FlyerInOKC

My Feedback: (6)

Dumb question, if you remove the shields to allow for better lubrication is the factory grease rinsed out or left in place to heat and leak out the crankcase vent?

1200SportsterRider

It washes out very quickly, I for one don't bother to remove the shields, the lube passes right through them. If a bearing happens to grenade, the shields contain most of the debris.

Glowgeek

The grease will get washed out eventually, even when using 2RS (rubber sealed bearings).

I remove shields from the rear bearings and the inner seal from the front bearing because I have seen them pop off and cause damage. In our 4 stroke engines the rpm is not high enough to worry about breaking ball retainers, besides a shield or seal would not stop the debris from exiting the bearing. For the purpose of running in higher reving engines, 14K and up, they make bearings with plastic retainers.

Linkan2

ok let me explain. What's coming from the factory (saito). The motors that have crankcase ventilation at the front have ZZ metal shields. the advantage of them is that these ball bearings retain the oil better than open bearings. Open ball bearings that sit on motors with the crankcase nipple rear cover. naturally has a better flow on the oil to be able to lubricate the camshaft. this is just a tip, have never had a ball bearing crash and I run all on 10% oil or less The PS Saito factory has all the time to test what is good for us consumers

Hyjinx

Thanks LonI guess I never noticed the designation zz ( or simply don't remember) on the Bocas I have installed. Seems like most of the shields I have removed were indeed metaliic. But definitely some non metallic. Post looked like the author had a manufacturer statement.
Aaron-

Glowgeek

The camshaft lobes, camshaft pin and tappets are the highest wear item in saito singles, as per the dozens I have overhauled. The more oil that moves through the cam box area the better imo, another reason I remove the shields from the rear bearing. I have never had a replacement hard chrome bearing fail, knock on wood, or for that matter any other internal parts fail, but then I do use aro religiously after flying. I have converted a few rear vented Saitos to front vented as well due to seeing less cam/pin/tappet wear in front vented Saitos when torn down for overhaul. I'm not knocking Saito, they do what they want, I do what works best for me.

Captcrunch44

i know I don’t say much but this bothers me.
i realize there’s a vast amount of knowledge on this forum and we all think that we know so much that quite a few questions are silly. But remember we all were there once.
I just want to point out again that there is no stupid question. The only stupid question is one that was never asked.

acdii

Where ya been Mike?

1200SportsterRider

There is a stupid answer though, that says the shields don't contain the pieces when a bearing blows. it's known far and wide that they do.

Hyjinx

Relative to the type and extent of the bearing race and balls failure noted in my experience.
Although relative can be a debate in and of itself.
Seems like my life offers more different than right or wrong for ponderings sake.
Oil well

Captcrunch44

[QUOTE=acdii;12670677]Where ya been Mike?[/QUOTE

well I have the worst year in my life since my dad died woke up one morning and my wife and kids said they’re moving out they didn’t even hardly say goodbye six months later we’re divorced and they’re living in another town and I have a whole house to myself it’s been going on a year now haven’t been very ambitious for working on airplanes engines anything the only thing I consist of is working every day and sleeping. They said I was too mean.
i finally got into the shop last night and relocated the tank on my 110 inch Rasco with the 200 or three I was going to run it and the ignition battery was completely dead and gone zero.
I will probably put new battery in tonight I love how the tree cylinder sounds.
I still need to get up and see Gary and maybe take a loop down and Dave. I still have plans to stop and see mike on the way to Texas in may.
that’s about it in a nut shell

acdii

All I can say to that is WHOA. Here I thought you had got Covid and just wasn't feeling well.

Where in Texas are you heading? I still haven't made any vacation plans for the year due to the VID, but we were planning Texas for last year, however there were some requests for Utah.

Glowgeek

Larger pieces of a "grenaded" or "blown" rear bearing might be temporarily contained by a metal shield to some extent, didn't say they wouldn't, but smaller bearing bits and metallic dust will quickly exit when the shield is pushed away from the races. It's no assumption, or stupid, to state what I did.

Besides, the metal shields are not designed to contain the debris of a "blown" bearing. A broken ball retainer will munch the crap out of a metal shield in mere seconds of run time at high rpm. The ZZ metal shields (removeable) are designed to keep out large debris and help to contain grease. I have seen plenty of munched bearings in my lifetime of working on all kinds of equipment and have never seen a shield intact when a ball retainer fails.

So now what happens when a bearing is failing but has not yet broken the ball retainer? Do I want shields to obstruct the small metal wear particles from exiting the bearing? Heck no, I want all that crap to get flushed out the vent so I have more time to recognize that the bearing is failing. That debris needs to be ejected/flushed from the bearing before it closes up tolerances and causes overheating of the bearing. When that happens the ball retainer is sure to fail shortly thereafter, and there goes the metal shields as well.

Running shields or rubber seals inside our little engines is a recipe for additional damage that may have been avoided.

triumphman49

My Feedback: (149)

Hey Capt, Bout 5-1\2 yrs ago was working out of state. came home for the weekend a day early to find big U-haul box truck loading up. Had moved wife of 18 yrs in with 3 pickup loads, she made 3 trips with the box truck. Been sole supporter all my life living paycheck to paycheck. 1-1\2 yrs later lost half 401k and saddled with 60,000 in debt and 4yrs support thru divorce. At 71, got 2 payments left and bout a 1\2 year left to pad bank account, before I quit the rat race and follow schedule on front tag on my van - 8am coffee, 10-5pm rc flying, 7pm beer mug.
Got my 5 buds (cats) to care for and keep me company, and more toys than I'll ever get to play with. But I'm SO ready! Good Luck with the Rascal, I've got an 80" just waiting with a 62a up front. Do enjoy these forums and empathize greatly with all hardships others have had to endure.

T-man49 in Al
Mike #723

Jesse Open

Dave,

I will be running off a couple of batches of those choke "clips" as you call them. About 100 in both brass and steel. I will send you a few as soon as they start to roll off the press brake .
Despite what you may have heard, a VERY simple part to make.

Captcrunch44

yeah we were married for 29 years. I’m still in shock.

Jesse Open

Cap,

I just read your news! That is a very tough one to hear. I surely hope you are doing better soon. Please feel free to call on us any time.

Gary

Glowgeek

Me too Crunchy, just read your post. Man, I feel for you. That's a long time to have someone in your life and then poof, everything changes. Hang in there brother, things can change back just as quickly.

the Wasp

My Feedback: (1)

Hi Capt, it's good to hear from you !!

Jim

Glowgeek

Sure, simple part to make, especially when you use a press break. VERY simple if you use a turret punch first. I took a job creating production drawings for sheet metal parts and programming their Strippit punch press, Waterjet cutter and press break for a year before moving over to Dell Computer. Fun job and it's amazing how intricate and how fast custom sheet metal parts can be made using those tools.

Monty Python

Mike the front bearing never fails if you swap them out both front and rear at the same time, the front bearing is sealed and lubed for life, it's the rear bearing you always hear first and in flight don't know how to describe the sound but it's noticeable on a close flyby. I leave the rear main cages on cause I figure the manufacturer had a good reason and lube passes easily through the bearing.



Dave, it was an Aussie skipper

Glowgeek

Lol. Good one Pete.

FlyerInOKC

My Feedback: (6)

He was probably drinking Pete's favorite Emu beer too!

Glowgeek

The ship is obviously powered by one of those cantankerous fa125's too. Not enough power to buck the wind!

FlyerInOKC

My Feedback: (6)

I hear Pete when he has had way too much Emu he like to run the 1.25 he hid from Saito so he couldn't bury it.