FOX 35 front bushing

Is it possible to replace the front bushing on a FOX 35 case without having to machine the old one out IE: heat and press. Secondly, can you get the replacement bushings? Thanks, Dave Markley

Hello There

Yes it is possible to replace the bushing BUT only if it is of a vintage that is not available.

A new Case from FOX would be cheaper. I migyht be slow at machining but itwould take me a few hours to set up and do the job and if the shaft is worn oval then there is more work.

Many engines have then bush cast in the case when the case is molded and the outside of the bush is knurled to grip the case.

I believe that FOX have a fixed service fee which is the best way to go, then on the othere hand if it is a common Fox buy a new engine. Firstly the are so cheap in the US. secondly if the bush is worn the rod and other parts will be worn.

May be someone else will have a different point of view but that is what is so good about aeromodelling there are many answers to one question.

safe and happy festive seasion

John Quigley

LAST EDITED ON Dec-11-04 AT 09:28 PM (CST)
 
ohh i could see a big job here...for one case...from scratch i could do it in 6 - 8 hrs..with no tooling ur lookin at about 400 bucks maybe 500 and im cheap...in a collette closer..not an index type...an exspansion arbor locating from the sleeve bore and seat to maintain squareness...id drill then bore to new bushing size for a light press fit on an oilite bushing with an .010/.015 undersize crank bore...i'd install the bushing there ...it would never spin on ya it expands faster than the aluminum case....you'd still be on the arbor...mount the arbor in a good mill vise at the proper angle and drill the venturi hole through th bushing...return to verticle location and finish bore the bushing leaving .002/003 hone stock...remove from arbor...then hone and your done..see simple and it would probably be better than original...jim

Front bushing?? The Fox .35 Stunt has a one piece bushing that is full length and cast in. It won't come out unless you machine it out.

>Is it possible to replace the front bushing on a FOX 35 case
>without having to machine the old one out IE: heat and
>press. Secondly, can you get the replacement bushings?
>Thanks, Dave Markley

As others have said, buy a case. If other parts are worn, send the whole engine to Fox. They will replace all worn parts for the cost of parts only. No labor charges added. If the cost exceeds half the cost of a new engine, they will substitute a new engine.

While you are at it, if you have a bunch of worn parts, put them all in the same engine and send it in. Got some chewed up head screws. Those are the ones to send. Broken needle valve? That'll work. Got a head with a broken fin? Sounds like the one to use. Send it in and get "the works" treatment.

Leonard, being a seasoned tool and die maker I think I could do the job myself in about 45 minutes, not the 6 to 8 hours that the worlds slowest machinest suggested in a previous post!!! just locate on the bore, remove about 1/2 of the current bushing, turn a sleeve from oil light bronze,mill the opening for the intake, heat the case, freeze the new sleeve and install,not a big deal. All this said it probably makes more sense to do what you suggest and get a new engine for 1/2 price. PS I sure could use the TT 36, Thanks, Dave Markley

LAST EDITED ON Dec-12-04 AT 08:02 AM (CST)
 
wind
my advise to you...send that to fox to fix...jim

LAST EDITED ON Dec-11-04 AT 11:14 PM (CST)
 
As Jim says, and from someone who has had to write a shop order or two, the machining costs are always in the setup time.

Len had a real good suggestion. Fox built their reputation on engine service. I wonder if they'll take my 36 Rear Exhaust?

tom i honestly dont think i could do a good true job in less than about 4 hrs....i dont guess on stuff like 50 year old cases that u cant replace...in this case its his and he can junk it if he wants...im thinkin pressin any part of that bushing out might spoil that case...i would not do it to a johnson...the shaft hole is definately NOT concetric to those bushings except by luck..maybe... they were clamped to th motor mounts drilled and reamed...then i threw a fixture on a b.p. that located on th sleeve bore for finish boring and bored em after all other ops were done to get them absolutely square to the sleeve bore...i got a nasty scar from that op so i remember it well....and a fox who knows....they had oodles of alignment problems always...like i said if i fixed it it would be better than before....i am tempted to do engine repairs....ohhh i almost forgot....me n Hi...or Hi n I...made a 1/2 a in 1973 for sam benvides' helicopter so he could sell it to marx toy company...but...thats another story...jim

