Fuji 099 SII

I saw you post "25%" nitro and thought - not a good idea but then RTFMd and saw
 

Instructions I left on RCGroups some time back:

http://www.rcgroups.com/forums/showpost.php?p=23295444&postcount=228

state 40% nitro for speed and free flight (competition), but emphasize minimum oil content 20% with at least 5% Castor. I kepted nitro level below 30% to conserve plug life.   

GallopingGhostler wrote:Instructions I left on RCGroups some time back:

http://www.rcgroups.com/forums/showpost.php?p=23295444&postcount=228

state 40% nitro for speed and free flight (competition), but emphasize minimum oil content 20% with at least 5% Castor. I kepted nitro level below 30% to conserve plug life.   

That is a nice and informative posting. I occasionally visit that forum but, like so many, it is inhabited by some serious, humourless individuals that seem prone to picking written arguments over nothing.

This, apart from engineering sites, is the only one I post to. It is the most communicative, participative site I have come across.

Here one can show what to do and what not to do. Be part of a learning process and tease (inflict sarcasm and humour) without retribution. Politeness rules! All opinions are accommodated in a friendly manner.

After seeing your original post. I had not come across what I would term as a bog standard hobby shop engine of that era being recommended to run with such high nitro 25%) and then to see the manual promoting 50%.

You live and learn!

ian1954 wrote:That is a nice and informative posting. I occasionally visit that forum but, like so many, it is inhabited by some serious, humourless individuals that seem prone to picking written arguments over nothing.

Thanks for your kind words and your observation with RCU is also true. It is one of the reasons why I no longer post there as "OkiThumper" (spent two years in Okinawa Japan as a civilian engineer employed by the U.S. Government and "thumper" is a large single cylinder engine motorcycle - mine a Suzuki LS650 Savage). There are some who will argue on the pinhead of a needle over the most trivial issues, very childish indeed. I requested cancellation of my account then.

This, apart from engineering sites, is the only one I post to. It is the most communicative, participative site I have come across.

I graduated in 1981 from the University of Hawaii with a Bachelor of Science in Mechanical Engineering. I used to post prolifically in engineering, science and computer forums, but since retiring, haven't spent much time there.

Here one can show what to do and what not to do. Be part of a learning process and tease (inflict sarcasm and humour) without retribution. Politeness rules! All opinions are accommodated in a friendly manner.

True, the audience here is well mannered, the administrative moderation is excellent, and all act like adults in meaningful discussion. Other sites I like are the Hip Pocket Aeronautics and Brotherhood of the Ring forums. Stuka Stunt, Stunt Hangar, and RC Universe overall have decent moderation I gather, too and I have posted there on occasion.

After seeing your original post. I had not come across what I would term as a bog standard hobby shop engine of that era being recommended to run with such high nitro 25%) and then to see the manual promoting 50%. You live and learn!

Yes, these engines have been a learning process. For example, I didn't know that some engines don't run well on heavier inertia plastic props, but run well on wood props. This includes my Enya .09-III TV and Fuji .099II-S ABC. When I went to wooden props, they became much easier to start and adjust.

I've found that at least for myself, the Enya plain bearing cross scavenge engines are powerful and the smaller run as well as the more modern Schneurles. I was surprised to see that the Enya .09-III TV was a tad more powerful than my 1964 OS Max .10R/C, although the OS is a fine running little engine. Add in the Testors McCoys, Gilberts, Foxes, and even now the earlier Coxes, I consider all of these fun engines.

Although this is an older thread, rather than initiate a new one, felt it more appropriate to continue the old. Afterall, this is a technically and historically oriented forum versus a social only oriented one (although we socialize ).

Back in 1973, the now closed Hobby Shack of Fountain Valley, California gave me one of the sweetest deals. I wanted better stunting from my single channel 36" CG Junior Falcon, so I ordered an OS Pet .06. They were out of stock, so they substituted the OS Max .10R/C at no additional charge.



Even up to the early 1990's until I left the area (worked at Douglas Aircraft Company, 3855 Lakewood Blvd, Long Beach, CA 90807 - still remember the address), they were fantastic to deal with. Around 1989, picked up 2 Fuji .099S-II R/C engines on closeout (Magnum line replaced Fuji) for only $10 each.





