blw

My Feedback: (3)

Airraptor,

I'm going to have to disagree with you concerning Evolution 2 strokes to OS 2 strokes. I think the crankpin thing is just urban lore, to be honest. The only problem I know of with Evos are the ones that shipped without an o ring under the carb.

That Evo crankshaft will run you $19.75 at Horizon, but the OS crank sets you back $39.99 for the 46 sized engines. OS engines are throw away items in most cases because it's too expensive to buy parts. For example, a complete new Evo .46 is only $15 more than a piston/liner replacement set from Tower for the AX. Something is very wrong with the pricing structure.

airraptor

My Feedback: (66)

BLW i do agree with you and thoughts are the same. As far as the EVO's reliability goes though i would have one unless had the crank reheat treated. we have had about 5-6 engines at the field. of those six 3 had the pins break off. 2 on the 46 thats in the trainer mustang planes and the other was a 60NX.

I will say that Horizons customer service is a million times better than hobbico's. If Horizon sold OS and TT engines I believe tower would Fold. OS engines are great Sport engines if you change out the bearings.

As far as my engines go i never run them dry at the end of the day unless they run out of fuel in the air. I never run after run oil in them either and my engines will last a bit longer than the guys that do run them out dry. i do have a flaw in my thoughts though. I dont fly as much as the other guys do at the field. I am lucky to get 2-3 days a week. So mine will naturally last longer since not putting as many hours on them. maybe i will start having the guys record flight times and get an exact hour number.

NM2K

My Feedback: (14)

I am not disputing anything that you are saying.

An altitude of 4.8k feet means that there is a lot less air than at sea level. The air at that density doesn't hold much water, compared to air at sea level. It is normal not to have as much rust at that altitude. Lucky you. (smile)


Ed Cregger

Hobbsy

My Feedback: (102)

Someone back a few posts said that they let there engine idle out the last bit of fuel, that is a really bad idea. If you pull the backplate immediately after that, there wil be a teaspoon or in the case of a larger engine a tablespoon of unburned fuel in there. Its best to let it run out at fairly high rpm, no need to worry about running out of lube, the parts are weil oiled.

p51Dpony

You could all be barking up the wrong tree, seriously, think about it.:  Everyone at that field has engine bearings go out.. why do you think their field lease was so cheap -that field is sitting on an Indian burial ground, the ground and the air above it are cursed.

RCER88

My Feedback: (25)

I add two cap fulls of castor oil to every gallon of fuel I open. The only bearing problems I have is blowing front seals. OS and clones. The only time I run an engine dry is if I fly it out in the air. I have engines with ten plus gallons through them and twenty years old never had to change a bearing.

crashprofector

Hi there,

I have 6 AX46, 1 AX 55, 1 AX75, 2 OS 32 & 37 Heli, TT Pro 46 & 61,

No bearing troubles as of date with any of the engines all run on Cool Power 10 or 15 %

As for the AX.46 have had scense they come on the market GREAT engine never a problem & so have eat just about as much dirt as glow fuel and are run very hard,

So dont know why you are having with so much problems, They may blow tommorrow but I would not bet own it.


GOOD LUCK

CRASH

Lightning Fan

My Feedback: (17)

I know I am going to get pounded with this response, but here goes.
I ran through two sets of OS91FX bearings, the first being the OEM, the second being the economy ones from Boca.  I'm on my third econo Boca set, and they have lasted years since the last replacement.  Both bad bearing sets had corrosion induced roughness in turning over.
Around the same time that I lost the first two sets of OS bearings, I had a TT40 rear retainer let go ... on a P-82 twin in flight ... which was exciting ... and it required piston and sleeve replacement. (P82 still flies ... throttle cut and land now!)

My routine was to use Byrons, run the engines out of fuel at end of day, and put light weight after run oils in the engines.

I got to thinking about why my chainsaw, weedwacker and other gas engines never had this issue - those engines sat in a uninsulated garage, with no special treatment.  Yes, I recognize that the alcohol is what captures the water, etc.  But the oils in those gas fuels seem to be heavier, and when you take a gasser apart ... it is coated with oil ... a two stroke glow has some oil in it, but the rust clearly shows that there are dry places, even with light ARO.