Jim I also was a tool maker and in 1960's I worked for Smith Corona in there tool shop. I took the McCoys with the silver bearings drilled them out from the rear on milling machine,heated the case and pressed in stock bushing that I had made a cut in for venturi.Reamed the bushing to fit crank and I did four of them in three hours after work using several hundred thousand dollars worth off there equipment.
Your point is well taken as every thing would have to be custom made. I had every thing ready to go when I started the job. I milled a Tatone mount up square and then drilled a hole in the back. This held the motor square in the vice on the mill table. I had premilled the bushings to size and made the cut for the venturi.The time working on each motor was only fifteen minutes but the rest was prep work. The bearings in the McCoy was very soft not hard like brass. I did another one years later in my garage using only a drill press. It was crude but it worked just as well and it took me all day to do that one. $5oo is cheap.
Ed

sounds like you know ed...thanx for th vote of confidence...jim

I once did a Johnson small shaft bushing with nothing more than a drill press. I drilled the case from the front. The case expanded from the heat as I drilled so the hole turned out tapered. I then pressed a bushing in from the front. It got real tight tword the rear. I hand drilled the venturi opening. It ran really well. The only problem was I used an oilite bushing. It didn't last long. You know what they say, young, dumb and.........

As Marvin stated oil light doesn't work well. I tried oil light years ago trying to get a better bushing and it didn't hold up to the vibration. In the end I found out it was the crankshaft not being ground properly that caused most of the wear.

Fox used to have oversized crankshafts, I sent a good case, 50's ventage (Badly worn bearing) it was honed out for one of the new crank shafts. It was cheaper than a new case. It was very nice work.
You might check if they still provide that service.

The Randy Smith/Larry Foster High Zoot Fox 35 shaft is slightly oversize and fits in many of the older worn cases very well. I have three of them and they are great and are much better balanced than the stock unit.

Bigiron

To anyone re-bushing engines, phospher bronze is the metal you want. Oilite will not take the shock load. Also the thickness of the bushing should be kept to a minimum for best heat disapation.

> The Randy Smith/Larry Foster High Zoot Fox 35 shaft is
>slightly oversize and fits in many of the older worn cases
>very well. I have three of them and they are great and are
>much better balanced than the stock unit.
>
> Bigiron

A bit off topic... but I haven't seen Larry Foster posting as of late. Hope all is well and he's just too busy "makin Foxes" that he doesn't have time to play. Then again, after some of the previous threads... maybe he doesn't want to play.

I wouldn't blame him one little bit!!!

Bigron

Hi to all, although I don't get on the forum much anymore this one caught my eye. The Hi-Zoot crankshaft that Randy Smith sells is his crankshaft and was done by him. Please don't give me any credit for this wonderful crankshaft that he makes.

As for putting a new bushing in the Fox 35, I would recommened just buying a new case. In the end it's well worth going this way. If your running the older style case then it is well worth the investment.

LAST EDITED ON Dec-14-04 AT 03:53 PM (CST)
 
"phosphorus bronze" i think maybe that is what we may have used in the johnsons ...##### memory i couldnt remember till you mentioned it...i was thinkin "porous" bronze ....then i said "nah that dont sound right"...it worked better than oilite...it wasnt a wear thing...i think it may have been a heat issue...i think oilite once up to operating temperature siezed up...jim
ps ... good thing i didnt fix winds engine ... ha ha ha ha

LAST EDITED ON Dec-14-04 AT 04:04 PM (CST)
 
Hi Wind, There is another way to go about this project. Call Fox and ask for current exchange price for a new 50th anniversary Fox 35. Then you box up your old engine plus payment mail it to Fox and trade it in for a new Fox. (about $45.00 plus postage minus muffler,if you want the muffler is a few bucks more) Best deal I have seen for a new stock Fox in the box.

willied

The whole essence of our hobby is basically wasting time doing things we could buy cheaper.

I've bought Cox .049 crankcases where somebody had taken the time to bore it out and insert a bronze plain bearing.

I've seen 36's where somebody replaced the ball bearings with plain bearing to beat a rule.

High performance 40's downsized to 36, same reason.

Profile planes with the controls inside.

Re-busing a Fox 35 Stunt wouldn't be the biggest waste of time by a long shot.