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Thread: 1/2 A Fuel


  1. #101
    combatpigg's Avatar
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    RE: 1/2 A Fuel


    ORIGINAL: GallopingGhostler

    combatpigg The Ford 6 had mixture distribution trouble due to poor design. If the air / fuel charge doesn't burn completely, then it washes away protective oil and leads to early parts failure. They created a very complex ''thermactor'' system to alleviate the problem and it worked very well until it broke down. Once it broke down it became such a difficult and expensive system to replace that it wasn't feasible to work on.
    Wasn't the Thermactor system an air injection reaction system of about 1970's vintage, with a fan belt driven air pump which put fresh air at each exhaust port to burn unburnt fuel after it left the combustion chamber? There was an ''anti-gulp valve'' triggered by vacuum pressure, which cut off the air during deceleration to prevent backfire? My 1970 Mazda 1800 had such a system. The system AFAIK did not affect mixture settings, or did it?

    I'd think that any mixture problems needed to be dealt with prior to leaving the exhaust valve. It wasn't until the advent of feedback control systems, a computer controlled carburetor that the problem of stoichiometric efficiency was achieved, as carburetors were averaging devices. Chrysler Corporation was one of the first to successfully achieve EPA compliance with a computer in the early 1980's. A special computer controlled valve replaced the carburetor's power valve.

    I'm glad our model planes were not mandated for air injection into the exhaust stream by EPA, to say nonetheless.
    My 1982 F150 had the system you describe but it also had a swinging baffle in the exhaust manifold that directed hot air to the base of the carb when the engine was cold. Real hot air. This eliminated the old problem of raw fuel washing down the cylinder walls during a cold fire up. This engine [with 1 barrel carb] never needed a tuneup until it was time to rebuild the engine 20 years later.
    This system helped keep the atomized mixture in full suspension. The straight six has a natural tendency for the fuel mixture to chill as it travels down the runners, so in effect the Thermactor system did effect the A/F mixture by ensuring that it was more completely combustible.
    I still own that truck [it just turned 30] and eventually stripped off all the complex smog gobbledy-gook, put a simple Canadian carb on it with manual choke and use it mostly "on the farm" now.
    WHO GUNNA FEED MAW KEEEIDS..???

  2. #102
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    RE: 1/2 A Fuel

    ORIGINAL: GallopingGhostler

    tru, today toward the end of daylight, I put my Fuji .099S-II R/C engine in my test fixture.

    This Fuji engine is unique in that it is a true ABC engine, albeit a baffle piston one. Since I don't have a tach, can't give performance figures, but the engine ran strong.
    Are you sure it is ABC? If I remember correctly then the .99S-II was a regular steel/iron and cross scavenged. I have one somewhere but can't find it now. I have a few of the .099 SR ones too and these are ABC and schneurle ported. They are also closer to .11 in size (1.79cc) and are a fair bit stronger than the .099S-II. Fuji also refer to the Schneurle porting as Inner By-pass system, but that might be for patents sake or something...

    The manual for these engine recommend 30% castor (no nitro) for running-in and 25% castor for regular use (still 0% nitro). For RC they also have a recommendation of 20% castor and 5-10% nitro.

  3. #103
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    RE: 1/2 A Fuel

    ORIGINAL: Mr Cox Are you sure it is ABC? If I remember correctly then the .99S-II was a regular steel/iron and cross scavenged. I have one somewhere but can't find it now. I have a few of the .099 SR ones too and these are ABC and schneurle ported. They are also closer to .11 in size (1.79cc) and are a fair bit stronger than the .099S-II. Fuji also refer to the Schneurle porting as Inner By-pass system, but that might be for patents sake or something...
    Below, I have included 3 pictures of my other un-run, not used Fuji 099S-II engine.

    The engine is ABC per the box. It's retail price at Hobby Shack was $17.99 US, but it was on special clearance for either $5 or $10 each. The more expensive .099-SR was not, hence why I didn't purchase it.



    You'll notice the brass sleeve in this next side shot of the 099S-II:



    However, it is a true baffle piston engine, as revealed by this next shot with the cylinder head removed:



    As you see, it is as I stated. The Fuji 099S-II engine is an ABC baffle piston engine by design. Given its low horsepower output of only 0.16 HP, it is the same HP as with the Enya 09-III and 09-IV. The Enya .09 is actually .099 ci in displacement and is baffle piston. One difference between the Enya and the Fuji are the compression ratios. The Enya has a 7.5:1 whereas the Fuji has 5.5:1. Perhaps this is what accounts for the Fuji rated top RPM of 12,500 RPM versus the Enya at 13,000. I've never seen a baffle piston Schneurle. The O.S. Max 10LA ABN, a true Schneurle with about the same displacement puts out 0.27 HP, the AP Hornet .09, another Schneurle puts out 0.25 HP, both considerably more than the Fuji and Enya. With the Fuji rated at the same HP as Enya, I thus surmised that it is not a Schneurle.

