Debra
04-30-2007, 09:26 AM
ENGINE REVIEW: Saito .62
By Chris Chianelli
I reviewed my first 4-stroke engine in 1986 and ever since I’ve been totally captivated by these rocker arm, poppet valve, and pushrod wielding wonders. From their low throaty sound to the way they show a large prop, whose boss, I love it all! It’s a guy thing I guess. I also still have the first Saito engine I ever reviewed; an FA.45. I would never part with any of my Saito 4-strokers right back to that first FA-.45 no-way, no-how. My hording of them is a statement of how much enjoyment they have brought me because of their longevity, reliability, performance, and novel appeal. Except for two Saitos that I gave as gifts to two of my flying buddies, I still have every single one that ventured into my work shop.
The latest Saito
The FA-.62, exemplifies a Saito manufacturing philosophy, a philosophy I call a virtue. “Always strive to make a good thing even a little better if at all possible.” And that’s is what the have done with the FA-.62. They have taken the crankcase from a FA-.50/.56 and used it for the .62. As a result the .62 is only 10-gram heavier than the .56 , but oddly enough 15-grams lighter than the .50 owing possibly to a thicker cylinder wall on the .50. But the real magic here is the .62’s extremely smooth operating characteristics. This little engine produces very low vibration levels. Quite a surprise as the .62 is restricted to crankshaft and counterweight dimensions originally laid out for the .50! A little beefing up of the web counterbalance and a lightened, forged piston and conrod seems to have certainly helped.
Break-in & weather conditions
The fuel I used for break-in was a mix of 15% nitro and 18% lubricant which was a blend of synthetic and a touch of castor oil. Castor offers excellent protection against corrosion. Something to think about when running 4-strokes as a bit of unburned methanol, the main component of glow fuel, always remains in a 4-stroke’s crankcase. Methanol is hygroscopic (attracts moisture) and that’s the problem. Good anti-corrosive properties are important with any engine, but especially 4-strokes. Also, castor helps take away heat.
The two things to be careful of when using castor in a 4-stroke are; never use more than a little bit (the synthetic/castor blend in the fuel I used was 80/20 respectively) and make sure the castor is of very high quality as poor quality castor will prematurely varnish, and varnish is bad. I ran four 10-ounce tanks of fuel during break-in and an APC 11 x 6 prop while keeping the RPM at or below, 4,500. I did this for the first tank and a half with cooling off periods every 3 to 4 minutes during the first two tanks. For break-in go ahead and use the glow plug that comes with the engine. When you run the engine for performance, I strongly recommend switching to an O.S. F plug. When it comes to idle and throttle response performance, nothing compares to the F plug.
Weather conditions were 40 degree F., 78% humidity, and a barometric pressure of 997m.
The Power
After much coercion and being called “old man” by my friends, for the power readings I used a fuel containing 18% lubricant of all synthetic. After all, anti-corrosive technology has improved greatly over the years—old habits die hard. I also boosted the nitro content to 25%. The extra nitro not only improves the throttle response and idle but, if used correctly, can actually serve to make the engine run cooler. Simply put, the extra nitro allows you to reap excellent performance but still retain a somewhat richer setting. If you try to squeeze the last 200 or 300 RPM out of the engine, that’s where you’re going to run into problems. Back off a few hundred RPM from peak and you’ll have reliability, lots of power, and an engine that is going to last. Trust me on this one.
But the biggest surprise this engines had in store for me was its power. Take a look at the smallest prop figure: 12,400 on an 11 x 6. That is very close to what I used to get on my hot loop-scavenge ported engines back in my early 2-stroke days. Turning a 14 x 6 at 9,400 RPM is very respectable, and, after break-in, far from causing the engine to run too hot. Not to mention the engine will gain 300 to 500 RPM when it unloads in the air.
Prop RPM Idle
APC 11 x 6.........................12,400.................. .2,800
APC 11 x 7..........................11,800................. .2,800
APC 11 x 8..........................10,900................. .2,700
APC 12 x 6..........................11,100................. .2,400
APC 12 x 7..........................10,600................. .2,400
APC 12 x 8...........................9,600................. ..2,200
Master Airscrew 13 x 6......9,400...................2,100
APC 13 x 7 ..........................9,900................... 2,200
APC 14 x 6...........................9,400................. ..2,100
Now take a look at those idle figures. All these figures were very reliable and transition to full power from these very low idle RPMs was truly excellent with no burbling at all. This is where I have to also give credit to the O.S. F plug. It has an unrivalled ability to retain heat during the exhaust and intake part of the cycle to “spark” things off again on the power stroke portion.
Saito does it again
Simply put this engine delivers in every way. In terms of smooth operation, throttle transition, idle and overall quality, fit and finish, and of course, performance. The RPM figures don’t lie. While 4-strokes deliver their power in a very different way than 2-strokes, I think it’s safe to say, today’s 4-strokes rival 2-strokes in everyway...and them some in my book. I was impressed with this little 15-ounce engine.
