Rudolph Hart

W8ye gives a timely reminder about being in to much of a hurry to mount and run a brand new engine.Embarrasing as it is i did that once with a new 115 by mounting it to a soft pine board with self tappers meaning to mount it properly for the first full throttle run later...well i forgot or could,nt be bothered and at full throttle it began to lean forward and started splintering the pineboard with the prop,levered itself loose ripping the throttle mount off and severing the fuel line before going for a quick fly around the shed.Let us know what your problem turns out to be even if you don't do anything as silly as that described above

FNQFLYER

Johnny boy you said the crank bearing slid off the crank.  Now it depends on how loose it is but that could be your problem.  Once again in Old Timer use we change bearings a lot (running 15 x 8 and 16 x 8 Graupner props in Texaco puts lots of strain on the bits (all done for fuel efficiency ).  We have found that when bearings get loose on the shaft the are generally loose in the crankcase as well.
Temporary solution (for us) is to locktite the bearing into the crank as well as onto the shaft.  Before you do that ensure you have the appropriate debonder in case of mistakes.

FNQFLYER

People, the RCM site does have the Saito book available as of the w/end, my mate bought one (at least they took his money and gave him an expected delivery date)

johnboy151a

My Feedback: (68)

I hope it's just a case of me not being a great tuner. If I'm told the crank is the problem, I will probably spend the cash and get a crank and another set of bearings.

I will wait for Mr. W8ye to run it and tell me what he thinks. I hope I'm the problem.....

John

captinjohn

This is not a reply...it is a STATEMENT:

FNQFLYER

Old Fart, trust you will be ok, Yasi didn't get you hopefully Carlos won't either.
Still sorting the shed but the engine runs are almost upo us, Canowindra in April (send the missus to Canberra) and then we have Calvert (SAM QLD) in June.
I am getting caught up in promoting O/T here in FNQ as well as scale so time is some what short but fingers crossed al will be back to normal this w/end 

Rudolph Hart

Hey i'd like to hear some more about what you are doing re propping up fourstrokes.Finally some relief this coming weekend from the howling easterlies of the last three weeks and maybe a chance to fly the midget mustang,cheers all

FNQFLYER

Old Fart, if you know of an organisation called the Vintagents (SAM 84) here in QLD you'll know a bit about our "radical aproach" to all things aeronautical especially with regards to (not in order of importance or relavence) the MAAA, and things aeromodelling, especially in regards to O/T flying.
So to propping of Saitos.  Firstly you will (to get best effect) do some mixing in your T/x.  Firstly make the flap (or any other unused rotary / drum switch ) the master threottle control with it being switchable back to normal throttle (usually, on JR, through the landing config switch)  This gives you a fixed RPM setting in the climb which is most important to achieve max fuel efficiency as well as constant speed etc and thus the light won't go out in the glo plug.  The idea of having normal throttle control is to get the a/c of the ground safely and out of ground effect.
Now you set the drum control of the throttle to say 4,000rpm or what ever speed gives you reliable positive climb without the a/c acting like a home sick angel
And there you have it.  I would start with a 15x8 on a Saito 65 and work around that.  I use Graupner club type props when I can get them and in order APC the Master Airscrew classic.  The prop diameter and pitch depends o 2 things ambient (local) temp and atmospheric pressure (height above sea level of the field mostly) and the fuel you are using.  In Texaco mode I use 10% nitro and 2% synthetic oil
When initially tuning the engine (usually on the test stand) you set the high speed needle to give a reliable 6,500 to 7,500 with a range of prop sizes (in the brand you choose to use) from 14 x 6 through 14 x 8 to the same in 15 inch and 16 inch.  I lean towards the 8 inch pitch for the 65 and the 6 inch on the 62 with a slight increase in operating (climb) rpm for the 62.
You also have to understand that these are Texaco applications, if you were using that engine for duration (and why would you when the 62 is around) you would have to step down to a 13 x6 (prefereably a Bolly if you can get one) feed it steriods (at least 30% nitro) and retune to to get max rpm.  In the Texaco tune and with big props you stand a real chance (if your engine is marginal) of breaking bits should you suffer a crash under power, and a close watch must be kept on the bearings if you are going to be truly competitive.  My method for checking crank bearings is to put a prop on the engine and then try to rock the prop sideways while the engine is secured to a test stand or aircraft, and at least once every 6 months (or engine removal from the a/c for what ever reason) remove the back plate and with the aid of a strong light check the internals for condition etc
That should get you started.  Let me know if it helps or be a bit more specific.  I have run of "at the mouth" a bit but you have my standard lecture to those who wish to follow in our foot steps   

