Meschmidt:

I realize that post about the Quadra and the Herbrandsen was tongue in cheek, but I'm curious about your numbers. If they were guesses no problem, but my eye was caught, so I plugged them into some calculations.

A 24" prop running at 12,365 rpm static has a tip speed of 882.86 mph, if that rpm is in the air, then the 21.55" pitch at 70% efficiency gives an air speed of 176.63 mph, and the resultant propellor tip speed is then 900.36 mph. If the tip speeds are really running that high I'm surprised the prop tips aren't squared off- they'd be a lot more efficient that way, the diameter could be decreased without lowering the thrust.

Finally, your added 157 rpm at a 21.55 pitch only adds 3.2 mph if there is no slip at all.

Please, I'm not trying to shoot you down, the numbers just looked wrong, I've never been into that kind of racing, and I'm curious.

Bill.

Only $961 more? Wow what a bargain! I will get four just to have 3 spares............................................ ................NOT!

I am thinking that with a hemogladius of 3 degrees off dead center of rotational stringionatomally that you would most certainly get an extra 2.23% of Rotational enersion brought on by the extra 6.89% of Aeropladidius. Also if you figure in geomorhic gains then I can surely see how he came up with his figures. Its really a simple equation that when mathmatically figured with the right equations and a little BS comes out just about any way you would like it to. We can talk about Monogenerotology and it effects in relation to pitchless reflexation in another thread sometime since I know every RC Modeler just eats this stuff up and is eager to learn more about my theories in Aerobull****ersology!

Ray:

You forgot to factor the "Veeblefetzer Effect" into your dissertation.

Haw.

Bill.

In our flying field, we must have no less than 9 LA 40s, most of them are great, it is true that 1 does not run perfect but it is the owner fault since playing with it damaged one of the needles. Although he is really vocal about dead sticks and the Da... engine!

3 years ago, 2 rookies did a terrible job breaking their engines and they sounded always funny and did not performe as they usually do.

Our flying field is almost at the tip of the BAJA, 200 yards from the ocean and salty sand mixed with dirt is what is made of. As a sunday flyer I have to replace my OS 46 FX once a year, it does not last longer in this enviroment!, however the LA 40 has survived for 4 year by now!.- The MDS 40 did not last even 6 months !!

Maybe Our flying field, just like the BAJA 1000 are there to test to the extreme!! And yes it could be a little more expensive at the begining I agree, but it always start and if damage, parts are supplied through our La Paz hobby shop ( 150 miles away from Cabo San Lucas ).

So, at the end maybe not all engine are for all types of flying flields; what I mean to say is maybe all engines are good but the way we break them and where and how we use them is what make them winners or loosers, Don`t you think!!!

Mancha:

Have your hobby shop stock the Bru-Line air filters, and then use them. Your engine life, even with your ABN engines, should go 'way up.

Bill.

Bill:
some of Us use them a couple of months a year just before the rains, some years the dirt has turned almost into powder!. But I admited, I am lazy since this filters need to be wash before the next sunday so the engine breath right and I don`t always do it, so I don`t always use them.
I stick to after run oil.
Thanks Bill for remaind me, I will put the filters back this Saturday, it is time.

Mancha:

After run oil is good, but it does nothing to stop air borne dirt from getting in the engine. If you think an annual engine change is easier than washing an air filter, that's your choice. I run them almost all the time. Here's pictures of a couple of mine.

Bill.

Thanks Bill, I am in; I put them back tomorrow.

Good Day to all,

I would have to disagree with the OS FP and LA bashing, I put at least 250-300 flights on an old Elder 40 with an APC 11-4 (about 7.5 lbs) and it flew great (25 minutes on an 8 oz fuel tank, Canadian onces though:0) They are not great power but as one fellow said proped right for the application and they work great. I had trouble with ASP's untill I learned how to rework the carb..not that fussy about MDS at this time.. but I don't have the patients for the small stuff any more.. Pretty tought to beat an OS, YS, Saito or Thundertiger for performance. Good engine or bad has alot to do with operator :0)

Riverdancer

i've heard bad things about the MDS engines, heard they have bad carbs
NOT ALL OS's are bad the fx are GREAT engines once there tweeked the LAs are the bad ones

Lazy:

I differ, sir. The OS 46 FX is the one that most commonly peeled the liner, although the other OS engines did too.