My box says $17.99, but I paid $10.00 each for them. I have the sales slip squirreled away somewhere, but would have to search. The unique thing about this engine, which I have is the last version of it, is that it is true chrome plated brass cylinder with aluminum piston but it is not Schneurle. It has a baffle piston and is cross scavenged, like the earlier one with Meehanite iron piston running in a steel cylinder.


My OS Max .10R/C and Fuji .099S-II R/C side by side with heads removed.

If you will notice, the Fuji brass cylinder is a copy of Enya. (My Enya .09-III TV is actually .099 in displacement.)

Fuji replaced their other sized engines with Schneurle porting. (They called it I.B.S. - Inner Bypass Schneurle.) However, it seems they were frantically pushing out the door the last of these. When I took the engines home, I opened the back plates and found them both with good doses of machined aluminum bits (swarf) inside the crankcases. I carefully disassembled both, washed them out with solvent, then reassembled.

Normally they don't recommend disassembling an engine unless you know what you are doing, but in this case I would have had disastrous results if I ran the engines without doing this. Since, I have done this to all my engines. Shortly after, one of the magazine engine articles (can't recall if it was Clarence Lee, Joe Wagner or other) mentioned to do this to the latest imported engines, because they too found similar results of aluminum swarf*.

* https://www.dictionary.com/browse/swarf : noun - an accumulation of fine particles of metal or abrasive cut or ground from work by a machine tool or grinder.

Both of these have the same 0.25hp rating.

Showing that the Fox was pretty gutless.

706jim wrote:Both of these have the same 0.25hp rating.

Showing that the Fox was pretty gutless.

Or rather that Fuji's advertising claims  were somewhat exaggerated-given the earlier 099-S produced less than half that stated power on test (0.105 BHP), and the larger Fuji 12 still only managed about 0.15BHP-you'd have to be really optimistic to believe that a slightly improved version of the 099 would more than double its power output....

  ChrisM
  'ffkiwi'

PS The relevant test reports-including those on the Fox 15- can be found on sceptreflight....

I'll check them out (Scepter reviews). Always interesting to visit that site. I also owned the Fox "Rocket 0.099" Now THAT was gutless! I doubt it produced any more power than the Babe Bee.

However the Rocket 0.099 was the engine I learned to fly with so maybe horsepower doesn't really mean that much.

horsepower is a bit deceptive....along with revs....too many of our recent engines produce impressive horsepower.....at revs which require-in some cases-ridiculously small props. Older designs producing moderate horsepower at rev ranges corresponding to reasonable prop sizes can often do surprisingly well. Even in the top levels of performance-such as FF F1C it took nearly 50 years for us to grasp the concept that engines turning 32-33000 rpm on 7 inch props (which were approaching transonic speed at those revs, allowing for 10% unload in flight-introducing another set of issues in the process) didn't work half as well at pulling a model as the same engine geared 4:1 turning a large diameter 2 or 3 bladed folding prop at <10,000rpm....the result was the Verbitsky Reduktor-which I was one of the privileged few to see on its first public outing-in NZ of all places- in April 1998. [a stunning piece of technology, I might add]     Nowadays geared F1C engines are as common on the FF field in F1C as direct drive ones-though one hell of a lot more expensive!

Illustrating the point-one of my FF colleagues-and arguably the best FF power man in NZ-tried out a Stels .36 in the 1990s-and found he had to go down to an 8x4 to get any useful performance out of it-again a typical high revving design that didn't perform in practice-though it might well have done better in AMA Combat-for which I assume-by the .36 capacity, it was designed for.. [to put this in context-in NZ a 21 size FF is about as big as anyone would use-we don't have the range of capacity classes you do in AMA power in the US-our Open power is simply anything up to 10cc. Anyway in the early 90s-several of us decided we were going to try out some of the Brit .40 size designs which were utterly dominant in their Open power class at the time-and 3 or 4 of us tried our hand with 40 models...Rex Bain getting in on the act slightly later with the Stels .36...I think he was mainly motivated by its small physical size and lightness-compared with the K&B torpedo 40RR  and OS 40SR engines the rest of us were using..]

I have fond memories of the Fox 09-it was so different to all the other engines-and for it era-was not really any worse than its competition....look at the performance figures for the Fox versus the early versions of the OS Pet, the Enya 09-II and the OK Cub 099....I still have two Fox 09s squirelled away....and MY first desperate CL attempts were with a McCoy 098 (which model I can't recall now) which I subsequently swapped for an ED Hornet diesel-which proved far more amenable-and which I still have....looking back over 50+ years-the McCoy probably wasn't given much of a fair chance on straight 75:25 glow fuel-which was what the club fuel was-whereas the diesel mix -good old 1/3-1/3-1/3 was not quite the same handicap on the Hornet...

