BretR

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Hello,

I am going to be building a Great Planes Extra 300 40 size kit over this winter.

I currently have a 4*40, and have a TT Pro 46 in it for an engine.

I was thinking of putting a slightly larger (the TT Pro 61) engine in the Extra.

What do you guys think?

Will it still fit in the cowl (I have the fiberglass cowl)?

Will it be too much power for this plane, or make it too heavy?

Also, any links or suggestions for building this kit, I would appreciate it.

Thanks!

bret.

MinnFlyer

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No, I wouldn't go anything bigger than a 52 (2 stroke)

Ideally, get a 70 class 4-stroke. (OS 70 - Saito 72 - YS 63)

DGrant

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I've got a Magnum .91 4-stroke on mine, I can say, it will handle a .70 better. I had some problems with the first one(I did build 2) in that the tail-feathers folded...something about power I think. Oh well, I built the second one identical...with new .91 4-stroke...only added flying wires...still going strong and that was back in '01, plane is still very fun, and a great flyer. It just goes up just about as fast as forward.
It might depend on your experience level greatly, but it does work, just plan and build. I've wondered what one would fly like with a .46. But, I think I've wondered more what it would fly like with a 1.08

PS.. see Avatar.

BretR

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Thanks for the responses.

I think I am going to stick with a 2 stroke, in order to save some $$'s.

Does anyone else have suggestions and examples of what engine they have successfully put in this kit, and how it flew?

Thank you.

leftnut

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it'll cost the same after you get the in cowl muff.lol
i have the arf and the kit
so a .46 wouldn't be enough power ?
i was thinking of getting the o.s 4 stroke .72 for 1 one them.
i think i'll leave .91xl in me 4* .60
i'm afraid of putting anything greater than a .46 in the arf.lol
i striped the wing , added tri and expoxy in all the gaps of the spar.
i extended the rudder 1"

the gp300 is heavier than the gp cap232.
that i know. i think the wings are the same.

DGrant

My Feedback: (4)

Yeah...your better sticking with an OS70, or even a good running .46-50 2stroke. I did do some other things to the second one that I forgot about, and I do apologize..it's been a while since I built it. I built in laminated c/f spars on the rear tail group, and added the flying wire kit, as well as it was a kit plane, so I was very sure of the firewall tolerances/fit. It's tight too. The plane came down one time from probably 100' into mud...sank about a foot, no damage to firewall, although it did shift the wing real good. Good enough the plane was in "intensive care" ward for a week. It came back though...before that, the landing gear got knocked too. That's another area we can talk about if you need. I know the weakest link in there, and it's fixed in mine.
It is a very solid flying plane, that really seems to groove, all in a decent size package. With experience it's a sharp flying airplane that will do what you want, at same time, if you are ready to graduate to a finer flying plane, and stay sane on the sticks, you will grow with it. I actually used as a stepping stone to my 27%Midwest. I went from the GP's Extra, to a Goldberg Sukhoi that was nicely powered, then right to the 27%'r. Good plane...and this(#2) is still with me. Covering is fading, don't use "true red" monokote. It fades terribly, and dulls.. It was a sharp looking plane, it's still OK I guess but any case it's FUN!! Good luck with your project.

OH....I'll see if I can post another pic if you want.. hehe

BretR

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Thanks again guys.

I checked some prices, and I can get an OS Surpass 70 for $280 (Canadian), and a TT Pro 61 (2 stroke) for $150.00, so I am not sure here... I probably won't be buying either for a little bit, so I will think on it for a while. I have never run a 4-stroke, so I am not as familiar with them, but there are several guys in my club that are, and they would help me out I am sure.

Dgrant, (nice looking extra by the way...) I will probably bug you again when I get the the part for the landing gear mount. I have read that some people have used a piece of birch instead of what is supplied in the kit for the mount. I have it on my list to do 'something' with the LG mount, and if you have a good solution, I will probably get some more info from you in the future.

I may end up running this plane with the .46 from my 4* for a while just to see how well it flies with that before deciding on it's 'permanent' power plant.

Thanks for the info guys, if you have any more, I am all ears.

leftnut

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nice clean scheme dgrant.
you don't mine if i cover mine just like that, do ya..?
than again...all my beautiul planes don't survive and the ugly dose.lol
too late on the red monokote[] i stocked up on that stuff.
red works best for visiblity for me.

yeap..the landgear surpport didn't seem right to me for the kit version.
i doubled up the ply,add tri and epoxy the heck out of it.
the ARF version is better in that area.

phread59

May I humbly suggest an Irvine 52. Should do your plane justice.

Mark Shuman

BretR

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Thank you for your reply Mark,

I am not able to get that engine at the couple places I usually buy supplies.

It looks like the closest would be a Webra Speed 50 GT, but it is even more than the TT Pro .61 ($185 vs. $130)

Can anyone tell me if the TT Pro .61 will fit properly inside the fiberglass cowl of the 40 size Extra?

Thanks,

bret.

DGrant

My Feedback: (4)

I doubt you'd get any but the smallest .46 to fit totally within the cowling. Even then, you'll have the hole for the battery. The .61 would work just fine in this plane, and doesn't sound like it'll break the bank. There's very easy ways to cut the cowling to fit. Don't let that detour you on the engine you want.

BretR

My Feedback: (1)

DGrant,

I expected to have to cut the cowling a bit (for the front, to allow airflow, the side for the cylinder head, and underneath for the exhaust), I was just wanting to see if I would have problems fitting a .61 in otherwise.

Thanks again for all the info. I will check in again when I start the build this fall, and maybe post some pics if anyone is interested.

Cheers!

bret.

sir-crash-alot

My Feedback: (4)

Has anyone looked at mvvs engines. They are a little more expensive but the put out a ton of power. There throtle transition is second to none. A mvvs .40 has the power of a .46 or even some .50 sized engines. They are built extremly! Try them out they are awesome!

DGrant

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Bret...I have a 4-stroke .91 in my Extra, I only cut out pretty much exactly what your expecting too. I had no prob. The most important area of that cowling to cut out though is the venting, on that one it's underneath in the area of that landing gear. You'll know what I mean though. It should have more area cut out of it then anywhere else. There's a pattern somewhere in the manual I believe that gives you a guide on cutting that part of the cowling.

phread59

Zac you are not just whistling dixie. I have a 40 with a tuned muffler in a Sig Midstar 40. It gets right with the program. Power out the wazzo on 10% fuel. They make a 49 that would fit under the cowl. If you modify the fuse some you could tuck the tuned muffler under the plane. It would indeed make that puppy go.

Bret the Webra would also be a great choice. They are a very,very strong engine. Seriously overlooked by most people. They do not get the recognition they should. Good luck with whatever engine you get. And good luck with the plane.

Mark Shuman