Fox 36X ABC piston/liner/rod/pin sets

[Brian Gardner]

Just a brief update guys.

I've received the sample engine and will get to measuring it up & drawing sketches.

B

[Brian Gardner]

Measurements done, sketches drawn all ready for the machinist. Sorry I've been slow. I can't measure stuff very accurately on days my hands shake.

All input by you guys and others has been carefully taken into consideration. This without a doubt will be a performance upgrade :-)

Rods will be bushed, piston will suit 36X and 36XBB, piston baffle beefed up so you guys don't melt it, more bearing area for the pin etc. Head shims will be supplied too.

I can't wait to get these done and out to you guys and then hear the feedback.

There are 30 spoken for on the list and I'm doing a run of 35 sets.

[Fredvon4]

Brian, I have followed this many your other new P/C and rod efforts

If you ever do a run of Fox 36 MK 3/4/6, I am in for 4 sets as I have 4 MK 4s and 3 MK6s that I want to use well into the future

Fred

[Brian Gardner]

I'd be happy to do those, but we need orders for 20 to get it off the ground Fred. We need to do a run of ST46 and ST60 to catch up first.

Brian, I have followed this many your other new P/C and rod efforts

If you ever do a run of Fox 36 MK 3/4/6, I am in for 4 sets as I have 4 MK 4s and 3 MK6s that I want to use well into the future

Fred

[dave siegler]

I will take a set if there are any left.

[Brian Gardner]

Dave, do you mean Fox 36X? I can add you to the list for when these are ready.

I will take a set if there are any left.

[dave siegler]

yes 36x, sorry. 

[Brian Gardner]

No problem. The batch size is a few more than were on the list, so you're in luck.

[Brian Gardner]

OK guys, I apologise for the delay (it's normal with me). The parts are all machined and we will have 5 more sets than orders so a few extra late people hopefully won't miss out.

I still have to do my final quality checks but as I get through them I will contact people starting at the top of the waiting list as I get them ready. I've been hospitalised recently for my spinal cord damage again and my medications increased accordingly. So I will be slow. I apologise in advance. I'll get through them as best I can as my condition allows but I will not compromise on quality!!.

On another note we've started on ST46 again.

Brian

[Steve Hines]

I think I'm on the list if not please put me on the list.

Steve

[Chris Wilson]

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.

Hi Brian,
            are you going to use oil holes in the rod ends?
I only ask because I believe they are detrimental on an overhung crank.

[Brian Gardner]

I think I'm on the list if not please put me on the list.

Steve

Yes Steve, you are on the list.

[Brian Gardner]

Hi Brian,
            are you going to use oil holes in the rod ends?
I only ask because I believe they are detrimental on an overhung crank.

I remember we discussed the rods. I know we decided to bush both ends...but I can't remember what the consensus was for oil holes. I'd go with yes we probably agreed to go with oil holes.

We also made the exh port in the liner narrower (it was bigger than the aperture in the case) to stiffen the liner.

We also beefed up the piston baffle.

There were a couple of other small refinements that people requested.

[Andrew Hathaway]

Has anyone else got one of these together and running yet?  Mine came in last week.  The machine work and quality of the parts is amazing as usual.  I tore down an Ebay 36X BB that had some nice wrist pin grooves in the front and back of the liner and extremely soft compression and started cleaning it up for the conversion to ABC.  A new $7 R8 ball bearing, and a considerable bit of time spent polishing the crank and it was ready for conversion.  The Gardner ABC parts mostly dropped right in, the bottom end of the rod took a little coaxing onto the crank pin.  Chances are Fox machined the pin on this particular engine on the big side of the tolerance. After I'd double checked the crank pin for burrs, the rod popped on with a firm push from a wood dowel. 

I've run it a few times on the test stand, 7% nitro, 23% oil - castor/klotz blend.  It turned an APC 10x4 at just under 16k rpm.  After a couple heat cycles, I switched to an APC 9x6, on the same fuel it went 16.2k+.  I suspect that like the other Bristunt ABC conversions it'll keep getting better with more run time.  Right now I'm running one head gasket, no venturi restrictor, with backplate pressure.  After it's been run a bit, I'll run some higher nitro fuel through it. 

[Brian Gardner]

Guys, I'm part way through posting these out. I'm contacting everybody on the waiting list as I have them ready. Apologies for the long wait.

Brian

[Andrew Hathaway]

The quality is well worth the wait.  Six months from concept to an exceptional finished product doesn't seem bad at all.  I can't say enough positive things about the Bristunt ABC conversions.  This 36X ABC is one of the strongest running Fox combat engines in my stash. 

[Carl Cisneros]

I must have missed it some place, but what is the price of the assembly?

thanks much

[Motorman]

Hi Brian,
            are you going to use oil holes in the rod ends?
I only ask because I believe they are detrimental on an overhung crank.

