Edgeflyer Posted September 17, 2020 Share Posted September 17, 2020 I have a 30cc size aerobat to equip with a motor. The choicevis between 4 stroke glow, possibly large 2 stroke, or 2 stroke petrol. Such as ASP 180FS glow. or MVVS 30cc petrol. I have experience of glow but petrol seems increasingly popular. Proz and cons? I'm interested in relative aspects such as noise levels, ease of use, reliability, power to weight and fuel economy. Please contribute your experiences. Thanks Quote Link to comment Share on other sites More sharing options...
FlyinBrian Posted September 17, 2020 Share Posted September 17, 2020 A petrol engine will need a good exhaust (canister) to be reasonably quiet, Probably cost c100.00 for header and can. Fuel cheap and easy to obtain, fuel consumption low. Four stroke glow, great sound reasonably quiet but glow fuel is expensive - normally run on 10% nitro so c22.00 gallon - on the plus side they are frugal on fuel. 500cc will last a 120 4 stroke glow about 15mins MVVS 30cc petrol two stroke- noisy if not on a pipe / canister. MVVS pipe and header will be over 100.00 Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted September 17, 2020 Share Posted September 17, 2020 Everything that Brian says . The range of Krumschied silencers distributed by Stuart McKay are brilliant and yes are expensive . but you get what you pay for . Two stroke glows tend to scoff the fuel and are still noisy but on the plus side are considerably more powerful than a similar sized petrol . Have you looked at the NGH 38cc or the 30cc four-stroke petrol from just engines ? Good sound frugal on fuel and not overly expensive . Very mixed reviews around . A club member has two and had no problems and swears by them and the supplied silencer is adequate for most sites if propped correctly .Any of the two-stroke s available that come with a so called silencer will need a decent silencer added to the cost as the supplied units are flying site losers Quote Link to comment Share on other sites More sharing options...
Brian Cooper Posted September 17, 2020 Share Posted September 17, 2020 Silencers, especially for two strokes, have always been an issue with engines whether they are glow or petrol . . The ones supplied by manufacturers are rarely adequate for keeping the noise down, and the "silencers" supplied with petrol engines are pathetic.... they are constructed from the thinnest materials possible and behave more like amplifiers. So, yes, additional costs for a decent silencer have to be considered when using a petrol engine if noise is an issue at any given flying site. Four strokes can be just as loud but, with only half as many exhaust beats, they tend to be more pleasant to listen to, so we can get away with the standard silencers. As a general rule, glow is good up to an engine size of about 20 cc. For anything larger, a petrol engine comes into its own. . The running costs for petrol engines is miniscule compared to glow engines. . Quote Link to comment Share on other sites More sharing options...
Former Member Posted September 17, 2020 Share Posted September 17, 2020 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Nigel R Posted September 17, 2020 Share Posted September 17, 2020 Less expensive glow fuel is available, Weston 5% Prosynth is currently £14.29/gallon, works for me. Quote Link to comment Share on other sites More sharing options...
Brian Cooper Posted September 17, 2020 Share Posted September 17, 2020 Yup, another vote for Pro-Synth here. . I changed to this fuel over 20 years ago, and haven't looked back. Engines run faster, cooler and sweeter on this fuel, and they also remain clean inside and out. . It is by far the BEST glow fuel available, regardless of what some detractors might say. . Quote Link to comment Share on other sites More sharing options...
J D 8 Posted September 17, 2020 Share Posted September 17, 2020 Not mentioned so far is smell. Not so much running bit but carting petrol and petrol engines in the car. The smell can invade the car some. If you and others using the car don't mind then ok. I do not have model petrol engines but sometimes carry strimmer/ brush cutters and am not keen on the smell. Quote Link to comment Share on other sites More sharing options...
tigerman Posted September 17, 2020 Share Posted September 17, 2020 Forget Petrol ,get a Laser 180 four stroke .I was in the same mind has you I was persuaded with my Wots Wot XL to go for the Laser 180 and that is what I put in my Wots Wot XL .Sounds great ,more then enough power and oh so reliable .Go with the Laser 180 you will not regret it Quote Link to comment Share on other sites More sharing options...
Bruce Collinson Posted September 17, 2020 Share Posted September 17, 2020 Personal experience; much more frugal, much cleaner. Nasty smell. Walbro carbs seem to come in two disparate versions; those which take and hold tune, and the others. Zenoahs fairly docile and not too loud but heavy. Slight extra complexity with ignition, kill switches and tank plumbing in an aerobat, to maintain air flow into the tank without emptying it. Tygon a bit dearer. Observationally; I've watched clubmates spend far longer sorting petrols than glows, and whatever the noise meter says, even if you find a way of getting below 82dB it will still sound loud because they all seem to have a particular frequency which is intrusive. I gave up with a DLE and put a Saito in. BTC Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted September 17, 2020 Share Posted September 17, 2020 Either choice is fine, each have there own pluses and minuses, reliable ? There's thousands of flyers using both with little or no trouble, then there's the fiddlers who're never sorted. Quote Link to comment Share on other sites More sharing options...
