sarpet

Imade third port,os.15cva liner,some crankshaft job and get over 16000rpm apc8x4 and 15%nitro,standart muffler
Icopy that idea from os.15cvr car engine

AndyW

My Feedback: (1)

Unfortunately, no run tonight, something came up. Tomorrow for sure.

Thanks to all.

Andy

AndyW

My Feedback: (1)

Oh, boy, that sounds real good. Can you post pictures please.

aspeed

I would be afraid to cut another port in a nickel plated cyl. I have thought about it though. My LA .15's are faster than the older 3 port FP that I have. I have found it hard to get a lot more out of the LA, likely because of the two port cyl. affecting the breathing. Many motors run faster with a big carb, but the LA seems to have hit a wall somewhere. I think OS spends a lot of time engineering and testing. I have noticed that the Fora has the "Turbo" cut in the crank much different than the car guys are doing. They oval the crank hole a maybe a 15 degree angle. I guess it spreads out beside the crank. The Jett seems to have a slot milled across the face of the crank. I showed a pic of the AP .09 that was handy just to show that slots don't need to be cut in the case. The AP .15 has the slot cut right through to the piston, and it runs good too. Really not better than the LA. It really is pretty good considering.

AndyW

My Feedback: (1)

Good tips, thanks. About AP, I love their piston and liner design because you've reminded me that I've used them to overbore engines. I believe I used the AP .15 piston and liner on the OS Max .10 experiment.

ALSO, the AP .15 parts can be stuffed into the OS .15 LA and we can see what making it true ABC with full porting can do.

What I love about OS is that they will "sport" an engine but don't skimp on the crucial parts that impart longevity and customer satisfaction.

Notably, Bronze bushed case at both ends. Wish Norvel did that on all their engines. Plus, they bush the piston pin at both ends. Wish Norvel did that on ALL their engines, especially the .06 and .074. They give you a proper, effective, bolt on muffler and you can take out the baffling if you want, not having to GRIND it off,,, like Norvel.

Plus, plus, plus they give you a means to adjust the low end. Nothing fancy, just the airbleed screw but IT WORKS.

Mr Cox

That's a bit funny, personally I don't like OS simply because they do skimp on the crucial parts...

The OS .10FSR, for instrance, has a little hump on the carb for the airbleed screw but they apparently couldn't be bothered to drill and tap for it.

Next up was their so called "ABC" engines that were in reality merely ABN. Their reply to the obvious criticism that was then to change their fineprint descriptions to "ABC-technology", forcing other companies to then described their products as "true ABC".

I have always had much higher thoughts about Enya, they spend less on marketing and more on their engine development and customer service.

Here is what an OS .10FP, with their "ABC-technology", can look like inside;

aspeed

I have had good luck with the OS nickel so far. I don't put really all that many miles on them for sure. The .10, .15 and .25 seem good. I have had a used .32 with a little chip off the top of the cyl. that worries me though. I think the LA is better than the older FP. I may be the only one that thinks that way. The FP has three bypass ports, but is still slower. 6 bolts holding the head on, which is ok, but heavier, round head which is heavier and aluminum backplate which is heavier. The needle bends easier on the carb... Mine all idle very well, even the .10 with no airbleed. Well the backplate will break on the LA in a crash. Up here we have Hundred mile races with the LA .25, and they seem to last, and restart. Enya? have not seen a new one in many years, and they are not supported in hobby shops here any more. I have had a few with dismal results except for the .35. None were fast, although I am talking the 1970's. Supertiger and Rossi were the standard at the time. I suppose Enya would be a step above the plain bearing TTigers. It is good to know that Enya is still going though.

AndyW

My Feedback: (1)

Well, I wouldn't disagree with you on those specific points. I remember the OS, ABC controversy. Some corporate type thought we were what, stupid? Gullible? And I DO agree that Enya has impeccable quality, performance and longevity. The Enyas are less pretty on the outside but are virtually perfect on the inside. I had an Enya 11CX BB that was a car engine adapted to aircraft use. It was AAC and apparently, chrome plating is difficult and expensive. And the fit,,, that snap over was to die for, hot OR cold.

