42"wingspan p51d what size engine?
05-16-2005, 06:42 AM
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42"wingspan p51d what size engine?
hi im currently looking to build a p51d from a plan i have its all balsa and ply built.its orrigianally for 500 size electric but im looking to build it for glow power but im not sure of the engine size i should put in it.anybody got any ideas?.i have a 46 engine but feel this may be too big?.HELP!!!.
05-16-2005, 08:24 AM
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RE: 42"wingspan p51d what size engine?
The 46 SHOULD be OK. I would go more on the weight of the plane than the wingspan.
If after the mods needed to convert it to glow, the weight (including the engine and muffler ) will be coming in around 5 3/4 lbs the 46 will work fine. If it is coming in heavier, you MAY need a larger engine.
If after the mods needed to convert it to glow, the weight (including the engine and muffler ) will be coming in around 5 3/4 lbs the 46 will work fine. If it is coming in heavier, you MAY need a larger engine.
05-16-2005, 11:39 AM
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RE: 42"wingspan p51d what size engine?
cheers for that guys looking at the plans for this thing the engine looks like it might just fit but only if i put it right side up !!!.do you think this would look ok?,or do you think it would look better on its side?,doing it on its side would look better but id need to make some modification to the design!!!.i think the plane looks on the light side but in the plans hes used foam for the top deck and some under the fuselage near the front end !!,i think id probably use balsa block .then i need to sort out some landing gear for it too!!!.also i think i might strengthen the air frame in places.i was also thinking of trying some builders expanding foam in the wings along the leading edge between the bottom and top balsa sheets.i saw this idea on this site somewhere.seems like a good idea to add strength?.any help you guys can give me is welcome thanks!!.
05-16-2005, 01:42 PM
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RE: 42"wingspan p51d what size engine?
ORIGINAL: martno1fan
cheers for that guys looking at the plans for this thing the engine looks like it might just fit but only if i put it right side up !!!.do you think this would look ok?,or do you think it would look better on its side?,doing it on its side would look better but id need to make some modification to the design!!!.
>I don't see why you would need to modify the design. The cylinder
>head will stick out that should be all. With the cylinder head sticking
>out it will not look as "scale", but the engine will definitely run cooler.
>I would also seriously consider using a pitts type muffler if you do
>the engine sideways.
i think the plane looks on the light side but in the plans hes used foam for the top deck and some under the fuselage near the front end !!,i think id probably use balsa block .then i need to sort out some landing gear for it too!!!
>Light (within reason ) is a good thing. Converting an electric to glow
>you do need to make sure the fuselage is going to be able to handle
>the vibrations of the engine. Many designs use plywood "doublers"
>in the front half of the fuselage to provide the necessary strength
>and vibration dampening needed for a glow engine.
>
>For you landing gear, you want to have basswood, spruce or aircraft
>ply (not lite ply ) for the gear to attach to and be sure the LG support
>is intergral with the wing and fuselage to provide the strength needed
>for the additional weight of the engine and other components.
.also i think i might strengthen the air frame in places.i was also thinking of trying some builders expanding foam in the wings along the leading edge between the bottom and top balsa sheets.i saw this idea on this site somewhere.seems like a good idea to add strength?.any help you guys can give me is welcome thanks!!.
>The foam should work. Myself, I would use carbon fiber to strengthen
>the leading edge.
cheers for that guys looking at the plans for this thing the engine looks like it might just fit but only if i put it right side up !!!.do you think this would look ok?,or do you think it would look better on its side?,doing it on its side would look better but id need to make some modification to the design!!!.
>I don't see why you would need to modify the design. The cylinder
>head will stick out that should be all. With the cylinder head sticking
>out it will not look as "scale", but the engine will definitely run cooler.
>I would also seriously consider using a pitts type muffler if you do
>the engine sideways.
i think the plane looks on the light side but in the plans hes used foam for the top deck and some under the fuselage near the front end !!,i think id probably use balsa block .then i need to sort out some landing gear for it too!!!
>Light (within reason ) is a good thing. Converting an electric to glow
>you do need to make sure the fuselage is going to be able to handle
>the vibrations of the engine. Many designs use plywood "doublers"
>in the front half of the fuselage to provide the necessary strength
>and vibration dampening needed for a glow engine.
>
>For you landing gear, you want to have basswood, spruce or aircraft
>ply (not lite ply ) for the gear to attach to and be sure the LG support
>is intergral with the wing and fuselage to provide the strength needed
>for the additional weight of the engine and other components.
.also i think i might strengthen the air frame in places.i was also thinking of trying some builders expanding foam in the wings along the leading edge between the bottom and top balsa sheets.i saw this idea on this site somewhere.seems like a good idea to add strength?.any help you guys can give me is welcome thanks!!.
>The foam should work. Myself, I would use carbon fiber to strengthen
>the leading edge.
05-16-2005, 01:45 PM
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RE: 42"wingspan p51d what size engine?
A 42" span sounds like a .10-19 size. There's a big difference from a 42" Mustang to a 48" mustang. Speed 400 motors don't have the oomph of a .049...A speed 500 can't be that much more. I'd think a Norvel .074 or .15 is called for. What's the all-up weight supposed to be?
05-16-2005, 04:57 PM
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RE: 42"wingspan p51d what size engine?
Mart, it sounds like you got something around the size of a Cambrian fun-fighter there, if so it should be a 25 mate. It'll come in around the 3lb mark. I saw a messerschmitt same range with a OS32SX and it went unlimited vertical and put most speed planes to shame.
05-16-2005, 05:13 PM
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RE: 42"wingspan p51d what size engine?
cheers for that mate!!,long time no see ehh?,hows life been treating you?.you got my email if you wanna catch up sometime grant.
