Rebuilt Fox 36X

LAST EDITED ON Mar-06-04 AT 05:42 PM (CDT)
 
I bought this Fox 36X on ebay. The engine was in very bad condition. NO compression at all. It had .002" clearance between the piston and sleeve and .006" clearance between the crank shaft and the hole in the crank case. Rod clearance will pass at .001" clearance. Sence its easier to make a new sleeve than a new piston I made a new sleeve .002" smaller to fit the ware on the existing piston. The old piston is .7975" diameter so I made the bore of the sleeve .798" giving it .0005" clearance. I made the exhaust port .050" narrower and I made the intake port .100" wider keeping the timing spacing distance of .020" the same. The open intake and slightly restricted exhaust should give it a litter more torque. I bought a roller bearing to match the other roller bearing inside the back end of the crank case and bored out the case in the front just behind the propeller and put a roller bearing in the crank case. The bearing fixes the .006" ware on the case. Now the engine has 2 roller bearings on the crank shaft. I was worried the 2nd bearing would provide an air leak but it worked out fine. I started the engine with a 10x6 prop and it runs like a new engine. Not very nice looking engine on the outside but so what it runs great. If you take a look at the port inside of my engine and compair it to your own engine you will see the port is round and not square like the factor ports. No reason for a round port its just easier to make it that way. 4 hours of work and its better than new. Go to ebay auction 3174457557 to see a picture of what the engine use to look like. I flew the Fox 36X engine today on my Flite Streak and it ran excellent all 6 flights.

[photo not recovered: fox36x.jpg]

LAST EDITED ON Mar-06-04 AT 06:43 PM (CDT)
 
FOX 36X on a flight Streak. I bet it hauls astrioids. Better take all your vitamins before you pick-up that handle....Grins
A lot of motors have two bearings such as yours with no problem. Most of them use shielded bearings and some no seal a tall. They drip a little out the front due to crank case pressure. Supposed to be that way to lube the front bearing.

You are right about that fox 36x engine on the Flite Steak it is quick not quite as quick as my F2D combat airplane and not as manoverable either. I have heard some Fox 36x engines have another bearing in the front but I have never seen one. I took my engine over to motion indurtries so I could show them the bearing I already had in the engine and I bought one just like it for the front. I am not sure that was the correct thing to do but its seems to be working.

Just for fun went on the Bay and checked out your motor. Looks Like
Kaw Kaw La Phew. So is this a salt blast job on the outside??

Yes and No. I took the engine apart and put the crank case in a container of laundry bleach. I came back 5 minutes later and it looked like a valcano. The bleach was having some type of chemical reaction with the metal crank case. I dumped it out and washed it off. The engine was covered with white jello looking stuff about 1/4" thick. I scraped off most of the jello and washed it clean, soaked it in fresh water to remove the bleach. After it dried I blasted it to remove the dried up white jello looking stuff. Now the engine is clean but the metal is dark gray looking. I learned a lesson don't put and engine in laundry bleach.

>Yes and No. I took the engine apart and put the crank case
>in a container of laundry bleach. I came back 5 minutes
>later and it looked like a valcano. The bleach was having
>some type of chemical reaction with the metal crank case. I
....
>the engine is clean but the metal is dark gray looking. I
>learned a lesson don't put and engine in laundry bleach.
>

Gary;

My chemistry is a bit rusty, but odds are that if you are having a reaction that involves chlorine bleach and a gas is being given off, there is a good chance you are generating some type of chlorine gas. That stuff will kill you or scar your lungs, eyes, and anywhere else you have a wet tissue membrane that it is exposed to. Military terminology refers to it as a "blister agent."

Probably best to leave the bleach for laundry and pressure washing windowsils.

laundry bleach + ammonia = chlorine gas

LAST EDITED ON Mar-07-04 AT 09:26 PM (CDT)
 
Merck Index Ninth Edition page 858. Chlorine + ammonia = Nitrogen Chloride also know as, Nitrogen Trichloride, Chlorine Nitride, Trichlorine Nitride. This gas is very unstable and explosives at 93 deg F. Explodes in direct sun light or magnesium light. Pungent odor, heaver than air, very suffication gas, if you inhale this gas you can not get it out of your lungs unless you bend over or stand on your head, evaporates rapidly in air. Used for bleaching flour and waste control of citrus fruit.

This is why you should not mix laundry bleach with laundry ammonia it will blow the lid off of your washing machine if you put enough if it in the wash.

I use to put a quart of laundry bleach in an empty 5 gallon bucket then dump in a pint of ammonium nitrate fertilizer and run very fast. In the summer when it is hot about 95 degrees outside it will explose like a stick of dynamite. This is a cheap explosion for the 4th of July and just as much fun as M-80 firecrackers. You can get a real good explosion if you put a couple of tablespoons of bleach in an empty bean can then pour in a teaspoon of ammonium nitrate fertilizer.

I am not sure what the laundry bleach reacted with I think the Fox 36X engine is probably a zinc or aluminum casting. I did not add any thing to the bleach, no soap, no ammonia, nothing. The container of bleach says 6% Sodium Hypochlorite.

Merck Index Ninth Edition page 1115. Sodium Hypochlorite ClNaO, Cl 47.62%, Na 30.88%, O 21.49%. Used as a bleaching agent. Pentahydrate highly unstable. It says nothing about being reactive with any type of metal including a Fox 36X.

Why not do a cut-a-way like this?
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3179377483&category=34055

You would get more than you paid for it.

Someone trashed a good engine. It still has a good needle valve.