Jon H Posted September 17, 2020 Share Posted September 17, 2020 Posted by Brian Cooper on 17/09/2020 11:55:45: Yup, another vote for Pro-Synth here. . I changed to this fuel over 20 years ago, and haven't looked back. Engines run faster, cooler and sweeter on this fuel, and they also remain clean inside and out. . It is by far the BEST glow fuel available, regardless of what some detractors might say. . By detractors i guess you mean me as i wouldnt recommend this fuel to my worst enemy and will not warranty any of my engines on it. I know its see as a marmite issue, but if it wasnt a problem then i wouldnt be avoiding it would i? As a curiosity, beyond anecdotes i am curious regarding your qualifications to grant the award of best fuel On the OP, as has been stated both have advantages and disadvantages but the one everyone loves to talk about is cost. 'oh the fuel is so cheap' they all cry. True, petrol is cheaper than methanol, but does it really matter? I drive 70 miles round trip to my flying field. While i am there i order a pizza for lunch, and then consider flying a bit. On the BH weekend i flew 5 flights with my 50cc glow powered P39, 2 with my laser 80 powered hurricane and 2 with my saito 45 powered Niuport 17. That little lot cost me about 2/3 of a gallon of glow fuel so call it 12 quid for the fuel? Certainly the cost of the glow fuel was less than the cost of travel and lunch. Petrol engines have their place for sure, but forget the cost argument as like for like a petrol engine will be more expensive to buy and (depending on how often you fly) could take a decade to break even vs a glow. Ignore the reliability claims too. John Stone's point is absolutely correct. Quote Link to comment Share on other sites More sharing options...
Nick Somerville Posted September 17, 2020 Share Posted September 17, 2020 Love the simplicity of glow. No ignition battery. Laser 180 in my Pilot 78” Extra and flies for at least 15 mins on a 16oz tank. Plenty of power for vertical manoeuvres and sounds brilliant. Quote Link to comment Share on other sites More sharing options...
David Hazell 1 Posted September 17, 2020 Share Posted September 17, 2020 Posted by Jon - Laser Engines on 17/09/2020 14:18:16: By detractors i guess you mean me as i wouldnt recommend this fuel to my worst enemy and will not warranty any of my engines on it. I know its see as a marmite issue, but if it wasnt a problem then i wouldnt be avoiding it would i? Out of interest Jon, why would you not recommend that fuel, and which fuel _would_ you recommend? I'm using prsynth 10% at the moment and it's fine for my ratty old second hand super tigre 45, but that's 2 weekends flying, without looking inside the engine!!! Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted September 17, 2020 Share Posted September 17, 2020 Posted by Jon - Laser Engines on 17/09/2020 14:18:16: Posted by Brian Cooper on 17/09/2020 11:55:45: Yup, another vote for Pro-Synth here. . I changed to this fuel over 20 years ago, and haven't looked back. Engines run faster, cooler and sweeter on this fuel, and they also remain clean inside and out. . It is by far the BEST glow fuel available, regardless of what some detractors might say. . By detractors i guess you mean me as i wouldnt recommend this fuel to my worst enemy and will not warranty any of my engines on it. I know its see as a marmite issue, but if it wasnt a problem then i wouldnt be avoiding it would i? As a curiosity, beyond anecdotes i am curious regarding your qualifications to grant the award of best fuel On the OP, as has been stated both have advantages and disadvantages but the one everyone loves to talk about is cost. 'oh the fuel is so cheap' they all cry. True, petrol is cheaper than methanol, but does it really matter? I drive 70 miles round trip to my flying field. While i am there i order a pizza for lunch, and then consider flying a bit. On the BH weekend i flew 5 flights with my 50cc glow powered P39, 2 with my laser 80 powered hurricane and 2 with my saito 45 powered Niuport 17. That little lot cost me about 2/3 of a gallon of glow fuel so call it 12 quid for the fuel? Certainly the cost of the glow fuel was less than the cost of travel and lunch. Petrol engines have their place for sure, but forget the cost argument as like for like a petrol engine will be more expensive to buy and (depending on how often you fly) could take a decade to break even vs a glow. Ignore the reliability claims too. John Stone's point is absolutely correct. Hi Jon. I've only recently heard of Pro-Synth fuel from a couple of very satisfied users at our field. I was considering buying some the next time I need fuel. Your comments have got me questioning it's suitability though. I run exclusively Saito 4 stroke glow engines - an 82 and a 150. Other engines are all petrol. Could you please clarify what exactly is the problem with Pro-Synth fuel that makes it so bad that it invalidates Laser Engine warranties? Is it a problem with something specific to Laser engines or is it bad for all engines? Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted September 17, 2020 Share Posted September 17, 2020 One factor that hasn't been mentioned yet is the ease of cleaning the model after use. Glow fuel leaves an oily sticky residue which can be quite difficult to completely remove. Petrol fuel leaves only soot, which can be easily removed using petrol on a rag - i.e. no need to carry special cleaning fluids. Quote Link to comment Share on other sites More sharing options...
