toto Posted April 6 Share Posted April 6 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 Quote Link to comment Share on other sites More sharing options...
Richard Wills 2 Posted April 6 Share Posted April 6 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. 1 Quote Link to comment Share on other sites More sharing options...
toto Posted April 6 Author Share Posted April 6 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 Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted April 6 Share Posted April 6 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. 1 Quote Link to comment Share on other sites More sharing options...
Richard Wills 2 Posted April 6 Share Posted April 6 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. 1 Quote Link to comment Share on other sites More sharing options...
GrumpyGnome Posted April 6 Share Posted April 6 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. 2 Quote Link to comment Share on other sites More sharing options...
EarlyBird Posted April 6 Share Posted April 6 For me it would have to be a Saito FG21 which sounds nice and looks beautiful. Steve 1 Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted April 7 Share Posted April 7 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 ?.😡😨🤢 Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted April 7 Share Posted April 7 I have one of these to build and will be getting a DLE 20CC, seems to be a good combination Linds 1 Quote Link to comment Share on other sites More sharing options...
toto Posted April 7 Author Share Posted April 7 Rear or side exhaust ? Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted April 7 Share Posted April 7 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 Quote Link to comment Share on other sites More sharing options...
GrumpyGnome Posted April 7 Share Posted April 7 My flying chum calls them Christian Eagles too. Mind you, he thinks Dassault makes a Raphael..... 1 Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted April 7 Share Posted April 7 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 2 Quote Link to comment Share on other sites More sharing options...
Cuban8 Posted April 7 Share Posted April 7 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. Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted April 7 Share Posted April 7 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 ? Quote Link to comment Share on other sites More sharing options...
Richard Wills 2 Posted April 7 Share Posted April 7 (edited) 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 by Richard Wills 2 Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted April 7 Share Posted April 7 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. 1 Quote Link to comment Share on other sites More sharing options...
Learner Posted April 8 Share Posted April 8 (edited) 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 by Learner Quote Link to comment Share on other sites More sharing options...
Outrunner Posted April 8 Share Posted April 8 You will know if there are any petrol engines flyers in your club from the racket they make! 1 Quote Link to comment Share on other sites More sharing options...
Cuban8 Posted April 8 Share Posted April 8 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. Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted April 8 Share Posted April 8 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. Quote Link to comment Share on other sites More sharing options...
Cuban8 Posted April 8 Share Posted April 8 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? Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted April 8 Share Posted April 8 (edited) 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 by Simon Chaddock Quote Link to comment Share on other sites More sharing options...
Tom Gaskin 1 Posted April 8 Share Posted April 8 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 Quote Link to comment Share on other sites More sharing options...
Cuban8 Posted April 8 Share Posted April 8 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. Quote Link to comment Share on other sites More sharing options...
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