unit on it. Additionally, one of the best piston engines ever (Rolls Royce Merlin) had a reduction gear in it. If you are talking under 200hp then, maybe, the trade off isn't worth it but over that it is definitely a strong favorite. Consider that power boats have a similar operating regime to aircraft with similar requirements (i.e. torque is were it's at, not hp). They run reliably with reduction units. More power pulses per minute means more output and gearing down means more torque output. So running higher rpm yields more power and doing a 2:1 reduction doubles your torque. That is a pretty strong case. That's how turbines make so much torque. They spin the suckers at 45,000 rpm or more and gear it down to 2500. You don't have to make a hole lot of torque when you can multiply it by 18.
Anyway, I'm curious to know what kind of work you are doing there and what is going on that is of interest to an engine geek like me.
04-17-2008, 11:53 PM
#18
Race Director
Member Since: Oct 2000
Location: Deal's Gap 2004 NCM Motorsports track supporter
Posts: 13,915
Received 1,103 Likes
on
717 Posts
Which brings us to the lowly C175 with its reduction gearing, scuffed cylinder walls and all while turning 3200rpm at cruise.
On an aside note: I learned not long ago that the boys in WW2 in the pacific theater were having a terrible time with their fuel mileage considering the long distances covered. And who would teach them how to get double the mileage? Non other than Lindbergh himself. Talk about 'oversquare', running 36 inches and only 1800-2000 rpms!! Crew chiefs had a cow until they saw the light. That 30's technology is still being installed in aircraft today without any reduction gearing.
On an aside note: I learned not long ago that the boys in WW2 in the pacific theater were having a terrible time with their fuel mileage considering the long distances covered. And who would teach them how to get double the mileage? Non other than Lindbergh himself. Talk about 'oversquare', running 36 inches and only 1800-2000 rpms!! Crew chiefs had a cow until they saw the light. That 30's technology is still being installed in aircraft today without any reduction gearing.
Last edited by SouthernSon; 04-18-2008 at 12:14 AM.
04-18-2008, 09:23 AM
#19
Melting Slicks
As Brian said it is a compromise between a bigger engine turning low RPM's and a smaller one geared to have essentially the same airflow at a higher rpm. Think of it this way, an engine is a pump, and you have to move the air. You can do it with a bigger engine turning slower or you can do it with a smaller engine turning faster and a gear set.
Just remember, the RPM's aren't free. For a higher speed engine the reciprocating parts have to be stronger to handle the higher speeds, and stress is a speed squared parameter, so if you want to run twice the speed the parts tend to be four times as heavy. So the smaller engine turning faster won't be as light as you think it might.
Also, and this is probably the worst thing, the amount of heat generated will be related to the power generated. It is harder to get the heat out of the smaller parts because there is less area for cooling passages (for either air or water) and there will be more friction in the faster moving engine parts. For the most part expect that a smaller geared engine would have to be water cooled, and that also increases the weight (although it can improve the aerodynamic efficiency).
On a car the flywheel is on the crankshaft. On an airplane the flywheel is typically the prop. Putting a gearset between the engine and the flywheel can and often does result in nasty harmonics in the gearing and a short gear life, as Brian said, the gears get hammered because the firing is not damped out by a flywheel. Next time you are at the airport go along the flight line and try to wiggle the constant speed props blades on old recip airplanes. You will undoubtly find some that are getting loose. That constant hammering of the cylinder firing eventually works them loose and that's when you have to do a prop overhaul. Same thing is hammering the gears and eventually they wear out and break, or you have to make them a lot heavier than you thought they would need to be.
While most big aircraft engines in WWII were geared, they also didn't last very long, with fighter engines typically living for fifity hours or thereabouts, and while the transport radials were better, the biggest incentive (aside from speed) for the changeover to jets was that turbines had a much longer TBO. The P&W R-985 has normal TBO of 1200 hrs. Lately some folks are extending it to 1600, but it is a crapshoot if you get there. By contrast, most small Lycomings go 2,000 hrs between overhauls and that is a pretty good service life. Merlins being flow today see somewhere between 400 to 700 hours between overhauls (depending if they have transport heads or not), but you have to agree that none of these engines lasted a long time.
