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» 2019 Llanfair TH Village Fete
4S vs 2S Empty2019-07-12, 18:53 by Rich

» Proposals for Model aircraft flying ( CAA registration) April 2019
4S vs 2S Empty2019-05-08, 17:49 by Gary M Jones

» Police crash
4S vs 2S Empty2019-04-14, 15:36 by Roy

» Bit of indoors
4S vs 2S Empty2019-04-13, 16:49 by Roy

» For Sale
4S vs 2S Empty2019-03-03, 23:44 by Charles E Cornes

Saturday 7/7/18

2018-07-07, 21:07 by Gary M Jones

I was at the field today between 14:00 & 15:00 all on my own , good flying too. There is a dead sheep along the fence line towards the gate from the pits, I saw the farmer so reported this to her. I hope no one had plans for a BBQ Smile .

Farmer …

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4S vs 2S

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4S vs 2S Empty 4S vs 2S

Post by Stubbsy on 2011-10-31, 13:36

Still trying to get my head round the 2 stroke vs 4 stroke thing!

Am I right in saying that a 60(ish) size 4 stroke is roughly the equivalent power to a 50(ish) size 2 stroke?
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4S vs 2S Empty Re: 4S vs 2S

Post by Brian Colclough on 2011-10-31, 13:41

Ben, there's no hard and fast rule as power varies between manufacturers, I would say a 50 two stroke would be equivalent to a 70 four stroke, the two stroke fires on every revolution whereas the four stroke only fires once every two revolutions.

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4S vs 2S Empty Re: 4S vs 2S

Post by Rich on 2011-10-31, 14:00

If you want performance use a 2 stroke for funflys etc, if it's scale 4 stroke, the 2 stroke has a much better power to weight ratio.

For a given size 2 stroke roughly 1/3 more cc from a 4 stroke for the equivaent power

Brians somewhere near with the power comparison.

Andy will give you a boring in detail review soon

Look at the Chris Foss link it shows the recommended engine size in a WOT 4 http://www.chrisfoss.co.uk/#/wot-4/4538950500

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4S vs 2S Empty Re: 4S vs 2S

Post by Andy Sayle on 2011-10-31, 14:26

Here's the boring bit then.

2 strokes are generally cheaper to manufacture, weigh less, are more simple (fewer moving parts), and because they fire once every revolution, they potentially have the ability to put out more power for teh same capacity.

Four stroke engines are more complicated, heavier and more expensive, but tend to be more efficient (at the expense of power). They tend to rev less, and produce more torque.

It's a bit irrelavant though, everyone knows that Electric motors are betterer than both four strokes and two strokes put together (a six stroke?)....

Andy

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4S vs 2S Empty Re: 4S vs 2S

Post by Rich on 2011-10-31, 15:10

I'd agree up to 300watts direct

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4S vs 2S Empty Re: 4S vs 2S

Post by Andy Sayle on 2011-10-31, 15:33

I'd go higher than that I think, although it depends on the application. That glider running just shy of 2kW of mine was no bother at all..... The electric edge I had, was bloody awful though with 2kW onboard.....

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Post by Rich on 2011-10-31, 15:44

That glider you crashed you mean no way 2k

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4S vs 2S Empty Re: 4S vs 2S

Post by Andy Sayle on 2011-10-31, 15:50

My (ex)graphite that hit the Orme in various pieces after listening to Jeremy ask "how fast will it go in a dive then"? With the 18x10 prop on, 6s 2150mAh packs, it was pulling just shy of 100Amps (pack voltage under load was around 19.5v ish, depending on the temperature) I had to disable the current limiting on the Castle 80A Esc to stop it cutting out on me.

I normally flew it on a 16x 10 prop at around 70A though (1.4-1.5kW), that way the batteries were a bit less hot and bothered....

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4S vs 2S Empty Re: 4S vs 2S

Post by Brian Colclough on 2011-10-31, 15:56

This thread started off talking proper engines and as usual when Andy's involved we end up talking electric motor and electric fires, Yuck or words to that effect.

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4S vs 2S Empty Re: 4S vs 2S

Post by Rich on 2011-10-31, 16:11

Totally agree he's a thread nicker

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4S vs 2S Empty Re: 4S vs 2S

Post by Andy Sayle on 2011-10-31, 16:24

How dare me! Shocked I'll take the lashings as punishment please....


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4S vs 2S Empty Re: 4S vs 2S

Post by Stubbsy on 2011-10-31, 17:07

- to get back on track then - so a model that is said to be "ideally suited to a .62 4 stroke, would be adequately powered by a .52/.53 2 stroke? scratch
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4S vs 2S Empty Re: 4S vs 2S

Post by Brian Colclough on 2011-10-31, 17:24

Will be fine Ben leaning towards overpowered if anything but you have the throttle to hand Wink

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4S vs 2S Empty Re: 4S vs 2S

Post by Rich on 2011-10-31, 18:27

What if that fails, nothing is going right for him lately

"you who"

can't glue a bit of carbon on

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4S vs 2S Empty Re: 4S vs 2S

Post by Stubbsy on 2011-10-31, 19:44

As long as the sodding wings dont fall off I should be ok!

Plus - For your information Rich - I have NO TROUBLE AT ALL gluing carbon on thank you very much!





Its getting it to stay there I have trouble with!
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