flytaildragger

My Feedback: (8)

Thanks SNJ, this is gonna be a new experience for me, it's going in a 91" Zero

BobH

My Feedback: (2)

Doomking

My Feedback: (38)

jagdpanther9

i just went through the breather and added a 1/2-1 oz of oil. make sure to use only the oils that saito recommends . after you have the oil in the engine put your prop on it and without it bolted down rotate/flip it through many cycles while turning the engine every which way to get that oil worked into everywhere. run a very rich gallon through on the test stand at least and you should be good. i ran nearly 2 gallons through mine and did a valve adjustment before i even had the engine in the model and so far it has been bullet proof after more than 2 gallons in flight.

DH71TIGER

Hi everyone, will somebody please tell me the inside diameter of the Keleo ring exhaust for a FG-90 R3.
The inside diameter of the ring not the tube that the ring is made from.

Thank you in advance

ForcesR

It's approximately 178mm (7 inches) inside diameter. If you want the precise measurements from the OEM here it is. Ring dimensions: Saito FG 84R3 and Saito FG 90R3 Diameter: 8-1/4
Inner Diameter: 6.8125.

DH71TIGER

Thank you ForcesR that's perfect.

flytaildragger

My Feedback: (8)

I keep hearing about some owners of this most popular engine who have been experiencing catastrophic failure in flight.. I know it's a subject a bit negative, but I would like to explore any common reason that would consistently cause this very expensive problem and possibly avoid it?

SJN

Use good oil, and cool the engine well.

jagdpanther9

use the recommended oil , brake the engine in on a test stand not in the air with at least 1 gallon of fuel keeping the mixture rich.use at least a 24x12 prop to keep the rpm down. and like sonnich said keep the engine cool using baffling in your cowl . also on mine i have made 2 valve adjustments in the last 3-4 gallons of fuel. if you look back a few pages in this thread there is some good info on break in and tuning. by far this has been my favorite engine so far.

flytaildragger

My Feedback: (8)

I've been modeling for years, it feels weird to be nervous over this engine. So what I'm hearing you guys say, if one of these grenades, it's usually a pilot error?

jagdpanther9

i know of one for sure that the guy treated it like a 55cc two stroke and said "i will just brake it in flying it" . his grenaded. i saw a guy flying an FG90 in a ARF zero lean as heck hot as hells blazes and he got away with it. it was suggested that he fatten it up which he did and he went on his merry way for the rest of the event. really i dont think that you hear all of the success stories from all of the folks out there who are happy as clams flying the heck out of them. but when things go haywire people love to vent. the sayin goes something like " it takes 1 oh crap to screw up 100 at a boys"
i am very pleased with mine flying it hard in my TF corsair with a big grin on my face. what i heard made me nervous too but i just made sure to brake it in good and i am very pleased.

hpergm

Mine's prepped for the break in. Well oiled up, all valves checked (only one out of tolerance), instrumentation installed. At least 1lt vertical to make sure all cylinders heat up.

8

jimkron

My FG 84 was running great. After a rough landing cylinder #1 was cold, transition was terrible, rpm crappy. Tried everything to get it to ignite, plug change, carb change, fuel change, hours tuning...nothing worked. Called Saito guru Ray English. First thing he said was, "did you have a prop strike?" I replied, "not sure but maybe". I checked the prop and sure enough, the tip had hit the runway. Frankly, I didn't notice. Probably was too focused on bouncy landing...and all the cursing that followed. Anyway, prop strike moved the timing hub behind the prop that holds the timing magnets...a full 5/8"!!! Ray reset everything and the Saito ran perfectly. Don't quote me on the fact. I believe the allen set screw on the hub must line up the the center of each cylinder when the piston for that cylinder is a top dead center. You can check this...if you feel the need...by taking out the spark plug and sticking a small screwdrive into the hole. Rotate the prop until the piston is at it's highest point...the allen set screw should line up with the center of the cylinder. (I forget what stroke) Sooooo, PROP STRIKE...lesson learned.

Just a thought,

jim

jagdpanther9

awesome test stand hpergm ! braking it in is almost as fun as flying it! That is great info to keep in mind after a prop strike jim!

deadstick79

do you still have the FW 190 and FG 60 radial?
Dan

hpergm

Thanks Jagdpanther.

Dan, yes the FW190 lives on. The 90 will go to a GeeBee. Being a little bit wiser this time, I am going to try netralising gravity for the over-rich initial runs to get all jugs running at the same time. Will report how that went.

marksp

My Feedback: (9)

marksp

My Feedback: (9)

jagdpanther9

i really enjoyed braking in this engine but it was time consuming . i have to agree that these engines are very efficient and for the enjoyment of the performance and sound and efficiency they are worth every penny. at some point i would like to try out the FG-19R3 in a 55"-60" span model.

hpergm

First run today at the mountain (keeps the neighbours happy). Was able to hand start it (!).
Went through 1.5lt of 1:15 fuel. RPM was kept below 4k. Music (ring muffler) by Meier.
Instrumentation worked flawlessly and allowed me to control the heat balance/cycle of all cylinders by setting the Low needle leaner (but still rich) than the High and then making throttle adjustments*.


*There is a some theory behind this, but the logic loop goes like:
A. Rich carb settings = floods cold inlet chamber = "top" cylinder is usually leaner. In this video, Cylinder #1 is lower than #2 and #3 due to the stand inclination, so ehxibits the lower temps (basically, cold). Go to B.
B. One/two cylinder(s) firing = high gas pressure = increases burnt gasses blow-by = extinguishes opposite (2nd/3rd) rich cylinder (due to reverse blow-by, as piston rings are not yet seated). Go to C.
C. Reduce throttle a little = lower rpm = less frequent blow-by of firing cylinder = higher chance for opposite cylinder(s) to relight (Low needle is leaner than High). Wait until D.
D. Cold cylinder(s) relight = allow reaching of operating temp. Go to E.
E. Increase throttle a little to increase all firing temps (more frequent explosions) = high gas pressures = increases burnt gasses blow-by = extinguishes opposite cylinders or the temp of the firing cylinder(s) climb above 165C. Go to C.

Due to the volume of the inlet chamber and the hysterisis of the temp recordings, this feedback cycle takes more than 2-3 mins.
During that time, one can see the cylinders dropping and popping back up at random.

Break in is complete when:
(i) Between 1/3 and 2/3rds throttle no cylinder drops (i.e. B does not happen = all piston rings are seated properly, no reverse blow by).
(ii) Cylinder temps are within 5C of each other and less than 165C max (following the leaner carb setting possible to achieve this result).

hpergm

Break in progressing well; all cylinders are heat cycling and balancing EGTs well at certain throttle settings...
Mixtures are still set very rich. Max rpm does not go above 5.5k rpm - there is still some time to go until 6k is possible.
At this point the engine has consumed about 4lt of 15:1 fuel.

DH71TIGER

Hi everyone,

Due to health reasons, I am thinking about buying a hand held electric starter for my FG-90 R3, do any of you guys use a starter ? If so, which one ? I would appreciate some comment from somebody who actually uses one.

Thanks in advance

Andrew

liemtran75

DH71TIGER

Thank you for that liemtran75 .............. unfortunately I have just been told by Sullivan that Miller RC products no longer exist, the factory was destroyed in the recent fires in California.

Any other offerings would be apreciated ............ especially if someone is using a Sullivan S651 Starter .......... is it powerful enough to start a Saito FG-90 R3 ?

Thanks in advance

Andrew