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Engine basics => Four strokes only => Topic started by: Willis Swindell on November 12, 2009, 02:13:43 PM
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4 stroke seams a little slow lately. I had a little fun Sunday. I took my Saito 30’s out of my Heinkel 219 and installed two Saito 40’s. What a difference, first flight on 64 ft. lines about dragged me across the circle. Half ounce tail weight and 70 ft. lines now this is fun. I need to take the 2 1/2 oz. tanks off and install 3 or 3 1/2 oz. tanks, cuts off in the first overhead eight but keeps on flying with one engine.
Willis
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Two Saito 40's :o
Man, that is a lot of power. Willis, you are seriously channeling some "Tim Allen".
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Hi Willis,
This thing flying gotta be very impressive!
Love to see that flying on youtube
Martin
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Martin I E-Mailed you a short flight. Hope you don’t mind
Willis
OK Milton what do you think?
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Martin I E-Mailed you a short flight. Hope you don’t mind
Willis
How bout me. :-[
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Looks great! Did you draw your own plans for this model? How's it fly?
Can you give some specs- wing area, weight, span, length, tail size, bellcrank
size, etc? Did you use double control horns on the flaps ( looks like swept
TE on wing )? More pics please!!
NICE!
Stan Bidowski :)
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Stan
From memory, Time Machine 60 wing 660 square with a strait leading edge twin push rods both flaps and V elevators, Tom Morris controls. with the Saito 30’s 64 oz. a few more now. I blew up a side view of the heinkel to the size I wanted then stretched it to the length that I wanted. I got carried away with the rudders They are way to big but this is SEMI scale. The fuselage is covered with 1/64 plywood and does not twist at all.
Willis
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Martin I E-Mailed you a short flight. Hope you don’t mind
Willis
OK Milton what do you think?
Hi Willis thank you for sending the video, I appreciarted the sound of 2 4Stroke! You model looks great flying.
Martin
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Willis, received the video.
Willis, do you play the blues-because brother, your groove is outstanding!! Either you, your plane, or your engine combo is laying down a seriously good track. Your plane is definitely in the pocket-a winner.
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That He-219 has always been a great flying plane for Willis! I think you'd see him compete with it more but for the fact that the twin rudders easily get knocked off-usually as you get the plane out of the car at the contest!
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Funny the only time the rudder didn’t break off is when it flipped over on the grass and broke the stab.
Willis
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Dont you blokes realize stunt models are designed to teach people to be carefull going through doorways !
Drop of undercarrage would stop any flipping , if you fly of grass .
Nice aeroplane.A twinshould be compulsary for all aeromuddlers .
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Great stuff Willis!
Could I ask you to measure up and give us an accurate spec on the wing and stab spans and areas? I'd really like to compare your Heinkel to my PBY. I've been debating making the exact engine swap you've done here, Saito .30's to .40's.
Thanks!
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WWWarbird
The Heinkel has a 58 inch wing span 13 inch plus 10 inch cord. 667 sq. in. wing and the stab is 27 inches 6 inch plus 5 1/2 inch cord. 155 sq. in. stab. 16 1/2 inches hinge to hinge. and seven 1/2 inches from wing L.E. to back of prop I had to add 1/2 oz. weight to the rear for the 40’s.
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Thanks Willis. I've currently got 1.8oz machined stainless spinner nuts plus another 1oz of lead in the nose compartment on the PBY. I can afford the extra weight of the .40's and then likely take away some of the dead weight. You've got me thinkin'! ;D
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Willis,
My swap to .40's is complete, can't wait 'til spring! #^
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Neat plane. I particularly like the last pic of her, she looks like she's rounding out on final. Very nice. H^^
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Wwwarbird we expect a flight report and prop,tank size.
Willis H^^
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Willis,
I've got 3-1/2 ounce wedge tanks on it, that's the biggest "off the shelf" ones that will fit. If I end up needing bigger ones I'd have to make them, yuk.
