How to change model airplane engine bearings (part 2 of 2)

[Damianbmw123]

very nice video, but my engine is trx 3.3 and idk how to check the crankshaft??

[lexander5]

Thank you very much indeed.

[lexander5]

Very nice video. Just got a model engine myself and I've got a question: Is it normal that the engine's crankshaft can't be turned all the way by hand, even if the glowplug isn't fitted so there is no compression up there?

[xjet]

@lexander5 Yes. Most modern 2-stroke model engines have a tapered bore so the piston becomes tight as it moves upwards. When new, this often means they are quite tight to turn past top-dead-center. This is called "pinch" and is quite normal. High performance engines are often so tight that they "squeak" when turned over.

[Thegamer89ak47]

Were did u get the motor

[3801Catcher]

It looks like you've used a skateboard bearing, yes?

[gmanalready]

Very good video but as a professional engine builder, one thing I would NEVER do is put a scratch in a connecting rod especially across the beam as this will make a stress riser and potentially cause the rod to fail, this simply may not be an issue on rc engines but it's still not generally a good idea.

[xjet]

@gmanalready yes, it's not an issue on these engines, the conrods are massively under-stressed. In 40 years, I've never had a failure as a result of scribing a light cross onto one.

[yamahonkawazuki]

@xjet agreed. although i usually used a spot from a grease pen or a marker. no ill effects from it either

[Damianbmw123]

very, very nice and professional guide.

[ae85gt]

Hello mate, great clip and easy to follow. I have a question about castor oils. I noticed a post on the type of oil this motor was run on was a hi-tech ester-based synthetic. Here in NZ the popular brands of synthetic castor are the two brands you say use the low-tech PAG oil (Morgans & Klotz). What are some brands that use the hi-tech oil and what are the advantages over low-tech oils? Cheers :-)

[xjet]

@ae85gt Aerosave/Aerosynth (by fuchs) and Motul Micro are two ester-based lubes designed for glow fuel. The benefits are much better stability at high temps (they don't vaporize like PAGs), a stronger film-strength, better viscosity index (don't thin out with heat so much) and, in the case of the Fuchs oils) a fantastic anti-corrosion package that effectively eliminates the need for ARO and protects against rust when the engine's are not being used.

[TheGreatScat]

I have align 50 engine on my trex 600 helicopter, and I'm planning to replace rear and front bearing. Do I have to use a gasket on backplate and top head? It seems that your engine have no gasket. Thanks and nice vid!

[Mr7165]

7,5 ccm ?????

[xToXiicxT3RRoRx]

what oil is that

[xjet]

@xToXiicxT3RRoRx You can use any oil -- I prefer to use either Mobil 1 synthetic or castor oil. Doesn't make a lot of difference -- it's simply there to provide lubrication until the oil from the fuel can reach the bearings, cylinder etc.

[stefanoathens]

hello sir, i have a question. Why should the back bearings be without shield? would it be better they where with shield, so in case of failure the debris to remain inside the bearings?

[xjet]

@stefanoathens A shield will reduce the amount of lube (in droplet form) that reaches the bearing races/balls. If you use a good high-speed bearing with a polymide retainer, there is no dangerous metal cage to fragment and damage the engine so no shield is required.

[stefanoathens]

@xjet thank you

[MrrSatana]

It seems to me, that you use fuel with high content of castor oil.. The piston is black and some spots on the surface of the engine.

[xjet]

@MrrSatana Actually, this engine has done a *lot* of hours on fuel that contains just 2% castor, the remaining 10% being a hi-tech ester-based synthetic (not a low-tech PAG oil such as Klotz or Morgans).

[Wutz110963]

Very Good Video , I have in my OS55 stainless steel bearings

And i fly with Rapicon 30%

[the124Lscania]

have u got model sheep?

[vitommarques]

Hello "xjet" the oil that you used in the video, is it After Run oil?

If not, what oil is it?

[xjet]

@vitommarques Pretty much any oil will do. I mix my own fuel so I just use some of the oil that I use in the fuel but regular motor oil will do -- it's just to protect the parts from scuffing until the engine starts.

[gramcrocker]

Excellent presentation. Thanks

[XELA2T]

Thank you very much for part 1 and this one.

