flyingagin

Most of our stuff is in storage at the moment including a 700 volt electric fence charger. I am thinking that I could have some real fun with that. 700 reasons to pee some place else.

Ken

blw

My Feedback: (3)

If you have to decide on a 82, or 91, or a 100 it may come down to the prop making the decision.

i know what you mean about keeping the nose up. I have a Somethin' Extra with a 12.25" prop. I made a 1" block to make the gear taller and it can mow grass if I don't keep the nose up at all times.

jeffie8696

I prefer a taildragger with a four stroke for the ground clearance.

SrTelemaster150

I fail to to see the difference between a taildragger & a tricycle when it comes to prop clearance since the taildragger will be @ a similar attitude during take off & on wheel landings.

The nose wheel on a tricycle will actually prevent a nose down attitude on landings.

That being said I prefer taildraggers & have never flown a tricycle. It's just that I always consider the possible slightly nose down attitude when sizing a propeller on my aircraft.

Hobbsy

My Feedback: (102)

I just went ahead and ordered the lock nuts and prop washer, they are 10 buck at WholeSale/Lantz' Hobby Shop..

SrTelemaster150

Horizon still has the FA-150B & they are using the 8mm prop nut/ washer from the FA-170R3 for all engines W/8mm prop threads.

Any 8mm prop nut/washer will work.

Sorry that you had the mishap. I never had that happen on any of my CDI converted engines. The CR must be super high but then I don't see how it functioned @ all W/GI.

My 12.8:1 FA-180 was all but impossible to tune W/GI, but runs fine W/35° BTDC advance.

It could be fuel related. What was the HSN setting? I start W/3 turns out & usually end up @ 1 1/4 - 1 3/4 turns.

SrTelemaster150

I want to swing a scale length prop which is around 15". The FA-91S swings a 15 X 5 @ 9700 which is perfect IMO. I would vary pitch for more or less power.

An FA-100 isn't being considered as the 115 puts out considerably more power in the same footprint as the FA-91S. The additional 36 grams over the 100 will be a benefit on the short nose of a J-3.

It all boils down to what fits W/O cowl surgery. I want the maximum thrust W/airspeed as only a secondary consideration as long SS there is enough for a safe flight envelope. Even a 15 X 4 on an FA-82 should fly the plane @ 40 MPH W/plenty if thrust for vertical.

An FA-115 should give a bit more thrust & about 20 MPH more airspeed W/a 15 X 6.

The FA-91S falls right in the middle.

I need to mock up the engine/clear plastic cowl W/the FA-91S.

Sounds like a plan for today after I clean up the shop. It's a mess after working on my 40" worm drive tiller. Lots of garden dirt on the floor.

Rudolph Hart

Hey relax man,remember the old cheech and chong movie where they are both sitting in the front seat of a car and one has his hands on the steering wheel and saying 'am i driving ok?' and the other says 'i think we're parked man'.

I've talked to funnier accountants

Hobbsy

My Feedback: (102)

Thanks Dan, I had forgotten that little tidbit, 1.50 B

I found the problem, the engine was timed at 40 degrees BTDC unless the timing ring jumped forward when the engine stopped so abruptly. I can't imagine that happening though. I had a stroke of genius a while ago and came up with probably an old automotive trick. I had a glow plug like device here called a Gadget. I drilled a 1/16" hole through it and used a Sullivan fuel bulb to create a vacuum in the combustion chamber. It holds that engine at TDC with a surprising amount of force, no matter how little you move it off of TDC it literally flies back to TDC. It holds for about 5 minutes, plenty of time. The pointer is just out of sight in the dark.

PS, Lantz Hobbies is sending me the SAI170 etc pieces.

SrTelemaster150

Set 'er back to 35° then.

SrTelemaster150

Also, take a fine point black sharpy & mark the back edge of the prop hub & the crank case to check for prop hub shift. If the problem repeats itself.

Scribe a mark on the back of the delrin ring too.

blw

My Feedback: (3)

+1 and +1

OWIERK

I've got a new Saito FA-120S that I'm planning to put into a Phoenix Model 330S Extra. It calls for a .60-.90 2 stroke, I have a OS 60FX but I'm thinking it's going to be a little underpowered. The Saito 120 is my next best option. It looks like I'm going to have to mount the motor inverted. What if any problems can I expect? This is the first Saito I will be using so I don't know much about them except their excellent rep.

SrTelemaster150

There's a quick easy way to determine TDC that relies on a similar vacuum effect.

W/the throttle closed, the engine is slowly rotated to TDC on the compression stroke. The compression will leak down if you go slowly enough & you will end up W/no pressure in the chamber. The crank will only rotate a given amount in either direction due to vacuum for exactly the same amount. By watching the degree wheel you can then determine how many degrees that movement is & set your needle so that 0° is in the middle.

While I don't use this method as the initial set up procedure, I do use it to double check timing if I suspect it has shifted.

The vacuum bulb trick is pretty slick. I may have to see what I have on hand to make something like that.

FNQFLYER

Snr Tele, on the prop strike comment. Wheel barrowing with trike u/c a/c and touching the brakes on tail draggers on landing (in full size a/c) produce very interesting results especially to carbon fibre props. Metal ones not so much but in both cases they helped out my bank balance if I was around at the time. Big problem with model a/c (especially tail draggers ) is that the operators don't understand the finer points of using the elevator. Wheel barrowing a model trike ( landing on the nose gear) also produces interesting results.

Now to Saitos. That 30 I am installing. Not being able to turn the carby around has caused me a degree of pain with the installation, but it is in and the throttle is operable. I am going to use it in Texaco with controlled fuel (5% nitro and synthetic oil) and I'll be running a 10.5 x 4.5 APC as an intial test prop. Have got some APC 9's to play with as well. Should be an interesting day.

