the pope

Hi there Tim , I used to be a sheetmetal worker so I have a little experience with working with metal . If it were mine and had nothing to lose I would try and make the smaller piece smaller and the larger piece larger . Try sticking a piece of waterpipe ( a make do pipe stake ) in a vice and with a small hammer try and stretch and shrink the 2 pieces over the pipe .Being gentle is the key . If need be cut a couple of slots in the tail section if it wont shrink to your satisfaction .I dont think it would take much but I havent got them in front of me either . Even taping the end in with a hammer should help unless Im missing something in the pics . U could then screw or pop rivet them together with some high temp silicon . I wouldn't try and weld them unless all else fails as it could turn into a nightmare . Good luck from the pope.

1QwkSport2.5r

The rivets never came loose. The lip on the outer shell must have been rather shallow or broke causing it to come loose and fall off. There wasn't any of the lip broken off under the collar that held it on. I have some alumaweld rods that work pretty well, but I am Leary of trying to solder such a thin piece of aluminum. I'll try the pop can trick Earl suggested and see if I can make that work. If I can, I'll try it on the muffler. I want to try to fix the muffler because it was a fair bit quieter with the back shell in place.

1QwkSport2.5r

I thought about expanding the rear shell also - but being aluminum, I worry it would crack when I try to stretch it enough to fit over the collar the rivets went into. What's worse is the end of the outer shell where the stinger (exhaust outlet) is, the metal is very thin and not very strong. Tapping on it would be bad news I think. I'm going back and forth between trying to solder it together and just drilling some holes and bolting the back section on just aft of where the rivets originally went in to hold the collar in place.

hsukaria

It would look ugly, but how about clamping it down? You can use a metal wire and twist it at the ends to make it tight. Hey, I've seen uglier setups with the old strap-on mufflers...

spaceworm

Sorry, not a solution to the problem, but a question. Was it that the rear stinger was swagged by spinning it internally to the collar, and the collar was then riveted to the front section? Just very curious as to how this was assembled. Thanks and good luck.

1QwkSport2.5r

I think the rear shell was crimped where the open end met with the cast section and the collar was put over the two sections and then crimped around both pieces and riveted. It looks like the crimped lip on the rear shell just had too shallow of a lip and the bit of vibration just broke it loose. I just broke the collar off since it's useless anyway, and I may just go the easy route and bolt the rear shell on with three machine screws and locktite them and seal the seam with RTV. This can't be any more "agricultural" than the engine itself. When this Arctic front moves out, I'll run the Fox .50 on the repaired muffler and see what happens. I put a Bowman ring into that engine and fixed some blocked ports in the case among a few other things and run it up on glow to fit the new ring in and see if the muffler stays together. If everything works out, I will put the diesel head back on it and see if it runs any better. Last time I ran the .50 on diesel, it was down almost 1,000rpm compared to other Diesel Fox .50s.

Glowgeek

Just wanted to say this is a great thread for Fox Engines. Too bad they're no longer made and new parts are no longer available. I'll admit, I've only read the last 50 or so pages but I've learned enough to tear apart a used .40 and try to put it back in service. It's gummed up pretty bad and needs a thorough cleaning, compression check and sealed back up. I'll post some pics to see if anyone here can date stamp it.

hsukaria

So what is the reason that a glow engine has to be broken in using glow fuel before converting to diesel? Is it because the diesel fuel is so oily that the engine will take too long to break in?

1QwkSport2.5r

It's mainly due to heat (or the lack of) and engine speed I believe. Most conversions don't like to run as fast as they would on glow, so they take forever to break in that way and also they don't heat up nearly as much. Purpose built diesels take a long time to break-in.

Remember though; I'm technically inept and don't know anything, so take what I say with a grain of salt and consult a higher power.

hsukaria

I considered getting a model diesel engine a few years ago, but the cost of the fuel (and smell) killed it. My first ever engine as a kid was a diesel for control line flying.

1QwkSport2.5r

I mix my own diesel fuel, but even doing that it's still twice as expensive as glow fuel. It has a steeper learning curve as well - the typical tuning method for glow is fairly different than diesel. I agree there is a strong smell to it, but the ability to swing a much bigger prop with less noise is enough of a bonus to make it worthwhile IMO. It's not for everyone though.

hsukaria

It is also nice that you don't need a big muffler and that you can attach a hose to the muffler output and divert the exhaust away from the plane without any power loss. I think the cost and hassle of getting ether is what makes it a hassle for me. When I was a kid, I could walk into a pharmacy and buy the ether with no hassles.