05-16-2005, 05:24 PM
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RE: 42"wingspan p51d what size engine?
This is a pic of my 109F. It has a 50" wing span and weight was 6.25lbs. It had a fully enclosed OS .46VF rear discharge . The engine was set back to the oil cooler by an aluminum extension shaft I on my lathe. never overheated. It has also been flown with an OS .32
05-17-2005, 03:07 PM
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RE: 42"wingspan p51d what size engine?
A .46 is way too much engine for a 42" span model unless you're looking to be able accelerate straight up. Think about it, 42" is just barely bigger than 1/2A. I've got a GeeBee Model D and a Stinson 108-3 both with a 42" span and a Cox .074 Queen Bee. I also have a 42" span Illusyn IL2 Stormovic with a Thunder Tiger GP.10 in it. Plenty of engine.
I have an old Midwest sport scale P-51 that I bought back in the earlie 80's. It was designed for a .40. It has a 54" span, weighs, in at about 5-1/2 lb with a Tower Hobbies .40 and Goldberg retracts. When I tuck the gear up, this thing makes like a bread truck and hauls buns.
I would go bigger than a .15 in a 42" span model. Even then, i'ts gonna be a fast one.
I have an old Midwest sport scale P-51 that I bought back in the earlie 80's. It was designed for a .40. It has a 54" span, weighs, in at about 5-1/2 lb with a Tower Hobbies .40 and Goldberg retracts. When I tuck the gear up, this thing makes like a bread truck and hauls buns.
I would go bigger than a .15 in a 42" span model. Even then, i'ts gonna be a fast one.
05-17-2005, 04:13 PM
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RE: 42"wingspan p51d what size engine?
make yer mind up lol!!!
,just joking nice planes you have there !!!,do you have a plan of the 1st one i like the looks of her?.i think im gonna look for a 15 to a 25 depends whats available on ebay !!.thanks for the advice.
,just joking nice planes you have there !!!,do you have a plan of the 1st one i like the looks of her?.i think im gonna look for a 15 to a 25 depends whats available on ebay !!.thanks for the advice.
05-18-2005, 08:24 AM
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RE: 42"wingspan p51d what size engine?
Thanks, did you notice the pilot? I got the plans for the GeeBee model D in two sizes, the 42" span shown in the pic and a 54" span, .40 size. The little one turn out so good, I decided to scale her up. I just haven't got around to building it yet. I sell all my plans at a rate of $15.00 per foot of wing span plus $15.00 shipping. The 42" model would run you 67.50 and the $54" model would cost $82.50. Here's an example.
05-18-2005, 08:27 AM
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RE: 42"wingspan p51d what size engine?
Hi,
House of Balsa sells a 43" P51 Mustang Kit which is suppose to use a .19 - .21 size engine. The weight is suppose to be about 3 lbs. See it here: [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXM398&P=ML]HOB STANG[/link] I'm currently building one, but mine is going to be a bit heavier since I'm adding some mechanical retracts. Going to power mine with a GMS .25 engine. I'm almost to the covering stage, so perhaps I will have a flight report within the next month or so.
You can see some pics of my build progress on my web site shown below.
Good luck,
House of Balsa sells a 43" P51 Mustang Kit which is suppose to use a .19 - .21 size engine. The weight is suppose to be about 3 lbs. See it here: [link=http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXM398&P=ML]HOB STANG[/link] I'm currently building one, but mine is going to be a bit heavier since I'm adding some mechanical retracts. Going to power mine with a GMS .25 engine. I'm almost to the covering stage, so perhaps I will have a flight report within the next month or so.
You can see some pics of my build progress on my web site shown below.
Good luck,
05-18-2005, 12:10 PM
#21
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RE: 42"wingspan p51d what size engine?
I've buitl 3 of the 44" HOB P-51s... one as a sloper, the next two powered, with OS 25s... More than enough power.. The motors were removed and now they're slopers. They were too much of a problem powered. The long nose guaranteed an instant left turn on takeoff, despite my adding a steerable tail wheel.
And they weighed too much. Take off fast, land very fast...
No way could a .46 fit that size airplane.
And they weighed too much. Take off fast, land very fast...
No way could a .46 fit that size airplane.
05-18-2005, 12:18 PM
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RE: 42"wingspan p51d what size engine?
looks good wouldnt mind the plans when youve finnished with them .what materials you using for the formers ply?.im looking to beef up this design a little as its intended for electric and most of its balsa even the formers.im intending to use ply for the formers where i think its needed!!.i think this one should come in arround 3 to 3 1/2 lb .im thinking a 15 to 25 engine would be good?.
.what materials you using for the formers ply?.im looking to beef up this design a little as its intended for electric and most of its balsa even the formers.im intending to use ply for the formers where i think its needed!!.i think this one should come in arround 3 to 3 1/2 lb .im thinking a 15 to 25 engine would be good?.
05-18-2005, 02:58 PM
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RE: 42"wingspan p51d what size engine?
I have the Cambrian ME109. It has a 42" wingspan and has an SC .32 in the nose with an APC 10x7, it is a demon. Unlimited vertical, very VERY fast, turns on a sixpence and is a ***** to land. If you get the speed too slow it will just snap out of the sky.
05-31-2005, 02:05 PM
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RE: 42"wingspan p51d what size engine?
right i finally got my engine sorted out i bought a thundertiger 10 gp engine how does this engine perform? and do you think it has enough power?,so far the plane weighs in at 1,1/2 pounds but im only half way built still need to add top skin to wings pluss underside of fuse needs sheeting etc so im thinking the weight will come in arround 3 to 3,1/2 pounds with engine and electrics fitted!!. im thinking of covering the plane in brown paper and carpenters glue!!.[img][/img]