fox glow engine

Ha! Joe beat me to it !!!! Durn Dial-up !!!!

that's quite interesting

do you know how much it would be worth and what kind of fuel and oil i should be using?

Maxdeny wrote:that's quite interesting

do you know how much it would be worth and what kind of fuel and oil i should be using?

Well, I'm thinking Sig Champion 10% is great stuff for these, but there are others....no clue on it's value though.

Sig Champion is ok, as long as you use the 25% oil and not the 20%

Really you could use just about any fuel as long as the oil content is 22-29% with at least 50% castor I prefer Powermaster 10/22.

Many use Powermaster 10/22 mixed with 10/29. It gives a higher castor content. With some Synth mixed in to keep the varnish to a minimum.

Ron

I'm not exactly sure what i should be running some people say the motor was designed to run on 25% nitro and at least 20% castor oil and other say 5% nitro and 29% castor oil

what do you think

Maxdeny wrote:I'm not exactly sure what i should be running some people say the motor was designed to run on 25% nitro and at least 20% castor oil and other say 5% nitro and 29% castor oil

what do you think

so as long as i use at least 22% castor oil i should be good then?

Pretty unusual engine, I wonder what advantage a slant plug has. The needle bearing will be fun, you should maybe make sure they turn free and not gummed up.
Also a glued in carb.

The 36X is a ball bearing engine. The .36's were made in needle bearing version in the nose and also roller bearing. These don't need 29% oil and probably would not be happy using it. The .36X is a high timed engine which was used for combat. The .36X likes a 8 1/2 x 6 Rev up prop or 9x6 props. It likes a bit of a load so the newer thinner GF series Master Airscrew props might be a bit light on load. While my experience with them is mostly control line related, I would be somewhat concerned on how this engine idles for R/C. This isn't a stunt .35 and it doesn't want to run the same way and it doesn't require 29% oil due to being a ball raced engine. I run mine on 22% oil but I would have no issues on running it on 20% 50/50 fuel. There's little to no parts support on this engine. While this engine was designed to handle a fair amount of nitro, I wouldn't recommend it and I would keep the nitro level in the 10% range to avoid breaking a crank. Engines are somewhat difficult to put a price on. I can see it being of value as a donor engine for parts for those like myself that use them for vintage control line combat. As I mentioned, Fox has no parts for these engines. Gaskets can be found but essentially that's it. Glow is diminishing at a fairly fast rate giving up to electric therefore sellers can hardly give them away. These engines are loud. Loud doesn't equate in today's society. These engines don't care for mufflers, they will work but more than likely overheat robbing power and possibly cause the engine to just shut off depending on muffler style. These engines were available in control line and R/C. We use them for control line combat and they seem to be the staple engine for the 1960's period.

the inside of the engine is also unusual having a big notch sticking up in the piston with a matching indent in the top of the head

also the engine turns freely and has virtually no carbon buildup at all

Here are some pics:

when I open up the motor I found it was missing a head gasket and the crankcase gasket is almost definitely dead too and the only place i could find them was custom laser cut on ebay where the quality may be poor compared to new old stock

also does anybody know if this engine uses piston rings before I pull it all apart and try to replace them?

The Fox .36 has no means that index the cylinder. It also doesn't use rings.  In other words if you take it out, your jeopardizing the fit due to the liner not exactly going back into the case the same way. The piston microscopically scratches the walls of the cylinder and you could possibly reassemble without lining it back up the way it came out. Taking it apart also compromises the seal of burnt castor around it equally.  The other problem with these engines is the fact it was made by Fox. The machining of this engine isn't like modern CNC machining in which you just can't easily interchange parts from one engine to another even if it's a new part. I wouldn't make a habit of taking these apart unless something breaks or unless it ingested a lot of dirt. As of now, with the head off, the cases of these engines are extremely thin and fragile. Tightening the head back on can distort the case and put a bind in the cylinder liner  which can do it a lot of harm. With the glow plug removed and the prop off, turn the engine over by hand after assembling to make certain you don't feel a bind. The head gasket is aluminum and it's probably still on the head. It's more than likely still good and just needs to be reassembled.If you do have a replacement , you will have to pick it out using a small pick or knife blade, it isn't easily visible as it fills the entire groove of that head and it fits tightly around the center.  Just be sure that when you tighten the cylinder head back on that you do it evenly and in a cris cross fashion keeping an eye on the gap between the top of the case and the underside of the head. You can easily pull the head off center.  It doesn't need to be extremely tight. Now that you have removed the back plate, get a allen wrench behind the rod and pry off of the crank web and be positively certain the rod is moving back and forth on the wrist pin, this may require penetrating oil and heat to free it. You don't need the backplate gasket and you can assemble using Permatex anaerobic gasket maker, (not the RTV).

The notch as you referred is not unusual and is very typical of the period. The notch is a baffle. This baffle blocks and closes off the ports in the cylinder as the piston goes through it's travel. This type of design is known as loop scavenging. Newer Schneurle engines use a flat top piston and the ports have directional grooves cut into them