OK-the Rocket 09 didn't stack up too well against a K&B Greenhead 09-nor the Cox 09s when they appeared-but the former was an exceptional performer and the latter in a class of their own...but against more mundane competition-and suitably propped-it could hold its own. Coming from a background of diesels-especially sideport ones-I am still surprised how high the US glow sideports-the Fox, Gilbert 7 and Gilbert 11-will rev, providing you prop them appropriately....if I had the time or the motivation-it would be interesting to try them as diesels-and see how they performed....though the material specs might not be up to operating as a diesel. This of course assumes that the fits are good enough to sustain diesel operation-which might be an assumption that doesn't hold up in practice given all three were very much at the cheap end of the market....I imagine they'd perform as well or better, and be able to turn larger props-which is fairly much a given for a diesel-whether they'd keep the top end revs is hard to say without actually testing.The opposite never seems to hold up to well-engines designed as diesels never seem to perform very well as glows-generally attributed to not enough flow capacity to cope with the rates needed for efficient glow combustion...

ChrisM
'ffkiwi'

Chris, I have to agree. The power curves with sampler of prop sizes and test rpms are only indicators of potential, to help a modeller to select engines, propellers and fuel. As you alude to, brake horsepower itself can be deceptive, because there is also the torque curve. The Cox reed valves are very good torque engines. They are able to turn larger diameter props adequately (up to a limit) producing still useful thrust although not at their peak horsepower rpm.

Back in the 1970's, I found that the Cox Pee Wee powered my 1/4-A rudder only aircraft at the same speeds as the recommended Cox competition 4.5x2 prop if propped with a Top Flite white nylon 5.25x3 prop, but added a minute more of flight time. Simply by going up 3/4" in diameter provides 25% more disk area in the propeller's arc (15.9 sq. in. versus 21.6 sq. in.) and puts the propeller's wind further away from the model's fuselage for more thrust.

Here is the Dec. 1958 Model Aircraft engine curve:
http://sceptreflight.com/Model%20Engine%20Tests/Cox%20Pee%20Wee%20020.html



There is a later Sceptre Flight engine test article from the March 1976 Aeromodeller:

http://sceptreflight.com/Model%20Engine%20Tests/Cox%20Pee%20Wee%20020%20%282%29.html

It's HP curve matches the 1958 one. It has a flatter torque curve, differing just a touch from the earlier one. (Factors such as air temperature: 1958, 40 DegF vs 1976, 74 DegF and atmospheric pressure affect numbers.) Since it is close enough, I am borrowing the propeller numbers from the later one, as these props were available when I was flying, but had an earlier engine. It states:

Peter Chinn wrote:The range of available commercial props suitable for the Pee-Wee is very small indeed but, happily, Cox's own 4-1/2 in dia. 2in pitch prop, supplied for use with the Pee-Wee, is well matched to the engine's power curve. On test, our Pee-Wee, running on 25 per cent nitromethane fuel, delivered its peak power output at approximately 18,500 rpm. The Cox 4-1/2x2 was turned at 17,400 rpm, which suggests that the Pee-Wee will quickly accelerate up to its peak or slightly higher in flight. We also tried the engine on an old 4-1/2 x 2-1/2 Cox prop (which it turned at 13,700 rpm), on a 4-1/2 x 3 Top Flite wood (14,800), a 4-1/2 x 4 Cox (11,100) and a 5 x 3 Tornado nylon (10,900 rpm).

This explains why my 5.25 x3 Top Flite nylon, somewhere in the neighborhood of the Tornado, exceeded the 10k rpm bottom that Peter Chinn alluded to, providing useful work.

I have kind of the impression based on test results, the Fox .15X (sport version, not the racing XX) is close in hp to the Enya .09-III. I haven't test flown these in a CL aircraft yet, to provide any useful personal experiences on them. However, I must agree that if the engine, even if tested to be weaker, is properly propped matching its hp and torque curve, and is suitably mated to the right airframe to be used on, with proper nitro content fuel, that one will still have satisfactory flight results.

Thus I gather that most of the "flight sucks" comments are because the engine/prop combination have not been properly matched to the airframe.