Rudolph Hart

I'll need a couple of days to digest your post,thankyou for the way you wrote it.What i would like to do is run the 220 propped max at 6500 and cruzeing in a seagull mew gull.I have a short polished stainless shotgun pipe poiunting out the bottom of the cowl for added wank factor plus i reckon it will be loud which today is good

FNQFLYER

Thanks, for what you propose I usually set the engine up so cruise power is at about 50 to 60% throttle travel (thus you have an "Oh **** factor" of extra power available should it be required.  Props I usually start at the mid range of what is recommended and work up and down from there to find the optimum.  I also have a collection of test props (accumulated over time) from various manufacturers that also help with the fine tuning if you want to go that far.
You have Sherlock props over your way why not try them for a prop?   They build good racing ones I am told.
Let me know how the Seagull Gull goes please.  When I was at Vietnam Airlines (Boeing contract) I visited Seagull when they were in their start up mode, they horrified me but I sent a guy I knewto see them and they appeared to have listened to him as I am getting favourable reports about them.  I am playing (well hope to this year) with an ESM Storch and Swordfish, both to be Saito gas powered assuming I get my finger out.
It is pi**i**G down here at present, something to do with the blow building up around Vanvatu.  Poor buggers at Cardwell really don't need this 
Catch Ya  

the pope

Hey there OF I have the mew gull as well but im putting a 125 saito in mine. I am envious of your 220. you should read the thread about it on RC Groups as the lg could be a prob.I redid mine before i put the wings together ,its about a days job and Im glad I did it. If you choose to leave it stock let us know how it goes. There seems to be a bit of debate with the c o g as well. I read all of this before I bought it and as I paid $200 I thought it was a good buy for a 120 size plane.Cheers from the pope

Quikturn

My Feedback: (12)

Well I received my SS bearings from RC Bearings, took my Saito 65 apart and come to find out I was wrong about my main bearing being seized. What I was looking at that I took for the inner race was a metal shield of some sort. The main bearing is rough however, almost gritty like in feel and the crankshaft is very snug around the inner race like it should be. I'm kind of at a loss as to how the rust formed. I may not have run the fuel out after a flight I guess.

In any event, a new SS main bearing will be a nice upgrade and hopefully this won't again anytime soon.

w8ye

My Feedback: (16)

Looks like a low time engine

Quikturn

My Feedback: (12)

Yes, it is a low time engine. The crankshaft had some surface rust so I soaked it in some evaporust to clean it up a bit.

I got the bearings out and realized the front bearing is different. Fortunately, before I installed the front bearing.

The packing list says Saito 65,72 Stainless steel. Front bearing listed is a 608-2RS. Bearing in package is a 608RS. Not sure if that makes a difference. The front bearing that came out of the engine is 608LU.

Hmmm. Looks like it's time to contact RC Bearings.

w8ye

My Feedback: (16)

If the 608RS has rubber seals on both sides it is a 608-2RS

FNQFLYER

The "rust" that develops in engines over time is generally caused by residual nitro and water methanol.  Both are hygroscopic (have affinity for water thus soak it up).  I changed a set of bearings recently for the first time in an engine that had been used for over 10 years without being opened up.  Living in the tropics (and have done for many years since 1989) I follow the following procedure,
1/ always lean run the engine at the end of the day (or as soon as possible after I get home 
2/ I squirt some ATF in the exhaust and in the breather and turn the engine over, this is assuming that I am going to use it again soon and then I close the carby and wrap the engine in a piece of bath towl or nappy (the cloth type)
3/ If it is to be put away I fill the engine with ATF and put and old glo plug in it to seal the engine and then either put it in a freezer / ziplock bag that has been liberally dosed with ATF and seal and then wrap some tape around it after excluding as much air as possible.

