logair

I recently aguired a TF P-51 kit from a friend partialy built. It came with a Super Tiger 75 with an in-cowl muffler. I am thinking maybe this engine is marginal for this airplane as these kit's tend to be over wieght as constructed. I do have a good OS 120 four stroke with pumper that I could use. My question is of these two engines which one would be the best? I know that some people use larger two strokes, but I do not have any. I am not into pure scale stuff and fly off grass so not using retracts primarily since that was the way it was set up when I got it. Regards Logair

JP8650

My Feedback: (-1)

I would sell that super tiger and stick your OS 120 in it! Also what did you mean by over weight ? Is this P-51 a Red or Gold kit ?

logair

Gold

JP8650

My Feedback: (-1)

ok so why do you think they are over weight ? does it have retracts and flaps ? My TF 51 comes in at 12lbs with a YS 1.20 retracts flaps the whole nine.....I also have 4 servos in the wing

DavidAgar

My Feedback: (108)

The Top Flite Gold kits do have a reputation for being a little on the heavy side. The weight issue can be expanded by adding full retracts, flaps and such, however they all fly well. As for your engine problem, I am an OS man from word go. Having a 75 on it might be an issue in the grass on take off, but depending on your planes weight, the 75 should fly it. I know the OS will fly it.... Good Luck, Dave

ChuckW

2-stroke in a Mustang? That's gotta be some sort of sin if you ask me. I'd go with the 1.20 4-stroke.

JP8650

My Feedback: (-1)

I thought we were talking about a P-51 Mustang here? not a 3D foamy! Its a warbird and its going to fly alot like the real deal! And its also going to take off and land just like a real one! I guess im missing the point of what a over weight TF P-51 is? Because mine tips the scales in at 12lbs 10oz (dry) and its got.....

YS 1.20
20oz fuel tank
Century Jet retracts w/Robart air system
Flaps w/2 servos (hitech 5955)
2 Aileron servos (hitech 5955)
1 Elev. servo (hitech 5955)
2 rudder servos (hitech 5955 rudder & hitech HS-425BB on tailwheel )
1 Throttle servo (hitech 5985)
6.0v 1800m battery
Robart #308 pin hinges all around

And heres a couple pics

alanc

mine was fully glassed, retracts, flaps the lot, weight was just a tad under 13lb, it flew very scale on an ST 91, but, seeing as one of your countrymen overpowered one of our 72"hurricanes, try the same engine he didDA50-YES, REALLY!!!!

logair

Trying to upload image of my full scale Starduster One I built from plans and am still flying. Logair PS. Thanks to every one who took the time to answere my questions.

prop wash

Go with a Moki 135 or 180.Power. Tom

prop wash

WOW.Where did all those attachments come from?????Tom

rc34074

My Feedback: (5)

Is this a fairly new kit? some of the old Top Flite 60 size mustang kits were not designed for 4 strokes so there is only a limited mounting area for the engine so a 2 stroke is almost required, unless you revise how the plane is built. I know this because I had one of those early top flite mustangs with the short mounting area.

Is the ST 75 already mounted? if so, is it inverted? side mounted? How high is/will be the centerline of the fuel tank compared to the carburetor inlet?
A fuel tank with a centerline much above the carb inlet will tend to cause variations in the fuel mixture unless you use a Cline regulator or maybe a Perry pump. The cline will also minimize tendencies to flood the glow plug with fuel when starting the engine.

As for power the 75 will not have the power of the OS 120 engine, but it certainly will fly the plane - if it is not built heavy - a 12 lb plane will require the 120 to fly very well. a 9 - 10 lb plane will be ok with the 75. Is the 75 broken in? if not be sure to do this before you fly the plane.
I would also test the engine with the in cowl muffler setup (after breaking in the engine) before committing to this, because if this muffler has poor back pressure you probably will get poor mixture control in the midrange.

I know you didn't ask about retracts, but I would definitely not use the Robart 605 retracts that are shown for use with this plane. I consider them entirely inadequate for this plane. I would use possibly Spring Air retracts (www.retracts.com) or a better version of Robart retracts with an aluminum or steel frame. Of course there are some other brands of retracts that would also work in this plane.

Ed

logair

I did not get the box it came in but the manual and plans indicate the Gold edition. The fuselage was sheeted, horizontal stab. mounted, wing sheeted and joined, flaps, ailerons, elev. needs to be installed.It came with the new un-run ST 75 w/in-cowel muffler. The wing was built and sheeted with the fixed gear mounting blocks, that's ok with me since I fly off grass runway. The wing came with push rods and bellcranks for ailerons which I have removed in favor of two aileron servos. I am using flaps. I think I may use my good running older OS 120 surpass four stroke w/pump mounted inverted. I have an on board glow system I may use also. I started flying rc back in early sixties with single channel, escapement flying progressing to pattern flying. I did lay off rc while building the Starduster One shown in a earlier post. Finished it in 1990. still have it. but fly rc on a regular basis now. I did build the GP P-51 forty size with mechanical retracts. It is a great flyer just like the old pattern ships. The retracts are a constant problem to keep in adustment though. The plans show both the ST 75 and the OS 120 4 stroke. Thank's for your comments, Logair

jeffk464

Specs are 8-10 lbs.