How are rod oil holes bad? Every high performance Rossi/OS engine seems to have them.

MM

[dirty dan]

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

This reminds me of the time when a fellow (Doc Passen?) was promoting a new Combat motor produced in Italy. Howard was known to have a couple. I called to see what he thought. "Well, there's good news and bad news. The bad news is they are slow. The good news is they blow up."

Dan

[Brian Gardner]

Carl, the price depends on how many you order as the shipping gets shared. I'll send you a PM.

I must have missed it some place, but what is the price of the assembly?

thanks much

[Gordan Delaney]

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

Randy, why would he need baffles? super tigers had flat top piston.  .Then we could make new heads with the squish band heads. Oh no where do we stop. Oh well just a thought.
lYour bud,
Gordy

[Brian Gardner]

How does the performance compare to stock Andrew?

Has anyone else got one of these together and running yet?  Mine came in last week.  The machine work and quality of the parts is amazing as usual.  I tore down an Ebay 36X BB that had some nice wrist pin grooves in the front and back of the liner and extremely soft compression and started cleaning it up for the conversion to ABC.  A new $7 R8 ball bearing, and a considerable bit of time spent polishing the crank and it was ready for conversion.  The Gardner ABC parts mostly dropped right in, the bottom end of the rod took a little coaxing onto the crank pin.  Chances are Fox machined the pin on this particular engine on the big side of the tolerance. After I'd double checked the crank pin for burrs, the rod popped on with a firm push from a wood dowel. 

I've run it a few times on the test stand, 7% nitro, 23% oil - castor/klotz blend.  It turned an APC 10x4 at just under 16k rpm.  After a couple heat cycles, I switched to an APC 9x6, on the same fuel it went 16.2k+.  I suspect that like the other Bristunt ABC conversions it'll keep getting better with more run time.  Right now I'm running one head gasket, no venturi restrictor, with backplate pressure.  After it's been run a bit, I'll run some higher nitro fuel through it. 

[Andrew Hathaway]

My gut impression is that the ABC is running a good bit stronger than stock, but I can't back it up with numbers.  My other BB 36X might not be completely stock, but I'll see if I can get it on the stand with the same fuel and prop to see how it compares. 

[Andrew Hathaway]

In the interest of full disclosure...  My "stock" 36XBB shows signs of having been cleaned up a bit, the web in the exhaust stack has been milled out, and the liner shows some handiwork around the exhaust port.  I didn't perform any modifications that may be present, and I haven't had the engine apart to inspect it in detail.  I did pop the back cover to check that the rod was free on the wrist pin, and to check the ball bearing for rust, both checked out ok.  It has fair compression, but it's well broke in. 

The "stock" engine is setup for use with a bladder, no restrictor, ST NVA, etc.  I used the same 9x6 APC prop, Fox glowplug, 10% nitro 25% all castor Sig fuel since it's a steel piston engine.  I only ran it for about a minute, as it's Sunday afternoon and I don't want to annoy the neighbors, the tach stayed fairly consistent around 15.4-15.6, the highest number was 15.8 which only lasted a second and couldn't be recreated.



So the difference between a high mileage Fox 36X BB retrofitted with a new ball bearing and ABC set, and a healthy, mildly massaged Fox 36X BB, is at least 600rpm.  I fully expect that the ABC 36X will perform better once it's been run in a bit more.  If I could have found an NOS Fox 36X piston/liner assembly, I'd still be breaking it in, and it might never perform as well the ABC. 

[Brian Gardner]

Very cool It's good to see feedback like that. Thanks Andrew

[Brian Gardner]

I've got a few spare sets left if anyone wants extras etc.

Brian

[Al Ferraro]

NITRO AND FLIGHT TESTED AND THE RESULTS ARE SPECTACULAR !!!
C.T. Schaefer transplanted the Gardner ABC piston & liner set into his LS Diamond case tuned 36xBB. Three flights with his Voodoo on 10% Nitro hit 116 MPH. The engine ran great and the piston fit was still tight after each run. Tom decided to up the Nitro to 40% which pushed the Voodoo to 120MPH !!! After two flights of 40% Nitro there were no signs of engine wear and he used the same plug for all five flights!!!
How cool is that.
Al

[Motorman]

Randy, why would he need baffles? super tigers had flat top piston.  .Then we could make new heads with the squish band heads. Oh no where do we stop. Oh well just a thought.
lYour bud,
Gordy

Super Tigers have directional porting. The liner on the Fox is too thin for tiger ports. Without a baffle the Fox would direct the charge right out the exhaust.

MM

[Brian Gardner]

Al, that's awesome news. I'm really pleased this worked out so well.