About the OS .10 not having the adjustable airbleed. Well, like the Norvel .074, for some reason, they found that it didn't NEED a means to adjust the mixture at idle, so they left it off. I know that you got an .074 that DID need the idle adjustable but that is the only one that I've ever heard of. I would love to work with it to find out why.

An aside but related note. When LM was selling off their Norvel inventory, their .074 heli engine was going for 25 dollars. A stock carb and exhaust muffler throttle was of no use to us, BUT the bushed case and better means of throttle attachment were good features. The front case was shorter and it had larger diameter, cooling fins. Good for in cowl cooling. So I got me a couple and went to work. I adapted the CS/Brodak throttle on to which I added the adjustable airbleed. I reworked the case to take a bolt on muffler. These were last batch, Norvel LM engines and unlike the high pinch of earlier engines, these had none. I don't even recall them locking up at TDC if you didn't flip them over smartly. Yet, their top end was on par 19.9K or better and their heli exhaust throttle worked very well. This one is stock, https://www.youtube.com/watch?v=-h76s_N8WPs and this one has a custom exhaust throttle at the rear on a modified case. https://www.youtube.com/watch?v=SdUdlXOd_-4

So off I go and while this LM Norvel .06 delivered the same power, throttling was not as good as expected. No matter how hard I tried, with every trick in the book but no go. Throttling was OK, but not the best like we get with modified stock engines. The only difference with the LM engine was the shorter case. The intake port of the case was NOT the huge, rectangular shape of the aircraft engine. It was mostly round with these insignificant flats on each side which made the port just a hair oblong. Why they didn't just bore it round and be done with it I can't imagine. And the crank? Well, the port is rectangular.

I suspect that this mis-match between the crank intake bore and the case intake bore is interfering with good throttling. At least it does when trying to throttle at the intake. Having said that, it just occurred to me that my experience with throttling the TD .010 may offer a clue as to what this engine needs

And that reminds me of the VA MK1 .049. With a throttle with adjustable airbleed, it was the best throttling 1/2A I'd ever come across, (over 20 years ago). It was modern tech, unlike the Cox engines and very light with a very high power to weight ratio. And yet, I was sent one to do up and it just didn't cut the mustard. I worked on it a good deal to deliver the performance I had been raving about. In the end, I sent it to the owner with good, but not the best performance. I have no idea why this was so, just like your .074.

So, well, what can I say. This .15 has bushings on the rod and case when it would pass anyone's approval without, considering the price.

I CAN say this, I've never had an OS engine that I was disappointed with, especially quality and performance for the price. That's just MY experience, though, I'm sure there those like yourself, that have had bad luck with OS.

Getting back to the .15 we are working with, a run a few hours ago delivered only an additional 300 RPM. But I'm not through with it yet. The compression seal wasn't noticeably improved and I realize that the grey the piston took on is not as deep as the Norvel AAN pistons I'd done in the past. So, I'm going to anodize it some more, keeping a close eye at it and comparing a sample piston.

The aluminum alloy composition is likely the culprit. We know that silicon is the key ingredient to add to the aluminum but how much and what is the aluminum grade that they start with?

I'd written to 3 or 4 engine makers, OS, Enya, Norvel and, Fox. Yes, it was that long ago, Fox is no longer. Only Fox answered and I've got their alloy written down somewhere but the point was, I wanted to see how well each brand's pistons anodized. With that, I was going to take the best and pester the manufacturer to start anodizing his pistons, showing before and after videos with the sample engine sent to them no strings attached. Done in batches, it would be cheaper to do and would, in my past experience, deliver a superior engine. Better compression seal, better durability, more power and more mileage.

I had an AP Wasp .061 that I gave only three runs to loosen it up and get the needles adjusted. I can't remember the numbers but they were good. This was years before my YT channel so there's no record of it. BUT after anodizing, the performance jumped considerably. Again I don't recall the numbers but we're in luck. I have a stock, NIB AP Wasp .061 and will give it the same treatment we've done here.

I'll start a new post for that to avoid confusion.

Cross Check

Hi Andy,

The 'new unrun' OSFP.15 is boxed, to send Tues,28th.
You know what to do with it.
I have faith with Canada Post.
The delay, was finding the perfect box. I found it!
Everything is packed in in old "WardAir" cotton 'napkins/servietes...(great engine rags !)
There was room for a '70s' era engine, that 'might' beat an OSFP.15. (broken in, never abused)
Early Schnurle Ported? Timing is everything !
I know you are great at this stuff Andy !
Oh Yeah,
Take a picture of the 'Perfect Box' for everyone else here !
They will have a Laugh !

