earlwb

That is the earlier version of the Fox 36 I am running on my Sure Flight Cessa 182 foamy seaplane. here is a pic of the engine as I am breaking in the engine before I mount the floats on it. Back in 1978 as I visited Fox Manufacturing and bought a bunch of engines from their in the building hobby shop that they had there. Early last summer I put together this plane kit I had been saving, but didn't get it done until after our club staged their float fly of the summer. So next year for sure now.

The exhaust has a moveable exhaust baffle that opens and closes with the throttle on the carb. That helps improve the idle because at the time modellers were not using mufflers. Later when mufflers became more popular, Fox made mufflers with a large flange to fit over the holes in the sides, for when you removed the exhaust baffle. I found that one of the MAC's mufflers fit the newer .36 engines that have the bolt hole tabs on the sides of the cylinder.
On your engine, someone didn't remove the exhaust baffle, and appears to have filed slots in the muffler flange to clear the baffle ends.





Here is a Fox Eagle I 60 engine I put on the front of my scale Extra 500 plane. it has the old style carb on it. I am still breaking in the engine on it too. Yeah I have a lot of Fox engines on hand for using on things. I have flown the plane several times so far, and it only needs 1/2 throttle after take off to fly around with. The plane has a 72 inch wing span with the wing tips on and weighs 8.5 pounds.




here is one of my Fox 15's on the front of a small sport 3D plane.

earlwb

Oh yeah, here is a pic of my venerable old Fox 45 on my old decrepitStarFire 40 plane I bought from Tower Hobbies way back in 1991.
I use the plane as a test plane nowadays to test receivers out before I trust them in something better.
yeah this poor engine has been through a lot and takes a beating. But it keeps on ticking.

Sport_Pilot

The muffler was not modified, the recessed areas are to allow the baffle to work with the muffler on. The stock muffler is not very restrictive and it may idle better with the baffle in place. If using a non stock muffler then possibly you could remove the baffle. You don't know till you try it.

Konrad

Hello Guys,
I have a question or two about the older baffled engines. How was the wrist pin retained? I seem to recall that it was tapered. It was this taper that was forced into the piston. Is this correct?

I seem to have seen engines were the pin came loose. Then the taper would drive the wrist pin into the cylinder. There always a bridge between the exhaust port and the inlet port that would keep the pin from getting stuck in a port. Is the loose pin a common issue with the smaller lapped steel baffled FOXs?

Also there was a time when Duke used a roll pin to hold the wrist pin. I had a horrible time with these as the force of pushing the roll pin would often crack the wrist pin (this was often seen with NIB engines). The FOX 40Q was notorious for this. I could also hear that the hole in the roll pin acted as a crankcase pressure leak. It would bleed crankcase charge into the muffler prior to the cylinder sleeve inlet port opening.

Have any of you guy seen similar issues with the FOX engine? Also has the new line of engines improved since Duke passed away.

Friends don't let friends fly nickel,
Konrad

carddfann

Well, I don't know about the pins, but I'm sure some other guys on here can help you after they get logged on and see your question. Regarding any recent changes since Duke died, there hasn't been a whole lot of changes as far as a totally new engine line goes. However, Fox has been busy lately making some slight cosmetic refinements, new modern looking high speed needle, and some ceramic engines. I talked to them at last years Toledo show and they said they want to phase out ABC because the chrome plating they do in house isn't healthy. I'm thinking why not get somebody to do the chroming? Anyway, they are turning to ceramic liners starting with a totally new 60 C/L and their old .35. They recently replaced their 46 ABC with a 46 ceramic, but they don't show it on their website yet which I can't figure. If you come out with something new, how do you expect people to know about it without at least putting it on their site? They really under-use their site and that's too bad because its sit up nice. If you go to their site and look at their C/L engines, you'll find that they have nice color pictures now that actually enlarge big when you click on them and they show the fine cosmetic changes like in their 60. Notice that they have the cylinder fins wrapping around to the muffler flange. This looks better and adds strength for their 60. Also, new needle valve looks good. Their RC picutures are still the little black and white ones you can't see very well. They say they are working on a 25 ceramic. There's one problem that I see with the ceramic and that's the cost. I'm afraid they will totally price themselves out of the market (they're more costly now anyway) by going from ABC to ceramic. Hope they have a plan and wish they would advertise and see them compete more.