I'm going to have to start all over with the prop selection process, but I'm hoping that the Master Airscrew three blade 10x7's or 10x5's I have will work out. I've got some black Tornado three blade 10x6's I can try too. I know you can't tell how many blades there are when they're spinning, but it just doesn't look right with anything but three bladers on it.
It will be a while yet but I'll post a report at some point this spring.
'Til then, H^^
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What Bob would do...
Stick on a Thunder Tiger 11.3 X 6.5, adjust your choke or throttle for 8200-8300 RPM. Remove the Thunder tiger and without changing anything put on one of the 3 blade 10-x props. Run the engine and note the RPM.. If it's higher increase the pitch of the prop till it loads the engine down to the same number you had with the TT. If it's lower decrease the pitch till it's the same. Fly it and see what you got, fine tune the prop pitch and engine RPM till you are getting the lap times you want withen 8200 to 8400.. Do not go over 8500..
I really have no idea if this will actually work but I do know the Thunder Tiger 11.3 X 6.5 prop works and it seems like a reasonable approach to get in the ball park pretty quick. Of course this is assuming you have some way of adjusting the intake choke area which I believe is a necessity.
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Thanks for the advice once again Bob, sounds like a reasonable plan. But what Wayne might do though is try the same basic process, but starting with the new black Evo props since I can get them readily at the LHS. Maybe like a 10x6 or 7. Another thing is that I've only got room for a 10" prop, maybe 10.5" at the absolute max. I'm really curious about the Evo props because I had great improvement with them right at the end of last season but I ran out of weather. Right away though I got a feeling they might be a great prop for a lot of applications, I'm also anxious to try them on some .35-.40 single engine stuff too. They also ran real smooth and quiet. Anyway, I'm just hoping that in the end one of the three bladers will work out for the PBY, we'll see.
BTW Bob, I think you mentioned it before, but where is the best place to get the TT props from. I'd never even heard of them until you mentioned them.
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I am now using A zinger 11x5 with a 1/4 inch cut off the tips but planing to try a Master Airscrew 11x7 three blade cut 1/4 inch off the tips for clearance to load the engine a little more. This prop is really a 11x5. I bought a Evo 11 inch 3 blade prop a few years ago and it had a 3 1/2 pitch.
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I found the Evo props to be not that great but might be OK if they were repitched. The TT props can be ordered direct from TT see the "Props for Saito 40" thread below..
http://stunthanger.com/smf/index.php?topic=13100.0
When I tried an Evo 11-7 on one of my 40's I had to run the RPM up past the point I was comfortable with to get the lap times back up. This told me it wasn't really a 7 pitch, would guess something less than a 6. At the time I was looking for a stock prop I could recommend to replace the Rev-Up 11-7. The TT needed a little RPM increase over the Rev-Up (100 RPM) but was better than the Rev-Up overhead so now all my 40's are running TT 11.3 X 6.5's. Bolt it on and go fly, not bad for a $2.00 prop if you buy them 6 at a time. This prop should be your standard from which to judge anything else you try. If you have to put 3 inch wheels on for a few flights, so what at least you will have a good reference in which to work from.
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Thanks for the added input Willis, good stuff to know. (Sorry to pirate your thread BTW)
Bob,
Three inch wheels won't do me any good, it's the prop to fuse clearance that's the issue. When I designed it I wanted to keep the engines as close together as possible and didn't think I'd ever need bigger than 10" props, because I was going to be running .30's.
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Bob,
Three inch wheels won't do me any good, it's the prop to fuse clearance that's the issue. When I designed it I wanted to keep the engines as close together as possible and didn't think I'd ever need bigger than 10" props, because I was going to be running .30's.
Ya that would make it a bit difficult, hope you come up with something that works. Keep us informed..
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Will do.
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Go to three blades. H^^
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A few full size pre war racing planes with timber props had one prop in front of the other,
to give 4 blades. Looked to be dead on 90 deg. perpendicular just like a 'normal' 4 blade aeroplane prop.