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-   -   OS 46 VX DF engine conclusions (https://www.rcuniverse.com/forum/extreme-speed-prop-planes-104/7645422-os-46-vx-df-engine-conclusions.html)

RocketRob 08-13-2008 10:54 PM

RE: OS 46 VX DF engine conclusions
 
Thanks Freaking Fast.
I'm tight to get anything much larger than a 6oz in the ashley, but been working on it pretty hard of late.[8D]

I just dread painting.....

freakingfast 08-14-2008 09:13 AM

RE: OS 46 VX DF engine conclusions
 
Rob

If you are running a DF in that Ashley, I have only one question, are your eyes good?:)

mcdonald77 08-17-2008 11:07 PM

RE: OS 46 VX DF engine conclusions
 
I have one of these engines for sale in the classified section. its a few years old, but only started a hand full of times and has not been broken in or rev'd up high.

Jason

freakingfast 03-29-2009 01:05 AM

RE: OS 46 VX DF engine conclusions
 
Well I must be pushing over 200 flights with the clipped wing DF powered Diamond dust and about 175 on the same engine and bearings.
Today I had four flights on her and I finally heard the bearings whine so it’s time to swap out engines and order new bearings from RC Bearings.
So this engine has consumed an amazing 10 ¼ gallons of 30 % mostly over 25,000 RPM on the same bearings!

175 flights X 7 ½ oz. per flight = 1312.5 oz. or 10 ¼ gallons

The engine is very strong still and has good pinch when cold.

K&B HP glow plugs last between 17 and 20 flights.

The Hitec HS-5955TG servos are still tight. Note the HS-7955TG replaces it and has twice the resolution, a good thing!

pabrokenprop 10-30-2009 07:41 PM

RE: OS 46 VX DF engine conclusions
 
i have an os vxdf .46 on a Diamond Dust looking to make it SCREAM!! any ideas on how i can make this happen? i have been reading your forum and geting a few ideas from it. I would like to hear your opinion of my planes setup, if you would please. i know this engine has lots of potential but i just need the right hookup.

http://www.rcuniverse.com/forum/m_9214771/tm.htm

thank you.

freakingfast 10-31-2009 12:19 AM

RE: OS 46 VX DF engine conclusions
 
Well let’s see.

It looks like you are not running a header, but just the factory flange, so I think you are too short for even the APC 7.4X8.25 carbon.

I’d use a Macs #3521 15 degree fuse top header. Both header and pipe may need to be cut so that you don't end up with the coupling at the turn on the header and to get the 9 ½” distance from center of piston to the large diameter on the pipe apex (this is a reference length). But work your length down on your own since your pipe may be a bit different (start 1/2” longer). On your pipe the measured distance is where the big part starts to get small again (exhaust end),

Your pressure tap is not at the apex, this may give you problems with even fuel pressure throughout the operating range, only time will tell.

This header will let you run a 8oz. fuel tank (Sullivan #SS-8), when it’s running right it’ll suck that tank down in 3 minutes if you are running 30% nitro. Use real Du-Bro ¼” foam rubber under the whole tank bottom and smaller pads around the sides to keep it isolated. Don’t have the hold down strap too tight or the fuel will foam. I use a real OS bubble-less clunk. Another option is a bladder tank and you can hard mount it down. I’ve never needed a bladder tank. When you reach high rpm’s these two tank set-ups are a must.

Id bet that you have only a few threads engaging that prop nut on that small-thin sport prop. And if you modified that prop to get more threads, you’re lucky the engine didn’t come alive. Thankfully the tuned length was way too short for those props you listed.

When you go to the carbon you will need a “short shaft adaptor”
(Tru Turn part number TT-0141-A) is what you’ll need. Ream out the prop to fit the short shaft adapter. Turn the prop and hold the prop ream tool stationary for best hole concentricity than balance. Start reaming from the engine side of the prop. Take your time.


I hope you sealed the engine mount area with epoxy, the fuel will eventually eat away at the CA.

If not, remove the engine and use K-2r cleaner. Used in moderation can lift the surface oil. Use thin CA in the edges of the mounting holes and engine cut out to help keep the wood from crushing. Seal with epoxy when done. Check engine mount screws periodically for tightness.

I’m 51 and my eyes need extreme contrast from top to bottom so that I know what’s what. There’s not much time to decide on the right move to do at the speeds you are about to be traveling.

This is what it should sound like, this is an old clip seen here before. The poor guy had a devil of a time keeping it in the frame and was afraid to go past the fence LOL.
http://www.youtube.com/watch?v=5m0t925_elc

I hope info this helps.
Karl

pabrokenprop 10-31-2009 01:54 PM

RE: OS 46 VX DF engine conclusions
 
FF,
i have revamped the plane since those pics have been taken. i have gotten a slim and long tank with the foam under the tank.
as for the props i used an "end-mill" with a pilot to counter sink the face of the prop hub.. im sure now that wasnt a good idea.. allthough i never had a prop explode in flight prob cuz it hasnt been able to unload fully.. yes i did fuel proof the engine mount with clear "dope".. also as to the visual of the plane in the air i have added bight orange flames on the top side.. HELPS ALLOT!!! you are right about the header i might have to look into the macs header like i saw that u have on yours in the video..

thanks so much for your help...
I kneel to the DD king in hopes of being knighted "some day" LOL


pabrokenprop 11-09-2009 02:36 PM

RE: OS 46 VX DF engine conclusions
 
Hey carl
i flew her again yesterday and boy did that prop
help out!! I actually backed off the gas the first flight.
Only a few things i need to work on.
1 high speed needle setting
2 order the header and more props
3 and figure out why im burning plugs every flight
could that be caused by the % of nitro?
Im only running 15%? i know you run 30%.

