RE: Regarding SP series engines, props and airspeed...
 

Michael:
Unfortunately I have no records of the RPM I got  (this was 3 years ago), but as far as I remember it wasn’t much different than the RPM I used to get with the APC 3 blade prop (15.75 x 13).
I hit a tree with my plane and since then the engine is stored for a future use.
I think you need at least 12 in of pitch to make this Mustang fly.
Arruda

RE: Regarding SP series engines, props and airspeed...
 

Hi Michael,

I am glad that you finally managed to put things together. Yes once assembled the whole thing is sturdy and tracking of the blades on my exemplar is perfect.
However, I do not have any experience with props that have more than 2 blades, and so its hard to tell which pitch will work. I agree with your doubt that an 8 inch pitch is too small, and also that a smaller diameter would work better. Blades only are not too expensive.

I would suggest a standard 2 blade prop for the maiden flight to save nerves. Maybe its possible to make some taxi tests with 4blades thereafter to assess acceleration etc.


regards
Andi

RE: Regarding SP series engines, props and airspeed...
 

One more thing concerning the pitch gauge: As far as I remember there are 2 possibilities (different angles) to attach the gauge. What I did to find out which way is correct is to set the blades to about 0 by eyeballing, to assure the gauge is attached from the correct side.

regards
Andi

RE: Regarding SP series engines, props and airspeed...
 

You cannot set the blades to 0 pitch (at least not on this 4 blade hub!). 6 degrees pitch is where the stops are (and the lowest possible setting on the guage coinidentally). I made sure the blades were at the lowest pitch possible, then once I'd found the "sweet spot" where this guage will clip on to a blade I clipped it on and stuck the pitch pointer rod into the hole in the hub and it read 6, the lowest number on the guage. At that point I figured I was using the guage correctly. As I turn the adjustment bolt in (clockwise) the pitch pointer rod moves up the guage to higher numbers. Ergo, I think I'm using it correctly.

I realize the blades are just a faction of the cost of the hub. It's just that now I have to order another set of 4 blades and wait 2 weeks or so before I can try them. Ughhhhh! I had hoped the engine could swing these 16.6" diameter blades but I guess it can't. Looks neat though. Bet a 120SP would be able to swing 'em (but add too much weight to a 60 sized airframe, IMHO).

I may test run it again 1st and try leaning out the needle 5 or 6 clicks for 20 seconds and see what the engine does... if I lean it too much it should die, then I'd know where the way too lean point is! I wonder if there's a way to tell by engine temp if it's running too lean or not, and if so what's the temp range I should shoot for to keep from harming the engine?

As it ran out of fuel yesterday it sounded a lot smoother and more powerful for those last 10 seconds or so, making me wonder if I'm still running too rich... also I noticed a droplet of raw fuel collected in the air intake of the carb, which seemed odd again making me wonder if I'm still running it too rich.

Thanks ya'll!

- Michael

RE: Regarding SP series engines, props and airspeed...
 

Yes, I agree with your description.



I dont know the engines temperature, but I do know that temperature depends very much on where you measure it. So its not easy to get repeatable values.

Well thats funny. Maybe tweaking the needles helps a bit.
I always set needles with the model pointing skywards a few degrees.


regards
Andi

RE: Regarding SP series engines, props and airspeed...
 

Michael,

I've been following your Thread. Juice's thread also.

I did take a look at Vario Prop's website. Somewhat confusing as far as what you need for different engines setup.

I thought that hub was larger than 1/8 scale?

Do you have measurements on that?

Charles

RE: Regarding SP series engines, props and airspeed...
 

I only have the 4-blade hub, and it'll be hidden inside a P51 spinner so as not to be seen so it's scaleness is irrelevant to me as long as it fits and does the job. I don't know anything about the 3 blade hub, if I get a Top Flite Corsair ARF later this year (presuming my Mustang project turns out well) then I may get Vario's 3-blade hub for that plane.

- Michael

RE: Regarding SP series engines, props and airspeed...
 

I've been sending emails for two days and I get no replies?

Please, what's his correct email for Vario Prop?

Charles

RE: Regarding SP series engines, props and airspeed...
 

It has been a holiday weekend you know this right Charles? Not everybody works thru the Easter holiday.

I advise patience.

- Michael

RE: Regarding SP series engines, props and airspeed...
 

Michael,

Nice looking props!

Did you paint them black or do they come that way?

Charles

RE: Regarding SP series engines, props and airspeed...
 

They are made of a black material, Charles. I did nothing to them. They don't seem to be plastic either, I'm not sure what they're made of seems like some kind of graphite or carbon material. I still have to order a smaller diameter set so I can proceed on this project... I'm working on recovering the Mustang fuselage in chrome monocote and black trim (to match the real Mustang known as Quicksilver). [>:]

- Michael

RE: Regarding SP series engines, props and airspeed...
 

Hi,

did you try the prop already?

regards
Andi

RE: Regarding SP series engines, props and airspeed...
 

No, been too busy with work no time to play lately. [&o]

- Michael

RE: Regarding SP series engines, props and airspeed...
 

Michael211, anything new to report.  I was thinking of getting a RCV 90SP and Vario 12c setup for a Nitro planes P51 (basically a clone of a H9).  Todd