Take care,
Have fun,
Dave'crosscheck'Fallowfield
Maac 6437
Unabashed Combat Team

Mr Cox

This did sound OK to me for an 8x6 prop, is it really an 8x4 instead (as it says on youtube) ?

Mr Cox

Perhaps I'm just being too anal about throttling, but I really think that one needs a variable low end adjustment. There is no way that they can predict what fuel and prop each user will use, hence the need for a variable adjustment. The OS .10 FSR has a larger carb-bore above the throttle drum as compared to below it, so there is a low end compensation just not an adjustable one. On the .10 FP they did put an adjustable airbleed and this carb is a direct drop-in on the FSR too.

It is better than not having any compensation at all, like you'll find on the CS, Queen Bee, Brodak etc. But whatever tiny saving they bit they might save in production cost doesn't make up for it, to me. I have finally gotten some good use out of a Cox Queen Bee engine by converting it to diesel and by adding a fixed compensation for the low end (both an airbleed and the carb-bore trick).

AndyW

My Feedback: (1)

Hey, Dave, many thanks, geez. Now you do have me wondering. Stuff to look forward to, I love it. 70s era engine, early schneurle, hmmm.

Can anyone guess? One free piston anodizing goes to the winner, postage paid both ways.

I'll take a shot of the box and post it only if it isn't triple X.

So well, thanks again, wow.

AndyW

My Feedback: (1)

Good catch, you're right, it IS an 8 X 6 and I've edited the video. Methanol fried synapses on my part, I guess.

Mr Cox

No problem, it happens to all of us...

I think it would better to use an 8x4, or 7x5 prop, then as a testing prop and to improve rpms from there.

AndyW

My Feedback: (1)

All I can say is stand in line for being anal about throttling, trust me. It's just that when I do come across an engine that does away with the need, it's quite a remarkable thing, to me. And I always wonder about the science of the thing. You are exactly right in the variables affecting good throttling. Nitro content will affect ignition timing as does compression ratio and this can affect idle adjustment. Sometimes a variable will take the need for more air, (leaner) at idle, beyond what the idle screw can provide.

With the bottom hole of the carb larger than the top, this will provide very strong fuel draw at idle. Porting design, timing, (cylinder and crank) can determine the mixture requirement at idle.

I have had top quality engines with idle needles,,, rather complex throttles that would give fits despite the more sophisticated design. You can set the top end JUST lean, ( don't believe in the set it just a bit rich at the top to prevent a lean run idea. If you detect a lean condition in the air, YOU HAVE A THROTTLE, land the %$#&* thing and deal with it). The business of enduring a lean run, seems to have originated with free-flight and morphed over to RC, for some reason.

You can set the top just lean, idle back and set the bottom perfectly for an all day, tick over. BUT, when you throttle up, lots of smoke, spit and consternation is the result. So you tinker until you get instant throttle response but now, your bottom end is so lean that the engine quits after a minute or two. So now they have to invent REALLY complicated throttles with a middle range adjustment feature. Notably an Enya 60 I had for a big heli. That throttle must have had twenty pieces and was a marvel of engineering and quality. And it did the trick, perfect throttling as you MUST have for heli power. That throttle was so good, and the bore so HUGE, it's now on a Fox .74 and delivers significantly more power over the stock throttle.

And so, the question remains, Why do some engines need NO idle mixture adjustment, why do some work perfectly with a simple, airbleed screw and why do some need twin and even three needle throttles.

The answer is simple and complex. Our two strokes are mechanically simple but dynamically complex. Case in point. Many years ago, I made up an exhaust throttle for the TD .10. This was NOT an exhaust sleeve. There were two designs, one with a bullet closing the exhaust ( LiteMachines design) and the other a rotary valve as you'd see on a throttle. As with all exhaust throttles, the idle was perfect all day and transition was excellent.