Bill.

I have a global freestyle with a tower hobbies .46 on it and have logged some serious time. It has only given me trouble once, when I used some fuel someone gave me at the field(Thanks a lot guy). I highly recomend this engine becaues it has some serious power.

I'm going to have to retract a statement I made earlier about the tower .46.

I was bored yesterday and took it down off the shelf it's been sitting for 6 months, and bolted it to a test bench. I screwed with it for about 3 hours off an on, and finally think I got it purring along. needed a piece of fuel tubing slipped over the needle valve, low end needle completely reworked, and RTV seal put on the backplate. Now the thing idles smooth, doesn't load up on me, transitions nicely, and seems to be spinning an 11x4 really well at WOT. (don't have a tach yet.)

I haven't given it a clean enough bill of health to put back in a plane yet, but another day on the test bench, and I might put it in a trainer to use for testing. Good plane for deadsticks should they happen.

I have had a few deadsticks with my Tower .46 on my Great Planes Super Sportster, but I am to stubborn to remove it off the Plane. The unbelievable amount of power that this engine produces on one of its good days outweighs the bad days for me. I have yet to see another engine in its class that screams like a Tower .46 when its running good, which is about 50/50. There are many engines out there that are certainly more reliable like the TT .46 or the O.S SF .46, but for raw power there isn't another .46 size engine that will touch it, except when it dies and then there is no power. There are many bad points to argue about the Tower .46, but I don't think anyone will complain about them being underpowered unless they recieved one that was just total junk from the Factory, or it was broke in improperly. I have several other 2 stroke engines like the GMS .47(Same maker,not same engine), O.S .46 AX,and LA, EVOLUTION .46,TT GP.42, and just sold my O.S .40SF. The Tower .46 outpowers all of these by leaps and bounds. This is not just going by tech specs, but by seeing and believing. Is it a better motor than most?.................Of course not! The Tower is famous for being contrary, but I am just hooked on all that power in that small package! If they can ever get this engine refined, and work some of the bugs out, plus hold its current power output, it would be the best thing since Hot Apple Pie!

My Super Sportster with Tower .46 Pro! Still in one piece after more than a few deadsticks!

I thought I would come back and offer a few tips on what I have learned about the Tower .46 while on the subject. Maybe someone can get some good from this. First of all it has been my experience that 80% of the Trouble with the Tower .46 is in the low needle setting. Now I didn't come to this conclusion myself. I came to this conclusion from much research like, a call to Hobby Services, reading hundreds of post, hours and hours of tuning, flying, tuning some more, flying some more, and tuning some more, plus about 10 other people messing with the thing and offering thier advise, and reading articles in RCM Mag, and engine articles in Model Aviation plus others. After sifting through all this info, and seperating the intelligent conclusions from the ones who think maybe the timing chain is bad, I have finally almost become one with my Tower .46 engine. Its like a friend in the Hospital who you want to see get well.

Now most people including myself tend to reach for the High Needle setting when the Tower engine is not running up to snuff, and pay little or no attention to the Low needle. O.K now everyone knows that the Low Needle contols idle to mid range speed. High Needle controls past mid to High Speed, but one also effects the others operation and both must be in perfect sink for the engine to perform right. Now some engines you will get away with being off a little here or there, but with the Tower .46 it must be right on all the time. Not much leeway with this engine. With this said I recommend a Tachometer.

I know there are those who claim to have the perfect ear, but I will admit here that I prefer the Tach over my ear. As I said before the Tower .46 has to be perfectly set all the time which means that I tune it each time before I take it to the field because temp, humidity, etc. effects its opperation. Here is where I start. Set the High end first. Bring the engine to full throttle, and tune the high end needle to maximum RPM on the Tach. Now at highest RPM, richen the high needle till the RPM drops back down 750rpm from max(now write what it says on your tach down on paper). Now some may say 500rpm drop is rich enogh, which it is on most other engines, but on the Tower .46 the engine leans out considerabley as the fuel levels drop in the tank. The engine will seem overly rich on the ground, but it will lean out in the air, but by dropping back the 750 rpm on the high needle you will most likely maintain a slightly rich setting in the air. At a 500 RPM drop down it will more than likely lean out beyond acceptable range, get hot, and quit in flight as Tank levels drop!