    ORIGINAL: Mr Cox The manual for these engine recommend 30% castor (no nitro) for running-in and 25% castor for regular use (still 0% nitro). For RC they also have a recommendation of 20% castor and 5-10% nitro.
    True, this is stated for all Fuji engines from the .099 to the .25 ci displacements in the instructions:

    Fuji 099-25 Engine Instructions BW.pdf

    (Please note, if these images and PDF are unavailable means the number of hits have been exceeded. Please Private Message me and I'll E-mail requested files.)

    One must take these instructions with a grain of salt. For one, there is a discrepancy in the instructions. An 8x3 prop is recommended for .099 break in, yet the recommended prop sizes are 7x4 and 7x5. Normally for break in, one uses a smaller prop. Once broke in, a larger prop is usually specified for running. Hence I used a 7x4. Also, the Fuji 099S-II is not your standard Schneurle engine. It has an unusually low compression in comparison to at least Enya and OS baffle piston engines. I had no luck before on starting before. Thus I replaced the Fuji with an OS Max 15FP, which did run well on the recommended fuel. With the higher nitro content of the O'Donnell 30% Heli Fuel, the Fuji ran. Go figure.
    George Hostler
    Clovis MADS AMA Club, Vintage R/C Society (VRCS)
    And we know love by this, that He laid down His life for us, and we ought to lay down our lives for the brethren. 1 John 3:16

  4. #104
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    RE: 1/2 A Fuel

    ORIGINAL: lfinney if you have a cyclegear store nearby they stock benol oil and maxima 927 oil..both are castor oils, they also stock klotz, blendzall and torco oil products
    Thanks, lfinney, I didn't know those existed except for BeNOL. Next time I drop by the motorcycle shops in town, I'll keep my eyes open for these.
    George Hostler
    Clovis MADS AMA Club, Vintage R/C Society (VRCS)
    And we know love by this, that He laid down His life for us, and we ought to lay down our lives for the brethren. 1 John 3:16

  5. #105
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    RE: 1/2 A Fuel

    ORIGINAL: tru168 Thanks for sharing. That''s a beautiful engine you have. Good 1/2A engines are hard to find now. I just purchased Morgan cool power 30% heli fuel, I'm searching for castor oil now and will add a little castor into it and see if it can be good 1/2A fuel.
    tru, thanks for the compliment, but that engine although seemingly a nice one, as one would express in Japanese haiku, was literally a motionless stone. Before, I could not get it to run reliably. Yet same fuel worked on an OS 15FPS (CL version of the FP), so I put that engine in my Junior Ringmaster CL. I have been able to get it to run with high nitro fuel, so I may in future put it to use.
    George Hostler
    Clovis MADS AMA Club, Vintage R/C Society (VRCS)
    And we know love by this, that He laid down His life for us, and we ought to lay down our lives for the brethren. 1 John 3:16

  6. #106
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    RE: 1/2 A Fuel

    ORIGINAL: combatpigg My 1982 F150 had the system you describe but it also had a swinging baffle in the exhaust manifold that directed hot air to the base of the carb when the engine was cold. Real hot air. This eliminated the old problem of raw fuel washing down the cylinder walls during a cold fire up. This engine [with 1 barrel carb] never needed a tuneup until it was time to rebuild the engine 20 years later.

    This system helped keep the atomized mixture in full suspension. The straight six has a natural tendency for the fuel mixture to chill as it travels down the runners, so in effect the Thermactor system did effect the A/F mixture by ensuring that it was more completely combustible.

