Is this right
 

I love this thread...:p

Next year people are running ASP .40 engines on mufflers in the F3D nationals... Dave Shadel is going to have a hell of a time unloading his stock of worthless Nelson engines...
Not to mention Rob Metkemeijer in the Netherlands... although pretty lightweight, his new MB40 Profi engines will make great paper weights...

But there's a good side to all of this... we will be able again to start F3D pylon racing at our noise regulated field... those ASP's on mufflers must be more quiet than those Nelsons on unmuffled power pipes...

disclaimer
 

Didn't think I'd have to post this, but for legal purposes (and some humor):

Reported performance results do not guarantee similar performance in all ASP engines. Your results may be less than those reported in this thread

Ok
 

I understand this is not right for this engine to do the RPM's its showing but I would like to use this engine on my trainer without kill someone so how do I slow it down. Do I put a bigger prop or do I run it really rich? if I decide to keep it with the rpm its showing is there a prop a can buy that is safe with these readings? Also I would like to thank everyone that responded here I know it sounds far fetched but if I did see it TWICE with two different techs I wouldn't believe it. I glad to see I'm not the only one.

Re: Ok
 

In most cases, the transmitter will have a "Throttle" stick, usually on the left gimbal..it usually moves up and down. This will be invaluable in setting the speed of your engine in flight. I highly recommend using it, I think you will be greatly rewarded by incorporating the use of the throttle into your training experience.

Best of luck.

Is this right
 

I agree with Chuck - learn to use the throttle while flying. I always trim my planes for level flight with half throttle, then when I need it, I've got the extra power.

Also, I would suggest going one size larger for your prop. An 11 X 6 will place a larger load on the engine, bringing it closer to normal RPM's. If it's still to high, upgrade again to an 11 X 7 or (if you have ground clearance) 12 X 6.

Shallow pitch gives more accelleration / braking, and steeper pitch gives more top speed. Which prop you use depends on your flying style.

ASP
 

Strato,

I was not saying you were comparing the ASP to the Rossi.

If your ASP gets 22,500 RPM and any other run-of-the-mill ASP, same production line, same exhaust, same fuel and prop gets a very respectable 16K (already somewhat optimistic), you are definitely comparing two engines from the same production line.

You are also getting results that are as strange as a 20' tall man.

You, as well as Apapa, should be taking all the tachometers that you used and trying to measure something KNOWN to be spinning a prop at 22,000 - 27,000 RPM.

I would say your instruments are "strange", because you are both describing an impossibility. The fact that your props and your spinners are intact only accentuates the fact. Plastic spinners are limited by their manufacturers to 14,000 RPM...

Sincerely,

Re: ASP
 

It seems Spinner manufacturers have the same problem I stated above about Master Airscrew:

Every BB Engine spec I've EVER read for 40 sized engines lists a max RPM in excess of 15,000, and most are in excess of 16,000. Smaller displacement engines have even higher max RPM specs. (click here for OS FX series specs)

Based upon your statement, we can't put a plastic spinner on any nitro engine with ball bearings.

What The!?!
 

These numbers definitely do not sound right apapa-tell you what I'm gonna do; Send those Rossi's to me immediately and I will graciously offer my services as a tachometer technician and real-world-performance specialist (and $60 plus shipping to Texas) with the intention of ending the constant ridicule and harrassment you must surely face on a daily basis and reporting back to you and the RC world the results of my unbiased findings,
thereby doing you and the world a truly unselfish and benevolent service. And please; there is no need to thank me-this is what I do.

RPMs
 

Strato,

More than 95% of all .15 - .90 engines in the field, tach between 9K and 14K, on all standard sport props.
The specified HP@RPM figures given by engine manufacturers, can only be realized, when the engine is unloaded, in high speed flight. Most often, it doesn't happen even there.

When someone arrives in the field with an engine running 15K and more, the whole crowd surrounds him within 30 seconds.

The maximum safe RPM is real life figures and very few exceed them, but they are there for a very good reason. I am sure there is a safety margin involved, but it is not one-half of the actual mechanical limit.
If MA states 16K and an allowable gain of 2K is made in the air, I would believe the actual disintegration limit would be at 20K-21K.

This would mean 18K-18.5K on the ground.... I would not play with my luck by going higher.

Sincerely,

Is this right
 

I've said it before, and I'll say it one more time - I can't explain it. All I know is it WAS turning in excess of 20,000 if I tweaked it to max on a MA 10 X 6. I've since upgraded to a 11 X 6 to bring the RPM down, but haven't tach'ed it yet. If I had the skills, I could hover at 2/3 throttle.

DarZeelon - since it's only exceeding specs by 50%, it's more like a 10' man (150% of 6'8"). They do exist.

Most "bushinged' engines I've seen turn 12,000, and BB 14,000-15,500.

'Nuff said. I'm signing off this thread... I'm tired of defending myself against those who refuse to believe.

Horsepower
 

Strato,

Horsepower and Kilowatt numbers are cubically related to engine speed with a prop.

To spin a given prop twice as fast, you would need eight times more horsepower.

Output is a a force applied over a distance, per time unit.

To spin a prop twice as fast, you would need four times the force, to overcome air drag. And you will be applying this force over twice the distance per time unit; twice the speed.

The last time I checked, two times four equaled eight.

BTW, how many 10' tall men have you seen, anyway?