Now that you have the High Needle set to 750RPMs below maximum RPM it is time to start on the low needle. Please do these adjustments with engine off to avoid losing a finger. Start by moving the throttle till it is all the way open. Look at the brass idle bar inside the carb and turn the needle either in or out till you have a 2mm gap or about 1/8" gap between the two little brass tubes. Now this is an overly rich setting, but the engine should start. If not turn it in a few clicks until it does start. Now as I said before, the Tower .46 will lean out considerabley in the air so we are going for a slightly rich setting on the ground. On most engines you strive for a good throttle Transition, but here we want it to load up a pinch when going from idle to full throttle. When I say a pinch I do mean a pinch. So now you will turn the low idle in until you have a slightly rich Transition which is usually a slight pause(fuel sputter) when going from idle to full. Once you have done this run the engine up to full throttle again. Is the RPM the same number or within 50 RPMs of what is wrote on your paper? Remember that I said that both needles work together?

Well the goal here is to get both in sink of each other while in flight. If the number is way off then you need to set the High Needle to the setting wrote on the paper after the 750RPM reduction. Now go back to the low needle. Is the low needle slightly rich on the ground? Does it Transition a little rich? If it does then this is great! Now let the engine sit at idle for about 20 seconds. Now see if it will Transition to full without dying. Will it idle for 20 seconds, and then Transition to full without dying? If not then it is just a bit to rich and needs to be turned in till it will maintain a idle for 20 seconds without dying, but by no means run the idle to a lean setting to get it to maintain idle for 20 secs. It may be that you can only get 15 secs. This will have to do because it is better for the Plane to load up and die on the runway then to lean out and die on approach 200 ft in the air.

Now why I say 80% of the tuning is in the low idle is because you have to do alot of this by ear where with the High idle all you need to do is maintain the number you have wrote on that piece of paper. You will do the most fidgeting with the low needle to get the idle right and the Transition. Fiddling with the low may affect the high needle number by 50 RPMs either way, but this is fine because we have allowed for this by dialing back to 750RPMs. Now check you RPM at high. Is it close to the number on your Paper? If it is then this is great. Now drop to idle. Will it maintain idle for 15-20 seconds running slightly rich and Transition to full without dying? If it does then this great. Does it load up and die sometimes on the runway after the 15-20 sec idle time has expired? If it does this is normal(At least normal to me). Can you put your hand on the engine head without burning yourself after a 10-15 minute flight? Then this is great because it means the engine is getting plenty of fuel. You should be good for the day if everything is in sink, but you will find out that those settings have magically changed the next time you fly under different weather conditions. So all this will have to be repeated.

Now everything I have wrote here is just personal experience with my Tower .46 engine, and is what I do to keep it running. These steps may or may not work for your Tower .46, but I have found these steps crucial for successful flights with mine. You may decide that this sounds like a big headache, and just throw the thing in the trash. Just remember though that if you can get it running like it should, that this engine has gobs of power, and even sounds like no other. Even with the Tower Muffler on the TT .46 they don't sound the same. Also remember that I am not a professional engine guy, and it is always smart to get several opinions on something. This is just a post that I wrote to help some poor unfortunate soul who has tried everything else with there Tower engine, but may not have tried to do it the way I suggest. Do I guarentee this to work?..............Absolutely not! But if your frustrated enough you may want to give my suggestions a try, and you may get good results. Give it a try and let me know if it works or does not work for you.

Note: I run my Tower .46 with an APC 11X5 Prop, O.S#8 Plug, and 15% Cool Power fuel. Good Luck!

Lots of first hand experience, but too hard to read -- you may be losing readers. Break it up into paragraphs of similar subject matter & re-post. We need that stuff, but it is tough to pull out of your post.