JP8650

My Feedback: (-1)

And I bet thats with out flaps and retracts too and a 2 stroke. and no reinforcing of the landing gear area.

wulf190

My Feedback: (19)

I had an ST .75 in my Skyshark 109 and the thing was really fast. Weighed about the same as what the Mustang does when finished. The thing ran like crazy, idled great and sounded nice. Also fit like a glove in the cowl inverted and never once flamed out on me. I used a Jtec Inverted muffler which also fit well, and did not use on board glow as it just wasn't necessary. I would have zero problem putting that in a TF Mustang and would be confident it would do a nice job on it.

I_Fly

I owned an older version of the TF P-51 Gold Edition kits in the mid 90s. It was build very similar to yours and flew great on a 2cycle OS 61 SF. This engine was a bit nicer than the FP series engines because it had higher compression and ball bearing supporting the crank shaft. It did not have the unlimited verticle many pilots expect today but held it's own and flew well. That plane also flew well from grass without an issue. This plane was also my first attempt with a glass finish. This probably added a bit to the weight. I rember it being just under 10 lbs.

Bottom line the 75 should fly it. The 120 should provide excellent performance.

Ironically I have a TF P-51 Gold edition partially set up in my basement. It is mostly complete and waiting for the Sato 1.15. All that's left is to cmomplete the engine break in, cut and mount the openings in the cowl, and some details such as the canopy, pilot, and final balance check...

logair

Here is a couple picture of the plan the way I got it. Logair PS For some reason picture did not download. See later post

JP8650

My Feedback: (-1)

since when did TF change their gold edition kits from then till now?

rc34074

My Feedback: (5)

I flew my top flite mustang with a super tiger g90. This engine FLIES this plane, and if you keep the weight reasonable, as I said before, the 75 will fly this plane well. I think you should seriously consider going with retracts, but you obviously had some mediocre retracts previously, and that has soured you on retracts. I had a warbird flying buddy and together we kept each other going to find improved retracts etc for our warbirds. The retracts I recommended above are the ones we settled on after trying several brands. Spring Air had a patent on their air up/spring design and when their patent ran out then Robart and others started making the same type retracts. So far Robart is the only one who has made ones as good as Spring Air. Bet that comment will get some other replies comments . I mean as far as air up/spring down retracts.

Anyway. have you flown a warbird before? I see you ahve flown other rc planes from your gallery, and maybe even full scale planes. But if you haven't flown an rc warbird you might want to get an arf warbird like a Hangar 9 p47 as your first warbird. This would give you some experience with a lightweight warbird as you are building the top flite. Plus if you crack up the p47 you won't be as frustrated as you might be if you crack up the top flite after spending the time to build it.

Something to do as you are building the top flite is to beef up the retract mounting area. this will keep you from having to repair the gear mounts if you make a less than perfect landing. On the other hand if you decide to put in the fixed gear you should also beef up those mounts also. on the other hand if you are a perfect pilot you don't need to beef anything up eh?

By the way, you can see a pic of my top flite mustang in my gallery.

Ed

logair

Ed, I tried to post a picture of the P-51 as I recieved it. The wing is sheeted and fixed gear lg blocks installed. I do have a forty size GP P-51 that I have been flying for several years off and on. It has the old Dave Brown mechanical retracts. It is as I mentioned in earlier post a nice flyer, nice landing airplane. On grass have had to adjust retracts after a few flights in order to fit in wheel wells. I am going to try to send pictures now, hope they come through my Starduster experimental came through in previous post ok . here goes. Logair

CorsairJock

My Feedback: (90)

Anybody who has ever heard/ seen a full scale Mustang will tell you that a 2 stroke sounds more like the high-pitched/ smooth running sound of a Merlin than a rumbling 4 stroke. On the other hand: I think 4 stokes are more realistic sounding in radial engined warbirds.

But in my opinion, the "best engine for TF P-51": is an electric motor, since it allows the builder to keep that streamined cowl fully intact, with no mufflers and/ or engine jugs poking thru.

prop wash

I agree with Jim on the sound of the two stroke and as I have said a thousand times on RCU that one of the best power plants around is the Mark/Moki.I have two 210's in my Mustands and a Moki 180 in my H9 Jug and they are great engines and they are priced way below the gassers or 4 strks.The problem I have with 4 strks is that blasted mufler hanging out of the cowl.I use pitt style mufs on my planes and everything is in the cowl,no carbs hanging out or mufs.Not only that the Moki's are priced below 4strks the same size.My Moki 210 is less than my Saito 180,although I do love the Saito when it finally dies I will replace it with another Moki.
Jim I am going to try and make the rounds this coming year [2010] to as many War Bird fly-ins as I can,like the guy from Ohio. Have a great Thanksgiving and Christmas. Tom

check6ii

My Feedback: (12)

Put a nice YS-120 in it. You'll be glad you did[8D]