I then also realized that I keep my ships in a pole barn in Wisconsin.  I'm in and out of there constantly, and I turn the heat on and off in the fall, when the humidity level can be high.  My shop tools were getting surface rust on them.  What if the temperature cycling in fall and winter was changing the dewpoint such that water in the air was condensing on all surfaces?

I've done two things.  I run a dehumidifier now.  My tools no longer rust.  And I use 5W30 motor oil as after run, and spin well.

No bearing issues since doing this.

Before you tell me that there are consequences from using this heavier oil ... just understand ... I've been doing it for years now, and I've taken all these engines apart, looking for carbon buildup or some other damage from the oil.  I've seen nothing other than the fact that the bearings have oil on them, and much less rust.  No problems starting, and no glow plug fouling or premature failure.

So to the original poster ... I started flying at 12 in 1967.  We used to run a lot of sleeves back then, but that does not account for our perception that the bearing resistance to corrosion is worse than it used to be.  I think it is worse because of cheaper bearing materials, but I also think you can deal with it by using heavier ARO and controlling the environment a bit better.   I'll close with one more fact -

I have an Irvine 53 that I treat like crap.  I fly the heck out of it, and then let it sit for a couple of years.  I might put ARO in it, I might not.  No issues.
Stainless bearings in a quality product.

Release the hounds!

1QwkSport2.5r

I cannot speak about OS because I haven't run one and I never will unless someone gives me a brand new one for free. This will never happen, so I will never have one to run.

I havent had bearings fail in any engine I own, though I did put a set of stainless bearings with polyamide retainer in my TT .46 pro because of the metal-retainer bearings it came with.

I never use ARO of any kind ever. I have car engines that run on 12% oil that have never rusted a bearing and turn 38,000rpm or more. The reason is I use zero synthetic oil in my engines. Castor only. IMHO, premixed fuel should contain 20% oil, and at least 40% of that should be castor to not need any ARO added. 80/20 blends arent enough IMO.

When I'm done running for the day, I disconnect the fuel tank from the carb and plug the tank. Pressure line from muffler to carb inlet, and fire the engine until it wont fire anymore and stick it on the shelf until I run it again. My TT .46 Pro and Super Tigre S90K have been ran on airboats and have sucked a decent amount of water and they have silky smooth bearings. I like the old school fuel mix. Methanol, Nitro, and Castor. It works, and is 1/3 the cost of a premixed gallon of a castor/synthetic blend.

<shrug> I'll get a fire extinguisher in case someone sets me on fire for my comments.

gmeyer-RCU

My Feedback: (9)

condensation could be causing the problems.
I was talking to a fellow club member who was getting less than a gallon or two of fuel through his engines before getting rusty bearings on his engines of any brand he tried I was shocked because the only time I have had bearings go bad is when my engines sit unused for years. However after reading some of these posts and a recent experience at the field I think some of the problem is condensation here is why. On one of my last flying sessions I waited for a fellow club member to finish flying he fly's so well he can fly in the dark so from the time I got there to the time I left the temp. dropped 20 deg. my plane,radio, and all of my eqp. was soaking wet from condensation to the point that I was concerned that I was going to ruin my RD8000. So my point here is taking your plane from the hot car or maybe the engine is still warm inside to the cool air cond. basement could be causing condensation to form inside the engine.
One more thing to try is putting covers over the carb. and exhaust exit to keep air out after your usual shut down and after run oil Great Planes used to sell cover's or cap's for this I don't know if they still do. Greg

1QwkSport2.5r

I use foam ear plugs after the engine and exhaust has cooled enough to not melt the ear plugs - one in the muffler and one in the carb. Keeps the oil from dripping out and keeps moisture from getting in. Most of the time, I can re-use the same ones if I dont have any fresh ones on-hand..

Hobbsy

My Feedback: (102)

Ed, all 5 of m OS engines are LAs, never had a bearing problem.

blw

My Feedback: (3)

I've bought 7 Evo 46NTs, a .455 TPS, and the 36.