Ken Cook wrote:The Fox .36 has no means that index the cylinder. It also doesn't use rings.  In other words if you take it out, your jeopardizing the fit due to the liner not exactly going back into the case the same way. The piston microscopically scratches the walls of the cylinder and you could possibly reassemble without lining it back up the way it came out. Taking it apart also compromises the seal of burnt castor around it equally.  The other problem with these engines is the fact it was made by Fox. The machining of this engine isn't like modern CNC machining in which you just can't easily interchange parts from one engine to another even if it's a new part. I wouldn't make a habit of taking these apart unless something breaks or unless it ingested a lot of dirt. As of now, with the head off, the cases of these engines are extremely thin and fragile. Tightening the head back on can distort the case and put a bind in the cylinder liner  which can do it a lot of harm. With the glow plug removed and the prop off, turn the engine over by hand after assembling to make certain you don't feel a bind. The head gasket is aluminum and it's probably still on the head. It's more than likely still good and just needs to be reassembled.If you do have a replacement , you will have to pick it out using a small pick or knife blade, it isn't easily visible as it fills the entire groove of that head and it fits tightly around the center.  Just be sure that when you tighten the cylinder head back on that you do it evenly and in a cris cross fashion keeping an eye on the gap between the top of the case and the underside of the head. You can easily pull the head off center.  It doesn't need to be extremely tight. Now that you have removed the back plate, get a allen wrench behind the rod and pry off of the crank web and be positively certain the rod is moving back and forth on the wrist pin, this may require penetrating oil and heat to free it. You don't need the backplate gasket and you can assemble using Permatex anaerobic gasket maker, (not the RTV).

          The notch as you referred is not unusual and is very typical of the period. The notch is a baffle. This baffle blocks and closes off the ports in the cylinder as the piston goes through it's travel. This type of design is known as loop scavenging. Newer Schneurle engines use a flat top piston and the ports have directional grooves cut into them

okay I wont be taking it apart then as nothing seems to be binding or damaged

my only question is that you said the head gasket is aluminum and the ebay listing I found was selling gaskets made out of Karropak which is a standard multipurpose gasket material

are these worth buying or should I just stick with the aluminum gasket that is already there?

and I have Permatex form a gasket sealant and not Anaerobic Gasket Maker but that should work just fine

The last paper/fiber gaskets that Fox used that I'm aware of was in the first version Fox  sandcast stunt .35's produced in the late 40's 48/49. These were quite problematic when it came to head gaskets blowing out so the decision was made to use aluminum. Seeing that this engine is newer, I would be hard pressed to figure that Fox would be putting back in what failed for them in the past. I would probably find nothing wrong with using a modern fiber gasket material as I've been doing this with a lot of my Mccoy's lately. I would try and get a knife and be certain that indeed a aluminum gasket is in the head. They fit so tightly in there, it's easily dismissed as the head itself. If that's the situation, bolt it back on. One thing I do recommend is to chase all of the six holes with a 4-40  tap and clean them out well because more than likely visible metal chips and burrs are inside the holes. If the stock screws are Phillips head, I would consider replacing them with 4-40 allen socket heads. It makes them easier to tighten, remove etc. The Phillips get filled up with castor goo making removing and tightening very difficult and generally causes them to strip out the head.

                      To suggest that anything aftermarket would be sub par to Fox is somewhat of a funny statement. While I'm a dyed in the wool Fox fan, the majority of the machine work was very crude. You can probably and more than likely see the mating surface of the back of the crankcase where the 4 bolt case cover seats. The back of the case more than likely isn't even flat. I take the case and place it on a piece of 400 grit sandpaper on top of a piece of glass. Put a little 3 in 1 oil and proceed to flatten the mating area by moving the case in figure 8's holding the engine case as flat as you can. The high's will be readily apparent after a few seconds of sanding as to how much sanding will be needed to get the rest of the surface flattened. Just look at the surface and once the sanding scratches are continuously across all areas of the case your done.

              Just a little caution with the use of Permatex products. While they offer a lot of products, only a few work well with our application. I have had success with some of the RTV's, not all of them work well. They just don't hold up to alcohol and the exhaust residue. The anaerobic comes in tubes about 2" long. It doesn't have a short shelf life like RTV and can be stored for up to 2 years or more in it's tube. It cures in the absence of air which also makes it service removable.  It's formulated for aluminum and alcohol submersion. I'm not suggesting to run right out and purchase some, it's just the name Permatex can explain dozens of sealers and gasket maker. Not all can be subjected to alcohol. If your not in a rush, purchasing the .36X gaskets will certainly take any or all of the guess work out of the picture. On another note, the backplate of the .36's generally had a nipple casted into the backplate. This was a tap for those that wanted to use crankcase pressure to their fuel tank. Make certain there's no hole drilled through the backplate. These holes typically were tapped and if needed, you can put a very short screw within the hole with a small fiber washer under the head to seal it.

Ken Cook wrote: The other problem with these engines is the fact it was made by Fox.

yeah there is no support for this motor but I should be getting new allen head screws for both the head and back plate

ill see how it goes with the permatex and if it fails i might buy the gasket off ebay

also noticed the throttle assembly is on backwards

I think your going to enjoy it. Post your results when it's running as it's always neat to see a old shelf queen breath fire once again. That ole girl can be quite loud. I never ran one with the pivoting exhaust baffle so I'm sure that will quiet things down a bit. Enjoy and good luck!!! Ken

Hopefully I will be ready to try a test run for either this weekend or the next

I found a total of 3 aluminum gaskets in the head

for now I am just using one but if I should be using more please tell me

Try it with one. If plugs start blowing, put them back in. I would think they've been in there since it was made and now over the years the compression might not be the same as it was when new. That being said, the compression should come up a bit and assist in starting. One thing to note in regards to starting this engine. It wants to snort, fart, and backfire or all of the above. Don't prime through the exhaust with the glow plug clip on, wear a glove when flipping. The engine likes to be wet when starting. Don't be alarmed if fire comes out of the exhaust port when initially starting.

well I tried with just one and cleaned off the glow plug gasket and the compression feels great but I will fond out once the engine starts up

fire out the exhaust! fun!!