Brian

NITRO AND FLIGHT TESTED AND THE RESULTS ARE SPECTACULAR !!!
C.T. Schaefer transplanted the Gardner ABC piston & liner set into his LS Diamond case tuned 36xBB. Three flights with his Voodoo on 10% Nitro hit 116 MPH. The engine ran great and the piston fit was still tight after each run. Tom decided to up the Nitro to 40% which pushed the Voodoo to 120MPH !!! After two flights of 40% Nitro there were no signs of engine wear and he used the same plug for all five flights!!!
How cool is that.
Al

[RandySmith]

Randy, why would he need baffles? super tigers had flat top piston.  .Then we could make new heads with the squish band heads. Oh no where do we stop. Oh well just a thought.
lYour bud,
Gordy

Hi Gordy   some  versions of the  ST 35  had no baffle, these were a sort of rip-off on Loop charged engines, they were not single by pass, the were what ST called  AirFoil porting. I think that may have violated  the Doctors patent, I don't think the  FOX case  could use the  twin ports like the  ST35s did. And the sleeve would probably need to be thicker you you could direct the charge with the angled port.

Randy

[Brian Gardner]

Down to 3 remaining sets left fellas.

[Al Ferraro]

Setting the crank timing on my 36X BB. Now its ready for the ABC piston & liner.

[Kelley Crozier]

Down to 3 remaining sets left fellas.

Hello Brian: Any sets left?

Cheers

Kelley Crozier

[Andrew Hathaway]

I was just asking Brian if there were any more 36X sets left the other day, as I understand it they're sold out for now.  It wouldn't hurt to send him an email and ask to be put on the list for the next batch, but it will probably be awhile before another run is made.

[Al Ferraro]

       I had a chance to run my ABC 36xBB today. Using 10% nitro 23 % all castor oil fuel for the first few break in runs. The engine was very easy to start, ran with no vibration and turned 16500 RPM with an APC 8x8 prop. I then tried 20% nitro 23% half castor & half synthetic oil fuel, the engine turned just over 17000 with the same prop. This is a 500 RPM increase over my best steel P&L 36xBB engine. The set up that I am running is one.010 head gasket, one.010 liner shim, bladder pressure, no venturi restrictor, Nova Rossi C4-S plug, new Boca rear bearing and changed the crank timing. I feel there is still more to get out of the engine by removing the head shim plus more nito because the plug still look like brand new after all the testing. I cant wait to put this engine in my Super Satan and wind it up.
Al

[Brian Gardner]

That's cool Al. I'm really pleased this project came out so well for you guys.

Yes they are sold out. If you guys like I can start another waiting list for more. But we need to get through a batch of ST51 & ST60 first.

Brian

[Brian Gardner]

I've had a couple of guys email me about more of these sets.

I don't have enough people on the waiting list to do another run of them. So if anyone is interested email  or PM me to get the numbers up so I can help you guys out.

Brian

[Garf]

I have a Fox Rocket  set up with a 36X P&C and head. It runs like a Fox Stunt.

[Brian Gardner]

Hey Garf, we found there were variations in timing of the sleeves and given these were requested by the combat oriented guys we went with the higher timing numbers. I wouldn't expect these sets to give a quality "stunt run"

I have a Fox Rocket  set up with a 36X P&C and head. It runs like a Fox Stunt.

[Andrew Hathaway]

Has anyone else tried shoehorning one of these 36X ABC sets into any of the earlier Fox combat engines?  In theory anyway they should practically drop-in, but I haven't really tested the theory as I don't usually have more than one engine disassembled at a time.

I have a Series III with soft compression, so my spare 36X ABC set came out of the drawer and I did a bit of poking around to see if it'd work in the Series III.  The Series III has the picture window intake port in the liner, but otherwise the timing looks the same as the 36X ABC set, and the liner drops in the Series III case easily.  The piston is a bit of a different story, the 36X ABC pistons have the top of the piston curving into the baffle vs the stock Series III and for that matter the stock 36X with it's straight inverted T baffle, more on this later.  Also the wrist pin is beefed up a bit on the 36X ABC, it's larger than stock and larger than the Series III.  Where I hit a stumbling block is that the bottom end of the 36X ABC rod is a bit tight on this Series III's crankshaft pin.  I'm inclined to blame the snug fit on tolerance stacking, and Fox more than the ABC set.  Fox rods are so sloppy that the stock rods both fit the Series III crank pin and neither is remotely tight.  I think the ABC set's rod could be lapped to fit the Series III crack pin easily enough, but not sure I want to do that just yet.  Just from a quick comparison, the Series III rod is a symmetrical design, with only the backplate wear pattern and the chamfer to  differentiate front from back, while the 36X rod is offset a bit.  Also I want to say the Series III has a longer crank pin, and the bottom bearing of the rod is a bit longer to match.  Also the 36X rod looks just a hair longer, which shouldn't be a problem since the 36X liner is taller to raise the head.  The reason I haven't gone ahead and lapped the ABC's rod to fit the Series III is that I'm not sure the top of the ABC piston will pair up with the Series III head.  I don't want to modify the rod to fit the engine and then run into an issue with the head.  I would imagine that a 36X head would probably bolt right on the Series III case, but I don't have an extra 36X head...  The swap would work with stock Fox parts by just using the Series III rod with the 36X piston and pin, but due to the larger wrist pin in the ABC that's a no-go.  So I weenie'd out and put the mostly worn out piston/liner back in the Series III and tucked it back in the engine locker.