(I edited this message because it was originally supposed to be cancelled before posting. Wasn't paying attention)

tejician1

My Feedback: (2)

In the past, when I was involved with ducted fan jets...some of the guys were experiencing bearing failure or excessive wear and/or roughness with their 2 stroke engines....Since I was a aware of a product called Z-Max from my racing days....I tried it in my fuel...WOW !! right away I began to notice my engines ran a bit cooler and I didn't have any galling effects of bearing surfaces after a lean run....And..I don't know if this makes a hill of beans or not...but I didn't have to change my glo plug as often as I used to...it was customary to change plugs after about 6 or 7 runs....I was using a Rossi plug in my OS 91 DF & Rossi 81 engine(s)....I used the same plug for over 150 flights in my OS 91 DF/Dyna Max fan... and I didn't baby the engine or plane...I told others about the Z-Max and many scoffed at the idea...( you always get a few non believers ) When I finally got out of flying ducted fans I took the OS 91 and two Rossi 81's to another jet-head who tore down the engines and was amazed at the surfaces inside of the engines...He knew of the lean runs that I sometimes experienced and commented he had never seen anything like it !!! I told him it was because of the Z-Max in my fuel...I mixed approximately one ounce of Z-Max to every gallon of ducted fan fuel...

You guys experiencing bearing failure might aught to look into using Z-Max...I still use it in my Big birds..and my sport RC birds...and I've never had a bearing failure nor galled surface and best of all...my glo plugs seem to last longer also...Z-Max has been around since the 1930's with the Indy racing crowd....Any of you that are NASCAR or Indy fans have probably seen the Z-Max logo emblazoned in the front straight grass or on a big sign alongside the raceway....Quit scoffing and try it...!!! You can get it at any good auto parts store and in some Wal Marts....

tejician1

My Feedback: (2)

One other thing...I now use Z-Max in my vintage Corvette, my TR-6 Roadster and my 4X4 Dodge truck...and my mileage has improved on the Vette and my Dodge Truck...I haven't had enough run time on my TR-6 to check it's mileage figures...I just don't drive it enough !! You will get at least a 10 to 15% increase in mileage after one treatment....My son swears by the product and he uses it in all his work trucks and he works for a big automotive dealership....And for those of you that think I have stock or work for Z-Max...get that out of your head right now...I have no connections with Z-Max other than I like & use the stuff religiously in all my farm machinery...I also attribute the Z-Max for saving my field tractor's engine from having a failure due to gross overheating....I took the tractor to my dealer and he looked at it and became a believer in Z-Max....You will too if you just try it....

IRCantankerous

I fly at the field Airaptor flies at and I have one of the engines that has bad bearings. I fly in the T34 races and I am the slowest one there. I didn't lose the engine, it just sounded like a garbage truck taking off. Landed and rotated the prop and felt roughness in the rotation. Now this engine is one week old and has about 9 flights on it. So not very much flight time. Having heard that no one will honor the warranty, I have taken the engine apart and have found that the back bearing has rust. The front seems OK, but will be replaced. Having not heard about Boca bearings and already ordered the OS bearingI start to assemble the engine Brand new rear bearing is in and feels like the one I just removed. Now everyone will say I didn't install the bearing correctly, and of course I will say that I did. The bearing in the egine was not up to what I expect from OS and neither is the replacement bearing I was about to put in. I have serious concerns about the quality of things coming from OS. I am ordering another set of bearings from Boca and will let you all know what the out come is.

bjbellino

My Feedback: (176)

Have been using Byrons GenII 15%/with 20% oil, because I think their blending facility is top notch and reading their ad, it actually states that their fuels lubricate so well, their is no need to run after run oil. But I also think that any good quality fuel with enough oil content should give years of trouble free operation. Have seen guys have problems when they use the same steel fuel can and continue to just ad fuel into that can when it becomes low. I think they found out that they had some condensation in the can. Had much more trouble free results when they disposed of the plastic bottle ever time they ran out of fuel. Sounds like your club has tons of experience in RC. Can't believe Hobbico won't warranty these bearings for free, along with some recommendations. Just a thought, might take one engine and back the rpm back down to 13k(use it as a test case) and see if bearing life increases. Have always read and been told that engines "unload" when flown, but have never heard how much they "unload" rpm wise. Would have to carry some on board telemetry to find out?? Anyway, good luck with these problems.

