Fox 35 collectors edition

Great thread! @Ken Cook and @Onelife and others! Ken, your really making me more and more want to get a Fox engine. I love the descriptions of the engines and the events you have had happen with their use! Its definitely making me want to try and purchase a Fox motor. You seem to almost have a love - hate relationship with the engines and all the extra things you know about the owner and manufacturer and the hows and why of their evolution is fascinating. I think they are the more interesting for having started out so basic and evolved over time.

Yabby

Ken Cook wrote:     Last engine far left is the MK V. Now this is one of my favorites and probably the most disliked. It features one rear ball bearing and a bushed case. I love it, hit the ground, blow the dirt off and your back in the air. I've had great success with these, they're fast as can be. However, I've had two eat the circlip which retains the wrist pin. Eventually, play develops in the wrist pin hole and the up and down movement can dislodge the circlips and it's game over

Wristpin/circlip partial thread sideways.
In 1982 I put new barrels (twin) on my TZ GP bike, plus they had in 1982 $Aust $5,000 of port work, bench flow and mods to my chambers/exhaust to match them. I did five laps on them and blew the motor! I had used brand new piston gudgeon pin circlips with an ear on them to make it easier to put in. The little ear tag broke off one! ripped straight through the barrels chrome lining, so the barrels could never be used again and bits of metal went through the crank bearings. 30 cent circlip, cost of brand new barrels plus $5k in port work, and a full crank rebuild, new pistons, new rings etc. and new barrels and port work to replace the blown ones I never used circlips with ears again. All that damage and I had pulled the clutch and hit the kill switch/press button before the engine locked up. I rarely blew or damaged an engine even though I ran hand-grenade engines. We were fastidious with our builds and distance based rebuilds etc. Thankfully sponsors helped out big time as it would have just about finished me racing if I had to pay for it all myself.

One little wristpin/circlip. Ive still got the barrels in the shed. I cant stand to get rid of them. Lol.

Yabby

I can just imagine those engines screaming. Again I’m really impressed with the knowledge you have Ken. Nice work thanks again for sharing all that.

I found this video of my son flying one of the vintage combat meets we attended. https://www.youtube.com/watch?v=nEO0xmmce4w This is a Riley Wooten Demon with a MK IV engine. This plane was designed for older baffle piston engines which are much lighter and less powerful. In order to do this, I had to do a lot of extra reinforcing and I had to extend the booms by almost 4 inches. The Demon is old school, I built it because it builds fast. It has a diamond airfoil which is the worst. It slows in the turns and you can even see when the power cuts in this video how fast it slows in the glide. It was built for nostalgia and fun. This flight was also on 10% nitro, these engines really wake up when you get into the 35% and above percentages. There's no parts support for these and I've taken it real easy on them over the years. Every now and them I feed them the vitamin N and let em rip.

Awesome
That engine is screaming unbelievable and fast holy smoke no way could I keep up with that, it be rapped around me 3 times before I made 1 turn. Good build at those speeds and the turns amazing
What modifications did you do to the engine?

The stock head button is a POS. I've made Nelson buttons and I've reworked the stock ones by doing a hemi head. If this isn't done, say bye bye to a plug almost every flight. In the video, the venturi restrictor is removed as it's not needed on bladder. This alone changes the characteristics of this engine entirely. However, these are as friendly as a Fox .35. Prime it wet, hook up battery, smack the prop BACKWARDS and it lights right up. In addition, I do a clean up and grind off some material on the backplate to assist in fuel delivery. Other than that, just hang on.

Ken Cook wrote:            I found this video of my son flying one of the vintage combat meets we attended.  https://www.youtube.com/watch?v=nEO0xmmce4w    This is a Riley Wooten Demon with a MK IV engine. This plane was designed for older baffle piston engines which are much lighter and less powerful. In order to do this, I had to do a lot of extra reinforcing and I had to extend the booms by almost 4 inches. The Demon is old school, I built it because it builds fast. It has a diamond airfoil which is the worst. It slows in the turns and you can even see when the power cuts in this video how fast it slows in the glide. It was built for nostalgia and fun. This flight was also on 10% nitro, these engines really wake up when you get into the 35% and above percentages. There's no parts support for these and I've taken it real easy on them over the years. Every now and them I feed them the vitamin N and let em rip.

2:42 of excitement Ken. Your son knows how to avoid the dizzys. He sure is good.

Bob

Ken Cook wrote:I found this video of my son flying one of the vintage combat meets we attended.