    I still own that truck [it just turned 30] and eventually stripped off all the complex smog gobbledy-gook, put a simple Canadian carb on it with manual choke and use it mostly ''on the farm'' now.
    Oh, okay, now I understand, combatpigg. BTW, life was simpler then. Now, the vehicles are so complex, one needs an engineering degree to figure them out, plus the diagnostic codes are only hints, one must out think the computer. Talking about similar systems, the replacement rebuilt smog pump stopped pumping air on my 1990 Dodge D150 pick-up. It started running hot, the computer coded as running too lean. When I replaced the pump, it started running cool again. The computer tried to lean out the air fuel mixture, to make up for the lack of air in the exhaust stream caused by the malfunctioning worn out pump. It had throttle body fuel injection, extremely reliable. I got rid of it after 14 years and 245,000 miles without burning a drop of oil. Now I wish I had that truck, extremely reliable and a small 3.9 litre V-6 at that, fuel efficient and a good cargo truck with plenty of power.
    George Hostler
    Clovis MADS AMA Club, Vintage R/C Society (VRCS)
    And we know love by this, that He laid down His life for us, and we ought to lay down our lives for the brethren. 1 John 3:16

  7. #107
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    RE: 1/2 A Fuel

    GG, my Cherokee has the closed loop fuel injection with basically 2 timing systems. So far [330,000 miles] it has been pretty hard to beat, but I do not like owning a car that is smarter than me.
    Actually, if you get the right repair manual that teaches the basics of how these systems work, you can fix these cars with just a digital multimeter. You're right about the codes, they aren't always reliable but there aren't that many sensors to check with the voltmeter regardless of what the scanner code says.
    WHO GUNNA FEED MAW KEEEIDS..???

  8. #108
    GallopingGhostler's Avatar
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    RE: 1/2 A Fuel

    ORIGINAL: combatpigg Actually, if you get the right repair manual that teaches the basics of how these systems work, you can fix these cars with just a digital multimeter. You're right about the codes, they aren't always reliable but there aren't that many sensors to check with the voltmeter regardless of what the scanner code says.
    I learned a while back that one is better off purchasing the factory repair manual. On the Dodge D150, I had a problem with the anti-lock disk brake computer giving fault. Clymers told me to take it to an authorized repair shop. The factory manual told me that sometimes the computer gives false positives, to pull the connector off, let it power down, then plug back in. That cleared the fault codes. That spared me a $60 diagnostic charge at the dealer.
    George Hostler
    Clovis MADS AMA Club, Vintage R/C Society (VRCS)
    And we know love by this, that He laid down His life for us, and we ought to lay down our lives for the brethren. 1 John 3:16

  9. #109
    combatpigg's Avatar
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    RE: 1/2 A Fuel


    ORIGINAL: GallopingGhostler

    ORIGINAL: combatpigg Actually, if you get the right repair manual that teaches the basics of how these systems work, you can fix these cars with just a digital multimeter. You're right about the codes, they aren't always reliable but there aren't that many sensors to check with the voltmeter regardless of what the scanner code says.
    I learned a while back that one is better off purchasing the factory repair manual. On the Dodge D150, I had a problem with the anti-lock disk brake computer giving fault. Clymers told me to take it to an authorized repair shop. The factory manual told me that sometimes the computer gives false positives, to pull the connector off, let it power down, then plug back in. That cleared the fault codes. That spared me a $60 diagnostic charge at the dealer.
    It's hard to imagine how much "easy money" the computerized cars have generated for the repair shops and dealerships. I have worked around commercial HVAC systems in buildings enought to know that if you understand the basics of how and what the sensors are supposed to do and have a good blueprint that shows you where everything is, these systemes aren't that complex once you can break them down into individual sections / modes of operation.
    Chrysler stuck a timing sensor on the bellhousing of my Cherokee in such a way that you have a choice of pulling out the engine to replace the sensor, or else slit open the carpet and cut an opening in the sheetmetal floor board.
    WHO GUNNA FEED MAW KEEEIDS..???

  10. #110
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    RE: 1/2 A Fuel

    What a coincidence, combatpigg. I received training in Siebe/Barber Coleman and Landis/Gyr/Staefa/Siemens DDC systems. Worked with that and Automated Logic. Spent 2 weeks in Illinois getting Siemens factory training. The car computer is nothing more than a DDC system. And you are right. They put smog components and sensors in the worst places imaginable. It's sometimes hard to keep facility folks from dickering with the systems to the extent that requires someone to undo their "improvements".
    George Hostler
    Clovis MADS AMA Club, Vintage R/C Society (VRCS)
    And we know love by this, that He laid down His life for us, and we ought to lay down our lives for the brethren. 1 John 3:16

  11. #111

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    RE: 1/2 A Fuel

    After reading the Fuji instructions I think the larger prop is for flywheel action to help starting when new.

    Notice they're not referring to heat cycles but accumulative running time in the instructions. Also notice that they are running at peak and because of parts smoothing you need to peak it each run during break-in.

