Flyboy Dave

My Feedback: (21)

As long as it will turn over, it should run. If the carb is sticky or frozen, soak it
in some rubbing alcohol until it frees up. Check the plug, and use fresh fuel.

FBD.

RVM

Good looking plane!

scratchonly

Is your 80 inverted? Ican't get my inverted 80 to idle without onboard glow heat. If I try to lean it enough It blocks the spraybar and the hi speed goes lan and won't richen. Be carefull. I ordered the carb upgrade today and will report on it when installed.

larksrc

Thanks Dave.

JettPilot

My Feedback: (6)

If the Saito 72 is just a destroked Saito 82, which one runs better [sm=confused.gif] Do they like the same amount of Nitro etc ? What is the difference in the way the engines run by increasing the compression ? Aside from the power, what is the difference in operating between the two ?

JettPilot

Hobbsy

My Feedback: (102)

.82===bore=1.14
strk=.80
.80===bore=1.06
strk==.897
.72===bore=1.06
strk==.81

Since Horizon no longer lists the .80, I got the B&S figures from a NIB .80 for sale in the RCU MarketPlace. The only one of the three that is out of character for its bore and stroke is the .82. The B&S indicate that it would be a revver but it is in fact a torquer according to Clarence Lee and others.

loughbd

What you showed in your chart was cylinder pressures which AREN'T compression ratios. Most cars today will give cylinder pressures around 180 psi and their compression ratios are about 8.5 to 1.

dogtoes

Hi,

I just stumbled upon this thread and thought I'd chime in too. I've got a FA-65 that I purchased off of a buddy a couple of years ago. It's supposed to go into my GP Piper Cub 40, but since that project has stalled, I'll drop it into the TF Contender that I'm building. My hope is to mount it inverted. Reading the bits of the thread that I have, I don't "think" it'll be a problem. Hoping to do it without the need for an on-board glow system.

Now if I can just figure out what fuel I should use...

-Chris

scratchonly

Bill:
Today, on your advice I ordered the carb upgrade kit for my .80 which will not idle inverted without glow heat. Originally the add stated it would not be in till october but I find they have a couple in now. Will let the gang know if it helps when I get it installed, likely in a couple of weeks.

William Robison

My Feedback: (3)

Latest additions to Club Saito, (some duplication of previous, sorry)

343 RWeber
344 Uncle Ted
345 mprediger
346 juvaknin
347 larksrc

Lets welcome them all.

Bill.

William Robison

My Feedback: (3)

JP:

The FA-72, FA-80, and the FA-82 are a strange trio.

The FA-80 was the first, 27x22.8 bore and stroke, 0.796 cid. As stated earlier it was an ABC design. Most of the Saitos of the time were still ABC, nothing strange there.

When Saito wanted an engine between the FA-65 and the FA-80 they took the easy route and made a new crank case with a shorter stroke crank to use the FA-80 cylinder. But they didn’t want it to be so heavy. Since they were switching to AAC cylinders, they kept all the dimensions and just made it in AAC. Why should they make two cylinders identical except the material? They shouldn’t. The FA-80 got the new AAC cylinder as well. The FA-72 was 27x20.6 mm bore and stroke, 0.719 cid.

I suppose some people complained about the higher vibration of the AAC version of the FA-80, which was to be expected since the AAC version was a lot lighter than the older ABC engine.

So Saito pulled another “Why Not?” and overbored the FA-72 and made it 29x20.4 bore and stroke, called it the FA-82. 0.822 cid. Naturally it has the AAC cylinder.

Please note the 20.6 stroke of the 72 and the 20.4 of the FA-82. This is only 0.008” and I suspect Saito isx “Playing numbers” here. The two cranks have different part numbers but I suspect they will interchange with no problem.

Which one is best? All your choice. As was said earlier the FA-80 has been a bother to set up, with the carb upgrade that seems to have been solved. Immaterial for a new purchase, the engine has been discontinued.

The FA-72 has become a nice engine with the new back plate, the intake leakage problem having been solved.

The FA-82 is the latest of the three, and except for a larger diameter on the intake pipe and slightly larger fins on the lower part of the cylinder has all dimensions exactly the same as the FA-72. Either engine will bolt in place of the other with no changes. Not even the throttle linkage.

My choice? The FA-72 weighs 0.6 ounces more than the FA-82 and is less powerful. The only reason I can see for buying the FA-72 is that it’s $30 less expensive than the FA-82. For most of us that’s lunch money for one or two days, and I’d go hungry for a day to get the FA-82. I have just “Voted with my wallet,” there are two new FA-82 engines in my house right now.

But for you, it’s still yur hoice.

Bill.

William Robison

My Feedback: (3)

Dogtoes:

You have a nice engine. The FA-65 is the only current Saito single cylinder engine still being made in ABC, so it’s a relatively heavy engine. Give it reasonable care and you’ll enjoy it for many years.

You may not have quite the performance you want in the Contender – it probably wont hover – but it will be more than enough for anything other than “3D” flying. And it will run fine in an inverted installation.

