I have heard of 2stroke, 4stroke, and gas engines. I know 2stroke engines are glow. My question is, are 4stroke engines glow also, or do they all run gas? I appreciate any and all information you guys have.

You have 2 stroke glow and 4 stroke glow, then you have 2 stroke gas and 4 stroke gas.

like one of these http://www3.towerhobbies.com/cgi-bin/wti0093p?&C=GCI ?
ya their glow

What about saito engines? What are they usually? Specifically a saito FA56?

All Saito engines are 4-strokes

most are glow, one is gas

The FA56 is glow

The Saito .56, like most Saito engines, is a 4-stroke glow engine. It runs on the same type of glow fuel as most other RC engines and uses a glow plug rather than a spark ignition system.

Saito does make a couple of larger 4-stroke engines that run on gasoline though. These are spark ignition engines that use an electronic ignition system with a spark plug just similar to mowers, motorcycles and cars.

2-strokes, 4-strokes, glow, gasoline and everything else all have their place. Everything offers some advantages and gives up others.

The Saito is a glow fueled engine.
4 strokers sound a little better but weigh more and COST MORE and are a little more complicated...more moving parts etc.
2 strokers have a better power to weight ratio often better throttle control, are simpler in basic design, simpler to trouble shoot and cost less.
The four strokes are said to be quieter but actually they just produce a less annoying note. Decibels usually run close. So if Noise Perception is important to keeping your field a four stroke is priceless.
RC engine quality in either one has never been better so enjoy!

Actually, 4-strokes have better throttle response, and although they cost more, you will save that in fuel savings in one season.

Also, 2-strokes turn more RPM, but 4-strokes have more power.

Think about it this way...

A Dirt Bike is a 2-stroke. A Harley is a 4-stroke.

I am looking to buy a used at-6 texan equiped with the saito FA56. Does this sound like it could pull this plane? the plane itself has a 61"wingspan, retracts, flaps.

The main difference between 2 stroke and 4 stroke engines when comparing them side by side with cubic inch size is 2 strokes are generally less cost, more powerful, fewer moving parts, more crash damage resistant, lighter, better selection of sizes to fit more models........

4 stroke model engines are engineering marvels, most brands and sizes can be matched up with a corresponding airframe to deliver either stupendous or "scale like" performance....whatever you want.

That sounds like it will fly it in a very scale mannor

You will be flying that one "on the wing". That is, you won't have a ton of power left over. It will however, fly fairly scale like. A lot depends on how it was built, how much it weighs. Hope it won't be your first plane, or you have someone with some experience help you.

Right.

All too often we see the "Four Strokes have more power & use less fuel" statements here.

In a direct comparison of identical displacement TWO STROKE engines produce more power, but they need to rev higher than four strokers to do so.

To equate power output, you most purchase a larger displacement four stroke engine. However since the four stroke engine produces more torque at a lower RPM, larger props CAN be swung with the larger sized engines. At equal displacements this is not necessarily true and is marketing hype.

By the time you move up to the larger four stroke size, fuel utilization is only marginally less for an equally performing four stroke engine.

However the four stroke engines sound so nice, and some are SO tolerant of mis-tuning ( Saitos ) that we tend to like them a lot.

Ultimately you can use whatever you wish to use for your plane.

Let's look at the numbers.

It is generally accepted that a plane with a 60-size 2-stroke would need a 90-size 4-stroke.

The OS 61FX has a displacement of .607 Cubic Inches
The OS 91 Surpass II has a displacement of .912 Cubic Inches

The 61 will run at approximately 11,500 RPM
The 91 will run at approximately 9,500 RPM

This means that for every rotation of the 61 it takes in .607ci of fuel/air mixture, or 6980.5ci per minute.
Meanwhile the 91 takes in .912ci of mixture every OTHER rotation, or 4332ci per minute.

6980.5 - 4332 = 2648.5

So the 91 is using less than 1/3 of what the 61 is using... AND this does not take into account the amount of fuel loss generated by a 2-stroke (For a 2-stroke to operate, the new mixture blows out the exhausted mixture and some of the new mixture is blown out along with it - which is one reason that 2-strokes slime your airplane so badly).

If you burn 3 gallons of fuel per month at $20/gallon, you will save $20 a month

Cost of a 61FX = $180
Cost of a 91S = $300

So in 6 months, the 4-stroke will have paid for itself, kept your airplane cleaner, made your airplane sound better, and in all probability, contributed to world peace.

So not even taking mixture loss into account, a 91 4-stroke burns about 1/3 less fuel that a 61 2-stroke, it swings a bigger prop, and it doesn't spit slime all over your plane.

In the real world that 1/3 less fuel translates to about 1/4 - 1/6 less fuel actually used.

In practice I find my four strokers are not saving me anything significant in terms of fuel usage over the 2 stroke engines I could have used in their place.

Not that there is anything wrong with four stroke engines ( I do like them ), but this is not the big factor that it seems made out to be.

When dealing with .40 - 1.20 sized planes cost savings are not significant.

Going larger things change, but by the time I hit 1.80 CU I'm buring up so much glow fuel on my four strokers, that I'm better off going to gas instead.

My 1.80 CU four strokers seem to go through a gallon and a half a day at the airfield at a minimum.

opjose, would that by chance be a Saito?

There used to be a british tv show that explained how mechanics of things work, and it had little corny cartoons with it too. It was my favorite show, and the one on IC engines was the best. I will always remember SUCK SQUASH BANG BLOW!

Saito's, Magnums, O.S.'s, etc.

I'm not talking about the sloberingly rich glow fuel consuming mis-tuned engines either.

I consider my Saito's "sippers" once they are properly tuned, compared to my larger Magnum's or even my OS four strokers of equal size.


Of course if I don't get at least eight flights a day on a particularly day, I've hauled out to the airfield, then it's a bad day!


As one person so humourosly put it.

"Isn't it aweful? All that glow fuel sitting in the jug, so sad. "


I'm not knocking four strokers. I think they are great, and thus far VERY reliable...

But two strokers also work fine particularly within the .40 - .90 sized plane range.


I'll also futher add, that on my Skybolts, a Tower Hobbies .75 2 stroker outperforms my O.S. FS .91 on an identical plane, and they both consume an almost identical amount of fuel on equally timed runs.

Then you might enjoy this Brett.

I got bored one day and created this GIF:

lol, thats really cool (better than the one on wikipedia) , make that w/ solidworks?

the 4 stroke/2 stroke debate will go on.
the way i look at is any plane that will fly the way i want it to with a .50 ci 2 stroke or smaller will get a 2 stroke.
any plane that needs more power than a .50 ci 2 stroke will get a 4 stroke.
their are exceptions, but thats how i usually do it

If you like the sound of corn grinders then 2 strokes are for you.. [X(]

Right clicked and saved! Would make a sweet avatar, thanks Minnflyer!

You'll never get the file small enough for an Avatar.

My engine choices are:

Depending on the plane, a 2 or 4-stroke for 40 - 60 size planes.

From 60 - 120, I go 4-stroke.

Above that, Gassers

i thought the same thing. need a animated gif editor though. dont have one at the moment

Ok, here it is small enough for an avatar: