Author Topic: Fox 36X ABC piston/liner/rod/pin sets (Read 43163 times)

Brian Gardner · « **on:** March 26, 2014, 01:42:30 AM »

OK Guys,

In the thread about McCoy 35 ABC sets a number of people expressed interest in ABC piston/liner/rod/pin sets for the Fox 36X.

I took name and put them on a list. We appear to have enough numbers to make this fly.

In order to progress this we need a discussion on which Mk is required/most popular and what parts are interchangeable between the different versions. Loop scavenged or schnurle etc?

Once we come to a consensus I will need a loan of a good condition example engine to get measurements from.

So open to you guys now....please discuss.

Brian

Andrew Hathaway · « **Reply #1 on:** March 26, 2014, 10:56:17 AM »

I'd be interested in parts for the standard 36X. I'd expect the parts would fit both the needle bearing and ball bearing version. When you get into the bald head 36X MKI and later engines the internals are different as they're schnuerle ported.

Garf · « **Reply #2 on:** March 26, 2014, 11:59:30 AM »

I would be interested in a set for the 1st. model 36X with the single needle bearing. I think it also fits the .36 sport with the slant plug and plain bearing.

Tom Luciano · « **Reply #3 on:** March 26, 2014, 04:25:48 PM »

I'll be looking for the BB version from 65-73. This will work in the needle bearing version as well. I was told by someone very familiar with the engine that the only difference is the relief in the liner for the bearing. I believe this to be the one most will be seeking. I'm no expert and I'm sure someone with more expertise then me, will chime in. This is the version I will be seeking. As mentioned I will take 4 sets.

Fox 36x BB fitted for combat

Thanks,
Tom

RandySmith · « **Reply #4 on:** March 26, 2014, 04:40:57 PM »

Quote from: Brian Gardner on March 26, 2014, 01:42:30 AM

OK Guys,

In the thread about McCoy 35 ABC sets a number of people expressed interest in ABC piston/liner/rod/pin sets for the Fox 36X.

I took name and put them on a list. We appear to have enough numbers to make this fly.

In order to progress this we need a discussion on which Mk is required/most popular and what parts are interchangeable between the different versions. Loop scavenged or schnurle etc?

Once we come to a consensus I will need a loan of a good condition example engine to get measurements from.

So open to you guys now....please discuss.

Brian

Hi Brian
ALL of the FOX 36X engines were single bypass cross flow engines with baffles, there were NO Loop Charged ones (Dr Schnurle designed loop Charging) So they will all need baffles on them,
Should be a big increase in the life of the OLD Fox 36X with your ABC setups.
Are you making these with pins and rods ?

Regards
Randy

Brian Gardner · « **Reply #5 on:** March 26, 2014, 06:49:28 PM »

Quote from: RandySmith on March 26, 2014, 04:40:57 PM

Hi Brian
ALL of the FOX 36X engines were single bypass cross flow engines with baffles, there were NO Loop Charged ones (Dr Schnurle designed loop Charging) So they will all need baffles on them,
Should be a big increase in the life of the OLD Fox 36X with your ABC setups.
Are you making these with pins and rods ?

Regards
Randy

Yes Randy, that's the plan to do rods & pins.

I'm not particularly familiar with them. I did have one for a short while years back. So I'll be needing input from the guys that are intimate with them.

RandySmith · « **Reply #6 on:** March 26, 2014, 06:53:59 PM »

Then the new P/S sets should fit the 35X, 36X and 36X bb , maybe even the plain 36 shiney case :-)

Randy

Steve Hines · « **Reply #7 on:** March 26, 2014, 07:53:37 PM »

Brian I wanted the 36x and not the combat motor. never new them to have ball or roller bearings. maybe asking for the wrong thing.

Steve

RandySmith · « **Reply #8 on:** March 26, 2014, 08:14:55 PM »

Quote from: Steve Hines on March 26, 2014, 07:53:37 PM

Brian I wanted the 36x and not the combat motor. never new them to have ball or roller bearings. maybe asking for the wrong thing.

Steve

Steve the FOX 36X had a version that was called the 36X BB it had ball bearings, there was another that look just exactly the same that had roller bearings, they all used the same piston/sleeve , the BB had a modified rod

Randy

Andrew Hathaway · « **Reply #9 on:** March 26, 2014, 08:28:03 PM »

The 36X is a combat engine. There are a few different engines marked 36X on the case, there's the needle bearing 36X, ball bearing 36X, which are identical aside from the bearing, and the MK I & II Combat Special which look alike and have 36X marked on the case but share virtually nothing with the 36X.

Motorman · « **Reply #10 on:** March 26, 2014, 08:45:16 PM »

The needle bearing crank was slightly larger in diameter.

MM

Al Ferraro · « **Reply #11 on:** March 27, 2014, 07:26:44 AM »

Hi Brian,
Put me down for 5 sets of the Fox 36x BB. This engine has the baffle on top of the piston. The 36x BB has a small relief on the piston to clear the rear bearing in the case. Care has to taking in not making to relief to wide to pervent sub piston induction. I think the baffle should be made stronger something like the K&B 40 because the old piston is made of steel and some of us like to run 40% nitro to hear it crackle. This piston and liner set would work in the needle bearing engines with no mods. You could make a FOX SUPER DUPER STUNT by putting it into a fox 35 stunt by changing the rod & head. The new liner would also fit the 36 shiney case but I think the 36x has a thicker rim at the top of the liner and would give you more head clearance so you would have to do some checking. Motorman is right, the needle bearing crank is slightly larger in diameter than the BB but the crank pin is the same.
Al

Brian Gardner · « **Reply #12 on:** March 27, 2014, 08:09:21 AM »

Quote from: Al Ferraro on March 27, 2014, 07:26:44 AM

Hi Brian,
Put me down for 5 sets of the Fox 36x BB. This engine has the baffle on top of the piston. The 36x BB has a small relief on the piston to clear the rear bearing in the case. Care has to taking in not making to relief to wide to pervent sub piston induction. I think the baffle should be made stronger something like the K&B 40 because the old piston is made of steel and some of us like to run 40% nitro to hear it crackle. This piston and liner set would work in the needle bearing engines with no mods. You could make a FOX SUPER DUPER STUNT by putting it into a fox 35 stunt by changing the rod & head. The new liner would also fit the 36 shiney case but I think the 36x has a thicker rim at the top of the liner and would give you more head clearance so you would have to do some checking. Motorman is right, the needle bearing crank is slightly larger in diameter than the BB but the crank pin is the same.
Al

Without an engine on hand to check myself, how would the beefier baffle mate with the corresponding slot in the head Al?

Al Ferraro · « **Reply #13 on:** March 27, 2014, 12:14:14 PM »

There is lots of room on the exhaust side of the baffle to make it thicker with a ramp like the K&B 40.
Al

Al Ferraro · « **Reply #14 on:** March 27, 2014, 12:17:11 PM »

Lots of room on the exhaust side of the baffle

Jay · « **Reply #15 on:** March 27, 2014, 06:32:24 PM »

I would like to order 3 Rods and pin sets for the 36X ball Bearing engine.

Also I have both style 36X that you could use. Ball Bearing shaved head and the Needle bearing head with fins. The pistons and liners are different in both.

RandySmith · « **Reply #16 on:** March 27, 2014, 07:50:49 PM »

The 36X and 36 X BB I have here I used for combat back in the 70s 80s have the exact same piston and sleeve, I am not sure why others are different. I have some new in pack also.
Brian if you don't get one from anyone, let me know I can let you use mine

Randy

Andrew Hathaway · « **Reply #17 on:** March 27, 2014, 09:04:03 PM »

The only pistons/cylinders that should be different are the bald head MK I and MK II Combat Special, but then they aren't really 36Xs anyway. They have dual ball bearings, a bushed rod, and schnuerle porting, flat top piston/Swiss cheese liner, completely different from the 36X. By all accounts the MK I and MK II aren't very good engines anyway, not likely worth the trouble.

The 36X either with needle bearing or ball bearing should share the same piston/liner/rod/wrist pin, but I haven't had both apart at the same time to compare the internals.

RandySmith · « **Reply #18 on:** March 27, 2014, 10:05:10 PM »

Quote from: Andrew Hathaway on March 27, 2014, 09:04:03 PM

The only pistons/cylinders that should be different are the bald head MK I and MK II Combat Special, but then they aren't really 36Xs anyway. They have dual ball bearings, a bushed rod, and schnuerle porting, flat top piston/Swiss cheese liner, completely different from the 36X. By all accounts the MK I and MK II aren't very good engines anyway, not likely worth the trouble.

The 36X either with needle bearing or ball bearing should share the same piston/liner/rod/wrist pin, but I haven't had both apart at the same time to compare the internals.

The MK 1s were terrible motors, I blew up everyone I had, Duke sent new ones, The rods were sliced almost in half for lubing the pin, those destructed very quickly, many on run number one.

They blew up on Dukes fuel 10% nitro, I stopped using Missle Mist after the first motor grenade d . Duke fixed the design, and the second iterations were vastly better

Randy

Motorman · « **Reply #19 on:** March 27, 2014, 11:14:56 PM »

Fair warning, if you try to get too much power from any Fox engine the metallurgy will let you down. Not the least of which could be the crankshaft shooting out the front of the engine.

MM

Brian Gardner · « **Reply #20 on:** March 27, 2014, 11:47:20 PM »

Cool, we are getting somewhere here. I like the ramped baffle idea Al.

And it should be the case that the BB and Needle bearing engines use the same piston & liner...I'm happy there...

Another question I have fellas is what is the big end of the stock rod like? Were they bushed? Is there enough meat in the rod to bush if they weren't, or is there enough room in the case to beef up the big end of the rod to bush?

A number of years back I did conversion sets for the St35. They consisted of a stunt timed piston/liner/baffle head etc. I got good feedback on those. I also did one batch of combat ST35 sets but never got any feedback as to whether we had the fit tight enough etc. Anyone around that bought one of those that can tell me how they performed?

Greg McCoy · « **Reply #21 on:** March 28, 2014, 05:01:28 AM »

On a tour of the Fox factory I saw connecting rods in production. I-shaped extrusion with a series of holes top and bottom, then separated and contoured.

Al Ferraro · « **Reply #22 on:** March 28, 2014, 10:34:15 AM »

At last years combat festival I won the LS trophy for blowing up my 36x BB in my Super Satan. I was trying to document the Satan on video doing 120mph flight as it had done on prior runs. The engine never fully unloaded and broke during the timed laps but still managed 113 mph on its fatal run.

The baffle blew off the top of the piston just like Larry Scarinzi's did back in the 60s. This engine was jacked up pretty high and running 40 % nitro. After looking back on what happened to the engine, I should have opened the needle more on the ground and probably put a .005 shim under the head for more of a safety cushion. I have seen these engines take a beating and come back for more. Even today in drag racing with all the best parts and big bucks, guys grenade engines when you take it to the limit.
Al

Andrew Hathaway · « **Reply #23 on:** March 28, 2014, 10:53:56 AM »

Quote from: RandySmith on March 27, 2014, 10:05:10 PM

The MK 1s were terrible motors, I blew up everyone I had, Duke sent new ones, The rods were sliced almost in half for lubing the pin, those destructed very quickly, many on run number one.

They blew up on Dukes fuel 10% nitro, I stopped using Missle Mist after the first motor grenade d . Duke fixed the design, and the second iterations were vastly better

Randy

I haven't run the MK II in my stash, but it's evident it's run a bit. The rod is bushed at the bottom end, and cut liberally for oiling. In researching I haven't read anything good about them. Mine will probably get run a few times, just because and become a wall hanger.

Quote from: Al Ferraro on March 28, 2014, 10:34:15 AM

At last years combat festival I won the LS trophy for blowing up my 36x BB in my Super Satan. I was trying to document the Satan on video doing 120mph flight as it had done on prior runs. The engine never fully unloaded and broke during the timed laps but still managed 113 mph on its fatal run. The baffle blew off the top of the piston just like Larry Scarinzi's did back in the 60s. This engine was jacked up pretty high and running 40 % nitro. After looking back on what happened to the engine, I should have opened the needle more on the ground and probably put a .005 shim under the head for more of a safety cushion. I have seen these engines take a beating and come back for more. Even today in drag racing with all the best parts and big bucks, guys grenade engines when you take it to the limit.
Al

I haven't pushed mine very hard. I'm running the needle bearing 36X on a Voodoo, no restrictor, backplate pressure/hard tank, 10% nitro, 9x6 prop. A couple weeks ago I managed to blow the head gasket. The resulting leak burned the leading edge of the wing down to the wood. It might have been a hair lean. Clocked it at about 99.7mph in the same config a few months ago. Imagine it'd go faster with a bit more pitch, nitro, less engine offset, ball bearing, etc.

Quote from: Brian Gardner on March 27, 2014, 11:47:20 PM

Another question I have fellas is what is the big end of the stock rod like? Were they bushed? Is there enough meat in the rod to bush if they weren't, or is there enough room in the case to beef up the big end of the rod to bush?

The stock 36X rods aren't bushed, but there's a fair bit of meat. There may be less clearance between the OD of the rod and ID of the case in the needle bearing engine, but I don't have one I can take apart at the moment to check.

