Capt Crunch

I'm building two P51-D warbirds, one will be a sport scale go fast machine and the other will be built as scale as I can build it within reasonable financial constraints. Will build the sport scale first to get familiar with the aircraft both on the bench and in the air.

These are 60/120 size planes with the Top Flite 65" WS for the sport scale. The scale build is a Brian Taylor Bob/Holman Fiberglass/Foam P51 69" WS kit that I've been hoarding for decade and a half. Both are supposed to be 8 to 10 pounds finished but, I think I can lighten the Top Flite since it doesn't need all the scale detail.

There are a few YS engines in the engine cabinet and I'm thinking the YS 115WS and/or YS 140FZ. Although, there are also a couple YS-110FZ available, a second 140FZ, a 90 & 120AC, etc..

What engine would you choose and why? Is the 140 too much engine? I do like my planes fast but, also manageable. It's not much fun landing a rock with wings if you know what I mean. Thanks for any advise and experience that you can offer.

petec

My Feedback: (58)

I would go with e 1.40FZ personally. At 10 lbs the 1.15 might not give you the performance you want.

Capt Crunch

Petec, thanks for the reply. That is my concern as well but, the 115WS is supposed to be more powerful than most 120s. Do you have experience with the 115WS?

petec

My Feedback: (58)

I have not gotten my hands on one yet. The 115WS was designed for Warbird racing and most of those are 46 sized airframes. Will it pull your planes? YES.....Will it wow you on an almost 6 foot wingspan bird? Probably not. Back in the day a clean 2m patter bird with retracts and 1.20 was smooth and graceful and had plenty of power with a 1.20AC or FZ. Your Mustangs are not as aerodynamically clean nor as light. The 1.40FZ did well in the 2m early wide body designs and at near your weight.

Capt Crunch

Thanks, that makes sense and I appreciate the advise. Guess I'll need to build a smaller P51 for the 115WS. Any recommendations?

Now ow you have me thinking again and that's dangerous. I haven't had a pattern plane in awhile...

warhwk

My Feedback: (3)

I have had a couple of the TF P51 65" models with a YS 1.10 in both. Both needed tail weight to balance and brought the weight to 10.9 and 11.2 lbs. The 69" seems like a perfect fit for the 1.40.

Capt Crunch

Thanks warhwk. I agree about the 140 for the 69". I'm getting one convertered to ignition and it will likely end up in this plane. If your 65" was nose heavy with a 110 then a 140 will take some planning.

How did your 65" TF fly with the 1.10? Plently of power, just average or under powered? Did you have lots of extras or does that plane just build heavy? Where was your receiver battery located? Either way, that is good information and I can plan accordingly. Perhaps mount the battery in or over the belly scoop and move the rudder and elevator servos back in the fuse. The 69" will have a retractable tail wheel and that should also help.

Sorry for so many questions but, it's a lot easier to plan this stuff prior to the build.

warhwk

My Feedback: (3)

Both of my TF P-51's had metal geared servo's and a large JR retract servo with all 4-40 hardware. These added a bit to the total weight, but they still flew and landed easy with flaps that extended more than 75 deg. With full flap, they acted more like speed brakes and I had to keep some power on to keep from stalling. Moving the battery to the scoop would definitely be needed if you went with the 1.40.
My YS 1.10 runs a 15-8 prop about 9500rpm which gives it more than scale speed. Somewhere in the 70MPH+ range although it seemed faster due to the sound of the engine winding up. I've run a 14-10 on 30% nitro and I'm sure I cracked 90MPH. I'm not sure a 115WS on High Nitro would be all that fun, at least for my style of flying. I once propped an EZ Mustang on a 91fs to fly at over 110MPH, which due to it's small size felt supersonic. Flying it was exhilarating, but also very exhausting.

The YS on a high speed pass will definitely raise the hairs on the back of your neck!

Youtube link https://www.youtube.com/watch?v=1D_S...ature=youtu.be

petec

My Feedback: (58)

A lot of guys use the WM 46 sized Dago Red.

As for a pattern plane....of course you need one.

Jimmy Skids

My Feedback: (2)

I am flying the top flight gold 60 size Mustang arf using the YS 140L for power. I would suggest the 140 for anything in this size or larger. If you use the 140 for one and need a similar size motor for the other use the 120 AC... the weight is about the same. I did very little to adjust for balance. Definitely no weight in tail on mine.

For the 1.15 a WM Mustang or the new WM Racing Spitfire would be the size of plane to go with. You may need a few extra towels to wipe the grin off your face.

Capt Crunch

Hi Jimmy,
Thanks for the info. I have a couple YS 1.40s. Unfortunately, neither is an L. Is your P-51 a rocket with this motor?

I bought a couple 1.10s and the 1.15 thinking that they would be a good substitute for a 1.20 with similar output and less weight. It sounds like they are primarily used for over-powering smaller 40 to 50 sized planes. Maybe I'll sell the 1.10s and find a different kit for the 1.15.

Thanks is for the reference on the WM planes but, I'll try to find a kit that is good fit. I don't trust ARF construction and don't use the cheap hardware that ships with them. The other day I was having a conversation at the hobby shop with an old timer like me and we agreed that we could build a kit faster than ARF because we had a tendency to rebuild the weak points of the ARFs.

warhwk

My Feedback: (3)

[QUOTEThe other day I was having a conversation at the hobby shop with an old timer like me and we agreed that we could build a kit faster than ARF because we had a tendency to rebuild the weak points of the ARFs. ][/QUOTE]

Amen to that!

Jimmy Skids

My Feedback: (2)

Not a rocket, but then I race 40 size warbirds at speeds upwards of 150 mph. The 1.10, and 1.15 are great engines for 40 size warbirds. Since there are many kits available I would say the great planes Mustang or Corsair for them. The scratch built p51 I competed with last year started that way many versions earlier.

Jimmy Skids

My Feedback: (2)

... or you could contact Tim at 8th scale aviation for a list of short kits that he is providing. Really great scale kits built around racing warbirds. His email contact is.... [email protected]

Tommy_Gun

Top Flight Spitfire 10.5 lbs, YS 1.10 FZ, https://www.youtube.com/watch?v=VmpaROieHck
Top Flight TW190-D9, 13.5 lbs Oooollld YS 120, https://www.youtube.com/watch?v=TbY658zhHw8
Skyshark BF109-G 13 lbs, YS 1.10 FZ, https://www.youtube.com/watch?v=fNxgyEvE6WU
Just sayin' that the 1.40 could be used for an even larger plane. Something like a 72" warbird.

Capt Crunch

Tommy_Gun, thanks for sharing. They all have good power but, certainly not pylon racers either. Looks like the Spitfire is a little hard to slow down with that 14x12 prop. I just picked up a P-40 that should fly similar.