CJKling

My Feedback: (1)

Yup, that is where I started, but all components are present, it sounds like I just need to replace with the right bearing.

Mr Cox

An extra washer behind the prop-plate would be enough I think. It only has to make up for the slightly shorter front bearing.

CJKling

My Feedback: (1)

I don't doubt it. I've replaced bearings before though and for $12 bucks plus my time, I might as well throw some new ones in there that hopefully fit properly. This engine was used and abused (by me) ~10 years ago and has sat in a basement since then.

Propworn

My Feedback: (3)

Give me a break, dollar bearings. Yep at work we get offshore equipment because some in management seem to think they are saving a buck with cheap offshore junk. Those dollar bearings are the first thing to go and we swap them out with some decent ones. Yes they still may be offshore but you really do pay for quality. We have a saying at work about those bottom line bearings Garbage in Garbage out. Usually during the first month they start to fail luckily we tradesmen have ordered good quality (read a little more expensive) replacements so down time is minimal. Nuff said.

Dennis

Hircflyer

yup, the prop hub is missing

1QwkSport2.5r

LoL. If it were a high dollar engine like Jett, Nelson, Novarossi, etc., Then I'd agree with you. But it is an OS FX. Those $1 bearings are probably better than the factory installed bearings. So far in the dozen engines I've used them in, they are performing the same as the NSK, NTN, etc. bearings that often come in Japanese engines. But YMMV. If you have deeper pockets, more power to ya. I don't buy hype.

DaveHickey

I seem to recall that they usually used a shielded bearing to hold down the amount of air leaking around the front of the engine. Not a problem so much at high speed but I think you will get a more consistent idle and better acceleration if you cut down the air leakage on the front end.

D.H.

1QwkSport2.5r

The seals or shields on the bearing have nothing to do with sealing the crankcase. The fit of the crank inside the front bearing is what makes the seal once oil is present.

the pope

I had to add a sealed bearing to my magnum to get it to stop . I guess theres more to a engine than just a piston and liner . Hey Tim !

1QwkSport2.5r

It would be coincidence that a sealed bearing fixed your magnum being that the "seal" in the bearing will "leak" like a sieve. The crankcase seal is between the crankshaft and the inner race of the bearing. There are tons of engines that came factory with an open front bearing with no seal or shield in place.

Michael - there is more to an engine than just a piston and liner, but I don't want to hurt anyone's feelings, so we won't go there.

Propworn

My Feedback: (3)

Your just plain wrong. Name some. I have boxes of old engines and lots of new ones and not one comes without that dust shield/seal. Most new ones even leave the dust shield/seal on both sides of the bearing. You obviously don't have much experience with these small engines. On the bushing engines worn bushings cause minute air leaks making fine tuning/idling very difficult so yes the dust shield/seal can add to the sealing of the crankcase and better running. You obiously need to take a course in model engines 010 for beginners.

Dennis

1QwkSport2.5r

I think you're in the wrong here, but it doesn't matter. The fact is (and perhaps Hobbsy if he was so kind to share a photo of his engines with open front bearings) some engines DO in fact come factory with open front bearings. I only have a few myself, but I know for a FACT that many Fox, Irvine, Super Tigre, and Enya engines have at one time come with open bearings. I've had hundreds of engines through my hands in the 20 years being in the hobby. No matter how you argue the point, the crankcase seal is maintained by the crank to bearing fit as I stated several times. If a seal or shield (note that neither provide a perfect seal - far from it!) is required for an engine to run properly, then the engines that are currently running and flying planes without bearing seals or shields must be figments of our imagination. It's not possible that a rubber seal or metal shield is going to prevent an "air leak" that an open bearing won't. If the bearing leaks, it's going to leak oil and/or fuel OUT, not air IN.

I am not as experienced as I'd like to be, but I have a pretty good idea abot how they work, why they work, and how to make them work if they don't work. Prove me wrong and I'll eat my words.

Just a few engines that I had easily accessible that have factory OEM bearings with no seal OR shield. NIB Fox .46 as it came from the factory. Approved for sale by Harold Willie. Fox .50, last is an Irvine .46 late Mk III. There are many others out there too.

This discussion is about ball bearing engines, but the comment about bushing engines and air leaks. While a worn crank bushing can cause irregular running and unstable low idle, most often it isn't air leaking IN but fuel and oil leaking OUT from the bushing. It is not uncommon for a bushing engine with a LOT of time on it to find cracks in the crankcase below the front of the engine. But even with a worn bushing, the engine will still run reasonably well if not great in most of the rpm range, it will just be noticeably messy around the front of the engine. See this video at the 5:48 mark: https://youtu.be/f_W_EE2jO14

I'm done. Believe what you like. If you find some science behind your theory, by all means please share.

the pope

The seal is between the crank and the case and not the crank and the bearing . It would not shut down until I replaced the bearing with a sealed one so thats my story and Im sticking to it !

Propworn

My Feedback: (3)

Some is a long way from tons. The engines you choose to show haven't been manufactured in what 20 years. Even 20 years ago it wasn't common practice to use unprotected bearings. No modern engine I know of comes without shields/seals on the front bearing. The FX engine the op has is one of those "modern" engines. If an engine was designed to use a front seal it will run better with one in place.

1QwkSport2.5r

You have to have something to believe in just as our friend propworn does.. so if it works for you, great..

1QwkSport2.5r

Just because "modern" engines come with them (sealed bearings) doesn't mean they will run any different without them. If it runs differently, your high quality made engine isn't so high quality after all.

You're grasping at straws here, seriously. There is very little difference between engines made 20-30 years ago and the engines made today except the COO. Everyone is having crap made in china now. Even your beloved OS is made in China. A sign of the times I guess. Made in China is better than made in Italy, or made in USA I guess. I think the old stuff blows most of the new stuff out of the water with few exceptions.

I'm going to continue to believe what I know to be true unless someone proves me wrong. My engines with open bearings will continue to run (I've not had to replace an open bearing yet - the only ones I've had to replace in an engine were sealed or shielded) and I'll continue to enjoy them. Watch for my upcoming OS .25LA experiment. It's probably going to make the fanboys' skin crawl.