Fuel? I am a die-hard disciple of castor oil in the fuel, my personal choice is Omega with 15% nitro. A good compromise between power and cost.

And I’ve listed you as member number 348 in Club Saito.

Welcome to you also.

Scratch:

In 99 cases out of 7 the carb kit has tamed the FA-80. And do let us know your results please.

Bill.

Hobbsy

My Feedback: (102)

Bill, I have ordered an upgrade kit for my old .80 and two velocity stacks, the Horizon site says out of stock but they shipped the day after I ordered. I also ordered a couple of the new Cast mufflers, that should complete my change over to the cast mufflers except for my two .30s.

William Robison

My Feedback: (3)

Dave:

Horizon just got the SAI50GK93 stacks in yesterday - I know because they called me to release the back order I had for some.

I had intended to note this in one of my posts, but forgot. Thanks for the notice.

Are you getting the air filters?

Bill.

Hobbsy

My Feedback: (102)

Bill, up to this point I have never used air intake filters, just fuel filters. So far that has never effected any of my old fourstrokes, Enya .46MKII, Saito .80 and Saito 1.50.

JPal101

My Feedback: (32)

Just for the record I have a FA 72 that I have flown inverted since the first day I got it and never had a problem.

RcShacknet

Bill I contacted Horizon via the email The contact you gave me and I still hevent got a reply about shipping to Australia?

Also

If anybody could help me decide on a 3 or 4 blade prop for my FA-72? What can this motor handle? Im looking for simular performace compared to an Apc 13x6, but I dont have the ground clearance for this prop?

RC

NM2K

My Feedback: (14)

Notice that the OS.91FX that everyone gripes about running poorly had among the highest compression ratios. Those using this engine in 3D models and being used to four-strokes that are very nitro tolerant are going to have a rough time getting this engine to burn 20-30% nitro without a struggle. <G>

Nice chart. Thanks for posting it, Dave.

NM2K

My Feedback: (14)

If you are talking about the .60 sized Contender, the FA-65 won't be enough power. Also, the fuel tank will be too high for an inverted engine without lowering the tank. I don't think you have enough room in the front of that model to lower the tank much because of the steerable nose gear and associated steering linkage. I've built one or two of these models. Lots of fun, but you don't want to get into the habit of deadsticking them. That low aspect ratio wing can be a killer when the power is off.

Flyboy Dave

My Feedback: (21)

Artisan....did you mean the OS .91 FS at 135 ? I didn't see the OS .91 FX
on the chart.

Dave

NM2K

My Feedback: (14)

Yep, I misread it. You have to admit that that would have explained a lot of problems with that engine IF it were true. Thanks for the correction.

Flyboy Dave

My Feedback: (21)

....no problem. My ASP clone of the OS .91 FX (mine is ABC, not ringed)
has real high compression. It must be a Euro engine....anything over 5% and
you get the "fried eggs".

Sorry 'bout the off topic, fellas.

JettPilot

My Feedback: (6)

I also have ordered a Saito FA-82GK After putting all the saitos side by side, the size difference between the 56 and the 82 were so close, I could barely tell the difference. So much more power for only 2 ounces, I had to do it [sm=greedy.gif] What is the Vibration like in the FA-82, do you think I will have a problem with it on a camera plane ? Will it idle and run at low power settings well also ? I have a cline regulator also for this engine.

JettPilot

loughbd

The contender is a *****cat deadstick. We used to have an event called climb and glide. You ran your engine for 1 minute and then shut it off. The idea was to remain in the air as long as possible. I had a contender with a OS61FSR and tuned pipe. I couldn't last 1 minute as it would be out of site. It had an excellent glide characteristic and wouldn't tip stall. The whole wing stalled and the plane remained horizontal and the ailerons were still functional. great airplane. A Saito 65 will fly it but nothing spectaculat.

rlmcnii

My Feedback: (3)

JP,

I am not WR! However, I do have a .82 on a BruceTharpe Venture. The engine runs very well at low power settings. Mine spends most of its time at or below half-throttle and does fine. It will idle very well with no tendency to load up. Ventures are floaters and approaches are flown just above idle. Even after idling for a fairly long time it will transition out of idle perfectly. It also handles transitions from wide-open to near idle with no tendency to quit, even very rapid transitions. Mine has never quit in flight.

Due to ground clearance demands (the field from which I fly is pretty rough) it has a 13x8 wooden MA propeller. I have also used a 14x6 and the engine runs well with that propeller.

Mine does not seem to vibrate badly at all, certainly not objectionably. It seems to be noticeably smoother than my .91. No model airplane of mine has ever carried a camera so I can not speak to that concern. However, a more experienced Saito-operator (TW, I believe) remarked in an earlier post that most of the shaking of which Saitos are accused is probably due to an improperly-rich LS adjustment. You have probably noticed that these engines run more smoothly when properly tuned.

One of mine did have the exhaust pushrod in upside-down, as did my .91.

I think you will like an .82. rlmcnii