4 Stroke in a Wotty

[Phil May]

I'm looking to get a Wot 4 ARTF and I have an ASP 61 4 stroke which I wish to fit, is this motor suitable and will it have sufficient grunt to haul it around.

I have seen plenty with 46's & 53 two strokes but not a 4 stroke.

Cheers guys

Phil

[ken anderson.]

hello BP...I had a Wot 4 with a saito 40 4st in it years ago and that was ok...yours with a 61 4st will be a good combo with more than enough power.....

 

ken anderson ne..1.

Edited By ken anderson. on 18/04/2011 17:12:15

[Biggles' Elder Brother - Moderator]

Should be OK Phil - but possibly not "sparkling". It depends how you want to fly it.

 

I don't have much experience with the ARTF WOTTY but I do know the kit one well. The kit would fly OK with a 40-46, but it went a lot more lively with a 53!

 

Now 40-46 is roughly equivalent to a 60 4-stroke, but a 53 is more like a 70 4-stroke. So it will fly and will probably do reasonable aeros etc - but you're unlikely to get unlimited vertical and prop hanging out of it unless the ARTF is a lot lighter than the kit. IYSWIM.

 

BEB

[Diamond Geezer]

Hi Phil

Had a os52 in mine and it was really good a few of the other guys started to fit em

Geoff

[GrumpyGnome]

My kit built Wotty has an ASP 61 FS in it - flies beautifully. Won't go vertical for ever and it's not a prop hanger .................. but it aint a heli and I prefer to use the wings for their designed purpose

 

It's quite heavy now so I suspect the ART would be even better.

 

[Doug Ireland]

Posted by GrumpyGnome on 19/04/2011 11:55:30:

My kit built Wotty has an ASP 61 FS in it - flies beautifully. Won't go vertical for ever and it's not a prop hanger .................. but it aint a heli and I prefer to use the wings for their designed purpose

 

It's quite heavy now so I suspect the ART would be even better.

 

Well said GG!

[Braddock, VC]

I bought a wottie artf, fitted a saito 82 in it. I also had a mk 2 wot4 from the early eighties with a saito 82 too.

With the artf there will have to be some mods as the artf is designed around a 2 stroke, I built up a lite ply sort of cofferdam out from the firewall so the cowl would fit without a 15 mm gap.

I never got to fly the artf, I sold it on but the old mk2 flew brilliantly with it vertical descents at tickover with a 14x6 jxf prop were remarkably slow and vertical upwards was limited by eyesight or clouds.

The weights of the two were remarkably similar and in the past I've flown both the mk 3 wottie and acrowot with the 61 4 stroke, magnum in my case, and they were great about the same as the os 52 surpass but not as much grunt as the saito.

The kit built wot4 mk 2 originally had an os 61 fs in and I'm pretty sure that and the os 52/asp61 were much of a muchness with a 13x6 apc on.

 

But and this is serious fit a much smaller tank, IIRC my saito 82 has an 8 ounce tank (slec yellow) and 15 min flights at mixed throttle leave about a 1/4 of a tank, the os52fs is MUCH more economical and I reckon you'd get similar duration with a 6 ounce tank for your 61, it'll fly better too as not only the 61 lighter than an os 46 ax, with 4 ounces less fuel to start with you'll have a plane that's nearly 1/2 pound lighter at take off than you will with the standard tank coupled with an os 46 ax or one of the clones.

Edited By John Gibbs on 06/05/2011 00:03:43