    Another guess is since it has a lower compression ratio you may be able to use larger props without overheating once it is broken-in. A hot plug and decent half A fuel should help handling.

    Good luck with it.

    George

  12. #112
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    RE: 1/2 A Fuel

    Thanks for the inputs, gcb. I bounced it off one of the other very experienced flyers at the club today, and he echoed the same on wanting flywheel action during run in. This is the first that I've seen of that. Regardless, I got it to run fine with the 7x4. However, you have a point. I'd prefer running an 8x3, because at this 4,300 feet (1,311 m) elevation, the larger diameter prop has better thrust. The differences between props, smaller diameter with greater pitch and larger diameter with smaller pitch are more pronounced at elevation.

    Fuji got out of the small nitro engine business shortly after producing these ABC ones. This is a shame as from what I gather, their earlier engines seemed to be well constructed. I guess they weren't able to compete with other Schneurles such as OS.

    I let it run a little rich initially and did peak it out, not worried about semantics of break-in. ABC engines in general break in rather quickly. The instructions for accumulating 30 minutes run time prior to flying use seems to be geared toward the older lapped piston designs. It didn't seem to run hot at all. It was able to maintain RPM.

    I've got a few kits that this engine should prove useful in, first being the Daveys Fly Baby electric kit, possibly also Berkeley Impulse, Midwest Bebe Jodel, and Andrews S-Ray.
    George Hostler
    Clovis MADS AMA Club, Vintage R/C Society (VRCS)
    And we know love by this, that He laid down His life for us, and we ought to lay down our lives for the brethren. 1 John 3:16

  13. #113
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    RE: 1/2 A Fuel

    The low compression is odd, it is clearly the lowest in their line. Sounds like they had some kind of Texaco like application in mind for it, i.e. large props and low revs. I have three of the .099SR ones (all ABC) from different eras with small changes, I'll try to take a picture or two tonight.

    Regarding the flywheel effect, it is a little old-school but does help on iron/steel constructions where the sealing between piston and liner may not be that good during the first few runs (it improves with running). With a small wood prop you will struggle to even get them started, but a large diameter, low pitch, heavy plastic one you can get them going when hand flipping. On ABC engines you don't have that problem with sealing and are better of with a small prop to reduce the load.

  14. #114
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    RE: 1/2 A Fuel

    How is the compression ratio calculated..? From just the top of the exhaust port..?
    WHO GUNNA FEED MAW KEEEIDS..???

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    RE: 1/2 A Fuel

    The numbers are listed in the manual, I haven't tried to measure anything myself. All numbers seem very low to me, so I don't know how accurate they are. A wild exhaust timing could give very low numbers in theory, while a tuned pipe would give something else in practice. The engines come with a regular muffler and don't seem very "hot", but I haven't measured the timing.

  16. #116
    GallopingGhostler's Avatar
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    RE: 1/2 A Fuel

    ORIGINAL: Mr Cox The low compression is odd, it is clearly the lowest in their line. Sounds like they had some kind of Texaco like application in mind for it, i.e. large props and low revs. I have three of the .099SR ones (all ABC) from different eras with small changes, I'll try to take a picture or two tonight.
    The compression is noticeably lower, when I flip the prop. My Enya 09-III when flipped has a slightly higher compression. My OS Max .10 baffle piston has even more.

    ORIGINAL: Mr Cox Regarding the flywheel effect, it is a little old-school but does help on iron/steel constructions where the sealing between piston and liner may not be that good during the first few runs (it improves with running). With a small wood prop you will struggle to even get them started, but a large diameter, low pitch, heavy plastic one you can get them going when hand flipping. On ABC engines you don't have that problem with sealing and are better of with a small prop to reduce the load.
    I understand your logic here Mr Cox. What makes things odd though is the engine is not iron/steel, it is ABC, yet a baffle piston engine. It ran with the 7x4. However, I've got an APC 8x3 prop, will mount that next time and try again.

    ORIGINAL: Mr Cox
    ORIGINAL: combatpigg: How is the compression ratio calculated..? From just the top of the exhaust port..?
    The numbers are listed in the manual, I haven't tried to measure anything myself. All numbers seem very low to me, so I don't know how accurate they are. A wild exhaust timing could give very low numbers in theory, while a tuned pipe would give something else in practice. The engines come with a regular muffler and don't seem very ''hot'', but I haven't measured the timing.
    I'm thinking those numbers are probably correct. The Fuji 099-SR is 0.109 ci displacement. It's horsepower output is 0.22 HP. The OS 10LA RC is 0.27 HP; its displacement is 0.107 ci. That is a 23% difference in power output, but that may not be important as I guess it may be related to how they measure the horsepower. (The CL version of the Fuji is listed at 0.28 HP.)

