clytle374

Seriously considering converting my 100 to gasoline again. How much hotter are they running on gas?

Thanks
Cory

Just noticed that many parts seem different between the gas and glow models. Cylinder, rod, case all changed part numbers. I did see they put a real valve seat in the FG-17.

earlwb

Try Slimline http://www.chiefaircraft.com/sli-saito.html



Also keleo Creations does Pitts muffers for Saito engines too
http://www.keleo-creations.com/index...index&cPath=24

earlwb

The Japanese bearings have a huge markup to them due to the value of the Yen going up and up and up as the USDollar goes down more and more.
Boca Bearings are good, they tend to have less overhead so the costs are less too. Horizon has more overhead, but they are good though.
RC_Bearings has even less overhead and less cost too.

charlie1960

Thanks.

dirtrod

Thanks guys, I really just want to make sure that
the quality doesnt reflect the price, i have never
used rc bearings so i think ill give them a try this
time. thanks for the input,
TY

w8ye

My Feedback: (16)

I have not noticed a significant difference in temperature.

earlwb

The methanol in the glow fuel actually imparts a considerable amount of cooling effect with a engine. It helps cool the engine a significant amount. it is one reason why you can see some engines that have little to no cooling fins on them. Now with gasoline, it doesn't help cool the engine at all. So you need more cooling fins to help cool the engine. Also gasoline burns more hot than methanol does. So that is why you see people having problems with glow engine conversions. Now if the glow engine has lots of cooling fins on it, such as the later model Supertigre engines have, then you can usually convert them more successfully and have a good running engine on gasoline. But the Saito engines generally don't have a lot of cooling area on the engines, so it may or may not work all that well. I think the gasoline Saito engines have more cooling area by leaving the cooling fins a little longer. But I still have heard of people having overheating problems with them.

charlie1960

you wont be dissappointed.
if and when i need bearings again i will get them form rcbearings.

blw

My Feedback: (3)

I agree that methanol helps cool th engine but some will argue about it.

clytle374

It makes sense that it would run hotter, I was just wondering if it was close to being a problem. I see the crank has a different part number also. Can anyone compare the cylinders and see if the fins are longer? I've never seen mention of Saito changing that on the FG line.

Cory

Rudolph Hart

I read a lot of saito engine reviews and don't recall anyone saying the cylinder was different in any way,apart from the sparkplug hole.I think you would have to pay more attention to cowling cooling though.Don't know what they are like to tune as i don't have any gas saitos.The fg36 has noticably less power than my fa220 and it sounds a bit flatter too.

clytle374

I think I read the whole thread on the FG-20 here, and I don't recall anything either. I thought the hole was the same 1/4-28 as the glow version.

Not sure I want to loose the power either.

Thanks
Cory

w8ye

My Feedback: (16)

The crank is only different as it is drilled for a locating pin for the hub.

They redesigned the cylinders for the smaller gas engines.
Then they used the gas cylinders on the glow engines but the compression heights are different. The gas engines have a higher compression ratio and smaller intake manifolds.

The FG30 & 36 heads are made for the CM-6 spark plug. The Saito 180 and 220 glow engines are different with smaller fins.

Beej

Hi All,

I have a problem with my Saito 100 backfiring in the air (not on start-up). Engine has around 10 litres through it and running on 20% nitro 18% lubricant (16% Klotz 200/2% castor), 14 x 8 prop, max revs on ground 9600, needle wound back to 9200 on ground and low speed needle set as lean as possible to give reliable idle and smooth transition. So, a couple of weeks ago all was well, had 4 uneventful flights then on the 5th a loud pop on the way to WOT. Dead stick landing. Started again, no problem, took off again - same problem. Took it home, check the tank for leaks, check the plug (OS F), check for loose clunk etc, flushed the spray bar, checked the valves. Valves were a little loose so brought them in to 0.003. Back to the field, 5 flights no problem - really wringing out the engine - it was faultless. Sixth flight, take-off, WOT- POP! Dead stick. Back in the pits - WOT - engine dies.

So, one possibility I guess is that even through I have carefully adjuested the low end needle and I have smooth transition, it is too lean. Ditto the high end needle? Fuel flow seems fine and tank has been pressure tested. The thing that's really confusing me that every thing seems fine for a few flights the trouble starts. I dont think it's overheating - not particularly hot here at the moment, the engine is quite exposed in the mount so lots of cooling. Maybe I have been unlucky and picked up some minor blockage in the spraybar two weeks running? Fuel line from can to tank is filtered, and I have flushed the tank a few times just in case of small bits of loose nylon.

Any suggestions would be very welcome.

best

Beej

charlie1960

max revs on ground 9600, needle wound back to 9200 on ground


is that on the rich side or lean side of 9600.
sounds like you may be leaning out.

Beej

Thanks for the comment but the 9200 is achieved by richening the needle not by over-leaning it so it may not be that.

cheers,

Beej

Rudolph Hart

You don't say if it's a really quick aeroplane or not.If it is i've had the same problem with a 55' midget mustang and a 115.

charlie1960

how lean is the LSN?
sometimes it can affect the hi end.
it does on mine.
if i get the LSN too lean, i get a GREAT smooth idle, but a crappy transition, and it will pop like you describe.
seems as tho it struggles to gain rpm after 3/4 throttle and pops. it has slung the prop before.

other than that, i havent got a clue. except maybe a fresh plug.........i did have some fuel once that did it too...old fuel from the season before.
hard to start and didnt want to accelerate,just wouldnt run on it. fresh fuel. pop went away.

DustBen

My Feedback: (3)

Of all the 4 strokes I ever ran or owned, I was always impressed by the Saito line most of all.
One of most favorite versions was the .80 built on the .65 case. The weight to power ratio was hard to beat.

Beej

Thanks - I have the LSN as lean as it will go whilst keeping a smooth transition. I leaned it to the point where it hesitated mid range, backed it off until it was smooth, then for good measure richened it 1/8th turn. The strange thing about this is that the first few flights are fine and I dont change anything. Backfires have happened on climb out from take off or level flight so I dont think I am overwinding the prop to get the engine out of operational range (and the fuel is fresh). Plug is only about 10 flights old.

cheers,

Beej

hsukaria

Just for kicks, have you checked that the crankcase ventilation is not blocked? Not sure it would cause this problem, but jus to be sure.

Beej

Ahhhh interesting thought! Last time i wiped the plane down I thought there was very little oil on the underside. Will check.

cheers,

Beej

Rudolph Hart

Beej the reason i asked whether you have a quick aeroplane meant is the engine tightly cowled.In any event my first thought was that the engine is getting to hot,and you may still be to lean by the sound of it.

lopflyers

My Feedback: (12)

Hello fellows, I finally decided to put my P51 Miss America out of her misery. I just cant fly her so I am taking the Saito 100 out.
Now I need a plane to put it on. Suggestions?
I dont want another warbird[]

earlwb

Before I can suggest something, I would want to know...
What is your skill level with flying the model planes?
What was your problem or issues with the p51?