earlwb

No, they do not taper the wrist pin on the piston. But it can sometimes be a PITA to get out. After a engine has been run for a long time, the varnish build up around the wrist pin can make it tricky to get out.
Fox uses little circular spring clips to hold the wrist pin in place, so that it doesn't touch the cylinder wall. I do not remember them using little teflon pads like some other companies did, but they could have. I haven't had to take apart a Fox engine that far in quite a while so I forget if some engines didn't use a wrist pin spring retainer clip or not. Fox generally, sells the cylinder piston rod and wrist pin as a unit, so I haven't had to deal with it much on their engines. Older Fox engines hd a hole in the crankcase, where after you remove the cylinder sleeve you could pull the wrist pin out through the hole. Now that was tricky if the wrist pin had varnished up on you.

buzzard bait

I think their other problem is mufflers. A friend has a powerful little .25 but it's ear-splitting on a 9x6. Discouraged me from getting one even though the power impressed me. A ceramic liner won't change that.

Jim

Sport_Pilot

So buy one from Fox! I think they still sell the .25 and a muffler to fit. Also mufflers made by others would fit, though some may be strap on.

buzzard bait

That's the point, he has the stock muffler that came with the engine, and it's loud. Having to buy an aftermarket muffler just to get the sound to an acceptable level makes an engine a lot more expensive, and I don't think Fox uses the bolt spacing the others do, so now you're hunting for a strap-on. Not me.

Jim

controlliner

On the subject of wrist pins, the Fox .15x, .19 and .25 had the wrist pins pressed into the piston. The front hole in the piston was taper reamed and the pin was pressed in. If you ever removed the pin, it would never stay put later on. I have had a .15 X where the the pin started to float due to the wrist pin holes "egging" out from 25 years of use. It cut a lovely furrow into the leaded steel liner. You know, the engine was hard to start, but when I got it goin' it ran like a rocket.

jessiej

I like loud model planes, loud music, loud motorcycles, and loud guns. I suppose I have no claim to political correctness.

jess

Sport_Pilot

He never said he had the stock muffler. I think the modern Fox .25 muffler fits, but check with Fox. The present mufflers are much quieter than the older mufflers. Not as quite as the modern OS style double chamber muffler, but not as loud as a tuned muffler. The only thing I dislike about strap on mufflers is that they scratch the engine finish, but with the older Fox's it hardly matters.

earlwb

Humm, interesting. I'll have to check one of these days. I usually never bothered with it when the engine needed a new cylinder piston and liner, I would just install a new one. But you are talking a long time running the engine before it needed it. Thanks for the info.


Fox used to make a "Quiet" series of mufflers, but for some odd reason it wasn't popular with the flyers. So Fox discontinued them.
I never was really bothered by the noise myself. The regular mufflers worked Ok for me.

JPMacG

My Feedback: (2)

I'm about to pull the trigger on two new 25BBs from Fox for a TwinStar. Our field has a 96 dB, 9 foot noise restriction, and I am concerned that the stock Fox mufflers might not be adeqate.

Has anyone succesfully added a quieter muffler to a 25SS? I'm thinking maybe a baffled muffler or a single chamber muffler that is larger than the Fox stock muffler. I don't mind drilling and tapping some new holes.

Thanks

carddfann

I've never tried this on my Fox's or any other, but an old timer at our club suggested opening up the muffler and putting a little steel wool inside. He said "thats what we used to do back in the day." I think that might cause some problems after a period a time or if you put too much in. Seems like the exhaust oil will eventually clog up the openings between the fibers and increase back pressure. So maybe a person has to change the wool once in a while. I don't know, but it might be worth trying. What the heck.

Sport_Pilot

Our field has a 96 dB, 9 foot noise restriction, and I am concerned that the stock Fox mufflers might not be adeqate.

