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Author Topic: Fox L&J Rework Instructions  (Read 6459 times)

Offline Harold Brewer

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Fox L&J Rework Instructions
« on: August 16, 2017, 01:49:26 PM »
Since Larry Foster has quit the Fox rework business, there seems to be a void for upgradng the venerable Fox 35.  Does anyone have information on his rework procedure that could be shared with some of us dihard Fox lovers? 

Brew
 H^^

Offline Steve Helmick

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Re: Fox L&J Rework Instructions
« Reply #1 on: August 16, 2017, 02:04:51 PM »
I'm sure Randy Smith will build a Fox for you. Looks like more Zoot cranks are in the works.  :) Steve
"The United States has become a place where professional athletes and entertainers are mistaken for people of importance." - Robert Heinlein

In 1944 18-20 year old's stormed beaches, and parachuted behind enemy lines to almost certain death.  In 2015 18-20 year old's need safe zones so people don't hurt their feelings.

Offline Randy Cuberly

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Re: Fox L&J Rework Instructions
« Reply #2 on: August 16, 2017, 04:35:23 PM »
I would think that NIB Fox 35's to start with might be a serious problem.  Also parts for up grade like  hemi heads cranks, stuffer backplates etc.

Randy Smith is best bet.  Might be a bit more expensive than the original L&J engines but with the Hi zoot crank and an ABC/AAC piston/sleeve might be worth the money for nobler size airplanes.

Much better would be if Randy could figure out how to make more AeroTiger 36's...Mo' Best small engine. !!!

 #^ #^ #^

Probably won't happen however.

Randy Cuberly
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Online Brett Buck

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Re: Fox L&J Rework Instructions
« Reply #3 on: August 16, 2017, 07:21:55 PM »
Since Larry Foster has quit the Fox rework business, there seems to be a void for upgradng the venerable Fox 35.  Does anyone have information on his rework procedure that could be shared with some of us dihard Fox lovers? 

   I am sure Larry could clear it up, but a lot of the work consisted of finding acceptable parts and carefully fitting them, more than "improving" things. For instance, sorting through crankcases to find those where the cylinder bore was close to perpendicular to the crankshaft. He told me once that he had to reject some huge fraction of the crankcases for various flaws.  It also had a moderately higher-compression head, and a stuffer backplate. Only the increased compression was intended to improve the performance, everything else seems to have been for reliability.

    Brett

Online Dan McEntee

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Re: Fox L&J Rework Instructions
« Reply #4 on: August 16, 2017, 09:13:54 PM »
   Rework is kind of a misnomer as Brett points out. The biggest addition is the hemi head and stuffer back plate. The stuffer plate decreases crank case volume and that increases vacuum and fuel draw. That's an old two stroke tuner's trick. There are several different variations of the hemi head out there, from factory Fox units, to Marvin Denny heads and back plates (who originated the idea, I believe) the heads that Larry Foster uses and I think Randy Smith offers one.  He didn't do anything with timing as far as I know, and just worked with fitting parts and hand lapping. I believe he made the crank a little more "balanced" by grinding the counter weights, but it isn't exactly like Randy's Hi Zoot cranks. One of the biggest departures from "typical" operation fo Fox .35's was higher nitro, especially at the higher altitudes of VSC where a lot of his engines were used. They run much better and make better power on 15% nitro. I had discussions with Larry about this many years ago at one of my first VSC trips in the early 90's and this is about as much as I can remember about it. I wouldn't mind having the "recipe" on paper or a file if one existed, because it's something any one could do with common hand tools and nothing requires any machine shop work, and it would be great to have a correct instruction sheet.
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Offline Randy Cuberly

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Re: Fox L&J Rework Instructions
« Reply #5 on: August 16, 2017, 09:45:37 PM »
Incidentally, I believe Jim Hoffman was the "J" of "L&J".  He probably knows something about all of this.  There were several people that gave input on what to do and how to do it when Larry first started...In fact one of them was me.  However I'm not sure what Larry used and what he discarded but as stated before the engines were built from "custom parts" and very carefully assembled.  He told me at one time that he had a deal with fox for slightly oversized pistons which he then hand "taper lapped" to the sleeve.  He also said that he (don't know how this was accomplished) selected sleeves for best "roundness".  There were not timing or port alterations.  I believe he did do the "ice cream stick trick" to the by pass port on a few but it was likely special order or just for friends!  The ones I have and had did not burp!  Don't know why!

