JettPilot

My Feedback: (6)

William Robinson,

Given the huge amount of knowlege you have about Saito engines and RC eingines in general, I wonder why Saito or even OS does not hire you to fix these recurring problems they have with thier engines. They are good engines, but if all the stuff you addressed here was fixed by some simple design - material changes, they could turn good engines into near Perfect engines. With a little effort, Saito could fix these last few things ( bearings, oil system, backplates, mufflers, etc...) and be so far ahead of everyone else that everyone would buy thier engines. Have you ever been approached by them for consulting or anything like that ? If not, I will send general saito an email and suggest that he read this thread and subscribe to your notes

JettPilot

butchn

My Feedback: (2)

I am Somewhat new to Saito and I just purchased a "almost broke in" Saito 150 on ebay ... ya right ... its probably had about 50 gallons of fuel thru it, missing bolts and leaks like a sive thru the valve lifter seals, anyway, I went to remove the valve covers and I don't know if I just can't see them (I know my sight ain't what it usta be but) or if they are missing ... I do not see anything like the valve adjustment screws shown in the manual. I can't seem to find any real pictures of this part of the engine posted so I can verify what it is I have or don't have. Would appreciate any help on this.
Butch

William Robison

My Feedback: (3)

Butch:

Two shots of the real thing, just for you.

Hope this helps.

And you're in Club Saito as number 331. Welcome.

Bill.

Dave :^)

Hi Bill,
I think you got some bits of your beard in the photos!

Haw!

Dave :^)

Thunderchild

At least we hope it is his beard and he hasn't gone "Brazillian" on us

William Robison

My Feedback: (3)

Dang. First Kmot bugged me about the hair, and now you two.

Did you ever stop to think ithat deliberately ncluding the hair might be just bragging about the quality of the lens on my new camera?

Haw.

Actually, I seldom see the hairs until the pictures are done, and I'm too lazy to reshoot them.

Bill.

McEntyre

My Feedback: (77)

thank you do know the small 3 cylinder mesurement the r 90 thanks Donnie

William Robison

My Feedback: (3)

McEntyre:

Here's the first page of the FA-90R3 supplement, and a crop showing the dimensions.

Hope this is what you need.

Bill.

Thunderchild

Bill are those crops from a multi manual? They are a lot clearer than the "original equipment" manuals I have seen here in Oz. Any chance of obtaining a copy please?

FA-170R3 as well if not too much trouble.

Cheers,

TC

William Robison

My Feedback: (3)

All:

For a while we had all the Saito manuals in a dedicated site operated by one of our members. He left that company, and the site is down. I still have most of the Saito manuals in .pdf format, I will give copies to anyone who requests them. Please note that I must have your email address to do this, they will NOT go through RCU’s mailing system.

TC:

On the way shortly after this is posted.

Bill.

Thunderchild

Received

Thanks Bill.

Bonus! Extra manuals!!!!

Cool [8D]

William Robison

My Feedback: (3)

MORE ON CERAMIC BEARINGS

About six months ago I was sent an FA-100 with a failed rear bearing. The engine had new ceramic bearings installed and ran less than an hour before failure.

I discussed the installation with the owner, and could not see any error in his work. He did say the crank would not turn freely with the new bearings, and when the crank was in the case with only the rear installed the nose of the crank was visibly off center at the front. After I had cleaned the case and installed another set of new bearings the crank nose was not visibly off center, but it was still stiff enough that the crank counter weight would not hold the crank in position when the case was rotated. It should have been that free. Pulled it all down again, and gauged the case as well as I could, no distortion was apparent. With the crank installed into the rear bearing only all was free and the crank centered in front. But it was still a bit stiff with both bearings installed.

I discussed this with the owner, told him I was not satisfied, if this set of bearings failed I’d pay for his next set if he’d buy a new crank case to go with them.

He is flying the engine now, says it runs better and is more quiet than he remembers it ever being before.

History of the engine: Original bearings failed and replaced under warranty, owner installed second set, failed with less than an hour running time. Owner says engine never crashed. Speculation on my part: faulty machine work in production of the crank case. I could find no other reason for the repeated failures. So far, since the engine has been back in service all is well. We’ll see how long it lasts.

For those who would like to see the bearing, here are some shots, including one of the balls, and some pictures of the inner and outer races. Finally, a shot of one ball taken with my older camera. Until I got the new camera I was not able to get decent pictures of the races. Just for reference, the ball is 0.180� diameter.

Bill.

PS: The double sealed front bearing was still good. wr.

Tom Jones

My Feedback: (4)

Bill, is this beard hairs I see in these pictures, also. Are you shedding, molting or what. Tom

William Robison

My Feedback: (3)

Tom:

You will notice I only put a hair in one of that last series of pictures.

Shedding? Moulting? Take your choice.

Haw.

Bill.

TimC

Bill, will that race stick to a magnet?

William Robison

My Feedback: (3)

Tim:

Yes, but that's not conclusive. Some stainless alloys are magnetic.