Hobbsy

My Feedback: (102)

OK, on the last go around it ended timed at 33.5 degrees. I am going to go with that the next time I run it. I'll have to use a Mejzlick 16x8 or a Classic 16x8. I think I have spot on perfectly balanced Classic and a 15x7 three blade MA. I love three blade props.

Rudolph Hart

+1

Rudolph Hart

Hi mate since it is the first saito you will run i'd bench mount it upright,run it and become familiar with it's tuning requirements.Use a tach,they are very friendly engines.If it's a used engine you save yourself some fuel running it in.I've flown an 82 sidemounted in an extra 330 which would be easier to do they run best on their sides @9 o'clock all the way down to about 7 o'clock looking at the front of the engine to airframe.Depends on your fuel tank height too.There are plenty of comments about running them inverted on this thread.Good luck they make a nicer sound too.If you start with a 15x8 mas classic prop you won't go too far wrong.

SrTelemaster150

The aerobatic airplanes that had flat engines in the full scale usually have enough room to mount a big block Saito horizontally.

My 73" WS Cap 232 allowed me to mount an FA-180 @ 9:00 W/ just some small cut-outs for the rocker covers.

The 120 will be about 1.5mm shorter.

If you must mount it inverted, check the C/L of the carburetor W/the C/L of the tank. If the engine is mounted high enough on the firewall, they may be closer than you think. If the C/Ls vary by more than say 1/2", you may want to investigate the Cline regulator that is mentioned a few posts back in this thread.

Rudolph Hart

Don't panic ow,sr meant fa180...otherwise spot on fitting instructions

SrTelemaster150

OOPS!

I fixed that!

Cougar429

My Feedback: (3)

OWIERK, welcome to the club. Once set up you should have great performance and service from your Saito.

There are a few key differences to 2-strokes you should be aware of and they seem a bit more sensitive to inverted mounting. If that is your only option I would advise if possible to flip the plane in a holder or some other device and spin the engine a bit in a more conventional position.

Regardless, you should flip the motor by hand a few times anyway, (without glow heat) to clear any hydraulic lock or accumulation of fuel/oil from the cylinder before trying to start. This can also give you some feel if there is anything amiss internally. With the motor inverted you will find that accumulation will soak the glow plug and take longer and/or more glow energy to burn off the crud.

Since you stated the motor is new, I would recommend pulling off the valve covers and confirming the clearance between the valve stems and rocker arms. This has the advantage of also showing you if one of the valves has become stuck in the meantime. You will have to repeat that procedure once the motor has some time accumulated and should at least be on your schedule before or during each flying season. Although the factory specs seem fine, I tighten mine up to between 1-2 thousands, (.001=.002") and they show no problems.

Pulling the valve covers is an easy procedure, especially now or before stuffing it into a cowl. One added little note would be to add a few drops of oil to the valve bits and down the pushrod holes, (not too much) if things appear dry. Helps keep everything lubricated until supplied by what's in the fuel.

If you haven't seen it already, I will restate my own personal and primary safety warning: EXCEPT FOR STARTING, DO NOT HAVE YOURSELF OR ANYONE ELSE IN THE SAFETY ARC OF THE PROP!!!! This pretty much covers the entire half circle from in line with the prop disc forward and is a good practice at any time.

Unlike their 2-stroke brethren, these can chuck a propeller at some rather energetic speeds. Regardless of the "Safety Nut" setup, I have personally experienced or been witness to this bit of danger. Saitos seem especially sensitive to lean running when at higher throttle settings and can come to an abrupt stop, and I mean IMMEDIATELY! Unfortunately the propeller usually has enough mass to wind itself off the engine and continue merrily on its way. This seems to only occur at over half throttle if the HS needle is set too lean.

Because of this I make it a practice to do initial setups and maiden flights with wooden props. Not only are they more forgiving and usually lighter, (not as much mass to spin off if the motor stops) as well as sacrificial if I find the plane a bit more of a handful than expected, (Rare Bear would nose over at the best of times, which meant the prop and grass met often). Even at higher RPM's the prop will shatter before transmitting that energy into the engine and save it from mechanical damage. The only disadvantage is that changes in humidity affect their dimensions and can cause the prop nut to loosen. Good excuse to recheck everything before flying anyway.

Other than the prior advice I would add a few extra tidbits. Along with ensuring any tubing connected to the crankcase vent is as short as possible, pointed down and unobstructed, I would keep a few extra 4-stroke glow plugs handy. As with any break in, they usually suffer in the first little bit until everything seats and the wear stabilizes.

FNQFLYER

Old fart. Saito 30 in 4 pound model fuel allocation 12 mils, rpm 5,000 on a 10x6 APC 5 minutes 30 seconds on ground run. 10% nitro. Am going to fly it today with an 11x6 Taipan and see what develops. The brand new Irvine 25 glo after 8 oz of FAI fuel is turning 10300rpm on a 9x4 APC. More running today on that one and fine tuning the flight controls. The Burford model (Taipan 2.5) ran like a top after a 15 month rest. Only changes have been converting to 2.4gig (best comp radio frequency) More tuning today and my first real competition where I actually instead of support in 12 months. Been a long time coming back.

Rudolph Hart

Go get em' tiger good to see you flying again.2.4 gig is the best upgrade you can do.

blw

My Feedback: (3)

I like trikes okay but prefer tail draggers. Just bring your trike in nose high and do your takeoff roll with up elevator to keep it light on the nose wheel. I had a 12" prop on a Sig Kavalier with a Saito 56. It was a close fit on a freshly cut grass strip, but worked out okay. I remember the grass being high one day and there were mowed little grooves in the grass that evening from all the taxiing around I did. It was kinda funny to actually see the meandering trails cut in the grass.