George-I've always gone for larger rather than smaller props where there has been a degree of choice-I'm a believer in a large fan turning slower rather than a small fan screaming-where i can get away with it...in the case of diesels-which probably account for about 40% of my competition power models and 100% of my sport power models-a bigger prop ensures easier starting if nothing else. Coming late to CL-my first successful flights being in my 50s-I never really developed the CL diesel 'whack'....whilst being well versed in the FF 'flick'...so naturally prefer the flywheel effect of the bigger props. Certainly my 1.5 diesels are turning 8x4 or 8x3s whereas they probably need a 7x4 to reach peak-and while my compatriots are propping OS Max 15's with 7x4s-I consider this under propping them-going by the published curves-on that size of prop they should go beyond the peak in the air-which is pointless....

Your point re prop disc swept area is well made....and often overlooked...though I'm sure it can be taken too far....I have no idea how Joe Wagner managed to persuade a Pee Wee to turn a 7x2 plasticote on his 42" Miss America....

ChrisM
'ffkiwi'

ffkiwi wrote:George-I've always gone for larger rather than smaller props where there has been a degree of choice-I'm a believer in a large fan turning slower rather than a small fan screaming-where i can get away with it...in the case of diesels-which probably account for about 40% of my competition power models and 100% of my sport power models-a bigger prop ensures easier starting if nothing else. Coming late to CL-my first successful flights being in my 50s-I never really developed the CL diesel 'whack'....whilst being well versed in the FF 'flick'...so naturally prefer the flywheel effect of the bigger props. Certainly my 1.5 diesels are turning 8x4 or 8x3s whereas they probably need a 7x4 to reach peak-and while my compatriots are propping OS Max 15's with 7x4s-I consider this under propping them-going by the published curves-on that size of prop they should go beyond the peak in the air-which is pointless....

Thanks, Chris. Yes, regarding propping, I have found it important to not exceed the maximum brake horsepower rpm, if one wants to get the most out of their engines. Some just haven't caught on that rpm only isn't everything. Now, if they are propping those CL's with smaller diameter props to restrict their lap speeds for stunting, then that might be understandable. It could also be that they could get by with a smaller displacement engine to provide the same work. A few years back I did an interesting test, mounted my Enya .15-III TV and Masters 8x6 glass filled prop with throttle wired wide open to my Ringmaster Jr. I was turning the same lap speeds at 50 foot lines as i was my OS Max .15FP-S with a Masters 8x4. Plus, running burbling rich 2-cycle, was going from rich-2 to lean-2 in stunts. My OS doesn't do that.

Looking at the Sceptre Flight write ups for the .15 Foxes, I found it interesting that the 1959 steel fin test peaked at 13.5k rpm, showing that the 8x4 prop was probably the best choice. In flight it would unload to peak rpm. Thus, I wonder if some have been underpropping it to be unhappy with it. However, the later 1962 .15X, it was recommended to go no larger than a 7x5. It peaked at a higher rpm of 15.5k.

Regarding the Fuji .099S-II, it basically is an Enya copy internally, but only sports a 5.5:1 compression ratio. The Enya .09-III (.099 displacement) has a 7.5:1. This tells me that the Fuji would probably be happier on Cox fuel (25% nitro). The Enya is happy on lower nitro fuel and churns a 7x6 very well. I haven't used the Fuji yet on a plane, because it is a little heavier in weight.

ffkiwi wrote:Your point re prop disc swept area is well made....and often overlooked...though I'm sure it can be taken too far....I have no idea how Joe Wagner managed to persuade a Pee Wee to turn a 7x2 plasticote on his 42" Miss America....

I picked up from an Internet auction, a dozen Tornado 7x2 Plasticote wood props may be 4 years ago. I wanted to try them on my Cox .074 Queen Bee. That engine is an oddity being heavy. I picked it up new in the 1990's, thinking I could put it to work. It is another heavy engine, why I haven't done much with it.

Regarding Wagner's use of the 7x2 on a Pee Wee, he was regarded as an engine authority, having written engine articles for model magazines. The wood prop is very light compared with the plastic, so less flywheel effect. I imagine that for that specific model of prop, that it was one of the few that the Pee Wee was capable of turning.

Neither the Enya .09-III TV nor the Fuji .099S-II RC seem to like heavier plastic props. They hand start easy on lower inertia wood. Sometimes I feel like a fisherman knowing what lures to run.