I had several of the engines that he did over many years and they always ran very well and were reliable as a "Hammer".  They required careful break-in, presumably because they were "tightly lapped".

In fact I still have two of them.  No they're not for sale!  I had a matched pair for a twin that included a left hand crank in one but never used them and sold the "Lefty" to a friend in Texas.  Don't want to disclose his name because he might not want to be bugged about it.

Randy Cuberly 
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Offline Dennis Moritz

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Re: Fox L&J Rework Instructions
« Reply #6 on: August 16, 2017, 10:38:00 PM »
Piston cylinder fit. Lapping sometimes needed for the  best running Foxes. You need to know what you're doing to get this right. Lapping crank to bushing so crank spins free. Ditto. High Zoot cranks don't break. Big plus. Stuffer back helps. Jury out about hemi head. Might reduce power some. Torquing heads carefully to avoid piston bind. Can be tricky. I am talking about Dan Banjok's Foxes. Won Ole Time again at the NATs. I think. He wins with a Fox 35 Galloping Comedian often, just about everywhere. Even won some Classic meets. Fox 35 Ringer also won a lot. It preceded Comedian. Foxes 35s were made differentiy in different years. Fortieth is Dan's favorite. It has a tapered cylinder like an abc. Piston Cylinder lapping often required to get max performance. Some 40th's won't break in. Need to be lapped. And so on. If your Fox 35 is running well don't mess with it.

Online Brett Buck

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Re: Fox L&J Rework Instructions
« Reply #7 on: August 16, 2017, 10:42:04 PM »
Stuffer back helps. Jury out about hemi head. Might reduce power some.

 I suppose you checked the head volume of the stock and "hemi" used by L&J head, and found it lower? The power is substantially increased, and holds the 4-stroke to higher RPM.

   The stuffer backplate is there to keep the rod alive longer, not improve the power.

    Brett

Offline Dennis Moritz

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Re: Fox L&J Rework Instructions
« Reply #8 on: August 16, 2017, 11:14:34 PM »
I suppose you checked the head volume of the stock and "hemi" used by L&J head, and found it lower? The power is substantially increased, and holds the 4-stroke to higher RPM.

   The stuffer backplate is there to keep the rod alive longer, not improve the power.

    Brett
I said the stuffer back plate worked. Didn't say it increased power. Danny said it was a hemi head in his current Fox 35. What do you think. Do you think he knows. He said what I just reported. Guess you've got your Fox 35s to run as well as his. When. Right. Perhaps you fly a twin Fox 35 in competition with your home machined custom crank. Right.


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Offline Dennis Moritz

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Fox L&J Rework Instructions
« Reply #9 on: August 16, 2017, 11:16:34 PM »
I said the stuffer back plate worked. Didn't say it increased power. Danny said it was a hemi head in his current Fox 35. What do you think. Do you think he knows. He said what I just reported. Guess you've got your Fox 35s to run as well as his. When. Right. Perhaps you fly a twin Fox 35 in competition with your home machined custom crank. Right.


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Excuse Brett. He's probably feeling a bit off. Questioning his judgement about something or other. Brett has an obsessive need to trump me. Futile when I care to respond.


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Online Brett Buck

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Re: Fox L&J Rework Instructions
« Reply #10 on: August 17, 2017, 12:23:59 AM »
Excuse Brett. He's probably feeling a bit off. Questioning his judgement about something or other. Brett has an obsessive need to trump me. Futile when I care to respond. \

  Hmmm, I am not the one posting completely gratuitous and off-topic meta-comments. And for Christ's sake, learn to write a proper sentence.

