Saito .72 in Seamaster
11-05-2002, 01:56 PM
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Saito .72 in Seamaster
I take it then that a saito .72 would be way too much even with the altitude starting at 4500 feet. Im wondering which four stroker is best [ Saitos of course]. help me out guys, is my idea"overkill"
11-05-2002, 02:17 PM
#2
Saito .72 in Seamaster
A Saito .72 in a Seamaster.40 would be about right. The biggest problem might be prop clearance. You might think about a 3-blade prop if there's not enough wiggle room between the prop and the foredeck of the hull. Also, with all that torque, you might find you need more right thrust.
Also, at your high altitude, you might want to increase the wingspan a little. You could graft on one more bay to each wingtip to get a little more lift.
Also, at your high altitude, you might want to increase the wingspan a little. You could graft on one more bay to each wingtip to get a little more lift.
11-05-2002, 02:25 PM
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overkill
Three blade prop..........hmmm, would it work at this altitude? i dont seem to have a problem with lift, i will pass on the wing tip extensions. More right angle thrust too, OK. I will give it more thought too, thanks mjs
11-05-2002, 02:44 PM
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Saito .72 in Seamaster
Maybe I should 'splain about the 3-blade prop.
With a 4-stroke, you generally spin a larger diameter prop than with a 2-stroke of equivalent power. ALso, it's not uncommon for the prop to have greater pitch than a 2-stroke would use, since the 4-stroke has more torque, but revs slower.
The Seamaster has the motor mounted on a pod, and the prop diameter is limited 'cause it would be bad to hit the deck in front of the windshiels with the prop tip.
When you go to a 3-blade prop, it's generally appropriate to drop the diameter about one size from the recommended 2-blade prop size.
So, the three-blade prop lets you use about the same diameter prop on your 4-stroke that you would have used with a 2-stroke/2-blade combination.
The greater torque/greater pitch of the 4-stroke would cause a greater p-factor, probably making you need more right thrust for a no-rudder straight takeoff.
With a 4-stroke, you generally spin a larger diameter prop than with a 2-stroke of equivalent power. ALso, it's not uncommon for the prop to have greater pitch than a 2-stroke would use, since the 4-stroke has more torque, but revs slower.
The Seamaster has the motor mounted on a pod, and the prop diameter is limited 'cause it would be bad to hit the deck in front of the windshiels with the prop tip.
When you go to a 3-blade prop, it's generally appropriate to drop the diameter about one size from the recommended 2-blade prop size.
So, the three-blade prop lets you use about the same diameter prop on your 4-stroke that you would have used with a 2-stroke/2-blade combination.
The greater torque/greater pitch of the 4-stroke would cause a greater p-factor, probably making you need more right thrust for a no-rudder straight takeoff.
11-05-2002, 04:00 PM
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65 will do it
I live at 6,000 ft and have flown off a lake at 7,000 + ft. I have been flying my SeaMaster for years with a Saito 65 and I think it's perfect for the plane. It gets it off the water just fine and pulls it through all the aerobatics that the SeaMaster is capable of. It will do verticals into a stall turn like mad. I'm using a 2 bladed prop.
11-05-2002, 09:29 PM
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saito 72
hello.i have a OS 70 4 stroke on my seamaster.....mounted inverted...and it is just perfect amount of power...i use a 12-8 master airscrew two blade.........pault
11-06-2002, 01:54 PM
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.72 seamaster
OK guys, Im convinced, but im still pondering about the 3-blade prop setup, it will be nice if it works. Wont be till spring cause i wont fly my seamaster off the tarmac, i save it strictly for the water. Seeya
11-06-2002, 03:32 PM
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Saito .72 in Seamaster
I seem to be communicating poorly and I apologize.
In the seaplanes I have designed (note: none of which are famous) I try to keep the thrustline as low as possible, so the prop tip comes within a half-inch of the deck in front of the windshield. A bigger prop would come perilously close. This could result in a prop-strike during a rough landing or violent maneuver when the pod flexes a bit. As they said in Ghostbusters:"That would be bad."
The 3-blade prop option is there if you have an interference problem with the appropriate 2-bladed prop.
Apparently, from some of the posts, Seamasters can take a large prop without difficulty. This is probably then a purely academic, if not entirely moot, discussion.
Otherwise, 3-bladed props are reported to be somewhat less efficient than props with smaller numbers of blades, and single-bladed props have been used in competition where the last speck of efficiency makes a difference.
In the seaplanes I have designed (note: none of which are famous) I try to keep the thrustline as low as possible, so the prop tip comes within a half-inch of the deck in front of the windshield. A bigger prop would come perilously close. This could result in a prop-strike during a rough landing or violent maneuver when the pod flexes a bit. As they said in Ghostbusters:"That would be bad."
The 3-blade prop option is there if you have an interference problem with the appropriate 2-bladed prop.
Apparently, from some of the posts, Seamasters can take a large prop without difficulty. This is probably then a purely academic, if not entirely moot, discussion.
Otherwise, 3-bladed props are reported to be somewhat less efficient than props with smaller numbers of blades, and single-bladed props have been used in competition where the last speck of efficiency makes a difference.
11-06-2002, 05:00 PM
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Saito .72 in Seamaster
Yo Jim, Your communication is excellent! Your intellect is equally impressive. I will try a three-blade and judge the results then go from there. A pleasent day to you. Respectfully, Michael
11-25-2002, 05:52 PM
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Saito .72 in Seamaster
mjs,
I just had my maiden flight with my Seamaster with a Saito .72 swinging a 12x8 Master Airscrew prop yesterday. It was from a grass runway, but it taxis straight, flys great, with tons of power. I did not add any more right thrust. I did raise the pod up three eights of an inch to give me about a half inch clearence. Now all I need is a place to try it in water.
weez
I just had my maiden flight with my Seamaster with a Saito .72 swinging a 12x8 Master Airscrew prop yesterday. It was from a grass runway, but it taxis straight, flys great, with tons of power. I did not add any more right thrust. I did raise the pod up three eights of an inch to give me about a half inch clearence. Now all I need is a place to try it in water.
weez
11-26-2002, 01:57 PM
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Saito .72 in Seamaster
"OH-MY-HECK"!!! Its a real "Hoot" flying off of water, and a little bit easier. ST .51 scoots it right along but i sure would like a Saito .72. I have to buy two .56 saitos for a twin Islander right now but i will have a .72 before the float season arrives. Let me know when you try it on water. Seeya, MjS