They should be good for that, 96 dB is easy. Most are 92 dB and that is less than half as loud as 96 dB. Opp'd I missed that it was a twin. Two muffled engines at 95 Db would be somewhere between 96 and 98 dB. I suspect the Fox muffler is good for 92 dB as they are about twice as loud as and engine tested at 89 dB. So two Fox muffled engines may make the 96 dB limit, but it will be close.

I have seen Fox mufflers extended by taking the back half off and extending it with aluminum tubing between the half's. You could even put a plate in this extension with one or more holes to make a baffle, and turn it into a two chamber muffler.

JPMacG

My Feedback: (2)

Thanks for the ideas. I'll go ahead and get the engines.

carddfann

Fortunately I don't have to worry about noise restrictions and grumpy neighbors complaining. Our club just says anything over 1/2a has to have a muffler and no flying Sunday mornings before 11:00 AM. Nobody seems to ever bring this up when it comes to noise, but a lot of the big gas, 1/4 scale type Edges and such people fly are pretty darn loud, especially when they are prop hanging 5 feet off the ground over the runway. Wonder how many db that is. Louder it seems than someone running a little Fox 25. The loudest plane I have is a P40 with an OS 46 and an in-cowl muffler that exhausts out the bottom. The muffler doesn't have much volume and its mostly just an exhaust deflector. No that's loud, but I'm not giving up my scale appearance. I could go 4-stroke but hate to spend that kind of money for an engine to put in one plane. Four strokes are nice, but you get about 1/2 the power for twice the price. Maybe one day I'll break down and do it.

fourstar2

Well if you like performance i'd start breakin down soon. I remember when i was a little kid at the flight club, nobody had four strokes because just like you said they were heavy, complicated and underpowered not to mention twice the cost.But in the recent years that has all changed, when i moved and joined the area flight club to my surprise alot of the guys were running four strokes. To me they all seemed to be very reliable and powerfull. So i broke down and bought a saito 62a for my sig mayhem 40, and to my delight it was and still is probably the best engine i have ever owned. It is smooth running, reliable and powerfull not to mention a very nice looking quiality engine and it sounds great. I also have a ys 91 air chamber and let me tell you this, that engine, when swinging a 15x8 prop will lift an 11 pound airplane straight up like an anti gravity device. Granted most two strokes of equivalent displacement usually have more shaft horsepower than their four stroke counterparts but what the four stroke lacks in horse power vastly makes up forin torque meaning the power is imeadiatelly their when needed
Dont get me wrong though, i still like and fly two strokes as well, theres nothing like a high performance piped two stroke, to me they seem to be great for speed. of course you not going to get 15000screaming rpms out of afour stroke but because of the added torque of a four stroke that can easily be made up forwith a higher pitched prop when it comes to speed. About the only thing that is the same today about four strokesis the price, but in my opinion its well worth theinvestment.

JPMacG

My Feedback: (2)

I have several Saitos that I like a lot. But I'm not willing to blow $500 for engines for a Twinstar. Besides, I'm looking forward to trying the Foxes. I have not had one since my brorther and I flew control line 35 years ago.

BTW, I used to work in Cedar Rapids at Rockwell/Collins. I enjoyed the area very much.

NM2K

My Feedback: (14)

You sound (pardon the pun) like someone I'd like for a friend.


Ed Cregger

fourstar2

collins huh.... cool im origionally from Burlington.

Scirocco14

Question...how do I remove the connecting rod & piston from a Fox 45BBRC engine?  I'd like to replace the rear bearing; I bought this motor used on Ebay and the rear main is a little 'rumbly'...it was a little rusty when I took it apart to clean it. 

I've gotten the piston liner out but can't figure out how to get the piston/connecting rod assembly out.  I must not be holding my mouth just right?  [:@]

Thanks!

Mark

Hobbsy

My Feedback: (102)

It sounds like the rod is stuck on wrist pin and won't slide to the rear a little, it has to do that to get it off. Use a samll Allen wrench and give the rod a little pull toward the rear up inside the piston.

Scirocco14

Hi,

I tried that, and can see the connecting rod moving on the pin sideways but then hits the side of the piston pin boss.

However, looking at the piston closely, is it possible that this is a two-piece piston ? It looks as if there is a piston within a piston underneath, and a small slot in the piston pin inside it...

Mark