     Brett

Offline Dennis Moritz

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Fox L&J Rework Instructions
« Reply #11 on: August 17, 2017, 04:05:04 PM »
  Hmmm, I am not the one posting completely gratuitous and off-topic meta-comments. And for Christ's sake, learn to write a proper sentence.

     Brett
I thought I was funny. Inspired a little bit. You inspire me Brett. Have for years. Thank you.

As far as my sentence structure, take it up with my publishers and the theaters who produce my work. Or the folks who commission me to write. Or Netflix and the like. My agent says that's in the offing. Or count up the incomplete sentences in this paragraph. To make you feel better. Or buy my new book of plays that will be out this fall. Pages and pages of bizarrely constructed sentences. Feast your sensibilities. Mystify yourself as to why all those theaters would bother to produce them. Guess some things are beyond your ability to understand. Tho you insist otherwise.

As far as Fox 35s, why do you bother to give advice on their modification and maintenance? You'd prefer to hurl. As in the past, I report the practice of Fox 35 enthusiasts. Club members I fly with all the time. Folks who enjoy the relic from 1949. Still a symbol of our hobby to many.

Online Jim Hoffman

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Re: Fox L&J Rework Instructions
« Reply #12 on: August 18, 2017, 06:54:37 AM »
I am not the "J" in L&J.  The J is for Larry's wife Joanna

Jim Hoffman 

Offline Bill Morell

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Re: Fox L&J Rework Instructions
« Reply #13 on: August 18, 2017, 12:08:51 PM »
I thought I was funny. Inspired a little bit. You inspire me Brett. Have for years. Thank you.

As far as my sentence structure, take it up with my publishers and the theaters who produce my work. Or the folks who commission me to write. Or Netflix and the like. My agent says that's in the offing. Or count up the incomplete sentences in this paragraph. To make you feel better. Or buy my new book of plays that will be out this fall. Pages and pages of bizarrely constructed sentences. Feast your sensibilities. Mystify yourself as to why all those theaters would bother to produce them. Guess some things are beyond your ability to understand. Tho you insist otherwise.

As far as Fox 35s, why do you bother to give advice on their modification and maintenance? You'd prefer to





hurl. As in the past, I report the practice of Fox 35 enthusiasts. Club members I fly with all the time. Folks who enjoy the relic from 1949. Still a symbol of our hobby to many.


Seems like it would be easier for you 2 to just agree to disagree and to ignore each other.
Bill Morell
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Offline badbill

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Re: Fox L&J Rework Instructions
« Reply #14 on: August 18, 2017, 12:45:08 PM »

Seems like it would be easier for you 2 to just agree to disagree and to ignore each other.

Huh. For some reason I thought they were joking with each other, but I guess not. I've met some of the nicest people I've ever met on this forum, but there is some dicks.
Bill Davenport
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Online Brett Buck

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Re: Fox L&J Rework Instructions
« Reply #15 on: August 18, 2017, 01:36:17 PM »

Seems like it would be easier for you 2 to just agree to disagree and to ignore each other.

    I tried to do that with previous cyber-stalkers, and it only works some of the time. It's like our other problem child (in more ways than you think), you can try to ignore him but it's not that easy.

      Brett

Offline Dennis Moritz

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Re: Fox L&J Rework Instructions
« Reply #16 on: August 18, 2017, 05:30:46 PM »
    I tried to do that with previous cyber-stalkers, and it only works some of the time. It's like our other problem child (in more ways than you think), you can try to ignore him but it's not that easy.

      Brett

I taught young children for 35 years. I definitely know what you mean by that reference. This is not what's happening here.