Don't buy MDS. Stands for "Many Deads Sticks" and it's true. Engine is junk.

Don't buy ASP. Not sure if they're sold now, but they are cheap Chinese O/S knockoff garbage. ASP = "Almost Spins Prop". They wear out fast and blow gunk everywhere due to the poor fit.

When you'lre looking for a big engine, don't go buy one of the big Super Tigres. Ditto for the big OS BGX. They're are much better engines out there, like the Moki's.

Why you would ever buy a FOX is beyond me. I ran a Fox .40. Heaviest, lowest power .40 I ever ran.

(removed duplicate post)

Wow, now this is telling it like you see it. There are going to be some feelings hurt with this post, but I am glad you didn't hold back and let your thoughts be known. This post here is what this thread is supposed to be all about. What engines to avoid at all cost? Great Post!

I tuned my long winded post for you! Hope you don't fall asleep trying to read it all.

Amusing post.

1. How many people have ever contacted a manufacturer when they've been disappointed with their engine? If so, how did you treat them? How did they treat you? It seems amazing that we are quick to type up complaints, and not always so quick to call a manufacturer to give them a chance to resolve the problem. Most every company has been responsive and helpful, with the exception of my Enya experience. Enya stood out negatively from ALL the rest as having unusually slow service response, as well as inadequate service support. The engine was beautifully made, but I won't buy another Altech supported product.

2. I've had most of the glow engine brands mentioned above (except no MDS or Moki), plus a large number of others not mentioned. There has been the occassional problem child with Saito, OS, Magnum, HP, Enya, Thunder Tiger, YS, Fox, K&B, etc, but I can honestly say that I didn't experience any trend where most from one brand were big problems. Most run quite well and reliably, when given a chance to be broken in and given some patience.

3. IMHO, biggest problem that I've witnessed has been touched on by a couple of others...few people bother to properly break in an engine. Every one of my engines spends time on my test stand before it proves worthy to go into a plane. Who needs surprises in the air?? Even fewer modelers spend time to try to determine what fuel, glow plug, and range of props make that engine run at its best. Great thing about having a test stand is you can try a lot of those things out. Not all engines run great right out of the box, although some are easier than others. I've had Magnums (2 & 4 stroke) that ran awesome immediately, others after 2-4 tanks on my break in stand (2 minutes at a time), and another that took 2 gallons. Same with Saito, etc. I had one 80 that never broke in properly and I swear was evil. I'm sure it wasn't but I never quite got it figured out. The rest of my Saitos were really good.

4. Despite the bashing in this thread, I've found Magnum to offer terrific engines, with only the same occasional clunker as any other brand, and perhaps the best customer support.

5. At this point, my glow fleet is consolidated to 4 stroke YS or Magnum, and 2 stroke Magnum (around 20 glow engines). At least for the most part. Just makes life simpler. A Jett and a couple of others keep things interesting.

I have a Magnum 52 4 stroke that purrs like a kitten, so you won't get no arguement from me.

From my own experience:

Saito - what can I say, I love them. I have a .91(71 flights, ONE deadstick on the maiden due to it being too lean), and I just finished breaking in a 1.00 for my Funtana 90.

Magnum - Had a XLS .46 and it ran flawlessly from beginning to end. Easiest to start/tune 2-stroke I ever had. Several guys in my club have them, and tell me that Magnum's customer service is very good. One guy claims to have sent in a seized engine(he didn't store it correctly) and recieved a brand new one!

From the info I've gathered, YS truly makes the finest 4 stroke available. I am definitely going to get one one of these days and try it out.

Anyone have any experience with the new RCV 4-strokes advertised here on RCU?

OS - had a .25 LA, what a pos. Ran like crap from day one. Power output was anemic. Eventually would die all the time due to an air leak at the needle valve. I won't buy an LA again, ever.

A long time ago I had an OS FP .25(about 8-10 years ago). Can't remember much about it, other than it seemed to run pretty well.

When I was 12 or 13 I had a couple Cox control line models. The .049 was finicky to start sometimes, but tuned easily and I ran GALLONS of fuel through them without a whimper.