Bill.

TimC

Yes, I was curious what kind of stainless was used. Knife blades are usually one of the magnetic stainless steels. Too much nickel in the alloy and it will lose it's magnetic properties.

XJet

It's hard to tell whether that was perhaps caused by FOD (certainly looks as if there was some FOD involved but that may have been as a result of the failure rather than the cause of it).

If there were a small chip of material in the bearing (and ceramics can chip far more easily than steel) then that can lock under a ball and cause it to skid in the race. In a "worst case" it could also displace the inner race to the extent that could account for the "off-center" observation.

Perhaps it was a faulty bearing (does happen) right from the get-go -- or maybe some grit was intrudced during handling prior to (or during) installation. It only takes a very, very small piece of dirt to upset these bearings in this manner.

As for the type of stainless used -- I suspect they use 17-4 PH martensitic stainless, since martensitic alloys are the only types of stainless that can be hardened by heat-treatment and it's commonly used for such applications.

da50ex

Thanks, I knew it was in here somwhere. Works great and the new ceramic bearings are in and it sounds much better. Now with my 1st bearing change under my belt doesn't it earn me entrance to the club!?
John

TCrafty

Okay guys, I guess I've gotta become a card carrying member of the club. Got a Goldberg Sukhoi with a 180, a Burrito with a 72 and a Sig Senior with an old 50.

Got a few questions for you all. First, I just put a set of Boca Bearings in my 72. I bought it used and it only had one tank of fuel through it. Just turns out that the tank was about 30,000 gallons! Now it runs much quieter and runs fine but one guy at my field thought that it was down on power compared to his. He's bringing his out to the field tomorrow for a comparison. What I was wondering is if it IS possible to be one tooth off on the camshaft? I know that in the larger car engines, we would advance or retard the cams for better high/low speed performance. Is it possible with a Saito? I didn't put a new ring in the engine, should I?

Secondly, I've read on this forum about a guy who was flying a radial Saito and he mentioned that his engine flew the plane well but a single would be much more fun. Why would he say that? I'm showing my ignorance here but I've wondered about that. What are the benefits/shortcomings of radials?

I've probably got a million more questions but I'll step away from the mike for right now.

thanks

Andy

William Robison

My Feedback: (3)

John:

Sorry, I put you on the list at the time of your first post about the engine bearings. Somehow I neglected to post the announcement at the time I listed numbers 329 and 330. DA50EX is member number 328 in Club Saito.

Xjet:

FOD is a possibility, but I have to discount it as the engine ate two sets of bearings in a very short time.

It is possible the airborne dust at the location the engine flies is particularly nasty, and the engine does now have an intake stack and a Bru-Line air filter. If it were the dust I’d think other engines there would also be having repeat failures. Something to think about anyway.

Bill.

William Robison

My Feedback: (3)

Andy:

First, I have issued Club Saito card number 332 to TCrafty. Is that short for Taylorcraft? Welcome anyway.

Yes, the cam can be one tooth off in either direction and the engine will still run.

Pull both rocker covers and the glow plug. Turn the propellor in its normal direction and watch the rockers. First the exhaust will open, then as it closes the intake will open. At the point when the closing exhaust and opening intake are equally open the piston should be at the top of its stroke. Use a tooth pick or similar tool to feel the piston’s position. If you are a tooth off the piston will be obviously low.

Twins? Radials? More expensive to make and buy, and generally heavy for their power. Having more moving parts also gives greater friction losses. Using a single of the same piston displacement usually gives higher power and therefore much better flight performance.

Bill.

TCrafty

I'll go check it out. Thanks Bill. By the way, where's Mary Esther, FL? I'm right in Lakeland.

Yes, TCrafty is short for TaylorCraft. Had one for a while and will probably have another someday, model, not full scale. Thanks for the info on radials. My dream plane is a Top Flight Stinson Reliant SR-9. I had actually thought of putting either a radial or twin in one. My dad has several gas engines and I'd considered that as well. We'll see. Thanks again Bill.

Andy

Thunderchild

Maybe so Bill, but you just can't beat the SOUND

Who cares about performance when you are pulling a chariot circa 1937 around the sky with a beautiful piece of round engine art like, say a FA-325R5 chugging away up front for all to see and bask in its throaty burble?

BTW, I settled on a Stinson Reliant for the 325 my darling wife acquired for me.

I'm in heaven/

[email protected]

Hey Gents,

I just bought my first Saito - a low time 30.

I was surprised to find it making clicking noises when crank is turned.

Clicking does not coincide with any change in resistance felt at crank, so I don't think it is from bearing roughness. Instead, it occurs when a lifter rides past peak of cam lobe (in both directions). I deduced that cam is driven backwards by the force of the valve spring (through rocker-pushrod-lifter). Click comes from backlash being taken up between cam drive gears.

The question then for you experienced guys is - Is this normal with these engines? Is backlash excessive and should I fix it before running engine?

Philip