George-a compression ratio of 5.5:1 is abysmally low for a model engine-even by petrol ignition standards let alone glow-and goes a long way towards explaining the pedestrian output of the Fuji 099...I started collecting Fujis about a decade back and have accumulated a reasonable selection including the early twin stack 099 and some models of the 049 and 061-those these latter two are fairly thin on the ground these days. took me a long time to find an example of the 12....and somewhat ironically I obtained one from another kiwi collector! AFAIK they were not exported widely-and not to the US-but the UK saw a reasonable selection of Fujis from the 1960s till the early 70s. 099s 15s and 19s seem common-the two larger sizes-29 and 35 less so....and the 40 rather rare. I've even managed to get my hands on a 21 and a 25-though these are the latter end of the production timeline. I've only collected aero units-and certainly not the outboards-which go for huge money these days-though I did have an 061 outboard pass through my hands about 45 years back and ran it up to show my somewhat skeptical brother-who was into model boats-that they did actually produce useful work...

As yet I've never run any of the accumulated collection-apart from the BB 19-IV-which I used in a FF power model-for which I would describe it as adequate rather than spectacular! The gem amongst the range seems to be the 1 -IVS schneurle blackhead-which is remarkably potent for a plain bearing unit....they obviously got all the design compromises spot on with that particular model! These curiously-seem rather thin on the ground compared to the 15-III and 15-IV

The one model I've never seen in the flesh-not necessarily in person-but even on Ebay is the rear induction pylon engine-which appears on the instruction leaflet cum catalogue supplied with the last production engines-the ones that came in a dull metallic gold lidded box. It's there is the photos of the Fuji range...but was it ever marketed? no doubt a Japanese enthusiast could shed a lot more light on things-it looked interesting...I wonder how it performed...

ChrisM
'ffkiwi'

PS in light of your 5.5:1 comp ratio comment-I have several 099 and 099-IIs....it might be interesting to machine a snid or two off the underside of the head flange and up the comp to something more reasonable....

Thanks, Chris for the inputs, things I did not know, especially on the other Fuji's.

Seems I am a collector of ugly ducklings, now that I think of it. Got:

5 - .35 Testor McCoy Red Heads
1 - .35 Testor McCoy Blue Head RC
1 - .19 Testor McCoy Red Head
3 - .074 A.C. Gilbert Thunderheads
2 - .11 A.C. Gilbert Thunderheads
3 - .35 K&B Stallions (1 RC, 2 std.)
1 - .074 Cox Queen Bee
2 - .099 Fuji S-II's (my two turtle doves)
1 - .15 Fox X (the partridge in a pear tree)

They all perform, but weren't the top of their class for one reason or another, sort of the Idiocracy* of my engine collection. (Although, the Fox .15X really doesn't belong, because it was a decent sport stunt CL engine in its own right, when mated to the right airframe and prop. The Stunt Hangar crowd likes to use these engines for the Fox Hurl Contest - see how far one can throw them. They liken it to the days of old. )

* Idiocracy - a 2006 movie where not-so-bright U.S. military airman and hooker participate in a suspended animation program that goes awry, winds up in a dumpster and forgotten about until they wake up 500 years later. The U.S. has genetically devolved into an Alfred E. Newman nation of morons. Now they are the brightest and seek out solving the nation's greatest problems. (Sounds familiar today with our political scenes, doesn't it? )

In the US, Hobby Shack's parent, Global marketing was importing the Fuji back in the 1970's and 1980's, they were among Hobby Shack's main engine staple. I remembered seeing these dominating their display engine cases in both their sales area in the Fountain Valley, CA (near Anaheim where Disney is) warehouse and later sales store in Lakewood, CA (near Douglas Aircraft). In latter 1980's they switched to the Chinese line, Magnum. (I think those were manufactured in Taiwan.) This was shortly after Fuji came out with the vastly superior Inner Bypass Schneurle (IBS) line. (I don't know if this was because Fuji wasn't selling well or going out-of-business that required the switch. Fuji's late marketing decision to go Schneurle was about as bad as A.C. Gilbert getting late into the CL RTF business in 1963, after both Cox and Wen Mac already had the market locked in.)

Interestingly enough, I found that this link still works, with the most comprehensive history on this obscure company and its engines. Here's their link to the .099 S-II:
http://www.modelenginenews.org/ad/fuji_ch4.html#t6 - "End of the Twin-stacks: the Fuji .099S-II (Model 099-17)"

The Fuji English instructions were very generalized, not giving as complete advice as should be for its different lines / technologies of its engines. For example, advice on fuels and break-in props:


Why an 8x3 on a .099, both the weaker S-II and Schneurle SR? (That is like the 7x2 Plastikote on the Pee Wee. )

For speed and free flight, they are recommending 50% nitro! And, for R/C and C/L, 10 to 20% nitro. Also, the selection of props is generalized, especially for the .099, as there was the S-II and the SR IBS.


