at7driver

Hi all,

came across an older Fox Q motor today at a swap meet.. tuned pipe, spinner, carb rather then venturi,with manuals mentioning the Q500 racing. just wondered if anyone has any knowledge on these motors.. something to bolt on and have fun with, no racing.. just curious about power compared to todays motors.. etc..

thanks,

david

Ed Smith

A piece of total junk. I sent mine back to Fox and was told I did not know how to use them. This after fifteen years of operating high performance racing engines. The engine was a perfect example of stoneage machining. If you have any doubts then ask "Where are they now?"

Sonny Perez should be ashamed.


Ed S

Jimnie

Very cool,
Runs very good if you know how to set it up. Put a 9x6 Rev Up on it and see 18,000. If you don't want it let me know I might be interested as mine is long gone. They really don't have a very long life however.
Jimnie

at7driver

Thanks guys,

I am looking for a viper to put it on just to get some stick time with it and something other than the aerobats to fly on the weekends..

Do you know if fox still sells gasket kits for rebuilding??

thanks,


david

jaka

Hi!
Forget about the old FOX Q-500 engine. Total waste of time.
Get a MVVS Q-500 or Super Tigre Q-500 if you don't want to spend money or get a more expensive /powerful Nelson or JETT engine.

DMyer

My Feedback: (2)

Great engine if you like fiddling with the needle.... over and over. Never saw one actually get a good run in the air.

at7driver

HI guys,

I have got the engine, pipe etc.. cleaned up today. wondering what plug I should put in for a bench test.. also what prop would you recommend for bench testing this engine. thanks in advance.



david

Sport_Pilot

Is it the ringed Q500 or the iron piston Quickee Sport? If the former then use a castor syn mix for the oil the latter should be 100% castor oil. Some of the iron piston Fox's run well with a syn castor with lots of castor such as Omega, but will not last very long and will not tolerate lean runs well. Some Fox's will not run well on more than 5% nitro but I think the Quickee engines ran 15%, not sure. If the MK series carb they should tune well, unless the needle is real lose, if so some fuel tubing over the needle should fix that. Also the newer Fox engines and parts are better made than from that period so a new needle may fix that. Never had the Q 500 engines, but all my Fox's run great if you follow the tune up procedure in the manual, some will not tune like an OS or Supertigre. If it says to tune the idle needle first then do so.

at7driver

Hi thanks for the comments,

I will check to see if its ringed or not. I do have the manuals for the engine so will run it per the instructions. It does have a piece of fuel tubing already on the needle so thats taken care of already. anxious to get her on the stand and see if it runs OK. any plug recommendations would be appreciated..


thanks,
david

Sport_Pilot

Not sure about that engine, but generally I start with Fox plugs for Fox engines. I suspect the Fox Gold or OS#8 plug. If using nitro higher than 15% then perhaps the Fox #8.

combatpigg

My Feedback: (3)

The people at FOX are very approachable and will bend over backwards to help you with any questions you have about their engines. They're a good old American company that is trying to make a go of it in a world economy.
They have a checkered past. They are guilty of taking fundamental short cuts in design because of economic reasons. They tried to support fringe elements of the hobby like RC pylon racing and C/L combat as best they could, while still paying their machinists liveable wages.
I agree that any deals involving Fox engines in this category should be approached with caution. If you are an engine man, they might be a good source of raw material to practice your magic on.

HighPlains

My Feedback: (1)

You have no idea!

combatpigg

My Feedback: (3)

I guess the story isn't just an urban legend, then? It is ironic, because DF was put on a pedestal by many.

HighPlains

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I take it back, you DO know. I didn't think that one in a hundred knew the story.

js3

My Feedback: (3)

Well then, let's have the story!

HighPlains

My Feedback: (1)

I think it best not to go into it on a public forum.

at7driver

haha... Didn't mean to unearth bad memories or anything like that.. I am looking forward to messing around with this engine and hope to at least get her to run good enough to fly around the local field. Thanks for the plug recommendations. we are finally getting some rain so I am going to bolt it on the stand and see if she fires. I'll keep you posted..

thanks again,

david

js3

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You know my email address.

combatpigg

My Feedback: (3)

AT7, if it is the iron / steel engine, then it will need several rich runs with cool off time in between. Hold something behind the exhaust spray and look for signs that the metal grit has stopped appearing in the exhaust. If it is the ABC engine, under prop it with a 8x6 cut down to 7x6 [for break in] and run it at a slightly rich scream until the grit in the exhaust goes away and the high speed needle is steady. It should run at about 18-19,000 like this. Don't let the low speed needle be lean, you can fry the engine this way, always work from the sloppy side in and don't spend a lot of time exploring the throttle capability of these engines, just run them flat out. The high speed fuel circuit completely takes over at about 85% throttle and if you ever lose the vapor trail, land it and figure out why. Good luck!

Depending on the vintage of the engine, a final word of caution. The spring steel circlips that hold the wrist pin in place can rust and lose their tension. The chain of events that follow will destroy the engine in no time, so it is worth a look to see if they need to be replaced. The later ABC engine uses a different approach, the wrist pin is cross drilled and a roll pin is pushed into the side of the piston. It is hit and miss to service this set up without ruining the piston. In this case just run it 'till it pukes.

I didn't notice the photo in Eds' post until now. Those lower backplate bolts are extending into the casting.....if the upper 2 bolts are as long, they will press into the liner and cause distortion.
The .36 version of this engine was a world beater [for many years] before the Nelson .36 came along. The only catch was you had to replace all the internals with after market parts to run with the top 20.

2fast4u

My Feedback: (5)

In 25 years of flying, seen 2 Fox engines run worth a poop. 1 was a plain jane 40BB, the other was a 36X none R/C. The 36X was freaky fast. The other 2000 or so Fox engines I have seen were all on the ground making the owners mad as all get out.

GOOD LUCK!! You'll need it.

at7driver

HI Guys,

Thanks for the information. Got busy this weekend with my sons sailplane and club meeting. Hoping this week to get her on the bench and see if the old gal will fire. I'll keep you posted. thanks again.

david

Sport_Pilot

Have you tried out that Fox yet?

vertical grimmace

My Feedback: (1)

I would not discount Fox engines entirely. The Q-500 may not have been worth a darn, but I have quite a few C\L Combat engines that really kick but. Not close to the Nelson but otherwise they run great. I am really amazed Fox is still around though. I too know of DF's past. Too bad.

StanDouglas

How far back do you want to go about Fox. I best Christmas I can remember was around 1954 when I found a Fox 35 in a beautiful (to me) black box under the tree.

The next day I was flying it in Ring master. Best engine I had, much better than my McCoy Red Head or K&B!

Great memories.

SD

Jezmo

Not everything about ole DF was bad. I had one of those old 35's on a Ringmaster too. Had a later model BB45 ring that, after I learned the peculiarities of the carb, was not all that bad. Certainly not an OS but it ran good and lasted well.