This is a Riley Wooten Demon with a MK IV engine. This plane was designed for older baffle piston engines which are much lighter and less powerful. In order to do this, I had to do a lot of extra reinforcing and I had to extend the booms by almost 4 inches. The Demon is old school, I built it because it builds fast. It has a diamond airfoil which is the worst. It slows in the turns and you can even see when the power cuts in this video how fast it slows in the glide. It was built for nostalgia and fun. This flight was also on 10% nitro, these engines really wake up when you get into the 35% and above percentages. There's no parts support for these and I've taken it real easy on them over the years. Every now and them I feed them the vitamin N and let em rip.

That is some really fine flying by your son, and it is fast even though only flying on 10% nitro. Incidently, YouTube rolodexed with another combat flight, this time on bladder and I guess with hotter fuel also with a classic plane. Caption: "Nelson 36 powered Super Satan- just having fun ripping up the sky!!"



Engine is spun up more like it was a hopped up Cox, and I was amazed how fast it is, amazing what a little Vitamin N can do.

Just received 10 new Masters 10x5 props from an E-Bay seller for my legacy .35's, price was right at $2.62 each after all costs, getting harder to find.

George, the Super Satan in that video is far from the actual Super Satan. This is a upscale version to accommodate the Nelson.  Tom Luciano is the builder and owner of this Super Satan. Al Ferraro is doing the talking. They're both friends of mine from New Jersey. Larry Scarinzi is the designer of the Super Satan and he collaborated with Carl Goldberg to kit this plane. Unfortunately, the kit never came to fruition for a couple of reasons. This plane does have a lot of pieces within it and it's not a simple build. Goldberg wanted to redesign the kit and I'm certain Larry wasn't liking that. The original Super Satan still exists today. I've held it and it's finish is still amazing on it. Larry Scarinzi is a incredibly neat person and builder. In addition, Larry collaborated with Duke Fox on the design of the Fox .36X.

        As for the Nelson .36, that engine changed fast combat forever. The engine on Tom's Super Satan is the newest N36C which Henry made a few years back. We will more than likely never see them produced again. A Nelson stays together all day long and it runs faster than all of the Fox MK series engines. The MK VII is the closest to the Nelson but the MK VII has a flaw as well. The piston liner is AAC and the liners like to peel. Al Ferraro sent his MK VII to Henry Nelson and Henry installed his Nelson internals into that engine.

My son flying Tom's Super Satan that's Fox .36X powered vs Al with a Nelson .36. Tom's Fox .36X has been reworked with Brian Gardner ABC piston liner. Al wanted to see speed wise if the old Fox .36X could actually keep up with a Nelson. It seemed to pass the test.  
https://www.youtube.com/watch?v=BhwwAocrwIE&list=PL2gKf_iSP6MmcmZmnMl6kgBI0WBBSycpw&index=8

Mine from the 90's. Bought commercially and sold on ebay when I was "getting out of the hobby." Just dumb.



Pretty engine but I never ran it.

Ken Cook wrote:                The stock head button is a POS. I've made Nelson buttons and I've reworked the stock ones by doing a hemi head. If this isn't done, say bye bye to a plug almost every flight. In the video, the venturi restrictor is removed as it's not needed on bladder. This alone changes the characteristics of this engine entirely. However, these are as friendly as a Fox .35. Prime it wet, hook up battery, smack the prop BACKWARDS and it lights right up. In addition, I do a clean up and grind off some material on the backplate to assist in fuel delivery. Other than that, just hang on.

Ken forgive my dumb questions but what is a stock head button POS.
I love seeing these videos I really appreciate everyone that’s posted in this thread. I just bought that engine checks in the mail. And also a 50th with that ABC liner, hemi head and back plate. I love it thanks for looking out for me. Can’t wait to get them. It will probably tear the wings right off my shoestring lol or rap me up like a boa constrictor but just to hear the engine will be a dream come true. Thanks everyone. I didn’t know I’m deal with professionals. Love it and I really appreciate all the hard work you guys did.

rsv1cox wrote:Mine from the 90's.  Bought commercially and sold on ebay when I was "getting out of the hobby."  Just dumb.



Pretty engine but I never ran it.  