I think your inability to accept a difference of opinion (from me) causes your mislabeling and misunderstanding of what I'm doing. As in the past I outlined some of the ways Fox 35s are effectively set up by club members. You went on the offensive with a demeaning rude tone. No reason to be surprised by what you got back. I am not trolling. My initial post flatly stated information. Your response had a different tone. I responded in kind. Not a problem for me. Recreational. Sharp dialogue. Creative. Actually. I wouldn't be surprised if our back and forth is recreational and creative for you. We've been at it a while.

So friend. Ease up a bit on what I say. I'll do the same. Or choose not to. Also. Believe me when I say I'm referring to practices used by folks you would agree know something about what they do.

I love your remark about sentence structure. My sentence fragments. Mike Palko once described my style on these forums as run on sentence, run on sentence, run on sentence, followed by a fragmented sentence. Mike is very smart and accurate here. Also very funny.

Poets and some prose writers of fiction as well as some playwrights, use punctuation differently than writers of expository composition. Formal writing uses punctuation to accurately notate sentence structure. Creative writing often operates differently. Punctuation can be used to shape rhythmic phrasing. Punctuation can be used to help Indicate the flow of a thought or the curve of an emotion.

Obviously I do not do formal writing on these forums. I can labor through writing effective business documents. Here I have fun.








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Online Dan McEntee

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Re: Fox L&J Rework Instructions
« Reply #17 on: August 18, 2017, 06:54:21 PM »
Brett, I value your opinion and consider you a good source of information.  What I have done with several individuals is to use the ignore function available on this site. Of course PM's and emails can be deleted before reading. Might be a good solution, works for me.

As I remember there were tungsten slugs added to the counter weight of the L&J Fox. Hoping the new high zoot cranks come through, much better solution.

MM

  Have you ever seen a L&J Fox .35? None that I have , or have seen the inside with the back cover off, have any weight added to the counter weight of the crank shaft. I have 5 I think of varying vintages, plus a few "copies" that I did myself, and in conversations with Larry about his engine he never mentioned adding weight, no need to as you can't balance a single cylinder two stroke that finely anyway, especially the Fox.35. :Larry would talk quite freely about the work he did. It's just been so long ago that some details may be forgotten.
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Offline pmackenzie

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Re: Fox L&J Rework Instructions
« Reply #18 on: August 19, 2017, 02:02:04 AM »
FWIW a full blown L&J Fox done after 2003 had weight added to the crank in the form of lead, not tungsten
I have the full details in an email that Larry used to send out, if anyone wants a copy PM me.


Quote
6/1/2003 and later- counter weight is milled and filled with heavy metal to increase the   counter weight

Images below are of a crank I did following Larry's instructions, and another done "old school" by simply adding as much lead as possible to the counter weight.
Slot has not yet been filled with lead in the first one, old school method was suggested to me by a Fox racing guy.

Pat MacKenzie
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Offline kenneth cook

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Re: Fox L&J Rework Instructions
« Reply #19 on: August 19, 2017, 04:34:52 AM »
             Pat, while I'm quite familiar with the technique your displaying, I have had several pins depart on a stock Fox crank. One time it completely ruined every part in the engine with the exception of the cylinder head due to it getting wedged into window of the crank breaking the case when it tried to exit through the venturi. Anytime this is has happened to me it was on a 40th anniversary Fox. I don't know if that's just because I use more of them or own them but I haven't witnessed that problem on my earlier Fox's.  I was just wondering looking at the pictures while it makes perfect sense from a weight point of view if that now further weakens the pin area due to not having the material around the pin to back it up.

        I'm also curious to the L&J head . The Fox hemi head doesn't work very well in my opinion. I find starting problematic and I find that the stock head works better. While they included head shims, I had to lap the head button to the liner and forego all head shims because I needed to bump up the compression for starting. I had raced Marvin Denny a few times and we shared a few thoughts. Marvin explained he was designing the head and while there's another story behind it, he explained he never completed and refined it. It was sold as is without the needed modifications. He told me a few times to mail it to him and he would finish it and return it which I sadly never took his offer. While I have another Fox with a hemi head, I believe it's the Muggleton head, it works far superior.

