Best petrol engine for a Seagull Steen Skybolt

[toto]

As stated,

 

I have a Seagull Steen Skybolt that I bought some time ago. One of two biplane, the other being a Sebart Miss Ultimate.

 

I'm not anywhere ready to build or capable of flying either so this is just a bit of forward thinking. 

 

Initially I was going to go electric on the skybolt but I'm pulling towards IC. It's rated as a 15cc 2 or 4 stroke. I would want to go petrol rather than glow .... fuel availability and the mess etc.

 

What would be the best petrol engine to give decent performance, reliability and give the model that presence of sound ?

 

As mentioned I am not intending doing anything with this as I am currently happy on electric power for the foreseeable future but it would do me any harm to be looking about.

 

Cheers

 

Toto

[Richard Wills 2]

Can't help specifically on the petrol Toto, but mine has an OS 120 4stroke glow in it, and I wouldn't want less than that.  If it must be petrol, I would think a 20cc would be the way to go.

 

The model is a great flyer on the whole, predictable and doesn't have any bad vices.  Like you said not ready for it yet, but unlike say a heavy Pitts, it is relatively easy to fly.  

[toto]

Thanks for that Richard.

 

What gives the best sound, a single cylinder or a twin. I think you can get a 20cc stinger in single or twin. Is there any advantage to spending the extra on a twin ?

 

Cheers

 

Toto

[Paul De Tourtoulon]

I would recommend a DLE 20RA, Dle are good engines, Ra is the rear exhaust so easy to hide it, the Rcgf engines are cheap, ( many are copy's of copys ) and that reflects in the way that they vibrate, twins are normally less powerful than singles.

[Richard Wills 2]

If sounding good is a priority I would say look at 4 strokes.  For me 2 strokes are a means to an end, but sound awful especially under silenced petrols which most are.  I would rather have electric in a scale plane than a 2 stroke.  Saito FG-21 would suit the Skybolt I should think.

[GrumpyGnome]

A number of dle 20s in our club. Very reliable. Relatively vibration-free... cheap to run!

 

Like all petrols, unless you spend lots on an after market muffler, quite noisy. Something to bear in mind if your site is noise-sensitive.

 

Four stroke sounds much nicer imo, but costlier.

[EarlyBird]

For me it would have to be a Saito FG21 which sounds nice and looks beautiful.

 

Steve

[Paul De Tourtoulon]

11 hours ago, EarlyBird said:

For me it would have to be a Saito FG21 which sounds nice and looks beautiful.

 

Steve

Big money🤢 maybe a Saito or other 150 four stroke methanal if you have a noise problem, did someone suggest electric ?.😡😨🤢

[Lindsay Todd]

I have one of these to build and will be getting a DLE 20CC, seems to be a good combination 

Linds

[toto]

Rear or side exhaust ?

[Frank Skilbeck]

If you don't want to faff with extra ignition batteries and CDI unit then the Zenoah Magneto units are a good option, e.g. Zenoah G260PU 26cc, not the most powerful but good reliable engines.

 

I acquired an old Kalt 23cc (Rebadged Zenoah) in a Christian Eagle biplane, hadn't been run for years, I changed the carb diaphrams and it runs great, still as noisy as a DLE though.

 

Just engines do them https://www.justengines.co.uk/shop/petrol-two-strokes/zenoah-petrol-two-strokes/zenoah-g260pu-26cc-aero-engine/?v=79cba1185463

[GrumpyGnome]

My flying chum calls them Christian Eagles too. Mind you, he thinks Dassault makes a Raphael.....

[Lindsay Todd]

I have a DLE20 RA rear exhaust in the cupboard all ready, just need to find time and space. I was actually thinking of another Pitts at the time but the slightly longer fuselage of the Skybolt should make the flight characteristics slightly less 'skittish' whilst still being very capable of all the gyroscopic manoeuvres, that's the theory anyway. 

I was thinking of a repaint in the Toyota livery of Brian Lecomber's Piitts S1-T from the late 80's/ early 90's just for sentimental reasons but I actually really like the black and gold once I opened the box so that will have to wait for another time.

Linds

[Cuban8]

22 hours ago, toto said:

As stated,

 

I have a Seagull Steen Skybolt that I bought some time ago. One of two biplane, the other being a Sebart Miss Ultimate.

 

I'm not anywhere ready to build or capable of flying either so this is just a bit of forward thinking. 

 

Initially I was going to go electric on the skybolt but I'm pulling towards IC. It's rated as a 15cc 2 or 4 stroke. I would want to go petrol rather than glow .... fuel availability and the mess etc.

 

What would be the best petrol engine to give decent performance, reliability and give the model that presence of sound ?

 

As mentioned I am not intending doing anything with this as I am currently happy on electric power for the foreseeable future but it would do me any harm to be looking about.