Al Ferraro · « **Reply #24 on:** March 28, 2014, 11:04:11 AM »

(Another question I have fellas is what is the big end of the stock rod like? Were they bushed? Is there enough meat in the rod to bush if they weren't, or is there enough room in the case to beef up the big end of the rod to bush?)
Brian, The big end of the rod does not have a bushing. The Fox MKIV Rod (part # 13727) has a bushing in the big end of the rod and fits the 36x baffle engines. The only problem using the MKIV rod is that it's not offset like the 36x engine rod. The offset centers the rod in the piston when assembled. The 36x has a shoulder on the crank pin that's why the rod needs to be offset.
Al

Al Ferraro · « **Reply #25 on:** March 28, 2014, 11:22:18 AM »

In Andrew's photo of the piston you can see the relief on it. This is needed when the piston comes close to the rear bearing in the case of the BB engine at bottom dead center.
Al

Brian Gardner · « **Reply #26 on:** March 28, 2014, 06:49:51 PM »

Thanks guys, a picture tells a thousand words as they say.

Robert Schroeder · « **Reply #27 on:** March 31, 2014, 12:28:58 PM »

A question if I might, probably to Randy Smith. Are the .36X piston, rod, sleeves compatible with the Rocket .35 combat specials to include the red head?

Bob

C.T. Schaefer · « **Reply #28 on:** March 31, 2014, 07:40:33 PM »

The top flange on the 36 is thicker to allow for the longer stroke. You can use the 36 stuff in the 35's but the timing and compression will be different. Maybe, if Brian makes these for us he could easily make the .35 sleeves to order by just using a thinner flange on top.

RandySmith · « **Reply #29 on:** March 31, 2014, 08:17:19 PM »

Quote from: Robert Schroeder on March 31, 2014, 12:28:58 PM

A question if I might, probably to Randy Smith. Are the .36X piston, rod, sleeves compatible with the Rocket .35 combat specials to include the red head?

Bob

Hi Bob
I do not know thew answer to that one, I never tried to use the P/S in a Black head or Red head? Maybe some one else has tried this, I will check my parts and see what I have in Black Head combat and Red head

Randy

Brian Gardner · « **Reply #30 on:** April 03, 2014, 01:53:23 AM »

Ok, thanks to Tom & others (apologies ..names escape me at the moment) we have samples headed to me with details sorted as far as the big end of the rod & piston baffle etc. We'll take into consideration that these may potentially be run on high nitro fuel so the baffle and piston crown will be beefed up as compared to the stunt pistons we do.

There are some similarities with the 35, but not enough to make it a "dual purpose" kit.

I only have 18 units spoken for at this point, so unless more people put their name on the list I'll probably just do a run of 20 to 25 sets.

They will be to suit the 36X and 36X BB. It will include ABC piston/liner/bushed rod & pin.

It will take a few months so be patient guys.

Thanks to everyone that has given input and offered sample parts. It's been a good team effort so far.

Lyle Spiegel · « **Reply #31 on:** April 03, 2014, 02:32:56 AM »

I would like to add my name to list for the Fox36BB P&L set with wrist pin. I have my original engine which was fun very little and has never been crashed or taken apart. For rebuild will need new gaskets and possibly would be good to replace the bearings. Concerned about availability of these parts.

Paul Pomposo · « **Reply #32 on:** April 03, 2014, 05:12:55 PM »

I would like to put an order in for 1 of your piston/liner sets for the 36X BB version.

Gordon Tarbell · « **Reply #33 on:** April 03, 2014, 07:21:03 PM »

Brian put me down for two, Thanks.

Brian Gardner · « **Reply #34 on:** April 03, 2014, 07:44:10 PM »

OK guys, you are added to the list. It looks like I need to increase numbers as we are up to 27 sets.

Brian

Garf · « **Reply #35 on:** April 07, 2014, 10:43:11 AM »

I would need a payment method other than PayPal. What is available?

Brian Gardner · « **Reply #36 on:** April 08, 2014, 05:12:18 AM »

Paypal is most convenient. Some guys get their friends with paypal to send the money.

Alternatives are things like Western Union but lots of fees involved that I would have to include in the price.

Michael Stinson · « **Reply #37 on:** April 08, 2014, 01:03:48 PM »

Brian,

The 36X and 36X BB have the same Piston and Cylinder (old Fox part #36X04).
The case, Crank Shaft and Connecting Rods are different; but the Cylinders are the same. No Bearing Relief was needed on the 36X.. The 36X Mk I and II Combat Specials should not be considered as they just come apart (over optimized without the engineering or upgraded metallurgy). This part number is good from the original straight plug 36X in 1964 to the last one made. I have new parts if you need one to copy.