          Does someone here have a picture of the L&J head ? Ken

Offline Dennis Moritz

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Fox L&J Rework Instructions
« Reply #20 on: August 19, 2017, 06:48:43 PM »
Ken is one of the Fox 35 enthusiasts in the Philly Flyers. On any given day you're likely to see a number of club members flying this relic of 1949. An icon to some in our sport. The Foxes get the job done effectively. Dan Banjock's competition record proves that time and again. Interesting side note: Mike Palko the father of electric powered control line stunt (before he shaved every day) worked his way into Advanced (was it expert?) flying a Fox 35 powered Twister.
« Last Edit: August 20, 2017, 08:44:31 AM by Dennis Moritz »

Offline Steve Holt

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Re: Fox L&J Rework Instructions
« Reply #21 on: August 20, 2017, 12:05:54 PM »
The head Larry used on the L&J Foxes was a one piece design that he coordinated with Randy Smith.  It bears no relationship to the 2 piece Fox hemi.  It definitely increases power.  The other mods besides the ones already mentioned are filling the bypass port to fix the "burp" and truing the bottom of the mounts so that the motor didn't wobble on the mount beams..  I believe the head is still available from Randy Smith.
Steve

Offline Fredvon4

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Re: Fox L&J Rework Instructions
« Reply #22 on: August 20, 2017, 01:00:53 PM »
Interloper here not knowing a thing about the L&J reworked engines

How do they compare to a Lew Woolard tuned Fox .35 or .40 ?    I have one of each...recently acquired, as Lew is still doing this at over 92 years old

And just a bit of a snarky comment 
While I do have two reworked Silver Foxx Fox engines... not flown...

Two of my three stock Fox .35s actually start predictaby, and cycle 4-2-4 with no apparent hesitation or burps on my profile planes...despite my not adding the wood plug

I do know my personal flying ability and maneuvers do NOT invoke the burp condition

I can see where a very serious PA competition flyer wants the best of the best... but for stunt, and more to the point the limited planes a Fox .35 is suited for.... is not the stock engine good enough?

Truth is, I have no need for the Silver Foxx modified engines... just a bit of history to have in my stash for my son to exploit some day





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Offline Ron Cribbs

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Re: Fox L&J Rework Instructions
« Reply #23 on: August 22, 2017, 01:45:00 AM »
Fred,

The L&J has the modified crank. Lew doesn't use those. At least not that I have seen. Funny that Lew wasn't even mentioned in this thread, even though he has been mod tuning Foxes for nearly forever. The burp is just that, a burp. I have engines that do it, but it doesn't cause an issue if you are aware it's coming. Good flyers just fly through it. Not every Fox does it either. I tend to stick with pre-1954 foxes for this reason. I do have, and have flown later model Fox engines with the burp and it's not a big deal.

I also find it funny that an engine that is so bashed is still relevant almost 70yrs after it's intoduction. In today's stunt arena the Fox .35 is more of a sport engine, but I wouldn't hesitate in competing with a L&J or a Silver Foxx engine in a local contest.

I sent a text to a Wichihawk today and was informed that Lew, while slowing and working through health issues will still modify a good stunt engine for you.


Offline Randy Cuberly

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Re: Fox L&J Rework Instructions
« Reply #24 on: August 22, 2017, 03:26:06 PM »
I have four L&J Fox 35's, two of the early ones and two built on 50th anniversary engines.
Being curious about the "Crank discussions I removed the back covers from all of them and low and behold "stock cranks" no indications of any rework of any kind.  Which is in fact is what I believed all along from conversations with Larry.  I'm not trying to say Larry never built any engines with different cranks but I don't think he did it as a regular habit.  I did this with the intention of taking pictures of mine but am having trouble with my Nikon (battery problems I think)...will take pictures when I get that taken care of!