Not to say that the Lycosaurus is a state of the art engine, but the basic layout and power to weight, reliability and life are still pretty good. It is a testament to the original designers that they got it so right so long ago when there weren't computers or CAD or anything other than slide rules and paper. If there was something better out there for the price, it would be selling like hotcakes, but there really isn't.
There haven't been any successful small geared prop engines for the above reasons, certainly nothing that will last 2,000 hours. There are lots of people who have tried to make a successful small geared engine, and most have eventually given up. In the 400hp and lower class it is probalby better to go with the larger displacement engine and skip the geared alternatives.
Just remember, the RPM's aren't free. For a higher speed engine the reciprocating parts have to be stronger to handle the higher speeds, and stress is a speed squared parameter, so if you want to run twice the speed the parts tend to be four times as heavy. So the smaller engine turning faster won't be as light as you think it might.
Also, and this is probably the worst thing, the amount of heat generated will be related to the power generated. It is harder to get the heat out of the smaller parts because there is less area for cooling passages (for either air or water) and there will be more friction in the faster moving engine parts. For the most part expect that a smaller geared engine would have to be water cooled, and that also increases the weight (although it can improve the aerodynamic efficiency).
On a car the flywheel is on the crankshaft. On an airplane the flywheel is typically the prop. Putting a gearset between the engine and the flywheel can and often does result in nasty harmonics in the gearing and a short gear life, as Brian said, the gears get hammered because the firing is not damped out by a flywheel. Next time you are at the airport go along the flight line and try to wiggle the constant speed props blades on old recip airplanes. You will undoubtly find some that are getting loose. That constant hammering of the cylinder firing eventually works them loose and that's when you have to do a prop overhaul. Same thing is hammering the gears and eventually they wear out and break, or you have to make them a lot heavier than you thought they would need to be.
While most big aircraft engines in WWII were geared, they also didn't last very long, with fighter engines typically living for fifity hours or thereabouts, and while the transport radials were better, the biggest incentive (aside from speed) for the changeover to jets was that turbines had a much longer TBO. The P&W R-985 has normal TBO of 1200 hrs. Lately some folks are extending it to 1600, but it is a crapshoot if you get there. By contrast, most small Lycomings go 2,000 hrs between overhauls and that is a pretty good service life. Merlins being flow today see somewhere between 400 to 700 hours between overhauls (depending if they have transport heads or not), but you have to agree that none of these engines lasted a long time.
Not to say that the Lycosaurus is a state of the art engine, but the basic layout and power to weight, reliability and life are still pretty good. It is a testament to the original designers that they got it so right so long ago when there weren't computers or CAD or anything other than slide rules and paper. If there was something better out there for the price, it would be selling like hotcakes, but there really isn't.
There haven't been any successful small geared prop engines for the above reasons, certainly nothing that will last 2,000 hours. There are lots of people who have tried to make a successful small geared engine, and most have eventually given up. In the 400hp and lower class it is probalby better to go with the larger displacement engine and skip the geared alternatives.
Last edited by Solofast; 04-18-2008 at 09:44 AM.
04-18-2008, 10:45 AM
#20
Team Owner
Thread Starter
Member Since: Mar 2001
Location: Boston, Dallas, Detroit, SoCal, back to Boston MA
Posts: 30,607
Received 239 Likes
on
167 Posts
Weight's the key.
The big radials and V12's are great engines, but they weigh more than some of the aircraft we provide power for.
Some have put reduction drives on car engines, the latest craze has been automotive diesels. But they're not making in to 2,000tbo ( time before overhaul ).
I can tell you what I'm working on after the big show.
Till then, I can't really post anything.
The big radials and V12's are great engines, but they weigh more than some of the aircraft we provide power for.
Some have put reduction drives on car engines, the latest craze has been automotive diesels. But they're not making in to 2,000tbo ( time before overhaul ).
I can tell you what I'm working on after the big show.
Till then, I can't really post anything.