What Engine ????

Glow/Nitro and gas engines, propellers, fuel and other stuff associated with making lots of noise and thrust.

What Engine ????

Postby debandy » Tue Oct 04, 2011 9:01 pm

I have just built a (Flair) "Piper Cub" and I am unsure what engine to put into it,I have looked on websites and there are 100's,someone says 2 stroke then otheres say 4 stroke.I dont want anything super powerfull,but also dont want something that is going to strugle on take ok.Also my moneypot is getting empty with Xmas on the way so I dont have stupid money to spend on one.
I have been flying small electric planes, so this is the first larger one of my own I have flown.The wing span on the "Cub" is 72 inch
I would appriciate any information or advise, cus all these engine numbers are going way over my head lol
Thanks
Andy
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Re: What Engine ????

Postby Sid Sideslip » Tue Oct 04, 2011 9:13 pm

How much does it weigh? Without knowing the weight, a rough estimate with a 72" wingspan would be a .60 two stroke, though a .46 may suffice. If two stroke engine noise sounds awful to you, then you could opt for a nicer sounding, but more expensive 4 stroke. The four stroke would need to be a bit larger, probably .60 to .90 size.

Have a look at the HobbyKing site to give you an idea of what they offer, which is at the low end in terms of prices; the two stroke I bought from them (a Leo .40) is quite good, though perhaps not quite as powerful as more expensive brands. Expect to pay around double the prices shopping for name brand motors locally.
Last edited by Sid Sideslip on Tue Oct 04, 2011 9:34 pm, edited 1 time in total.
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Re: What Engine ????

Postby RCModelReviews » Tue Oct 04, 2011 9:27 pm

Lots of factors involved here.

Do you want it to fly "scale like" at full throttle or would you like to be able to hover it (yes, model Cubs can hover)?

If you have a link to the product it would probably be easier.

As for the 4-stroke/2-stroke question -- some say that a 4-stroke sounds more scale than a 2-stroke but I say that single-cylinder 4-strokes in something like Cub just sound like a lawn-tractor rather than a 2-stroke, which sounds like a chain saw.

If you put a 4-stroke in a fast plane like a Mustang, add a MAS K-series prop and leave off the muffler then they *can* sound quite realistic -- but not in a Cub.

4-strokes are going to be more expensive to buy but unless it's a Saito, it'll use less fuel than a 2-stroke of the same power.

Show us the model and we'll be better-able to come up with a suggestion.
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Re: What Engine ????

Postby debandy » Tue Oct 04, 2011 11:34 pm

ASP FS91AR Four Stroke Glow Engine

sorry to bother you, but what size is the, compared to the ones below that have been listed.
here is the link to the " Cub "
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Re: What Engine ????

Postby debandy » Tue Oct 04, 2011 11:35 pm

ASP FS91AR Four Stroke Glow Engine

sorry to bother you, but what size is the, compared to the ones below that have been listed.
here is the link to the " Cub "
http://www.flairmodels.co.uk/Aircraft/V ... rs/Cub.htm
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Re: What Engine ????

Postby Sid Sideslip » Wed Oct 05, 2011 12:22 am

debandy wrote:ASP FS91AR Four Stroke Glow Engine

sorry to bother you, but what size is the, compared to the ones below that have been listed.
here is the link to the " Cub "
http://www.flairmodels.co.uk/Aircraft/V ... rs/Cub.htm


The ASP is .91 cubic inches which is about 15cc.

The recommended engines from your link are "Engines .25 - .40 2 strokes, .35 - .52 4 strokes." These sizes are all in cubic inches btw. I'm guessing it's a light model for its size, because the recommend engines are on the smallish side.

Going by that guide, the ASPFS91AR is too big, the ASP FS61AR* Four Stroke Glow Engine from HobbyKing would suit better (* .61 cubic inches or about 10cc) .

It all depends on how much extra performance you want, over and above what's needed for a good take off and general cruising around.


http://www.hobbyking.com/hobbyking/store/%5F%5F8985%5F%5FASP%5FFS61AR%5FFour%5FStroke%5FGlow%5FEngine%5F.html
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Re: What Engine ????

Postby RCModelReviews » Wed Oct 05, 2011 4:16 am

Sid is right.

Aside from the power issue, there's a *lot* more weight in a .91 4-stroke than in a .61 one.

You may have troubles getting the CG right with a very heavy engine up-front if the model has been designed for a smaller/lighter one.
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Re: What Engine ????

Postby debandy » Wed Oct 05, 2011 6:38 am

Hi
Thank you all very much,so the ASP Engines the Numbers in the middle ASP FS91AR define the size of the engine .91, another question,is FS at front of the model number meaning 4 stroke.??
Maybe a silly question to the pro flyers,but when you are just starting its all a bit foggy lol.
I would just like to explain when I was 36 I had 3 minor strokes in 10 months physicaly you can not tell,but mentally it takes a while for infomation to sink in, but it does and when it does i'm like an elephant,I never forget again.
When I found out I had a stroke, apart from my family my only concern was my flying,so I paid and had 2 medicals and luckily I was given permission to carry on flying.I fly other big planes from other members and it realy gives me a buzz,so that is the reason I bought the piper cub.
Just wanted to explain because some people are not as patiant as others,and I may ask a similar question a couple of times,I appologise
thanks
Andy
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Re: What Engine ????

Postby RCModelReviews » Wed Oct 05, 2011 6:59 am

No worries Andy, my wife suffered a brain injury and has exactly the same problem as you.
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Re: What Engine ????

Postby RobC » Wed Oct 05, 2011 9:05 am

I've got an 84" vintage cabin style model which weighs 7lb and has plenty of power from an old OS 48 four-stroke. Flair reckon on up to a .52 four stroke for the Cub, I'd just go with their advice and put an APS or SC 52 FS in it. I've got an SC 52FS in an Acrowot sports model, and it will turn a 13" prop quite happily (and quietly). It would be fine on a 12*6 in the Cub.
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