I'll probably end up putting the spare 36X ABC setup in one of my better 36X engines, then use the stock take off 36X piston/cylinder in the Series III.  I'm curious if anyone else has tried the 36X ABC set in anything other than a 36X.  I would expect it'd drop right in a 35X or Blue Ribbon 35 since they're both closely related, but I haven't tried it.  Spares for all the early Fox combat engines are virtually impossible to come by, so it'd be nice if these reproduction parts would retrofit.  It's probably not worth the trouble to make ABC sets specific to the earlier engines since they have other inherent issues that the piston/liner/rod wouldn't address.

[Andrew Hathaway]

The Rockets are kind of a half-ass Series I or II Combat Special.  The early ones have tame timing, small intakes, etc and might run a bit more like a Fox stunt than the later engines that frequently have the removable venturi restrictor, larger ports, the picture window liner, etc.  My red head Rocket 35 is a temperamental and shaky runner that thinks it's just a slightly hotter and heavier stunt 35, my silver head Rocket 35 with the picture window liner thinks it's a plain bearing, 1pc case Series III. 

Assuming the 36X ABC setup would drop in the Rocket 35 case, and the Rocket had a large intake port in the crank and bored venturi or removed restrictor, I'd expect it'd run like an early Combat Special.  However it'd still have the short plain bearing supporting the crank, which is egged out on most of the early Fox CS'es I've looked at.  The crank in my Series II for example is so sloppy the bottom end of the rod is shiny from scrubbing the inside of the case at BDC.

[C.T. Schaefer]

The 36x has a longer stroke so the liner is higher to accommodate that. You could put the 36x p/c into practically any fox 35 motor but it wouldn't line up right. Sure it will run but........ . Also there is more room in the 36x series for a heavier rod that wont clear in the earlier engines. A special ABC set for the combat 35's? The 'Blitz' article points out the weak point in the 35x and I remember, the series lll. When you lean on them a bit the crank gives way.  TS

[Chris Wilson]

How are rod oil holes bad? Every high performance Rossi/OS engine seems to have them.

MM

Because a hole will let the oil out part way along its travel.

The back and the front rod eyes are plenty big enough to supply an ingress and egress for oil and since all single hung cranks have directional flow (from flywheel or oil slinger to back plate) the addition of an early exit is indeed detrimental.

Perhaps not critical enough to cause failure but why do it?

The reason is simple, its a hangover from engineering lore that is in use with double overhung cranks.
They have two crank arms or oil slingers, thus are feed from both ends of the big end and so critically need an exit somewhere in the middle.

Oil is not forced into the 'oil' holes in the side of a rod eye due to massive G forces telling it otherwise, so they were never going to feed anything - they were always intended as exits and make no sense on a single overhung crank design.

I would content that Rossi and OS 'got away' with their use and have seen no data on their benefits but have heard proof that the reverse is true.

[Brian Gardner]

The first production run of these naturally sold out.

I've had a couple of emails over the last couple of months from guys wanting them. I need more numbers to justify a run of these.

So if there is anybody else out there wanting them be sure to message me to build a list so I can make this happen again for the fellas.

Brian

[Fredvon4]

Brian I am bumping this up by responding

Back last month in another thread on breaking in a Fox 36X you said there was almost enough orders on a waiting list for another run of the Fox 36X ABC sets

I sent you an e-mail asking to be put on the list for the next run if you get enough interest

Fred

[Brian Gardner]

Fred, well done on finding this thread, I was looking for it just a few days ago.

I have the numbers to make another production run happen.

If anyone wants a set let me know before I finalise numbers.

We are still finishing off the ST51 sets and these will follow.

Brian I am bumping this up by responding

Back last month in another thread on breaking in a Fox 36X you said there was almost enough orders on a waiting list for another run of the Fox 36X ABC sets

I sent you an e-mail asking to be put on the list for the next run if you get enough interest

Fred

[Frank Imbriaco]

Private message sent

[Brian Gardner]

Received & replied thanks Frank

Private message sent

[Fredvon4]

Bumping this up as I have received a few messages asking me about second run of the Fox 36 X ABC sets

Brain has said a second run is in the works after one of his other projects gets done

[Brian Gardner]

Fred is right above. We are doing a second run of 20 sets which will start shortly. If anyone else wants a set get back to me quickly before machining starts & it's too late to accommodate extras.