Sincerely,

Is this right
 

You’re getting those reading on your tach because you’re in Canada. If you calculate in the exchange rate then you will have the same readings we get in the states. ;)

Is this right
 

Hello!
I don't know if I should cry or laugh.....!!!???
Not any engine in the world, be it racing ,pylon or any other .40 class competition engine would ever spin a 10x6 Ma prop that fast.
In pylonracing ,which I have flown for 22 years ,both F3D ,sport 40 and Q-500 no engine can turn that fast...and believe me we use much mor powerful and better engines than the Rossi you have shown. In our "newcomer class" Q-500 in sweden we only standard .40 engines equipped with ordinary 10x6 propellers and use only 20% castor oil and 80% methanol. Our most powerful .40 engine which is the webra .40 GT spins these props at approximately 14000 rpm. A sport 40 engine like the
MVVS Q-500 with a 9mm carb on the same fuel and spinning a 9x6 APC is rewing approx 18500rpm.
A Nelson , Jett,IR (Russian F3D engine)or Dutch MB (F3D pylonracing engine) which turns a 7,1/2x7 carbon prop at more than 30000rpm delivering more than 3,5hp would never reach the rpm you mentioned on a 10x6 Ma prop! And these are the worlds most powerful .40 engines........
Your Rossi is just a standard ABC sport engine with a very noisy magic muffler silencer ..not one I would use on a trainer!
And forgetabout a APC turning 22500 rpm using a 10x6 Ma.
Every ASP I have seen turn those props at 12500-13500 rpm at best.

Sorry! But your tach most be malfunctioning!
Jan K
Sweden

Whew
 

This thread wore me out thinking that all my engines are slugs.

Is this right
 

we are selling the lot and keeping our 2 asp's now turning at only 13/14thou hoping to improve to 20, will keep every body posted.

Is this right
 

ps. we will need to do some serious cg mods on our cap232 when we replace the moki180 with one of our 6hp asp46's.

Is this right
 

i sure do feel like a sucker for paying through the nose for ys two strokes and pipes-never again!

seriously though, strato, you are also getting wild readings from a featherlite gasser and these were also confirmed with other tachs so the problem MUST be something canadian in nature. what kind of "strange brew" are you guys using for fuel and is it for sale?

all in good fun,
dave

Is this right
 

I have a plastic spinner on my LA .15 for combat and it is turning 17,500. It is a small spinner, but it is still intact.

If the guy tested it with 2 tachs, 2 props, on different days in sunlight I believe him. Let's have him take a pic of the engine/tach while producing the numbers so we can put this to rest.

Is this right
 

Any chance you have had a few prop nicks on that 10-6? Over time sanding away a small nicks on the tip of the prop will make it shorter, so you would be spinning a 9.5x6 or 9x6 instead of 10x6.

Is this right
 

Any chance you have had a few prop nicks on that 10-6? Over time sanding away a small nicks on the tip of the prop will make it shorter, so you would be spinning a 9.5x6 or 9x6 instead of 10x6.

Duke Fox was stumped once!
 

Someone claimed they had an engine of his that ran much better than other's of the same model. Duke observed the performance and paid the man to take it back and run some tests. Duke wanted to know what was differant so that he could duplicate it on newer models. Well the engine did indeed run much better than it was supposed to. He measured everything and other than some tolerances coming out to the loose side and the timing more on the hot side of tolerances there was no apparent differance. He concluded that the tolerances added up to be just right to improve performance. So he decided maybe he would make a higher performance custom made engine with the exact same tolerances. But after duplicating everything the new engine would not match the performance of the first engine! Nowhere near it! While somewhat above average in performance it was nowhere near improved enough to be worth blue printing the engines to those tolerances. He never did figure this one out. I don't think the performance was as much as apapa is talking about.

Is this right
 

this engine that turns that rpm should be used for quickee 500 pylon racing.at that rpm it would be out in front.i point overlooked here is FUEL CONSUMPTION.how long does this super 40 run aon a tank of fuel??and what size tank?more rpm = more gallons per minute.if two asp are using 10 oz tanks and one is running 10 min at 10k then the one running 20 k should run 5 minutes if it runs for ten,i think i smell somthing.

Is this right
 

I agree....I would like to see the pic!

Is this right
 

I love this thread! How do we go about rating it with 5 stars? Actually some very good information has come out of it. Now I'm late for work....

Ernie

RPM
 

Apapa, Dennis (Strato),

I don't know how musical your ears are, but when the engine doubles its speed, the pitch of the sound it makes increases by one, complete octave. Take measurements at various throttle openings and compare 11,000 indicated RPM to 22,000.

Also, were you with your back to the sun while taking these readings? It is possible to get double the correct RPM, if in addition to the light background color, the prop blades, or one of them was/were reflecting sunlight back to the tachometer. It is possible that one prop revolution is counted as 3, or 4 blades, i.e. one-and-a-half, or two revolutions.

Another possibility: If two different tachometers use the same internal software, they would err the same way, even if they are from different manufacturers.

Try this: A .40-.46 engine producing 1.9 HP, would be using about 1.5 ounces of fuel per minute. If this engine produces 6.4 HP, it would need about 6 ounces of fuel per minute.
This would mean a full 10 ounce tank, given some fuel is used for starting, adjusting and setting up to take readings, would be empty within about 90 seconds, at full bore. Is this the case?

The engine turning only one-and-a-half times as fast, would also need to suck in air, through the same carburettor, four times as fast. A volumetric efficiency of 233% of the regular piped 130%, or 303%..... without a rotary supercharger.

Just about as likely as 130 degrees Fahrenheit, at the north pole in the middle of the winter.

YOUR READINGS ARE WRONG! Now, prove me wrong.

Sincerely,