Bensen days thrust tests

StanFoster

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Here are the pictures of the thrust tests. Greg Spicola had the highest thrust to empty weight ....with 360 pounds of thrust versus 358 pounds pounds empty. Unfortunately for Greg...he was done before I got over to take the picture.

The pictures in order are Scott (tell me his last name and I will edit it in)

Scott pulled 340 pounds

Chris Wilson pulled 320 pounds

Chris Spadafora pulled 260 pounds

Bob Simmons machine pulled 340 pounds
 

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Cool, I wonder if my 447 pulls the same as Chris's.
 
Mike Gaspard pulled 300 pounds and had an empty weight of 302 pounds. He was just under Gregs ratio.

Mike Bantana?? pulled 260 pounds

Carl Schnieder pulled 275 pounds

Skip Comlodi pulled 450 pounds
 

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Ron Awad had a pull of 350 pounds

Tim Verroi pulled 340 pounds

Rudy Graffeo had the highest thrust at 490 pounds

Tim Hay pulled in at 410 pounds
 

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And for an answer to the person requesting info on the HKS motor.... carl schnieder's pull test of 275 was with the HKS motor !

I will see if carl will do a short interview regarding his choice of the HKS 4 stroke 2 cyl. motor.

Nuff-said
 
I reckon the thrust number in reality might be bigger since it has an offset between the rope and the thrustline which may diverge a downward force?
 
Without knowing about props and aerodynamic factors, it's hard to tell much for sure, but doesn't 275 pounds with the HKS place it closer in performance to a 503 than to a 582? If so, that's in line with anecdotal comments I've heard in the past.
 
My RAF:
Subaru EJ-22 with carburetor
68" 3-blade warp drive prop @ 13 degrees pitch
5260 rpm

The engine was cold when the test was done, would the results been diffrent if I warmed the engine prior to the test?
 
Carl Schneider has always marched to the beat of his own drummer.

His cows had computer tags before there were computers.

Carl hates monopolies but was born too late to enjoy President Theodore Roosevelt’s monopoly busting.

He’s no dummy; he knows Rotax is the only practical engine for a lightweight gyro, amounting virtually to a monopoly. But as an evangelical antimonopolist, wouldn’t touch one with a 10’ pole.

He had a brief diesel dalliance several years ago; a lightweight aero diesel that, I imagine, turned out to be vaporware rather than hardware. I don’t know the full story on that one; but if he actually bought one and it flew, we would have heard.

Then there was the AMW period, a 3-cylinder water-cooled 2-stroke that sounded like a Ferrari but didn’t stay glued together as well.

The last half dozen years has been a Hirth frolic but even Carl can tolerate only so many blown engines.

Should the HKS stay glued together, Carl won’t long be satisfied with a gyro so marginal that the next move has to be planned 2 miles before he gets there. He knows the joy of the “pull the trigger and go” flying method.
 
I am preserving this information on the PRA website. If anyone could provide make of gyro, engine on the gyro, and prop configuration, it would be appreciated and is good historical information.
 
Rotax 582 Blue Head. C gear box with 2.62 to 1 gear set. 60 inch 3 blade warp drive prop, pitched to allow a static RPM during pull test of 6430 rpm. Had I took a degree of pitch out of the prop, I could have achived closer to 6800 rpm and perhaps gotten a additional 10 pounds of thrust.... maybe.....
 
Rotax 582 with 67" hot prop Kiev tuned to 6300rpms 2.58:1 gearbox turning 5900rpms on my pull of 360 :cool:
 
McCulloch 90 hp w/ Holley 1940 carb and A.R.D. CDI conversion.
52" diameter x 26" pitch Tennessee Prop.
300 lb. static thrust @ ~3250 RPM.
Max RPM level flight - 3600 RPM.
 
GyroRon said:
Rotax 582 Blue Head. C gear box with 2.62 to 1 gear set. 60 inch 3 blade warp drive prop, pitched to allow a static RPM during pull test of 6430 rpm. Had I took a degree of pitch out of the prop, I could have achived closer to 6800 rpm and perhaps gotten a additional 10 pounds of thrust.... maybe.....

Heh... that would be cheating though... The RPM should probably be for what one flies with. Not a competition.

Greg,

What gyro do you have?

This really has to be good information. If we could make a point of getting the following information, over time we can build good charts. This info can only help folks. Be fair and truthful. It ain't a competition.

gyro type
engine type/hp/redrive
prop type/blades/size/pitch
gyro empty weight
rpm at test
lbs pulled
 
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I wonder what the Simonini would pull, by the way, they are making a redrive for the Subaru engine as well.
 
Just another note. We need air temperature too in addition to the engine/prop/pitch data if we want to compare apples to apples. Hotter temps mean higher RPMs. I don't know if thrust is increased though with those higher RPMs on a hotter day.
 
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