After posting details on this device, I had a request to make one up for a fellow in Japan. No, not that Japanman. Anyway, I was pretty busy and couldn't promise that I'd have the time so I asked a bit of an outrageous price for it,, 300 dollars and the buyer said YES. Well,,,, so I went about making another one for the buyer's own engine but the throttle would not work as well as mine, on MY engine. Flipping throttles showed that his worked on MY engine, but not on his. ??????????

It took me months to figure this out. I made a third throttle and still the same anomaly. So, one day I burned the plug on my engine and NOW, with a new plug, it would throttle as poorly as the buyer's engine. ??????????

Here's what it was. On my engine, I noted at the outset, when breaking it in, that the glow plug head was leaking, no matter how hard I wrenched it down. You need to be careful as too much muscle here can distort the cylinder. So I took the plug out and refaced it on the lathe. It clearly showed signs that the face wasn't perfectly flat . I didn't shave off a lot, or maybe I did but that was the key to my engine working well with all three throttles. FINALLY, happy that I could deliver a good, working, throttling engine to my Japanese customer, I wondered what was behind all of this.

Here's the deal. When you throttle at the intake, the engine goes rich at idle so you need to adjust the mixture when throttled back. When you throttle at the exhaust, the idle mixture goes LEAN. This is why, in the early days without mufflers, why exhaust baffles were hooked up to the simple throttles of the day, throttles that didn't have an idle adjustment. You did have to play with heat range and brands of plugs sometimes but throttling could be very good.

Here's where compression ratio plays a role. When you INCREASE compression ratio, this requires you to lean out the main needle. This in turn, leans out the bottom end. The customer's engine had the stock, compression ratio and at idle, the engine ran rich despite the top end being crisply leaned out. I could get that idle dead nuts low and reliable by turning in the main needle but when throttling up, the engine would sag, lean.

So, I made up 3, trimmed plugs and gave my customer a half dozen, spare copper gaskets with instruction on how to fine tune his engine for good throttling.

So there's more than the throttle involved in good throttling, some of the elements of engine design are involved. Much of that is getting a situation where you put the engine's mixture DEMAND in a range that the throttle can handle. I've had engines that needed more air at idle and opening up the idle hole did the trick. The engine was rich with the idle screw, OR needle at full lean. In the old days, with crude throttles, someone discovered the trick of making a tiny slot in the barrel and most times this did improve throttling. Norvel put the slot in the carb body (Aarrgh) but this isn't adjustable. Well, it IS if you venture to file out the slot a bit more but too much and there's no going back. And it's certain that the slot you get isn't EXACTLY the same on every engine.

Your .074 might have had this problem, I can't recall if I offered you those solutions at the time. I mean being over compressed. Or even under compressed. Or the slot thing.

In the end, even if MOST .074s don't need an adjustable idle screw, I agree with you that this feature should be on all engines. And that reminds me of the MP Jets .06. If you owned one, it was a curious beast with high and low tech combined in its design. It was a low tech, steel on cast iron design. But it had schneurle porting with a neat, bolt on muffler. It was very powerful AND it had one of the best, two needle throttles I'd ever seen. The crazy thing is that when the simple, Norvel throttle was going for 25 dollars, this MP Jets jewel of a throttle had the same price. I adapted one to handle a TD .049 and with a proper muffler it throttled quite well, better that the Cox .06 RC.

BUT, it seems a lot of folks were having problems either with reading the instructions, or not having the skills and understanding, or even desire to get good throttling, so the MP Jets folks were contemplating eliminating the idle screw. Both I and Ed Carlson of Carlson Engine Imports screamed bloody murder at this and the Jets people relented. Ed, if this is not exactly how it went, the gist of it is correct, as I recall.

In any case, thanks for the opportunity to dredge up all of these neat, throttling discussions. Today is sunny, time to get that piston re-anodized and try again.

AndyW

My Feedback: (1)

Actually, I agree, I tend to use props with the pitch half the diameter as Cox gives you on 90% of their props. But a lot of folks like the APC and most use the 8 X 6 for .15s. That's a general statement based on my observations. AND, I'm not a fan of APC in the larger sizes, over (1/2A) so I don't have an 8 X 4 as far as I can see. But if I find one, I'll give it a try. Of course, the bench is just a tool, the proof is in the flying.