378

My Feedback: (4)

The 18 CV-RX in my car has three gallons on it and it turns over smooth as silk. All I do is run it until it shuts off, pull it over to BDC, and that's that. I don't use any ARO, I don't use any castor additives, nothing like that. Just running the Blue Thunder 20% Sport dry and sticking it on my shelf at BDC.


The 46AX in my airplane I've only run twice, and then only on the ground, so I can't say much about it's longevity. But, I will say that I've had no problems from it's bearings either, it still runs just fine.

123Cat

Kero power , all true , and if I might add,, you can crash it into the ground and not brinell the bearings ( plain bearings that is ) and they seem to run OK too in a pretty loose state, also too bearing manufacturers say that most bearings are ruined during assembly due to brinelling , wrong size bearing housing out of round bearing housing and also you can be using counterfiet bearings , even F1 teams get caught out with those, they are impossible to tell from the genuine bearing and they are copies

Sport_Pilot

Even that is not enough. I put my igniter on and run the starter till it quits popping. Then Itake the igniter off and run the starter a bit more. Just because it quits popping does not mean all of the fuel is gone, just enough not to be able to ignite.

p51Dpony

it seems many people don't have a problem even though they don't do any special babying of the engine.  I can bet that those that have problems have some of the mentioned issues:
     1- condensation in and on the engine, happens in every climate but is worse in humidity and places that have bigger temperature fluctuations and faster temp fluctuations.  a slow temp fluctuation may not cause condensation at all.
     2-non castor formulations may be more prone, we all know methanol is a hydrophilic molecule and so by itself is harmful to metal.
     3-breaking-in an engine too fast, means probably more metal particles from the sleeve/piston to contaminate and erode a bearing
     4-bad bearings?  I don't know how this could just occur to one of the best engines out there, if truely as original poster said maybe the club got engines from a bad batch or more likely they were all using a bad batch of fuel.
     5-bad alloys? I doubt, I have a bunch of old engines, most of them are just bushings on the crank, I think the engineering and alloys of modern engines, especially the o.s. (read "top of the line") are the best ever, you do get what you pay for and there are better engines you can buy but there are even more worse engines you can buy.

lots of great posts in this thread, enjoying all the inputs thanks-all.

airraptor

My Feedback: (66)

P-51 I do not think it wa a bad batch of fuel, engines or so on. This has been hit or miss over last three years with engines bought from internet, to three different LHS.

I do know the one thing we count on with OS engines is that the bearings are the first things to go just dont know when.

I just put New boca ceramic bearings in my 46 last night. The bearings i removed had one 10 ounce tank through it and 4 8 ounce tanks through it. all in one day. I will pull the bearings apart tonight and take a good look at the bearings. The rear bearing inner race already looks like it has a a bit of rust forming or the castor is baking on it either way that isnt good.

378

My Feedback: (4)

I believe factors 1 and 3 are the biggest culprits. My cars stay in my bedroom, where an air conditioner runs 24/7/365. There's no humidity to speak of and the temp remains relatively stable. I also didn't rush the breakin on the car engine, did a by-the-book heat cycle on it over five tanks, which is also what OS recommended.

jeffie8696

Ihave had great luck with bearings.
1) Use after run oil, Iuse 10W30
2) Run engine dry
3) Use fuel with enough oil
4) Use Boca Bearings when the stockers give up the ghost

tonyob

I've been in this hobby for 3 years, fly almost every weekend, keep a log and do about 30 hours actual flying time a year using 31 litres of fuel (just over 8 gallons US). Never a problem ever with a bad bearing in either my OS 2 strokes, my ASP 4 strokes and my Saito 4 strokes.

Live in a humid subtropical climate. Mix my own fuel, 10% cheap nitro, 18% coolpower blue. Very careful about fuel storage. After run process is to take out the glow plug and squirt lots of WD40 or Innox (lanolin based spray lubricant similar to WD40) into the cylinder. If I have easy access to the carby, I also squirt down that, then spin the motor a number of times by hand.

Other pilots where I fly have had bearing failures, they don't do any after run treatment.

Your mileage may vary.