By Chris Chianelli
I reviewed my first 4-stroke engine in 1986 and ever since I’ve been totally captivated by these rocker arm, poppet valve, and pushrod wielding wonders. From their low throaty sound to the way they show a large prop, whose boss, I love it all! It’s a guy thing I guess. I also still have the first Saito engine I ever reviewed; an FA.45. I would never part with any of my Saito 4-strokers right back to that first FA-.45 no-way, no-how. My hording of them is a statement of how much enjoyment they have brought me because of their longevity, reliability, performance, and novel appeal. Except for two Saitos that I gave as gifts to two of my flying buddies, I still have every single one that ventured into my work shop.
The latest Saito
The FA-.62, exemplifies a Saito manufacturing philosophy, a philosophy I call a virtue. “Always strive to make a good thing even a little better if at all possible.” And that’s is what the have done with the FA-.62. They have taken the crankcase from a FA-.50/.56 and used it for the .62. As a result the .62 is only 10-gram heavier than the .56 , but oddly enough 15-grams lighter than the .50 owing possibly to a thicker cylinder wall on the .50. But the real magic here is the .62’s extremely smooth operating characteristics. This little engine produces very low vibration levels. Quite a surprise as the .62 is restricted to crankshaft and counterweight dimensions originally laid out for the .50! A little beefing up of the web counterbalance and a lightened, forged piston and conrod seems to have certainly helped.
Break-in & weather conditions
The fuel I used for break-in was a mix of 15% nitro and 18% lubricant which was a blend of synthetic and a touch of castor oil. Castor offers excellent protection against corrosion. Something to think about when running 4-strokes as a bit of unburned methanol, the main component of glow fuel, always remains in a 4-stroke’s crankcase. Methanol is hygroscopic (attracts moisture) and that’s the problem. Good anti-corrosive properties are important with any engine, but especially 4-strokes. Also, castor helps take away heat.
The two things to be careful of when using castor in a 4-stroke are; never use more than a little bit (the synthetic/castor blend in the fuel I used was 80/20 respectively) and make sure the castor is of very high quality as poor quality castor will prematurely varnish, and varnish is bad. I ran four 10-ounce tanks of fuel during break-in and an APC 11 x 6 prop while keeping the RPM at or below, 4,500. I did this for the first tank and a half with cooling off periods every 3 to 4 minutes during the first two tanks. For break-in go ahead and use the glow plug that comes with the engine. When you run the engine for performance, I strongly recommend switching to an O.S. F plug. When it comes to idle and throttle response performance, nothing compares to the F plug.
Weather conditions were 40 degree F., 78% humidity, and a barometric pressure of 997m.
The Power
After much coercion and being called “old man” by my friends, for the power readings I used a fuel containing 18% lubricant of all synthetic. After all, anti-corrosive technology has improved greatly over the years—old habits die hard. I also boosted the nitro content to 25%. The extra nitro not only improves the throttle response and idle but, if used correctly, can actually serve to make the engine run cooler. Simply put, the extra nitro allows you to reap excellent performance but still retain a somewhat richer setting. If you try to squeeze the last 200 or 300 RPM out of the engine, that’s where you’re going to run into problems. Back off a few hundred RPM from peak and you’ll have reliability, lots of power, and an engine that is going to last. Trust me on this one.
But the biggest surprise this engines had in store for me was its power. Take a look at the smallest prop figure: 12,400 on an 11 x 6. That is very close to what I used to get on my hot loop-scavenge ported engines back in my early 2-stroke days. Turning a 14 x 6 at 9,400 RPM is very respectable, and, after break-in, far from causing the engine to run too hot. Not to mention the engine will gain 300 to 500 RPM when it unloads in the air.
Prop RPM Idle
APC 11 x 6.........................12,400.................. .2,800
APC 11 x 7..........................11,800................. .2,800
APC 11 x 8..........................10,900................. .2,700
APC 12 x 6..........................11,100................. .2,400
APC 12 x 7..........................10,600................. .2,400
APC 12 x 8...........................9,600................. ..2,200
Master Airscrew 13 x 6......9,400...................2,100
APC 13 x 7 ..........................9,900................... 2,200
APC 14 x 6...........................9,400................. ..2,100
Now take a look at those idle figures. All these figures were very reliable and transition to full power from these very low idle RPMs was truly excellent with no burbling at all. This is where I have to also give credit to the O.S. F plug. It has an unrivalled ability to retain heat during the exhaust and intake part of the cycle to “spark” things off again on the power stroke portion.
Saito does it again
Simply put this engine delivers in every way. In terms of smooth operation, throttle transition, idle and overall quality, fit and finish, and of course, performance. The RPM figures don’t lie. While 4-strokes deliver their power in a very different way than 2-strokes, I think it’s safe to say, today’s 4-strokes rival 2-strokes in everyway...and them some in my book. I was impressed with this little 15-ounce engine.