As to the roughness when you turn the engine over, I suspect pitting (from rust) of the balls in the beaing race / cage especially if it goes away when fuel / oil is introduced to the engine.  This is more of a cause for rejection and rebuild than rust as if the balls grab on the race or shaft you can have a big engine failure

Quikturn

My Feedback: (12)

This is my first 4 stroke engine that I've operated and perhaps I need to figure out a way to oil the case better. With 2 stroke engines, when you put oil down the carb throat it gets back to the crankcase with a few flips. That's not the case with 4 stroke engines as the main bearing gets lubed with blow by. I try to put oil in the breather tube but it seems tricky. Maybe I should use a syringe to inject oil into the case?

w8ye

My Feedback: (16)

The syringe is a good idea

I use auto automatic transmission fluid as it seems to do a good job of removing the old and rust prevention

Rudolph Hart

I've got a small squeeze bottle of atf and have a piece of fuel line 100mm long with a brass fuel tube end which hooks up to the fuel line on the vent nipple,i usually flip the engine upside down and gently give the bottle a few squeezes to get a couple of ounces in there and turn the prop by hand then with a starter.Had'nt thought about dropping some down the exhaust,good idea mate.

Rudolph Hart

Hi mate the 125 should suit that aeroplane well i'm only using the 220 because i don't have a 180 plus the 220 fits in the cowl easily and it makes a nice bark.Landing gear is an easy fix re the grub screws falling out,not aware of any cg debate do you have a link?

Heaps of sharks having a massive feeding frenzy here at the beach and have had helicopters parked over the house all morning,neighbour said he saw a great white early this am.

FNQFLYER

They protect those things over your way (White Pointers)  methinks that a degree of selective culling would not hurt and BTB I believe the same should apply to our crocs.  Re the 220 prop it down and both diameter and pitch otherwise you will be playing catch up.  We had problems with a Dragon Lady (in Malaysia) that was fitted with a dual plug 125 went like the clappers until the prop nut came loose and it engine over revved to destruction.
I will be interested to hear how it goes, my mate at Rosewood has a 115 powered World Models Midget Mustang that gets away from him a bit
Good luck

Quikturn

My Feedback: (12)

OK. I managed to find a front bearing that fits my Saito 65. I bought this some time ago for a 2 stroke engine but it has a metal enclosure. Is this a sealed bearing or a shielded bearing or is there even a difference?

The left bearing in the photo is 608RS and the one supplied from RC Bearings for the Saito 65/72. The ID on this bearing is too large. The center bearing is 608LU and the original that came off my Saito 65. The right bearing is the one I have laying around and is 608Z.

Here's my question. Am I OK to use 608Z? I know the rubber sided bearings are designed to hold grease. Will the metal shielded bearing hold grease as well? My concern is that it could dry out and/or allow oil/grease to leak out during operation.

FNQFLYER

Never worried about crank shaft bearings holding grease.  I would suggest that you take the old bearing to your local bearing shop and get them to replace like with like.  In my case I generally have got a better quality bearing cheaper especially when they know what it is being used for

FNQFLYER

Old Fart have you seen the new one page heavy a/c certification yet, been just released to us from the illustrious MAAQ committee secretary

Rudolph Hart

If the bearing has a metal enclosure only it is normally a shielded bearing as opposed to a sealed bearing and on saitos i look to fit them on rear mains only you can even pull the rubber from the inside of the front bearing i've heard,no harm done what do others think?

Fnq i take your advice re propping the 220 not trying to go overboard at the mo trying to sort out a good 10 pitch prop so the mew gull will fly at full size scale speed and low revs what do you think?