However, their specifications table is more specific.

But then, most of us here are from the earlier generation of boomers where you still had to have a bit of common sense to make things work. One read engine articles, books, etc. that gave further advice on treatment of engines, rules of thumbs on prop selection along with fuel, and etc.

It wasn't a simple look up on the inner net with "expurts" , which sometimes can be a can of worms   in itself.

George -when I still lived in Christchurch ('94-2009) one of the grand old men in the Christchurch MAC was a guy named Ian Henry-who was one of the 'originals'-ie contemporary of some of the greats like Carl Goldberg and Sal Taibi-and actually corresponded with the latter-in other words someone who was a modeller in the 1930s...and onwards. He was equally at home with classic spark engined vintage models as much as F1Cs....and did in fact represent NZ in FAI power in the late 60s or early 70s from memory-he was well into his 80s when I got to know him-but still liked to fly-he couldn't retrieve due to his age and restricted mobility-but enjoyed flying his FF fleet on the engine run alone-DTing the models off the top after the engine stopped-this usually had the model landing within 100 200 metres from the launch point-and he was happy with that-the reason I mention him is that he was the first-and only guy I've seen actually use Gilbert engines in models that actually flew-and he quite liked them...he also had a couple of Cameron glows-15 and 19- which got the occasional outing. He was rather fond of the 'Civy Boy' design-and its derivatives-and had a fleet of about half a dozen in different sizes-all with relatively rare and obscure engines up front.

My biggest regret-now that he's gone to his rest some time ago-is that I didn't get him to teach me everything he knew about ignition engines....

What I should do-to add to our knowledge base-is this coming winter-when flying is not an option-is do some comparative testing of the Fuji's against their opposition-OS Enya and the like-having examples of all of them from 099 thru to 35....in a variety of variants. I 'll make a start on the 099 first I think...and stick to APC props-so at least we have a current reference.

ChrisM
'ffkiwi'

Chris, you were very fortunate to have contact with such a man as Ian Henry, sounds like a very knowledgeable and enjoyable person to be friends with. Sorry to hear that he passed on before you could glean his knowledge of ignition engines.

Somewhere, I have a letter from the late William "Bill" Winters, who was the chief editor of American Aircraft Modeler, which as far as I know, became our US AMA's Model Aviation magazine chief editor. Back in the late 1980's, I sent him as a gift, 2 Jetex 50 engines still in their original packaging. I picked them up in a hobby store somewhere, can't now remember where. The engine pellets became unobtainable. I thought it would make a nice nostalgic gift and thus sent them to him.

Somewhere I have that thank you letter squirreled away. If I ever locate it, I will scan and post it. It was manually typewritten on his personal correspondence paper. He spoke of his experiences flying the Buzzard Bombshell and how to get it thermalling and out of thermalling.

I remember specifically a rant of his in an article, when manufacturers were discontinuing cross scavenged engines for their new Schneurle line ups. He liked the older technology engines, because as he put it, they were "torque" engines, could mount larger propellers with greater thrust for his style of flying. Somewhere I read of an old ignition engine free flight, can't remember what model, but the engine used on this 72+ inch wingspan model was only 1/4th hp, basically .15 size. However, that ignition engine (Brown Junior?) could turn a 16 or 18 inch prop. an 8 inch prop on a glow .15 just wouldn't cut it. Efficiency must be equated by the entire package, not engines specs alone.

The higher revolutions and smaller propellers typical of Schneules are less best suited for slower flying and wider fuselage aircraft. They are are not quite as miserly with their fuel consumption in comparison to the cross scavenged engines.

Regarding documenting your engine tests some time future when opportunity permits, especially the Fuji .099S-II, I think this is an excellent idea.

And, regarding old timers, I have a 66" Vanguard 66 kit, an AJ Free Flight Service reproduction. One of these days I would like to build it, if our FAA doesn't make such aircraft illegal. It would be good with RC assist and my Enya .35-III TV. Like the original, all the parts are die printed, a throwback to my old Comet rubber powered kits requiring a sharp modeling knife and patience.