GR7Racer

My concern with your install is that the pipes are at the aft end of your exit air cutout. Any negative pressure created by them will be aft of them.... And you don't have any exit hole there. I'm going to guess that the cutout in the cowl that you have between the cylinder head and pipes will actually act as a scoop and stuff air into the cowling...not let it out. That will make the air stagnate in there and you will build heat fast. Most people just say to cut a hole three times the size of the entry hole and it will work, but it's not that simple usually. You need to locate that hole in an area that is in a low pressure area, or create a low pressure area with a cowl flap.

I made my own baffle setup on my install that is similar to what Pe Rivers recommends. The air that comes into the chin scoop is ducted to the cylinder and forced to go through the fins. I also have another baffle plate that guides the air to the exit hole once it goes through the fins. This baffle also serves to isolate the carb from all the hot air aft of the cylinder.

Ken

fhollahan

Thanks for the input. There will be air going across the fins right underneath. I think what I'll do based on your comments is one, use the baffle that came with the kit to direct air straight across the motor. Second, I'll create a baffle similar to what you have in the rear hole to create some suction out of the hole.

kalzone

hi all here is a short video of my mustang . i have converted it to electric power system is the eflite power 360 and cc160 hv esc. sound system is by Mrrcsound
https://www.youtube.com/watch?v=0WmUvO3szo4

vertical grimmace

My Feedback: (1)

http://www.redwingrc.com/index.php?m...roducts_id=344

Oldcrow p51

Thanks for advice. actually I want to use greater torque then the recommended but the mount in elevator very tight.
Is it possible to do some modification in elevator to use bigger servo like jr 8411?

marksp

My Feedback: (9)

Wow! The sound is cool, but that monster motor swinging that huge 4-blade prop is awesome! Can't wait to hear how it flys!

how many transducers in your sound setup?

Cheers

Shaun Evans

LOL,

I just looked up that engine on Tower. $770 with muffler? Or, to us working stiffs, TWO DLE 55's? Yeah, I think I'll break out my ol' toolbox and do some of that modeler sh** for an hour or two and make the DLE work.

kalzone

In this video two are working but I have 4 onboard to second two will be hooked up soon

david57

Nice! What prop are you running?

Sekhet

My Feedback: (1)

I’m thinking about using the ROTO 85 FSI two cylinder 4stroke engine and yes I know that I’ll have to move the firewall to get it to fit.
Does anyone have any experience with Roto?

kalzone

It's a vairoprop from Germany. It's ground adjustable from 0-22 on the pitch. I had the same prop on my corsair had it set to 16" and it was pulling 120 amps in flight and went 146mph

sjhanc

My Feedback: (3)

http://youtu.be/HTKD1gU-MQQ This the link to my plane flying with the VarioProp.

BarracudaHockey

My Feedback: (11)

How cool. I hope we meet up at Ocala or somewhere this year, I'd love to see that in person.

david57

Like the 4 blade. I have one of these comings and am undecided on engine for it.

sjhanc

My Feedback: (3)

I will be working at the Ocala clubs Dawn Patrol this weekend. I will have the plane there and will fly it after the event ends in the afternoon. After that I plan to fly it at OTOW March 28. There is another pilot in the area who has a GS Spitfire that's electric I'd like to see fly.

fhollahan

I would stay with a mini servo and not modify this area for a bigger servo. It is way overkill and you are going to add tail weight to unnecessarily. If you are close (within 10%) on the torque requirement on the elevators you are fine. This is not a 3D plane and the elevators are small.

Oldcrow p51

Thanks fhollahan.. I already followed your advice and bought 2 NX3421 Jr mini servos and they fit very well.. I hope we can see more photos of your P51 building.

Shaun Evans

Hi,

Anyone know off the top of their head what size hole I need to drill to get the DB parabolic spinner to fit over a DLE 55? And, for that matter, what size DB prop adapter? Thanks in advance.

vertical grimmace

My Feedback: (1)

You should not need a prop adapter as the center of the DLE 55 stud is threaded. That is if your spinner is using a thru bolt. Are you using a single bolt prop adapter or the stock stud with 4 prop mounting bolts?

If you are using the prop adapter, the threads size is 10 mm x 1.5 if I remember correctly.

Shaun Evans

Hi,

Thank you! I'm using the standard prop deal. Same size?

vertical grimmace

My Feedback: (1)

The dia of the stud size would be slightly less I would think than the smooth stud. It is the same as a DA 50, if that helps. I get the single bolt prop adapter installed when I buy my engines, so I do not have one to measure.

kalzone

AWESOME! what sound system are you running? what batteries and how many ? any idea on the amps your pulling? what pitch did you settle on?
just flew mine for the first time today

sjhanc

My Feedback: (3)

I am using the Benedini sound system, The motor batteries are a 6 pack of Hobby people 3200mah 4s 30c lipos wired 12s 2p and a new Zippy 6 pack of 3300mah 4s 35c lipos wired the same. I was using 12s 5300 45c Gens Ace lipos but the current load is to much for a 12s pack. The 6 packs run cooler as the current is divided between the parrallel packs. Each cell only sees half the load. Current load was 134amps with the VarioProp set at 18 inch pitch during climbout from takeoff until the gear retract then drops to 80amps as the plane accelerates to fast cruise (80-90mph). An acceleration from cruise to top speed initially draws 130amps but drops back much lower as it tops out. One session with a GPS speed app on board recorded with an on board sport cam captured top speeds of 107-114mph. Lift-off was at around 23mph and full flap landing speed is 33mph. The next flight will be with the pitch set at 20 inches because the Rimfire 65cc motor is still over-revving the varioprop. The design rpm limit for it is 4800rpm. I never use full throttle for takeoffs so I might reduce the transmitter's throttle servo upper travel to control the top rpm. I don't want it to fly faster than it was getting to before the Varioprop as the airframe is not glassed and I have already had a D model fuse break in half at a radar clocked 122mph. There is a design flaw in the fuse that produces a weak spot at the back of the cockpit. It can easily be fixed by installing 3/4 inch balsa triangle stock on both sides of the bulkhead there (4 pieces). I get 5 minutes of high speed flight at half throttle and up to 2 go a rounds for landing. & minutes total.

sjhanc

My Feedback: (3)

Sorry about the mistakes, the editor isn't working. I get 7 minutes total flight time. I could stretch it longer if I could fly slower but that's no fun with a P 51.

fhollahan

Here are some build pics. Getting to the end of this now.

1. Fuel tank and throttle servo installed.
2. Engine with Choke and Throttle linkage. I had to do this outside the fuse as the carb sits between the firewall. I went with a 4-40 rod on the throttle. What they provided was to flimsy in my opinion for an 8 inch or so distance from servo to link.
3. installed an rcexl opto gas engine kill switch and added the light next to the ignition battery switch to show whether it is live or not.
4. Installed the DA ignition module.
5,6,7. Engine and Jtec wrap around muffler installed and cowl. Vent line from tank at bottom.