If anyone Knows the control line sore on eBay ( Bob Brooks) he just dug up some new fox engines that 50th being one of them. He has a gold mine of fox engines he might want to part with

Ken Cook wrote:George, the Super Satan in that video is far from the actual Super Satan. This is a upscale version to accommodate the Nelson.  Tom Luciano is the builder and owner of this Super Satan. Al Ferraro is doing the talking. They're both friends of mine from New Jersey. Larry Scarinzi is the designer of the Super Satan and he collaborated with Carl Goldberg to kit this plane. Unfortunately, the kit never came to fruition for a couple of reasons. This plane does have a lot of pieces within it and it's not a simple build. Goldberg wanted to redesign the kit and I'm certain Larry wasn't liking that. The original Super Satan still exists today. I've held it and it's finish is still amazing on it. Larry Scarinzi is a incredibly neat person and builder. In addition, Larry collaborated with Duke Fox on the design of the Fox .36X.

Thanks for the history lesson, Ken. I can understand Carl's standpoint. He is a businessman, and was thinking of the market, most model builders would not be willing to go to the depth, level and cost of build that Larry went for an ultimate competition level plane. Also, it had to be successfully built within a cost that would sell kits plus earn a profit. I would think most top competitors would do like Larry and modify a kit using their own balsa and materials to give it a competitive edge. I noticed the tail booms to hold the movable elevator, it is a lightweight but strong geodesic framework versus say, functional but heavier solid sheet balsa.

From what you describe, I gather that the availability of the Fox similar to the Coxes allowed for a then network of tweakers to resolve weaknesses plus improve performance and durability. Personally, because most of my modeling was small RC and CL, and as a hobbyist versus a competitor, plus never saw CL combat competition, never got steered in that direction. Perhaps if I had been exposed to it and encouraged in it, I would have taken a different history.

Ken Cook wrote:As for the Nelson .36, that engine changed fast combat forever. The engine on Tom's Super Satan is the newest N36C which Henry made a few years back. We will more than likely never see them produced again. A Nelson stays together all day long and it runs faster than all of the Fox MK series engines. The MK VII is the closest to the Nelson but the MK VII has a flaw as well. The piston liner is AAC and the liners like to peel. Al Ferraro sent his MK VII to Henry Nelson and Henry installed his Nelson internals into that engine.

Interesting, yeah, seems there is a trick for durable chrome coatings, certain other engines and manufacturing production lots suffered pealing. The OS FP comes to mind. Also modelers failing to understand oil requirements that some still required sufficient Castor like the K&B Sportsters for long life.

It kind of reminds me of for example, in the auto industry. Spoke to a Mazda dealer mechanic in Hawaii when buying parts for my 1970 Mazda 1800 (not rotary) back in 1975. He was overhauling an RX-2 or -3 rotary engine. People didn't understand that one needed to maintain coolant levels and change coolant when needing replaced. (Then, the rust corrosion inhibitors in the coolant would break down, needed replacing every 2 years.) Engine would overheat, ruining rotor seals.

K&B Sportster construction was revolutionary and novel for its time, but similar to the Mazda and owners used to the steel liner reciprocal engines, modelers I gather treated those engines like OS Schneurles. Anyway, my thoughts with my limited knowledge.

Ken Cook wrote:My son flying Tom's Super Satan that's Fox .36X powered vs Al with a Nelson .36. Tom's Fox .36X has been reworked with Brian Gardner ABC piston liner. Al wanted to see speed wise if the old Fox .36X could actually keep up with a Nelson. It seemed to pass the test.
 

That was quite a treat to watch. It would be understandable what the less expensive Fox .36X would be competing with the cream of the crop Nelson.

Onelife wrote:If anyone knows the control line store on eBay ( Bob Brooks) he just dug up some new fox engines that 50th being one of them.  He has a gold mine of fox engines he might want to part with

Stay tuned announcement? Or, perhaps contact Bob personally outside his store for non-store items?

I checked just now, he must have sold them out very quickly. Bob has only 2 Fox .35 Stunt engines with tongue muffler, rest are OS, Enya, Super Tigre and Veco.

E-Bay shtterman (Bob Brooks): Engines for sale

Unlike the Fox .35 stock head, the MK series engines use a two piece head. It consists of inner button which is retained by the cooling fins. You wouldn't know this looking at the engine. You see almost nothing of the button insert itself. The button has the threads for the glow plug and the combustion chamber milled into it. In the case of the MK engines, the early button were almost completely flat the plug element was recessed up inside. This caused some form of turbulence within the hole and it would rip the element clean out of the plug. Later head button designs were hemi'd. It was a hemi within a hemi known as the double bubble head. While I'm aware it worked well, I only have one on my MK VI. The MK VI came stock with this style combustion head. I took a page from K&B on their rear rotor Tornado engines that I frequently used and copied that head design onto the Fox.