I've run APCs quite a bit faster on the bench compared to the fat, wide blade of a Cox prop. That Cox just wouldn't spin up like the APC even though they were the same size. But in the AIR, the Cox out pulled the APC quite strongly. I've seen this with glow AND diesel engines. If you look at both, you'll see that Cox takes the bottom. flat portion very close to the hub. The APCs are the opposite. I once took an APC and sanded the bottom side flat all the way to the hub and gained a free, 500 RPM. The top side was still fat as heck at the hub but I didn't go there, don't want a blade making a sudden departure.

Personally, I think that APC has designed their props to withstand 10X the RPM they'll ever see in practical use. That fatness at the hub is way overkill. SOME of their 1/2A props are more reasonable and that's puzzling because the smaller engines spin far faster.

In my opinion, Cox props got it right, exactly right, and that was WAY before computer design aids. They LOOK right and they perform where it counts, in the air. I wish that the Cox design was available in all sizes all the way up to gassers. And in fact, for a time there WAS a company offering just that but they disappeared from the scene long ago. I forget the brand.

Cross Check

Hi Mr Cox,

With Respect,
Trying to throttle down these puppy engines,
Is like a dog on a leash...
Then letting it go...

PM your address, Mr Cox,
I'll send you one of my Ken ENYAs .09
Small carbs and consevative timing, larger props, are friggin cool!

My OS.10 ' fleet' , so far, has not been good.
(they idle great, but don't throttle up !)

Hence,

Andy is 'sprucing' up the OS.15

And, Fine needles, take half the Click's

Cheers,
WobblyPeteMoss

AndyW

My Feedback: (1)

Pete,

On your OS .10s, what brand fuel, nitro, glow pug?

Do the Enyas have idle mixture adjustment ? Can you send a link from Ken's website ?

Also, just to clarify. Most of what I say about the OS .10 is for the FSR version. I believe it was an ABN engine. The .10s that I upgraded to a .15 or so were steel on iron. Is the .10 LA an ABN engine and is this what you have?

So my assertion that the OS .10 didn't need an adjustable airbleed may be only partially correct, depending on the model.

OS has made so many versions of all sizes that what, with being of action so long, it's hard to catch up.

AndyW

My Feedback: (1)

Google is your friend.

++++++++++++++++++++++++++++++++++++

Attached Files

• Ig11226.pdf (467.7 KB, 218 views)
• Ez81677.pdf (411.4 KB, 166 views)

AndyW

My Feedback: (1)

More from professor Google. http://www.enya-engine.com/ListAP2CYL_E.html

I see that the Quicky .09 has ball bearings and the .09 IV is plain, but is it bushed? Also the P.C. is described as lapped. Would that mean iron on steel?

AndyW

My Feedback: (1)

Here we go with pics. The Quicky, BB is on the left.

Mr Cox

The Enya .09 IV (and earlier) is plain bearing (bushed) and their description of lapped is referring to the piston and cylinder being iron/steel technology. There is also a single ballbearing version, destinguished by having a red anodized propdriver. The quicky is a quite resent development with twin ballbearing, still lapped iron/steel technology. Their CX engines are ABC or AAC, such as the .11CX Ultra. There is also a hidden treasure in their "super sport" .15 engine which is actually ABC without using the CX label.

OS .10 FSR engines where iron/steel with a very nice fit to them too, plus they have a boost port in the liner. The later FP is ABN, and they should have the boost port too, while the LA does not. The FSR runs very well but it helps to shim off the head a little too (in a lathe) for a higher compression ratio.

Cross Check, thank you very much for the offer. I think I already have enough Enya engines to last my lifetime though, especially as they are very hard to wear out...

Falco250

Hi Andy, I'm happy to hear that your life is gradually getting back to normal; I fully sympathize and understand as I myself lost both my aged parents around end of 2013.
I was wondering if you ever went further with the 1/2A Gasser development?

aspeed

Cross Check, I had fairly good performance out of my LA, and FP .10, (and the next earlier steel .15) The head spacing was much too big on mine. I made them around .010 to .014" and they run a bit stronger. I had to make shims up, because it was about .005" with no shim, and .020" or something with the one provided. A turbo head helped a bit too, I ran no muffler for the tests.

AndyW

My Feedback: (1)

Geez, Mr Cox, maybe time for a name change to Mr Enya ?