If you consider making them for the Mk 3, 4, 6 or 7, I also have clean examples.

Mike Stinson

Michael Stinson · « **Reply #38 on:** April 08, 2014, 01:07:37 PM »

Brain,

Here is the Fox 36X Parts diagram. Mike Stinson

Lyle Spiegel · « **Reply #39 on:** April 08, 2014, 02:43:39 PM »

Any info specific to bearings for the 36X BB version? If I'm going to install new piston / sleeve & pin I might need toreplace original bearings. Engine was stored with lots of oil but who knows how they survived after so many years - could open the engine and find they are pitted or rusted.
Also- what is availability of head gasket for a rebuild? I figure its a waste of time trying to contact Fox
Thanks
Lyle

Andrew Hathaway · « **Reply #40 on:** April 08, 2014, 02:57:26 PM »

The bearing is a standard part, should be available anywhere, R8 if I remember correctly. Brian's ABC sets for stunt engines usually come with a small stack of head gaskets, if these don't it doesn't matter much the Fox 35 stunt head gasket drops right in the 36X.

Brian Gardner · « **Reply #41 on:** April 08, 2014, 03:51:37 PM »

I can supply replacement head shims with the set. I usually only do this for the ST46 & 60. It's no problem.

Motorman · « **Reply #42 on:** April 08, 2014, 04:58:38 PM »

I don't know how you're going to get away with making this liner out of brass. Besides being too thin over all it's way too thin between the exhaust and transfer ports. I'm predicting allot of seized up engines. Hope I'm wrong.

MM

Michael Stinson · « **Reply #43 on:** April 08, 2014, 07:32:18 PM »

Brian,

Please put me down for 2 sets including wrist pins and rods. Mike Stinson

Brian Gardner · « **Reply #44 on:** April 08, 2014, 09:27:57 PM »

Quote from: Motorman on April 08, 2014, 04:58:38 PM

I don't know how you're going to get away with making this liner out of brass. Besides being too thin over all it's way too thin between the exhaust and transfer ports. I'm predicting allot of seized up engines. Hope I'm wrong

MM

The guys tell me the exh port in the liner is wider than the port in the case. We'll make the exh port in the liner a bit narrower to match which will give us a bit more strength. As for wall thickness I can't say till I receive the sample engine. Based on the photos above the wall thickness shouldn't be a problem.

Motorman · « **Reply #45 on:** April 09, 2014, 10:45:10 AM »

Actually if you make the exhaust port slightly smaller than the opening in the case it will produce allot more power. I would go .075" smaller on each side. It may seem funny to think of reducing a port for more power but, allot of raw fuel gets drawn out from the sides on those old cross flow engine designs. It would have the added benefit of making the sleeve stronger right at the sore spot.

MM

sadams714441 · « **Reply #46 on:** April 10, 2014, 04:07:40 AM »

I have an old brand new fox 36 rc engine does anyone know if that could be changed over for control line.
Steve

C.T. Schaefer · « **Reply #47 on:** April 10, 2014, 06:14:45 AM »

Sure. If it's an X motor you can just leave the carb in and fly. (The 36X r/c has a glued in carb so it would be difficult to put in a straight venturi) If it is a later model 36, the carb is held in with set screws so you can just make up a venturi and replace the carb.

Aubrey Williams · « **Reply #48 on:** April 13, 2014, 10:04:41 PM »

Brian -

Aubrey here in South Bend, Indiana, USA. I would love to have a set of ST .35 stunt cylinders and pistol assemblies. Your OS 35 and ST 46 were first rate.

Cheers, Aubrey

PS - I know you are not making them now, but if you ever do. That also applies to the ST V60 light case.

Brian Gardner · « **Reply #49 on:** April 14, 2014, 01:45:19 AM »

Quote from: Aubrey Williams on April 13, 2014, 10:04:41 PM

Brian -

Aubrey here in South Bend, Indiana, USA. I would love to have a set of ST .35 stunt cylinders and pistol assemblies. Your OS 35 and ST 46 were first rate.

Cheers, Aubrey

PS - I know you are not making them now, but if you ever do. That also applies to the ST V60 light case.

G'day Aubrey, I don't currently have a waiting list running for the ST35. Nobody has ever asked about them since we did the last batch approx. 5 years ago.