 

Cheers

 

Toto

Just a few thought that might help your decision. If you're looking to have a model like the Skybolt look and sound nice, then a two stroke of any description will never fit the bill in my opinion. It'll fly OK but the sound and character that you're after might never really satisfy you and you may become disappointed. Very much a personal thing.

If you're not in a hurry start saving now for a petrol 4st - don't dismiss a glow fourstroke - I run my OSs and ASPs on the lower (15%) content Laser fuel and the amount of residue is a lot less than 20% oil content fuels. Any glow fourstroke will be a lot less messy than a glow twostroke, just the nature of how they work and how the oil is used. Siting the exhaust in the best position to keep the residue away from the model is also important, so careful  planning during construction is to be considered.

Several Saito petrol fourstrokes in my club and they really are superb, but the bigger ones are a lot of money for ordinary mortals and even their .60ish size baby one is four hundred quid.

[john stones 1 - Moderator]

Not liking the uncomplimentary descriptions of the Pitts, it's a top aircraft and in anything like a decent size, it's a pussycat. Regarding which one, they're like the glows, all fit for purpose and some a bit better than others.

On Saito, I have no personal experience but the grapevine says they're not the most powerful, so err on the larger side maybe ?

[Richard Wills 2]

My description of the Pitts model I don't think is uncomplimentary.  I had the Blackhorse one, similar size to the Skybolt.  It is heavier, it is shorter coupled, it is much draggier, flys faster, and needs more attention to the controls but it is a blast to fly and I love it.  My comment comes from the Skybolt being a better choice for success earlier on in your flying journey

Edited April 7, 2024 by Richard Wills 2

[Paul De Tourtoulon]

1 hour ago, john stones 1 - Moderator said:

On Saito, I have no personal experience but the grapevine says they're not the most powerful, so err on the larger side maybe

Yes, my FG-30 swings the same prop at the same speed as my Dle 20Ra.

[Learner]

Are there any petrol engined planes at the site you fly at? If there are speak to the owners to get their views and have a look/ listen to see if that's the way to go before buying.

If there aren't ask yourself why, maybe noise concerns.

As mentioned in previous posts a 4 stroke glow sounds lovely

 

Edited April 8, 2024 by Learner

[Outrunner]

You will know if there are any petrol engines flyers in your club from the racket they make!

[Cuban8]

56 minutes ago, Outrunner said:

You will know if there are any petrol engines flyers in your club from the racket they make!

Not with any fourstroke petrols that I've heard at my club. Two strokes just have that crackle, energy and sound quality that can be a problem. I have mates who have spent hundreds of pounds on custom exhausts for two stroke petrols and I've not been at all impressed with the returns  in terms of 'silencing/muffling' - better yes, but would still be a problem at noise sensitive sites IMHO. Where I fly, two stroke petrols have fallen out of favour somewhat with us- we have housing developments and recreational facilities not a huge distance away from us so we have to be mindful of how sensitive some folks are at any sort of noise that carries.

[Paul De Tourtoulon]

The Dle 'canister" is worth a try on the Dle 20ra, it does quiet it down a bit and will give you a lot more power.

[Cuban8]

It obviously depends on where the model is to be flown. A site out in the middle of nowhere and very sparsely inhabited will probably be OK, although even then, walkers and farmers worried about disturbance to stock animals or wildlife can be problematic. Even other flyers find the noise tiresome after a while!.

Clubs who do have to be extra careful about upsetting their neighbours because of noise (i.e. most clubs, certainly here in the UK) often run into trouble with noisy petrol two strokes and it's caused  friction in the past within my two clubs over the years when models have had to be grounded.

This whole issue of noisy two stroke petrols has never been properly dealt with, either by the manufacturers or distributors.......or dare I say it, by the modelling press who IMHO, have always tiptoed around the problem. Manufacturers have supplied their products with inadequate noise reduction and we've let them get away with it. Those with many years in the hobby might remember the magazine cartoon ad of a face shouting out and saying "use an effective silencer" way back in the 1980s. Very wise words - but if there is no effective silencer provided or available, then what?

 

[Simon Chaddock]

I find hard to believe an effective silencer is not possible particularly as a 4 stoke is much better able to handle exhaust back pressure than a 2 stroke.

Is it just a case of providing the space for the necessary can volume? 

Edited April 8, 2024 by Simon Chaddock

[Tom Gaskin 1]

BCM exhausts were the best that I found when I was running petrol powered helis - far quieter than the 'exhaust diverters' that came with the engines.

 

Although since growing up I have completely cured the noise issue by going electric! 😉

 

 

Tom

[Cuban8]

Exhaust diverters and not much else - a very good description.

Fourstrokes, either glow or petrol just have a more acceptable note. Even with straight through headers on his OS twin cylinder, my friend's engine's 'noise' is acceptable.