    The recommended propeller sizes seems to be an indicator of the lower compression on the Fuji. The 10LA recommended break-in prop is 7x4; for trainer and sport it's 7x3 to 7x5 and 8x4. Whereas for the 099-SR, it is 8x5 for RC and CL, 8x4 for FF. The Fuji is designed to swing larger props as the norm.

    I just wanted to add that the Fuji 11S-RBB is ball bearing whereas the 099-SR is bronze bearing, yet the horsepower output is the same. Usually I'd expect the ball bearing one to have a slightly increased HP output, due to decreased friction. Also, there is a discrepancy in prop sizes as the prop table does not differentiate between the 099S-II and 099-SR, but the specifications do. I'm thinking the total literalness of the instructions need to be tempered with some common sense.
    George Hostler
    Clovis MADS AMA Club, Vintage R/C Society (VRCS)
    And we know love by this, that He laid down His life for us, and we ought to lay down our lives for the brethren. 1 John 3:16

  17. #117
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    RE: 1/2 A Fuel

    Also another note. When I purchased the Fuji 099S-II engines, I immediately removed the backplate. There were metal shavings in the crankcase. Apparently the factory did not bother to flush the engine crankcases but hastily assembled them. It was a good thing that I did not attempt to mount a prop and flip or start them.
    George Hostler
    Clovis MADS AMA Club, Vintage R/C Society (VRCS)
    And we know love by this, that He laid down His life for us, and we ought to lay down our lives for the brethren. 1 John 3:16

  18. #118
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    RE: 1/2 A Fuel

    ORIGINAL: Mr Cox If I remember correctly then the .99S-II was a regular steel/iron and cross scavenged. I have one somewhere but can't find it now.
    Yes, if you can find that one, I'd like to learn of the specifics on it. It could be that there were several iterations of the Fuji 099S-II, which had different changes between them, the last being the ABC version that I've got.

    ORIGINAL: Mr Cox The low compression is odd, it is clearly the lowest in their line. Sounds like they had some kind of Texaco like application in mind for it, i.e. large props and low revs. I have three of the .099SR ones (all ABC) from different eras with small changes, I'll try to take a picture or two tonight.
    Yes, if you get a chance, would like to see photos of those and also would like to know the differences between them. Were the 099-SR's as powerful as the other manufacturer's Schneurles of similar displacement?

    You bring up and interesting point. I've got a Hobby Lobby electric Miss Stik Senior, 55 inches (1400 mm) wingspan. It resembles a vintage Texaco. This would probably be the ideal engine for that plane.

    Aerocraft R/C Miss Stik Senior

    (Please note, the picture shown in the link is that of the Miss Stik Junior. Aerocraft R/C now markets these.)
    George Hostler
    Clovis MADS AMA Club, Vintage R/C Society (VRCS)
    And we know love by this, that He laid down His life for us, and we ought to lay down our lives for the brethren. 1 John 3:16

  19. #119
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    RE: 1/2 A Fuel



    ORIGINAL: Mr Cox

    The numbers are listed in the manual, I haven't tried to measure anything myself. All numbers seem very low to me, so I don't know how accurate they are. A wild exhaust timing could give very low numbers in theory, while a tuned pipe would give something else in practice. The engines come with a regular muffler and don't seem very ''hot'', but I haven't measured the timing.
    I've never paid much attention to bypass port engines, but the exhaust ports in some of mine look pretty low in the liner.
    Yep, I don't see how compression ratio is much of a "measuring stick" [for these little engines]unless it is simply the swept volume that is measured from the top of the exhaust port. Like you say, dynamic pressure from a tuned pipe and how well the engine pumps the mixture up to the top are the key factors and they are hard to give any sort of a static appraisal.
    Way back in the flat head engine days where the engines weren't strong enough to withstand high compression, I think ratios down around 6:1 were common.
    Alcohol engines [converted from gasoline] in drag racing would use higher compression [13-14:1], but recently I've seen some very high compression ratios used by the "gassers" in this region as well. They must have sophisticated timing control with knock sensors.
    WHO GUNNA FEED MAW KEEEIDS..???