The two engines made on 50th anniversary cases have AAC Piston/Sleeve assemblies that I installed as an after work.  but the cranks are as they were received from Larry, many years ago.

I have seen cranks done like those discussed with heavy weights but believe they were made with Fox Racing in mind.

Incidentally, the two AAC engines weigh about 5 ounces each and run very smoothly...not like the typical Fox at all.  Helps to use light material in the piston.   <= <= LL~

Randy Cuberly
PS:  Should mention that I also have one of Randy Smith's Foxes with the works and a Hi Zoot crank.  Have not looked at it .  I'm sure it probably looks different!
Randy Cuberly
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Offline pmackenzie

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Re: Fox L&J Rework Instructions
« Reply #25 on: August 22, 2017, 05:47:11 PM »
I think the "many years ago" is the explanation of why yours are not modified.
 As I quoted above from Larry's description of the modifications he did the crank mod became "standard" after 2003.

I have attached the images from his info email, and a picture of my L&J Fox.

Perhaps I should post the whole email, since Larry is no longer doing the work, and was sending it out to anyone who asked?
MAAC 8177

Offline eric rule

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Re: Fox L&J Rework Instructions
« Reply #26 on: August 23, 2017, 09:28:56 AM »
All of the comments in this thread are interesting. Since Larry Foster made over 1800 L&J Fox .35 over the years he and I worked together on them I think I can outline fairly accurately what he did to these engines.

Crank case:
1) machine bottom of mounting lugs to keep case from twisting when bolted to engine mounts.
2) ream out venture to create larger volume due to increased diameter of ST spray bar
3) run a broach groove just inside the bronze bushing and attach to oil spillway to stop the fuel from blowing out the front end due to wear on the bushing. Creates suction pulling fuel back from front end and stops the normal "Fox .35 wet front end".
4) partially fill bypass port to reduce volume.
5) rough up inside of crank case to improve fuel air mixture.

Con Rod:
1) drill small hole in con rod end to properly lubricate rod connection to the wrist pin on top and bottom

Crank shaft:
1) balance shaft to reduce vibration
NOTE; both Larry and I agreed that the Hi Zoot was a better unit since it was heat treated after machining where the standard Fox crank became a little bit weaker after he balanced it. Only problem with the Hi Zoot was the diameter was more consistent that the bushing in the engine so fit could sometimes be a problem.

Piston/Liner:
1) never use a Fox re-run piston/liner assembly.
2) swap out pistons and liners to insure proper fit (this is where the over sized pistons came in)
3) Hand lap the pistons to the liner
NOTE: when the AAC and Ceramic P&L's came available use these instead of the stock P&L's.
4) Do not change the porting just clean up any rough edges with polishing.

Install ST.51 needle valve assembly.
Install Fox Stuffer back plate and use a custom laser cut gasket.
Install L&J designed and RSM manufactured hemi head
Replace soft fillister head bolts with Socket heads in both head and back plate. Properly torque the bolts to insure proper fit.

This is what was done on all of the L&J Fox .35 engines.

The final thing was to use only fuel with a minimum of 27% castor oil and 10% nitro. For higher elevations use 15% nitro. Larry and I found that if you used 5% nitro fuel you could not get sufficient lube and this resulted in burning out the con rod ends. Going to 10 or 15% nitro meant running more fuel for a flight but thereby getting sufficient lubrication into the engine to reduce wear.

I hope this data is of help to all interested parties. Although I no longer have a stock of the L&J hemi heads I certainly have the AutoCAD drawing and if there is sufficient interest in obtaining these I can have a new batch run up. Just be aware that in order to keep a reasonable price we will have to get a minimum of 500 of these made up.

