Skysurfer1985

Hi lynn,

thanks for your fast reply.
Thought about that as well.
I will give it a try before the next flight when everything is repaired and checked.
Meanwhile, I am used to tighten the screws along the canopy after every flight... . []

How does your engine mount look like?
Have you already fixed anything to reduce vibration?


Greetz, Michael

RemoteJets

Mhhh, I didn`t had any vibration or what so ever on my 337.

Maybe because I use 2 diferent engines?


But on the other hand, our 4x OS 60 powered Hercules and ex-Nomad (.60 twin) also didn`t vibrate, but that`s because all engine are in line then........


I do use 2 nuts or locknuts on every bolt.

lynn1130

My Feedback: (10)

I agree with the lack of excessive vibration. There is vibration of some amount due to two engines turning. I have the 2 OS FX 91s that were in the P-61 mounted in this one. They are mounted inverted just as in the Blackwidow. I fired them yesterday and they are running fine. I rattled a couple of screws out of the rear cowl but used the silicone method to resecure.

SR-71

I planning on installing two Saito FA-100 Twins on my KMP 337. I assume I'm going to need to open up the sides of both the front and rear cowlings for the cylinders to poke through. Has anyone used two opposed twins on their 337? And if so, can you post some pictures? I'm curious to see what my end product is going to look like.

Thanks -

SR-71

T28c

My Feedback: (4)

Skysurfer,
You might want to try with your muffler using teflon tape. Run the engine and get it nice and warm/hot. as soon as you shut down, tighten the nut on it some more. I have done that on my T-28 with a Saito 180. That beast vibrates bad but i you have to rember thats a big piston banging in and out. I even went as far as drilling the nut to be able to safty wire it.
Are your props balanced? How about the spinners? they on straight and not wobbleing?

ScottMcM

My Feedback: (66)

I'm running a Magnum 160 twin up front, and a Saito 130 twin in the rear. You'll have to cut the rear cowl, but you might get away without cutting the front. I had to cut just a little for the 160 to fit. I'll try and get some pics by tomorrow

Skysurfer1985

Hi T28c,

I have already tried that method to tighten the nuts while the engines are still hot. It didn't work: It lasted 2-3 flights when the engine compartments were messed up with loads of oil. The teflon tape simply burned because of the high exhaust temperatures and the thread connections loosened.
I nearly got mad by facing that problem again and again.
Even heat resistent exhaust pipe glue used for motor sport racing applications has proven to be no long term solution although that stuff was f****** expensive.
However, now this issue is fortunately fixed with the help of a rubber damper that I simply mounted on each firewall and a tube clamp carrying the exhaust system.
The dampers decouple the engines' vibration perfectly and prevent thereby a loosening of nuts on the exhaust system since 4 stroke engines produce more vibration due to their mode of operation as two stroke motors.
For the inventors of these dampers are jolly good fellows!!!!!
Damn, these guys are genius!
Neither with my petrol fired two strokers nor with my methanol fired two stroke engines I have never had any trouble concerning vibrations.

Anyway, guess you are right with your idea about ballancing props and spinners.
I will recheck that!
In many cases that is a frequent aspect to be overlooked.

lynn1130

My Feedback: (10)

Yes, balanced props are very important especially with two engines. Out of balance props can cause issues with one engine. With two it can rip the plane apart.

Somewhat extreme but I have seen what happens when a prop sheds a blade. It broke a P-47 in half in the few seconds it took the pilot to shut down the engine.

lynn1130

My Feedback: (10)

Re-thinking the silicone adhesive thing. It works but I think lock-tite works better. I changed to that.

lynn1130

My Feedback: (10)

The 0-2 flew today. I should have some photos soon and will post them when I do.

I am glad that I had my "test pilot" do the maiden on this one. I had planned to do it myself but chickened out. The wing/horizontal stab issue with this plane caused a few exciting moments but once trimmed it flew pretty well. We lost the rear engine on final, which proved to be no issue as this plane would probably takeoff with either engine alone. The OS FX 91s are monsters for power. The engine out was caused by the carb coming loose. My fault for not putting lock-tite on the screws for the new carb. The landing was a little hard on the nose gear but nothing that a $20 part can not take care of. This plane was a show stopper at our usual Friday morning 1/8th Air Force fly.