What is you favorite stock engine?

I don't think I can answer that question. My Cyclon .049 but it too takes a lot of fiddling to get them correct.

I can understand that

GallopingGhostler wrote:

Onelife wrote:I know the feeling getting old sucks. I have liver cancer and lung and chemo every 3 weeks. I look back over my life and get depressed.

Hang in there, @Onelife, there's hope. Been walking with the Lord these 50.5 years, there's always hope. None of my father's side, males lived beyond 70 years. So far I guess I'm lucky because I have already exceeded his younger brothers, now approaching 69. Wife had breast cancer, breast removed and chemo. She is 20 years in remission. There is great freedom in now worrying about the future for there is more beyond. Will be praying for you.

James 5:16 (WEB) "Confess your sins to one another and pray for one another, that you may be healed. The insistent prayer of a righteous person is powerfully effective."

Onelife wrote:Speaking of depressed there’s a fox35 bidding now for over 300 and still got twenty hours to go

Rather than shooting for the top preferred, I have lowered my expectations, and have accumulated other engines. Most recent is the K&B .35 Stallions, now got 3. Picked them up for less than $30 bid each, all 3 are in excellent condition. Also picked up another Testors McCoy .35 Red Head for under $30 shipping and taxes included. It has like new compression, only missing the needle. I'll remove one from one of my parts engines. Also got a K&B .45 Sportster new with optional bulkhead mount backplate without box for under $60 total.

Although not the top dogs, but they are still good runners, will still do the job.

Onelife wrote:What does O&R stand for in drive washers

Perhaps, Olsson and Rice?

https://www.ebay.com/b/Ohlsson-Rice/bn_21832035

They were an early, prolific model engine manufacturer in their day. Perhaps they also made parts, or their parts could be substituted?

Onelife wrote:and what is a lapped piston

See the discussion in: RC Groups: Lapping (Cylinders and Pistons)

Thank you

I have a issue with a fox rocket I bought on eBay. It did not come with NVA so I put one on from a fox 35 stunt. There is just barely enough threads to put nut on end to hold it and it runs very sporadic fast slow fast slow it just seems like that Ventura it’s not the same size as the Fox 35. I read something about the case  on the hybrid I think I have the case before the hybrid and I need a NVA for a fox 36  ??? Am I close ??? I cleaned the gas tank thinking it was restricted I put a new glow plug on. And I put a NVA on I got from Lee on stunthanger Run a little better but still lean/ rich. ? What am I doing wrong besides everything?

The Red head Rocket came in a few different  variations. It came with the let's throw any piece of crap part left on the shelf. Some of them were similar to the .35 X internals.With the backplate removed, does the crankshaft have a full circular web shaft? Does it have the ground shaft which is semi circular? This would be a similar shaft to the .35X. Also, in the venturi stack, is there a round restrictor inside? Look close because they can sometimes be hard to tell. This would be a steel circular insert which seats right at the curve of the bell mouth.

         As for the spraybar, this wasn't the same as the stunt .35. These were brass single hole spraybars. Unlike the stunt.35 which has a hex on one side, the Rocket spraybars were round. You need a pair of pliers to hold the round side when tightening. The first Rocket series was the 1957 Combat Special, this morphed into the 1958 Blackhead and then the 1959 Red head. Some red heads are strong runners while others are terrible and they can shake pretty violently. I believe the Red Heads were produced up until the 1961 "Special" was introduced which offered a bolt on front end. This engine utilized 2 sets of needle roller bearings.

I can try and help with answering some of the issues. First off, your correct in terms of the venturi. It's not so much the venturi but your stunt needle valve. The Fox .35 stunt is pretty narrow as it's turned down to about .127" in the middle. This can cause fuel draw issues requiring the needle way open to get it to draw fuel. In addition, these Red Heads had a 4 bolt backplate with a pressure nipple cast into the center. Is it drilled in the center and did you confirm this by removing it and looking at it from the other side? In my post above, I mentioned a restrictor that goes into the Rocket case, is it in there? It will run without it but that would require crank pressure from the backplate which is usually why they're drilled. This engine like the .35 stunt likes a bit of a load so a 6 pitch prop is in order. Fox needle valves are pieces of crap so erratic and Fox needle valve go hand in hand. They just leak too much air and requires tubing over the threads. If you don't have tubing over the needle, your beating a dead horse. While it will rob power, the Super Tiger would more than likely fit the case and not only is it better than the Fox, it would fit the hole in the case and the Tiger diameter is about .156".