I learned all I need to know from your vids.

Very good explanation!

[sweetvid345]

do yo have to hone the motor

[xjet]

@sweetvid345 Not unless it's a ringed piston running in a plain-steel bore (very few modern engines are like that). The standard chromed bore needs no honing and shouldn't be touched.

[bossuniqueg]

how much the engine cost????????

[eddieacdc]

this is the best video i ever sen on youtube ! watt motor is that?

[cheekygit2002]

top man ,excellent video thanks

[crispyspa]

Thank you for this video.

Since that engine is in good shape after that many hours, I assume you use some sort of after run oil. What do you use? WD40? plain engine oil, or after run oil?

How do you prep an engine that will be sitting for a few months?

Also, could you critique my prop balancing video on my channel?

[realfastRC]

theres not any good plane engine breakdown and repair vids...you are a natural!!!you should continue making air repair vids like squirllod for cars and trucks!! really!! you're a natural teacher!!

[ianvaldivia1993]

what waght of mobil one

[xjet]

The weight of oil isn't important.

[bearhooverpup]

awesome video, thanks!

[sammyseefatpoon]

Very good, nice guy.

[scruttart]

Excellent clip very interesting & straightforward you are a natural teacher.

[YupHio]

completely agree. this guy is great

[soupahugly]

awesome. everything was perfect in this video. thank you for posting. i wish i had seen this before i disassembled my first nitro engine.

great job.

[alexedit1]

one of the best videos I have seen...no wait..THE best video I have seen since I started flying

[fruitykeith]

Again very good video thank you for posting this

[DaManzMoney]

Why wouldn't you change the wrist pin bearing while you had it out?

[xjet]

Because these engines don't have a wrist-pin bearing. The conrod is bushed at both ends - no roller-bearing as you'd find on larger engines.

[DaManzMoney]

Oh Ok I just heard you say wrist pin I didn't realize there was no bearing

[DaManzMoney]

I found this video one of the better teaching video's I've ever seen it was so clear on what and how to do it. I definatly rate this a 5/5 thanks for sharing it was great

[DaManzMoney]

Ha at :2 seconds he said cankcase

[DaManzMoney]

I meant at :12 seconds he said cankcase

[DaManzMoney]

Great video I learned abit of new stuff I'm not into these airplane engines but I do own I think its a cox spitfire airplane and a helicopter there the ones that had strings you hold and they go around in circles I never used them they were givin to me years ago and never had any1 explain them to me I forget what they call them the planes motor is bigger than the helicopter I'm more into dirtbike and snowmoblie engine and do all my own work

[netjunky41]

i ran a new engine for one season emptied the fuel out of it but it seems to turn harder. should i oil it, and with what kind of oil

[Syd1940]

A very safe way of applying heat to an engine on the bench is to use the hot air gun you use for shrinking covering film.  It's usually more than enough.

Not too keen of hitting a threaded shaft without a nut fitted to protect the threads. Even then, be very careful.

Thanks

[xjet]

That's why I use a piece of soft aluminum between the hammer and the crankshaft -- it protects the threads from damage even more effectively than using the nut.

[wirelesscps]

can you just freez the bearing just asking

[xjet]

You can freeze the bearing but the problem with that is that since aluminum is such a good conductor of heat, the bearing will quickly "chill" the crankcase casting when you start to push it into place so it will probably not go all the way home before the fit gets too tight. It's much better to heat the crankcase -- then chilling the bearing won't be necessary. Also note that if you do freeze the bearing, you need to use lots of oil to displace the water droplets once it's in.

[clintomo]

Great Post! Thanks.

[somegeek]

Friggin brilliant man - thanks for taking the time to post this!

[vinii240626]

bom video

[geany991]

tu payaso no ay ke poner aceite all

[psantaana]

Excelent videos. Thanks xJet.

[igehring]

very good instructions, but why didn´t you take the chance to give the engine a good clean ?

[xjet]

I wanted to fly again that afternoon! I'll do a separate video on how to clean your engine using the anti-freeze crockpot method a little later.

[igehring]

I understand your hurry !

The video on cleaning will be anxiously expected.

Thanks

[yahalloo123]

very good.