Repost: "Too Much Power"

[Bill Little]

This was lost in the "glitch"  and Sparky asked me to repost it.

I do not believe that a Stunt Ship can be "Overpowered".  If the engnie is set up right, balance of the plane is good, and the proper prop is used, more usuable "stunt power" is always a good thing, especially in adverse conditions.

Please give your opinion on what "overpowered" means.

Thanks!
Bill <><

[Leester]

I'll repost mine just for grins.
Overpowered is when I bury my spinner 3" in the ground instead of 2" 

[Bob Reeves]

Completely agree, good example is the Stalker .61 in a Nobler. Think most beginners relate power to speed, know I did back in the 60's when I tried to put a 35 on a junior flight streak. Like you said the trick is picking the right prop which seems to be somewhat of a black art and getting the CG reasonable without going over the weight the wing can carry.

[Charlie Pate]

A nats,world,s champ ,was quoted as saying a few years ago. " a piped 40 has all the power you will ever need !"
He is using a bigger engine now!
Wonder what changed?

[Busby]

And he will probably be using a 75 before much longer,talk about power/thrust.
The hardest pulling plane that I ever launched was one of Randy's new 75s, I was thinking to myself hurry up and give me the signal to launch before this thing pulls me over on the plane. Bob would probably be ticked if that had happened.
It accelerated to full speed in about 4 feet.

[L0U CRANE]

Bill,

Apparently also beamed into an alternate dimension were my comments to this one...

The only times we have "too much power" in stunt are:

In the case of a physical limitation on the strength of the flier. E.g., Bob Palmer lost several fingers on his flying hand in an industrial accident in the late 1940's. He couldn't hold the howling .65's in the usual stunt mode of the time, but kept flying. Legend has it the first Chief was flown on a Torp Greenhead .19. Certainly kept pull within Bob's abilities, and he became legend AFTER the accident.

Otherwise, we can have too much power if we don't set it up right. We don't need MACH=2 airspeed. We can tame powerful engines so that the model and the flier are both happy, with RPM set, in effect, loafing except under maneuvering loads.

Prop, fuel, plug, line length, setting all can come together so the engine is lightly loaded, at an RPM that is poised to meet the loads when they come. Run mode can be classic 4/2; rich, low 2-cycle, or pipe regulated - the end result is very similar.

Now, when the engine is run 'too hard' we are getting into more critical settings, with less reserve grunt to meet maneuver loads. We may get 2.5 sec laps and a sore shoulder, and see it all go away when the engine overheats, or overlean and sagging under load.

Sure, the engine can be set up to run max power all the time, but it is no help. In that sense, it is a case of 'too much power.'

[wwwarbird]

110% agreed. Excess power allows for adjustment, to little and your just screwed.

[Randy Powell]

If I could just figure out a way to get that Turbo V6 into my 600 square inch plane...

[Steve Holt]

I think what most of us mean by "overpowered" is when the additional power is not properly controlled or adds too much weight to the airplane.  I used an old Ringmaster as a break-in and checkout platform for a Magnum 36 and a Thunder Tiger 36.  While fairly light for modern engines, they were almost 2 oz heavier than the old Fox that came off.  The added tail weight for CG plus the weight of the engine put the Ringmaster firmly into the "dog" catagory.  The other issue was not having enough prop clearance to use a large dia., low pitch prop to control the power.  This airplane was simply "overpowered" or more accurately "over engined".

A similar case could easily be a Jr. Flite Streak with a LA25.  Or would a Skyray be better with a Magnum 36 instead of the FP20?

When the additional power is "free" in terms of proper fit on the airplane (weight, CG, fuel capacity, and prop size) I would agree more is better.  Getting it for "free" is the issue.

[proparc]

My reply to this post got lost in the "glitch".  I have used the term "too much power on the SSF forum in reference to my Saito 72.  Mainly, I described my big block as having too much power which, we all know, is just about right.  My 72's excess power just about gets the job done.  Or to put it in more graphical terms, it's when a you have a 305 V8 small block under the hood when a 283 V6 would do fine. Too much power is as American as apple pie.  Or conversely, sufficient power is Un-American and smacks of subversive elements LOL.

[Bill Little]

If I could just figure out a way to get that Turbo V6 into my 600 square inch plane...

I'll take one Keith Black Hemi, please.

Bill <><

[RC Storick]

I can grantee there is no such thing as too much power! While my Thunder-Bolt flew OK with a .61 it fly's better with the bigger .75. As anyone who has seen it fly with the PA.75 will tell you it's just idling around. It will almost lift me off the circle in the overheads.

[Steve Fitton]

I can grantee there is no such thing as too much power! While my Thunder-Bolt flew OK with a .61 it fly's better with the bigger .75. As anyone who has seen it fly with the PA.75 will tell you it's just idling around. It will almost lift me off the circle in the overheads.

Idling around??  Most cool!  What RPM/prop did you get to work on it??

Steve

[Eric Viglione]

Bill - How many angels can you fit on the head of a pin? About the same answer to your question.

The answer is different for everyone, every type of power, and every airframe. A lot depends where you draw the line of what you are willing to do to make a motor work.

I will give you a short version, at least as far as I'm concerned with the way I like to run motors. For me - Too much power is when I can not de-tune the engine  run enough to haul the airframe without sacrificing the "intelligence" or quality of the run.

Most single speed runs are boxed in by pipes, porting, or running the motor past the peak of the torque curve etc... If you have to run the motor well below that peak, there is always the chance of conditions leading to a runaway, wind-up, or as you say- too much power.

That being said, I think the power to weight ratio is a much bigger factor. Too much power is probably a somewhat rare thing in our limited reality.

My question is -  With the new motor size allowance: I wonder why we are still doing hot rod schnuerle porting, high compression and milder and milder timing on these new big motors, since I don't really want RPM, I want torque for our use with a little boost/break.

What I would really like to see is a modern metallurgy made (AAC? ABN?) 75 or 80 size  low comp hemi/baffle/loop scav rear exhaust non piped engine produced. At the RPM this theoretical motor would run, you would have lower GP and you wouldn't even need ball bearings, so it could be nice and light too. Lower RPM motors are less sensitive to prop pitch changes, so you could get away with 1/2" increments in your prop kit, probably cut the number of spares you carry in half. There are probably some that will jump in here and say my thinking is antiquated... oh well. 
 
EricV