Any input on needle and gas and plugs??
Thanks

sportrider_fz6 11-09-2009 09:03 PM

RE: OS 46 VX DF engine conclusions
 
Holy defying physics, batman!!!!

that is insane FF!!!! oh by the way Tron called and said they want there plane back:D

freakingfast 11-09-2009 09:15 PM

RE: OS 46 VX DF engine conclusions
 

ORIGINAL: pabrokenprop

Hey carl
i flew her again yesterday and boy did that prop
help out!! I actually backed off the gas the first flight.
Only a few things i need to work on.
1 high speed needle setting
2 order the header and more props
3 and figure out why im burning plugs every flight
could that be caused by the % of nitro?
Im only running 15%? i know you run 30%.

Any input on needle and gas and plugs??
Thanks
15 or 30% are fine.
If the pipe is too small(volume)it should be at least 8.5cc or if the header is too short the plug WILL go away. I betting it's your header.
The plug of choice for this setup is the K&B "HP" close second choice Enya #5.

The OS #8 is too hot and wont last more than one or two flights on 30% and perhaps 15% as well. The OS # 10(formally A5) and the R5 are too cold to get a nice idle and too hard to keep a good HS needle adjustment.

MJD 11-09-2009 10:33 PM

RE: OS 46 VX DF engine conclusions
 
Boy FF, that engine handles about like an FX. Crank it, walk out and launch. No fuss no cuss.

MJD

Sessholvlaru 11-15-2009 10:31 PM

RE: OS 46 VX DF engine conclusions
 
Where are you guys getting the 7.4X8.25 carbon APC props? They don't appear on their website, 7.4X8.1 being the largest pitch wise that they have.

combatpigg 11-15-2009 10:36 PM

RE: OS 46 VX DF engine conclusions
 
Try Performance Specialties or Darrol Cady. Call APC directly, too. APC updates their lineup depending on what's hot and what's not. They used to make a grey 7.2x8.6 that honked, but it's gone.

freakingfast 11-15-2009 11:21 PM

RE: OS 46 VX DF engine conclusions
 
There must be a dozen props they must have missed putting on the list at APC since the got a new webpage.
Data entry error my guess, missed sales are costly.

pabrokenprop 01-02-2010 02:30 AM

RE: OS 46 VX DF engine conclusions
 
is there a website for these places with the apc carbon props? Performance Specialties or Darrol Cady or any other props that could be used on the .46 vxdf? like the apc 8.75x7.5 or 8.75x8 pylon prop??

freakingfast 01-02-2010 03:37 PM

RE: OS 46 VX DF engine conclusions
 
APC has in their infinite whizz-dumb discontinued the 7.4X8.25 carbon. I called them about a month ago to see if they would make some more.... and they never bothered to return my call. The next size they have is the 7.8X8.1 but it has reduced thickness hub. I haven't tried it yet, so I don't know for sure if it's safe. The prop load should be close to the same, maybe a few rpms higher.

I've used the gray pylons and the tips come off, I'm not sure if it was the high rpm speed or the sudden change of direction of flight (sideways airflow) that did it.

I used a 8.8 X 9.75 (discontinued of course) and 8.8X9.5 with the pipe at a longer setting (lower rpm) than the carbon props.

The APC prop list is not working during the holiday. You can sometimes find props cheaper by not going to the source (APC) but rather a retailer if they stock it.

pabrokenprop 01-02-2010 04:06 PM

RE: OS 46 VX DF engine conclusions
 
i was getting the 7.4x8.25 from sig but they have ran out their stock. so i got some of the other 7.4x8.1 (thin hub) they work fine i flew 4 times balls to the wall and they held togather.. they do seem to be a lil slower.. but that could be on my part with the new header and 8.5 pipe.. i might need to richen or lean her out a bit more...

thanks FF

freakingfast 01-02-2010 04:23 PM

RE: OS 46 VX DF engine conclusions
 
I'm glad that you were the guinea pig....just kidding. Good to know it works! You may need to play with the header/ pipe length.
Did it sound higher pitch in the air than the 8.25 and what did it tach on the ground?

pabrokenprop 01-05-2010 10:30 PM

RE: OS 46 VX DF engine conclusions
 
I DIDNT GET TO TACH IT BUT WHEN I DO ILL POST MY FINDINGS.. AS FOR SOUND http://www.youtube.com/watch?v=4iwZWU2u7P0
"SORRY FOR THE POOR VIDIO"

PLANEINSANE1 12-13-2011 10:47 AM

RE: OS 46 VX DF engine conclusions
 
somebody's gotta wipe the smile off my face everytime i watch that flying dd video hehehhe.....sweeeeeettttt!!!!!!!

it sez in the website that dds are out of stock...can somebody sell me a kit pleeeezzzz???

ok no kits? please lend me some plans guys i beg you....planeinsane@yahoo

thanks in advance!<br type="_moz" />

PLANEINSANE1 12-13-2011 10:49 AM

RE: OS 46 VX DF engine conclusions
 
somebody's gotta wipe the smile off my face everytime i watch that flying dd video hehehhe.....sweeeeeettttt!!!!!!!

it sez in the website that dds are out of stock...can somebody sell me a kit pleeeezzzz???

ok no kits? please lend me some plans guys i beg you....planeinsane@yahoo

thanks in advance!<br type="_moz" />


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