Allison engines vs Merlins for racing

[Leo]

Re: Allison engines vs Merlins for racing

As I recall the weight limit was based on wake turbulence and such behind the larger aircraft )theory being that too light an aircraft would be thrown about and uncontrollable) rather than any political reasons on RARA's part.
Having seen many aircraft "upset" over the years, I can understand that a racer as light as, say, a Thunder Mustang or NXT would be slapped into the ground.
I once got myself too close to a C-5's wake while flying a sailplane. I was a couple miles behind it. All I can say is I have a LOT of respect for it all.
I think Mr. Nixon is right. The next area that modern methods and equipment can be played with is the Sport Class. Kinda why they were formed in the first place wasn't it? I love the unlimited but they have reached a point where changes and improvements are going to be aggregately small.

[Lockheed Bob]

Re: Allison engines vs Merlins for racing

Leo is right. The super sport class is getting right up there in speed. At my age prior to the post WWII war fighters I would say 99% of the racers were scratch built. After WWII the surplus fighters were just a cheap way to get into racing which as we know now isn't the case. We are now at the crossroads whether unlimited racing continues as we know it or???

[kiwiracefan]

Re: Allison engines vs Merlins for racing

I'm still amazed rara guaranteed that further depletion of rare hardware will continue by instituting a weight limit.

Maybe they think people wont watch the races if the unlimited class sees irreplaceable warbirds gradually giving way to scratch built racers?

I'm there to see the fastest planes in the world race regardless of it's origin or configuration.

Maybe that is the case, but also think about this, the last 3 scratch built unlimiteds have all been lost and claimed the lives of their pilots too

[Samuel]

Re: Allison engines vs Merlins for racing

I am surprised nobody has mentioned the Falconer. Seems like a great platform to experiment with and then move to the bigger unlimited engines. George Giboney was using a super charger on his, Blue Thunder has an electronic, sequential, tuned-port injection system. Imagine what the sport class could do if they had a payout like the unlimiteds!

[IcePaq]

Re: Allison engines vs Merlins for racing

Let me know when you current engine builders want to come out of the stone age.

I will gladly design an engine management system that is immune to intake tract explosions, get's better "mileage", will allow higher boost levels without detonation, and "de rich" automatically.

All I need is access to an engine of the type so I can figure out the crank reference scheme.

If you wait too long, you will be forced to buy a product you could get credit for designing.......well "co-designing".

I also have a line on the next level of piston material.

We just shipped a bunch to mahle who is making F1 pistons out of it to test this year.

[Wild Bill Kelso]

Re: Allison engines vs Merlins for racing

I'd be interested in what kinds of gains could be had simply by shoving a modern compressor design into the current superchargers...

Bingo! I wonder the same thing.

[Matt Jackson]

Re: Allison engines vs Merlins for racing

Let me know when you current engine builders want to come out of the stone age.

I will gladly design an engine management system that is immune to intake tract explosions, get's better "mileage", will allow higher boost levels without detonation, and "de rich" automatically.

All I need is access to an engine of the type so I can figure out the crank reference scheme.

If you wait too long, you will be forced to buy a product you could get credit for designing.......well "co-designing".

I also have a line on the next level of piston material.

We just shipped a bunch to mahle who is making F1 pistons out of it to test this year.

It is not news that there exists technology that simply could eclipse the current engine performance at Reno. The fact is the cost is prohibitive. There is not a current race team on the planet willing to develop a new engine for one race a year. We live in a economical situation that will not permit the development for this one event. Simply put no one will throw the money down the proverbial toilet. Does the technology exist ? you bet!!!!! Are there a lot of capable smart people out there to develop a better power plant? I am sure. The problem is there is no prize or compensation for the development. Simply put, you run what you got. Could we developed a faster air frame? Most certainly.
We all know that isn't going to happen either.

[Wild Bill Kelso]

Re: Allison engines vs Merlins for racing

It is not news that there exists technology that simply could eclipse the current engine performance at Reno. The fact is the cost is prohibitive. There is not a current race team on the planet willing to develop a new engine for one race a year. We live in a economical situation that will not permit the development for this one event. Simply put no one will throw the money down the proverbial toilet. Does the technology exist ? you bet!!!!! Are there a lot of capable smart people out there to develop a better power plant? I am sure. The problem is there is no prize or compensation for the development. Simply put, you run what you got. Could we developed a faster air frame? Most certainly.
We all know that isn't going to happen either.

I know a guy that throws every cent he has into developing an engine program no matter what the skeptics say. That my friends... is racing! Hate him or love him; that guy drives a bunch of nobodies in many peoples eyes to do whatever he wants because he has a dream that we all believe in; a vision to do the impossible with "what we have". He doesn't care what it costs. He is a racer no matter what people think of him.

