Kostas1

Guys,

i bought yesterday (still haven't taken delivery of it...)

a used SAITO FA-80
for my new
GreatPlanes Cherokee 40 ARF!

What prop do you suggest and
do you have any experience with this engine?

Please excuse the 108FSR from O.S.

-

optech

My Feedback: (9)

Start with a 13x6 and see what you get. If you can find a 13x7 that may better depending on the condition of the engine. I've used anywhere from a 12x8 to a 14x6 with good results.

Early .80s had really high compression and were hard to start and had nasty needling habits but made alot of power. Saito shimmed the cylinders and lowered the compression or you could buy/make a shim and do it yourself. Later models out the door came with lowered compression. This really tamed the engine but of course you lost a little off the top end. It was worth it in my opinion.

Mike

Kostas1

Mike ,

do you remember the rpm's with the 14x6 ? ( apc ?? )

rcdude7

My Feedback: (264)

A apc 14X6 would be the upper limit for this engine, a 13X7 would be good and a 13X6 would be light, running close to 11K.

optech

My Feedback: (9)

Sorry Kostas,

It was a very long time ago. About all I can remember was that it was not a lot of RPM. I had the engine in a Goldberg Cub. It climbed okay but I was younger and wanted a faster plane so I went back to a smaller prop. I think the prop I used was one of those black master airscrew plastic props. APCs were just becoming available.

Mike

Kostas1

I guess i should test a 13x6/7 prop and report back with numbers!

Kostas1

I guess i should test a 13x6/7 prop and report back with numbers!

Kostas1

Guys i will soon have my numbers to post!!!!!



[link=http://www.rcuniverse.com/forum/m_10245921/anchors_10407747/mpage_1/key_/anchor/tm.htm#]Saito FA-80[/link]

earlwb

You are a lucky guy, that engine looks like it is new.
I would not go with anything smaller than a 12x8. But the landing speed might be a little too fast for that pitch of a prop on your plane. On my low wing plane, as pictured, I tend to land it fairly hot and fast anyway. That may not work in your case with your plane. If possible a 13x6 or 13x7 might work better. But with a lower pitch prop the engine RPMs might go to high in the air when you are flying around as the prop unloads more up in the air.

I had recently replaced the bearings in my old Saito FA-80 a while back and made the video below. It was sort of a cheap thrill to actually get the camshaft back in correctly on the first try. I had bought this engine way back around 1990 and I have been running it ever since.
I used a APC 12x8 prop as that was what fits my old low wing sport pattern plane to clear the ground with. The prop doesn't clear by much either. I ran Omega 5% nitromethane fuel which uses a blend of synthetic and castor oil.
I was getting around 10,600 rpms on the test stand with it.
My engine has a fairly high compression ratio. I had read that the early versions had high compression ratios. So you want to be careful with the fuel if yours is like this as it doesn't like a lot of nitromethane in the fuel.

[youtube]http://www.youtube.com/watch?v=HfpKf6RqkIs[/youtube]

Kostas1

Οοοο 10.8k RPM with an APC 12x8 ?

That's a lot....i think that i will start with a 13x6 first...

The engine sure looks to be in very good condition...

Ah let me ask....does your engine has much compression ?

Because mine is almost impossible to turn by hand ...

Kostas1

Take a look at the muffler...it's an aftermarket made from DuBro !

earlwb

Yeah, my FA-80 is hard to flip over. My electric starter can just barely turn it over. You have to get a head start on it using the electric starter, and put the piston just after TDC on the compression stroke to get it going. By hand it is tough, I have torn up the soft plastic tubes on the chicken stick a few times hand flipping it.
I found that mine likes 0% to 5% nitro methane glow fuel. But It has quite a few hours on it, so it would likely use 10% now if I had to. Maybe a new piston ring is needed. But since it is running and idling good, I won't bother.

Do check the valve adjustments from time to time. They tend to close up over time which affects performance a lot and makes it even harder to start and run.

Kostas1

Thank's for your prompt reply...

I am going to test-run the engine as it came to me,
because i bought it used,
so as to see if it runs *out of the box*
and then ofcourse adjust-test the valve clearance...

earlwb

I forgot to mention that I have the regular Dubro muffler like yours for 2 stroke glow engines.
I might have a 4 stroke one too, but I don't remember. I accidentally found the 2 stroke muffler last weekend while looking for some engine parts.
I bought mine out of a clearance bin at the local hobby shop years ago.
It does look like it helps to quiet the 4 stroke engine more.

Kostas1

Hmmmm....

Hobbsy

My Feedback: (102)

Kostas, congratulations on the scoring the .80, I have one of the high compression ones and a newer plain one, The high compression one turns a MA Scimitar at 9,900 on 10% WildCat fuel with 18% lube. The high compression is not a problem, it demands respect and when given that it is a fine engine. I also have a high compression Saito 1.50, now that is an engine that can hurt you if you screw up.

Kostas1

Hobbsy,
it's always nice to read your posts!!!

I'm very happy with the purchase of my #3rd Saito , the FA-80 !

What diameter-pitch is the prop you mention on your post ?

Kostas1

[8D]

Hobbsy

My Feedback: (102)

Woops, sorry about that, it was a 13x6.

Kostas1

The MA Scimitar , 13x6 @ 9.900rpm produced 6.12lbs of static thrust...

Not bad..i'm wondering what the engine can do with an APC same size.

Hobbsy

My Feedback: (102)

Earl, your numbers coincide with mine. Yesterday I ran my old high compression .80.
Fuel=== WildCat 15% 2/4 with 18% all synthetic.
Fox Miracle plug
Prop===Bolly 13.5x6
Muffler==Davis SoundMaster In Cowl
RPM=======10,200.

Kostas1

In what rpm should we expect the APC 14x6 to turn ?

earlwb

Hard to say for sure, but something around 9,000 to 9,500 rpms ought to be correct.
I never tried running one that size on my engine yet.

Kostas1

I'd guess i will test that propeller,too.......

I am currently assemblying my Cherokee ARF and i have already installed the SAITO FA-80 on the firewall.

I will keep us posted!

Kostas1

Kostas1

My test-run and review.....

[youtube]http://www.youtube.com/watch?v=vfe0u9DABTw[/youtube]