1QwkSport2.5r

I just use John Deere ether I get from my local JD dealer. It's about $4.50 a can. It's a bit of a pain, but it's the easiest way to do it. Davis fuel is roughly $15/qt and I can make it for about $6/qt. I have an ST .45 that will turn a 13x6 at just shy of 11k on diesel. My K&B .65 will do about the same rpm on glow fuel. I find that pretty impressive.

hsukaria

Where do you get the castor oil? From the LHS? I wish I could get it cheaper. Can you also use Klotz Benol instead of the straight castor?

1QwkSport2.5r

The last couple gallons of castor I bought, I ordered from S&W fuels for $25/gal. I found another source through a specialty oil company for $18/gal. People that make their own soap use castor oil. American Specialty Oil company is the name of the place. They don't list pricing on their website, I had to email them.

You can use Benol, but it's a lot more expensive and isn't virgin castor. It's been polymerized I think, so it will mix with gasoline. Virgin castor is a better bet as it is cheaper, but Benol will work. It just doesn't have all the same properties as regular castor does.

hsukaria

Yep, Benol was the preferred choice for the NV engines gasser. I was looking for cheaper though. Thanks.

earlwb

One other alternative is to use a Dubro Snuffler Muffler. You mount it onto the front half of the muffler. I flew a Fox .45 for ages with a Snuffler muffler bolted onto the front half. It does sort of reduce the noise some, but it doesn't make it worse either. Muffler pressure was about the same as well. Come to think of it, one could probably just use a lawn mower muffler instead of the Dubro one too. I have done that too. The Fox 45 with the shorty lawn mower muffler is a example in the second pic. Now then the shorty muffler worked but that is about all one can say for it.

the pope

That cowl looks disgusting in the 2nd pic there Earl . The pope is impressed , a bit fancier than some of the pope's planes that dont even have a cowl . Cheers

Glowgeek

Your .45 looks identical to my .40 Earl. Is there a manual available or tuning instructions for this series of Fox engines? I have my .40 all cleaned up after 8yrs dormancy and need some tuning tips.

aspeed

I may have mentioned it before, but a Mousse can pipe is a great option. Just replace the back section completely with that method, and get more power too. http://www.spadtothebone.net/SPAD/Mu.../norvel_1.html

hsukaria

The muffler that Tim is dealing with is the MVVS 2-chamber muffler, with the second chamber fallen off. So the ideas of snuffler or mousse can, as good as they are, don't fit what he is working with. The muffler without the second chamber is a complete muffler by itself, but just a bit louder than without the secondary chamber. I had the same thing happen with my MVVS 77 muffler. I tried JB Weld and that also broke loose. I ended up running it without the secondary chamber although it was a bit louder. However, even without the secondary chamber, it was considerably quieter than a gas engine or a Fox stock muffler.

1QwkSport2.5r

I'm gonna shorten the stinger of the inner chamber and grind down the collar in the center so the outer rear shell will fit over the collar and just tap/screw it together. I'll JB Weld the screws in.

Hsukaria is correct. No bolting a back half of some other muffler on this thing.

earlwb

The plane was a Hobbico Starfire from many years ago. I was going to fly the plane until it fell apart. I flew the engine with a tuned pipe and then with a few different mufflers over the years. The cowl was slowly disintegrating over time. The plane came with a cheap plastic cowl and cheap plastic top for the fuselage. It was slowly breaking down over time. The plane still worked fine up until a colony of Harvester Ants moved in. I couldn't get them out of the wing easily. Then after I did manage to kill them off, I was worried that they ate the glue inside. So I pulled my gear out and disposed of it. But it was still working though. Heck I even flew it for a weekend with the ants inside. I still wonder what they thought of that though. The engine is now in my Combat Airmadillo. It still runs fine. I did clean it up some to remove the old castor oil stains though. It was getting pretty grungy looking.

earlwb

This instruction sheet attached here uses the MK-X carb on the engines.
[ATTACH]2147516[/IMG]

There is instruction sheet here is maybe for the old butterfly valve carb:
https://www.google.com/url?sa=t&rct=...14195076,d.amc

and maybe this would be of interest too:
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0ahUKEwj29NuopfvKAhXklIMKHZO4DJoQrAIIIygAMAA&url=http%3A%2F%2Fwww.rcgroups.com%2Fforums%2Fshowa tt.php%3Fattachmentid%3D4435609&usg=AFQjCNExvUaSSLdrmYBb6YvqGXM0S6mhRA&sig2=oQiYuwxk89vTytwYgRWzFw&bvm=bv.114195076,d.amc


The engine may need a good break in. It depends on how much it was used before it got set aside. But other than needing patience for breaking them in, the carburetor adjustments are straightforward. Duke Fox mentions the carb adjustments in the manual referenced above.

Glowgeek

Thanks Earl, hopefully the idle screw mods to richen/lean the midrange for the 45/50's applies to the 40/45's as well? Have you tried the idle screw mod to dial in midrange?