  20. #120
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    RE: 1/2 A Fuel

    It seems my memory is failing me, or at least I can't locate the .099S II engine. I've only managed to find 4 of the hotter SR types. It could well be that I have a mild case of the Tool-time Tim bug, and I only ever got the hotter ones...

    All I can offer is a little bit of a time line on the RS engines below. Starting from the left is the older version, steel/iron construction with a high boost port, and hollowed out head for improved cooling. To the right of that is another steel/iron construction with a slightly lower/later boost port opening. While the two engines to the right are both ABC but with similar porting as the black head one.

    Looking at the manual it may well refer to the older engines as neither the S or RS are listed as ABC there, while some larger models are listed as ABC. Perhaps they made a few ABC version near the end.

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  21. #121
    skaliwag's Avatar
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    RE: 1/2 A Fuel

    MILD Case ???
    Real Airplanes have Round Engines and Two Wings.

  22. #122
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    RE: 1/2 A Fuel

    And I used to be surprised to find someone who owns one Fuji engine.
    I try to be pessimistic, but why bother?

  23. #123

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    RE: 1/2 A Fuel

    RJL/MECOA hold the manufacturing rights for the Fuji range these days-but they're very pricey at the RJL prices-the antithesis of what Fuji were when they were made in Japan. I just wish he (RJL) would get his act together and list his spares holdings-I have a number of Fuji 099s in various states of dis-repair needing parts. The Fuji 15-IV IBS version is outstanding (for a mid 70's plain bearing 'cooking' glow 15) -leaves a Max 15 or Enya 15 in the dust, and would give the ASP15 and Norvel 15 a fair run for their money even now........

    ChrisM
    'ffkiwi'

  24. #124
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    RE: 1/2 A Fuel

    Interesting experiences and observations with these Fuji engines, Chris. So Fuji, although a less popular brand was actually an excellent product.

    If you were to contact Randy personally by E-mail, would he be willing to sell parts at a reasonable cost, to restore your Enya fleet of engines? You are right that at the current asking costs, these are disproportionate to what anyone unless a museum or die hard collector would want to pay. It makes more sense to shell out a few more coins and buy OS or Thunder Tiger, IYKWIM.

    Also thanks all for the vote of confidence on this little known Fuji 099S-II ABC baffle piston engine. Getting to know its quirks and working around them, looks like the engines I had almost written off 20 years ago is worth keeping and using.

    I left a scanned color instructions / brochure in PDF (2.8 MB) at [link]http://www.rcgroups.com/forums/showthread.php?t=955929&page=16[/link] as Message #228. You'll be able to see the Fuji engine line up, which did not show well in the black and white PDF.
    George Hostler
    Clovis MADS AMA Club, Vintage R/C Society (VRCS)
    And we know love by this, that He laid down His life for us, and we ought to lay down our lives for the brethren. 1 John 3:16

  25. #125
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    RE: 1/2 A Fuel

    ORIGINAL: Mr Cox All I can offer is a little bit of a time line on the RS engines below. Starting from the left is the older version, steel/iron construction with a high boost port, and hollowed out head for improved cooling. To the right of that is another steel/iron construction with a slightly lower/later boost port opening. While the two engines to the right are both ABC but with similar porting as the black head one. Looking at the manual it may well refer to the older engines as neither the S or RS are listed as ABC there, while some larger models are listed as ABC. Perhaps they made a few ABC version near the end.
    I've attached the color version of the Fuji .099 to .25 Engine Instructions. Took me a while to figure out how to add attachments, why I didn't do it before. There, you'll see the line up they are advertising, which may not be reflected in the instructions.

    It's hard to say whether the S or RS referred to in the manual is ABC. All I know is that the 099S-II I have is. After listening to your observations from the different variants of the same engine, come to think of it, to change from a steel liner and iron piston to a chrome plated brass sleeve and aluminum piston would be relatively simple, wouldn't it? Just change out the assembly, I imagine. If there were no changes to the porting, then I imagine their horsepower rating would be about the same, sans whatever minor variations in friction there was.

    If my 2 engines are symptomatic of problems with aluminum shavings left in the crankcases during manufacture, I'm wondering if some unsuspecting modelers received severe damages while running their engines, leading to them seeking out other engines. I've heard of similar problems with some other makes, but don't recall at the moment who they were.

    All I know is now I purposely open my engines and inspect them prior to running them.
    Attached Files Attached Files
    George Hostler
    Clovis MADS AMA Club, Vintage R/C Society (VRCS)
    And we know love by this, that He laid down His life for us, and we ought to lay down our lives for the brethren. 1 John 3:16


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