[toldjaso]

Re: Allison engines vs Merlins for racing

I know a guy that throws every cent he has into developing an engine program no matter what the skeptics say. That my friends... is racing! Hate him or love him; that guy drives a bunch of nobodies in many peoples eyes to do whatever he wants because he has a dream that we all believe in; a vision to do the impossible with "what we have". He doesn't care what it costs. He is a racer no matter what people think of him.

I also know a (probably different) guy who had electronic ignition on a former top unlimited racer as far back as 2008, but never got to work the bugs out of the system before it all got tossed in the proverbial dumpster.
Why is everyone so stuck on driving the turbos with the exhaust?
When the wheels are in the wells, and the hydraulic system is just bypassing, you could drive the turbo with a hydraulic motor.
You could also drive turbos with an electric motor, but that would add a lot of weight and complexity and such.
You could also drive turbos with a small apu, but that also would add a lot of weight and complexity and such.
Now, everybody can have a chance to shoot down my idea about hydraulic motors.
Please proceed!

[Lon Moer]

Re: Allison engines vs Merlins for racing

I also know a (probably different) guy who had electronic ignition on a former top unlimited racer as far back as 2008, but never got to work the bugs out of the system before it all got tossed in the proverbial dumpster.
Why is everyone so stuck on driving the turbos with the exhaust?
When the wheels are in the wells, and the hydraulic system is just bypassing, you could drive the turbo with a hydraulic motor.
You could also drive turbos with an electric motor, but that would add a lot of weight and complexity and such.
You could also drive turbos with a small apu, but that also would add a lot of weight and complexity and such.
Now, everybody can have a chance to shoot down my idea about hydraulic motors.
Please proceed!

Well, this is getting far from the A vs M topic.

The Formula 1 Series is currently heavily invested in their Kinetic Energy Recovery System (KERS) that is harvesting power from the engine braking and chassis braking systems and while "braking" isn't directly applicable to aircraft the technology involved will certainly be adapted to other systems.

But, as Mr. Jackson has said 'who's going to pay for it?'.

[toldjaso]

Re: Allison engines vs Merlins for racing

Well, this is getting far from the A vs M topic.

The Formula 1 Series is currently heavily invested in their Kinetic Energy Recovery System (KERS) that is harvesting power from the engine braking and chassis braking systems and while "braking" isn't directly applicable to aircraft the technology involved will certainly be adapted to other systems.

But, as Mr. Jackson has said 'who's going to pay for it?'.

As far as Allison vs Merlin goes, I always thought some one would (should) build a custom supercharger and bolt it to the Allison, but no one ever did.
In my opinion, the Allison is a better design for the core engine, but the blower is no match for the Merlin. The Allison is so smooth, that the P-38 Lightning (for example) had a solid bed engine mount, with a piece of asbestos truck brake shoe lining material sandwiched between the engine case and the mount on all four corners of the engine for vibration isolation. The Merlin has rubber elastomers to try to keep it from tearing off of the nose. The camshafts/ gearing for drives/ etc. are a better design on the Allison.
There are people who could easily pay for the development of all these neat things, such as different gearing for the nose case, but usually back out of the projects as soon as they get more interested in a different hobby, or a new girlfriend, or whatever.

[440_Magnum]

Re: Allison engines vs Merlins for racing

Now, everybody can have a chance to shoot down my idea about hydraulic motors.
Please proceed!

Two words: flow loss. Hydraulic fluid has never been an energy-efficient way of moving power from one place to another. Convenient: check. Reliable: Check. Effecient... just too much friction loss as the fluid flows through hoses, valves, pumps, and motors.

The electric motor idea is interesting. F1 is using "thermal energy recovery" now (in addition to "kinetic energy recovery already mentioned) where the turbo is coupled to a motor/generator that can harvest energy when the turbine is generating more energy than the compressor needs for developing boost, or apply stored electrical energy as a motor to generate boost faster than exhaust gas alone (as I sketchily understand the way they're doing things). But then again, it makes a lot of sense to carry a battery in a race format where the vehicle (car in F1's case) is constantly accelerating and decelerating, increasing and then shedding kinetic energy, changing the thermal flow through the turbo entering versus exiting every corner. Air racing is much more of a steady-state thing as far as the powerplant goes, so its hard to think of any portion of a lap where the engine system could be storing energy for use on some other part of the lap.

[N22252]

Re: Allison engines vs Merlins for racing

Air racing is much more of a steady-state thing as far as the powerplant goes, so its hard to think of any portion of a lap where the engine system could be storing energy for use on some other part of the lap.

"Gentlemen, you have a race... Now dive down that chute to get a good charge on your battery and save it for Sunday

[gp70442]

Re: Allison engines vs Merlins for racing

"... Now dive down that chute to get a good charge on your battery and save it for Sunday

Well consider that they are coming UP on the power down the chute, using almost if not all all of it at the start. It's basically a drag race once released.

GP

[IcePaq]

Re: Allison engines vs Merlins for racing

I suggested a system of motor coupled to turbo's shaft in 2009 but later found it was patented in 1994.

This is what next year's formula one engines may look like.