T28c

My Feedback: (4)

Congrats Lynn!
I can not wait for the pics. What props did you use? Im close to running mine up and breaking in, even though i have alot longer to go with the wings, booms and tail section. From what the book says its a long process to break in. How did your mufflers hold up? do they lossen like others?

lynn1130

My Feedback: (10)

The 91s in the O-2 were broken in and used in my VQ P-61 that crashed some months back. I used the same mufflers that I had in the P-61. They are J-Tec and since I had cut the stacks for the P-61 I sent them back to J-Tec to reattach new stacks so that they could be adapted to the O-2 cowls. I have had no problem with them coming loose on the O-2 but I did have that problem with the P-61 on the first flight. J-Tec made a mod for me that allowed the bolt to go completely through the muffler and I double nutted it along with Lock-tite.

I am using 14X6 APCs props on the 91s. Obviously, a pusher on the rear.

Skysurfer1985

Hi all,

does anybody of you know the paint shade of the Coastwatch Edition?
I am close to paint my repaired cowl and need the exact formula of the paint since it is not a RAL-based tone.
Maybe there is somebody who has experience... ?!

My congrats for you, lynn.
I'm sure you will have much fun with your new plane.

Wish you a nice weekend.

lynn1130

My Feedback: (10)

Try e-mailing Tomas at VQ. The plane has been out of production for awhile but he may have an idea where to obtain that color info. Hope that works for you.

MormonMike

My Feedback: (2)

An RCSpecialties Turbo Muffler works great on the rear engine with an OS.90. Just about completly concealed within the cowl, BUT........ my rear engine is inverted. Also use a silicone exhaust extension on end of muffler. MM

lynn1130

My Feedback: (10)

T28c-Do you have OS 90 4 strokes or OS 91 two strokes? I have 91 two strokes in mine.

T28c

My Feedback: (4)

I have two OS FS 91s 4 stoke inverted. I thought that what the guy I bought it from was setting it up for. Hope they will be ok.

lynn1130

My Feedback: (10)

First flight. The rear engine is out on final. The carb came loose and stopped the engine but even without the rear engine this planes flies like a champ.

T28c

My Feedback: (4)

Great pictures Lynn, I hope mine looks that good when it is finished

aerowoof

has anyone done a full cockpit if so where did you get the interior

T28c

My Feedback: (4)

What kind of Interior? Millitary or civilian? Some day I would like to do mine in millitary.

aerowoof

civillian

T28c

My Feedback: (4)

Top Flite makes the Cessna 182 interior kit. other than that im not sure.

Skysurfer1985

Hi folks!

Today I was out at the airfield to fly my C337.
Now it is much better with the vibration/harmonic problems that I have had to deal with before.
I am using Dubro's fantastic anti-vibration engine mounts which really work perfectly and all former trouble is gone - just like "click"!
Best invention I have ever made on that bird!
I can strongly recommend everybody to do everything to reduce vibration.
It is an unterestimated issue which can cause long-term damage to airframe etc. ... .
Me, I had to experience that as well.
With the engine mounts mentioned above it's the easiest and quickest way but of course, there are also other possibilities.
Sometimes it is just the "small" things you have to change to achieve quite much.

However I have another problem now. []
Obviously, the pusher prop at the back has got a dislike against the extended steel antenna I am using.
The prop likes to destroy it.
Today's result pretty much ressembled a pig's tail.
Looks quite funny - however the consequences of that happening are not too funny:
- a damaged boom
- a cracked rear cowling (which was freshly repaired and painted 2 weeks ago)
- a prop which can only be used to be nailed on the "wall of fame"

How do you have your antennas positioned in your Skymasters?
Since I still use the 35 MHz frequency bandwith I have to use the typical "long" antennas - compared to those of the 2,4 GHz system.
I tried to spread the antenna inside of one boom some time ago but got trouble with the range due to the rudder's steel rods.


Michael

lynn1130

My Feedback: (10)

I still us 6 meters (Ham band) so I have the long antenna also. I have the receiver mounted in the rear of the plane near the rear engine servo and the antenna running inside the plane, forward toward the front firewall. I have had no problems with this mount. I looked at ways to mount the antenna outside running from the center section back to the vertical stab so that it looked scale to the O-2 but was afraid of just what happened to you. If it came loose it would get caught in the prop, which might cut it off, ending a flight badly.