Regards
Eric Rule


Offline badbill

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Re: Fox L&J Rework Instructions
« Reply #27 on: August 23, 2017, 09:43:50 AM »
With the autocad file, I could also have the heads made and at a lower quantity. I'd have to know exactly what material also. Not sure what the cost would be but yes, it would come down the more I get made.
We're probably going to mod a couple crankshafts tomorrow; I saw mention of  tungsten being used to fill the hole, how is this done?
Bill Davenport
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Offline Randy Cuberly

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Re: Fox L&J Rework Instructions
« Reply #28 on: August 23, 2017, 12:54:45 PM »
All of the comments in this thread are interesting. Since Larry Foster made over 1800 L&J Fox .35 over the years he and I worked together on them I think I can outline fairly accurately what he did to these engines.

Crank case:
1) machine bottom of mounting lugs to keep case from twisting when bolted to engine mounts.
2) ream out venture to create larger volume due to increased diameter of ST spray bar
3) run a broach groove just inside the bronze bushing and attach to oil spillway to stop the fuel from blowing out the front end due to wear on the bushing. Creates suction pulling fuel back from front end and stops the normal "Fox .35 wet front end".
4) partially fill bypass port to reduce volume.
5) rough up inside of crank case to improve fuel air mixture.

Con Rod:
1) drill small hole in con rod end to properly lubricate rod connection to the wrist pin on top and bottom

Crank shaft:
1) balance shaft to reduce vibration
NOTE; both Larry and I agreed that the Hi Zoot was a better unit since it was heat treated after machining where the standard Fox crank became a little bit weaker after he balanced it. Only problem with the Hi Zoot was the diameter was more consistent that the bushing in the engine so fit could sometimes be a problem.

Piston/Liner:
1) never use a Fox re-run piston/liner assembly.
2) swap out pistons and liners to insure proper fit (this is where the over sized pistons came in)
3) Hand lap the pistons to the liner
NOTE: when the AAC and Ceramic P&L's came available use these instead of the stock P&L's.
4) Do not change the porting just clean up any rough edges with polishing.

Install ST.51 needle valve assembly.
Install Fox Stuffer back plate and use a custom laser cut gasket.
Install L&J designed and RSM manufactured hemi head
Replace soft fillister head bolts with Socket heads in both head and back plate. Properly torque the bolts to insure proper fit.

This is what was done on all of the L&J Fox .35 engines.

The final thing was to use only fuel with a minimum of 27% castor oil and 10% nitro. For higher elevations use 15% nitro. Larry and I found that if you used 5% nitro fuel you could not get sufficient lube and this resulted in burning out the con rod ends. Going to 10 or 15% nitro meant running more fuel for a flight but thereby getting sufficient lubrication into the engine to reduce wear.

I hope this data is of help to all interested parties. Although I no longer have a stock of the L&J hemi heads I certainly have the AutoCAD drawing and if there is sufficient interest in obtaining these I can have a new batch run up. Just be aware that in order to keep a reasonable price we will have to get a minimum of 500 of these made up.

Regards
Eric Rule

That's very interesting Eric, and I certainly believe you, my friend, however I'm sure you're aware that Larry did a lot of L&J Foxes locally here in Tucson several years before you were involved.

Most of mine I'm sure fall into that category!  He would put 4 or 5 together and then bring them to the field here in Tucson to run them before selling them.

Randy Cuberly
Randy Cuberly
Tucson, AZ

Offline badbill

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Re: Fox L&J Rework Instructions
« Reply #29 on: August 24, 2017, 09:37:01 AM »
I saw mention of  tungsten being used to fill the hole, how is this done?

Anyone? Or just fill with lead?
Bill Davenport
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Offline pmackenzie

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Re: Fox L&J Rework Instructions
« Reply #30 on: August 24, 2017, 06:49:42 PM »
Anyone? Or just fill with lead?

Larry used lead.
When I opened up mine to take the picture posted earlier there was a thick layer of white stuff built up on it, probably lead oxide :o
MAAC 8177

Offline Juan Valentin

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Re: Fox L&J Rework Instructions
« Reply #31 on: August 24, 2017, 08:51:45 PM »
Anyone? Or just fill with lead?
           
Hello Bill
              What I did in mine was drill holes in the crank  all the way thru the counter weight  and then epoxy some pieces of tungsten carbide with JB weld. Also did a cheap mod to the backplate by measuring the clearance I had and made a disc out of 6061 T6 which I glued to the backplate. I drilled the conrod for better lubing. I didn`t increase venturi size because I didn`t know it was being done. I don`t have a Hemi head on it. Here is a pic.
                                                                                                                                                                    Juan

Online Dan McEntee

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Re: Fox L&J Rework Instructions
« Reply #32 on: August 24, 2017, 09:00:01 PM »
   You have to be careful with the JB-Weld on stuff inside the engine. Alcohol will get to it over time. If I were to try and put tungsten in the counter weight, I would try the hole like you did, fill in the hole with the tungsten chips, then peen the edges of the hole over to help trap the chips? Might be even better to not drill through, so you have a blind hole and only one side to worry about. Just grinding the disc away on the rod pin side does a lot of good. I just have to wonder if adding weight to the counter weight is really necessary?  Are you able to add a significant amount of weight? What is the weight of a crank before modification, and the weight after adding the addition weight? Just curious, really.  I am still surprised to learn that Larry did add weight later on in his production runs.

  Type at you later,
   Dan McEntee
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Offline Randy Cuberly

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Re: Fox L&J Rework Instructions
« Reply #33 on: August 24, 2017, 09:53:46 PM »
   You have to be careful with the JB-Weld on stuff inside the engine. Alcohol will get to it over time. If I were to try and put tungsten in the counter weight, I would try the hole like you did, fill in the hole with the tungsten chips, then peen the edges of the hole over to help trap the chips? Might be even better to not drill through, so you have a blind hole and only one side to worry about. Just grinding the disc away on the rod pin side does a lot of good. I just have to wonder if adding weight to the counter weight is really necessary?  Are you able to add a significant amount of weight? What is the weight of a crank before modification, and the weight after adding the addition weight? Just curious, really.  I am still surprised to learn that Larry did add weight later on in his production runs.

  Type at you later,
   Dan McEntee

Yeah, it's my belief that a lighter piston as in "AAC" piston liner is a better solution if you can find one or get some made.
I too am a bit surprised by the weighted cranks!

Randy Cuberly
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Tucson, AZ

Offline George Albo

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Re: Fox L&J Rework Instructions
« Reply #34 on: August 24, 2017, 09:58:50 PM »
           
Hello Bill
              What I did in mine was drill holes in the crank  all the way thru the counter weight  and then epoxy some pieces of tungsten carbide with JB weld. Also did a cheap mod to the backplate by measuring the clearance I had and made a disc out of 6061 T6 which I glued to the backplate. I drilled the conrod for better lubing. I didn`t increase venturi size because I didn`t know it was being done. I don`t have a Hemi head on it. Here is a pic.
                                                                                                                                                                    Juan

Good job! I have a couple of questions. What is the thickness of the piece you used for the back plate and what did you use for glue, JB Weld?

Thanks,

George Albo
Darkness is dispelled with acts of kindness and selfless good deeds.

Offline badbill

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Re: Fox L&J Rework Instructions
« Reply #35 on: August 25, 2017, 06:42:29 AM »
Larry used lead.
When I opened up mine to take the picture posted earlier there was a thick layer of white stuff built up on it, probably lead oxide :o

I've got our machine shop machining them per the image specs in post #26, will probably just fill the hole with melted lead.
Bill Davenport
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If some is good, and more is better, then too much is just right!

Online Brett Buck

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Re: Fox L&J Rework Instructions
« Reply #36 on: August 25, 2017, 09:01:03 AM »
Yeah, it's my belief that a lighter piston as in "AAC" piston liner is a better solution if you can find one or get some made.
I too am a bit surprised by the weighted cranks!

Randy Cuberly

   Definitely better, because adding counterweight decreases the "up/down" vibration but increases the side-to-side vibration.

       Brett


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