Former Member Posted September 17, 2020 Share Posted September 17, 2020 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
martin collins 1 Posted September 17, 2020 Share Posted September 17, 2020 Gave up on glow years ago, i cannot stand getting my models covered in the oily slime then having to clean it all off............ Petrol or electric for me Quote Link to comment Share on other sites More sharing options...
Jon H Posted September 17, 2020 Share Posted September 17, 2020 I dont want to get drawn into another prosynth debate as we will be here for a week and then the mods will send the heavy gang in to break it up. Its also not the point of the thread. I also have a problem as i am walking the tightrope of saying what i want as a modeller, and representing a company as Laser. So, all i can really say is this. it is not suitable for use in Laser engines as it does not comply with our warranty spec and use may result in mechanical failure. Consider for a moment what would cause us to make such a bold statement. Especially when we are working with other fuel manufacturers on reduced oil options that we know are perfectly safe. This is not a bias thing and i dont own a dog. Sure model technics make our laser fuel but we get no kick back from that and i hate plenty of their fuels as well. If the product isnt good enough i wont warranty the engine. For example... Duraglo - Please, i beg you all to stop using this. I am also not a fan of Contest 10. Its expensive, messy, awful. Engines run ok on it, but techpower 10 would be so much better. Gary, your point about cleaning is mostly valid but it depends on the engine. I have had a number of customers come back to me after finding their petrol engines were spewing gallons of black stuff everywhere. I think you need to get to about 40:1 before they go clean. The 20:1 2 strokes etc i believe are still pretty messy. Edited By Jon - Laser Engines on 17/09/2020 16:23:57 Quote Link to comment Share on other sites More sharing options...
Tim Flyer Posted September 17, 2020 Share Posted September 17, 2020 The main plus for me with glow is simplicity inside the model so I don’t need to worry about ignition systems, leads and batteries (although I obviously stIll need a glow igniter and lead, but that’s all outside the model) . Methanol is also a great fuel for models with cowling due to its latent heat properties, so much less prone to overheating. My personal preference is for four stroke glows as I love their easy handling good throttle response and relatively soft sound. Some petrol two stroke engines I have seen don’t seem to throttle the well...(possibly due to carburettor design/set up). The main drawback for me in using glow fuel is fuel proofing and the need for specialist paint finishes. Quote Link to comment Share on other sites More sharing options...
Tim Flyer Posted September 17, 2020 Share Posted September 17, 2020 . Edited By Tim Flyer on 17/09/2020 18:02:24 Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted September 17, 2020 Share Posted September 17, 2020 post deleted. Edited By Gary Manuel on 17/09/2020 19:04:41 Quote Link to comment Share on other sites More sharing options...
Richard Acland Posted September 17, 2020 Share Posted September 17, 2020 I have always used glow engines, mainly four strokes as I like the sound and find they are what I call flying field friendly. They are all fitted with my own design on board glow systems so are easy to start. I have been interested in petrol engines as several of my club mates use them but they do seem quite noisy even when fitted with so called quiet silencers fitted. I can see the appeal when it comes to running costs versus glow fuel, so I suppose in the end it comes down to what you are happy with. Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted September 17, 2020 Share Posted September 17, 2020 IMO - Glow Put the tank in the right place, nothing else needed Set it up right then no onboard glow needed No ignition or CDI needed 4 strokes just sound better Using Laser lower oil content fuel then minimal cleaning, just wipe over while doing the post flight inspection Less things to go wrong For the amount of glow fuel I use compared to the cost of the model and the diesel driving to the field I can't see the benefit or the payback I suppose the more people that buy petrol then the more glow engines available for the rest of us... Quote Link to comment Share on other sites More sharing options...
J D 8 Posted September 17, 2020 Share Posted September 17, 2020 I was at the flying field early the other day with a gallon of glow set for as much flying as I could get in [ Like Jon I have 35ml around trip so when there I go for the day ] When a chap said " that will cost you a lot " . I got in a good day's flying and burned half a gallon [ all my engines above 40's are four strokes ] He burned very little petrol but that was because he could not get his motor to run until the day was nearly done. Just an observation but petrol's under 25cc tend to give more problems. Quote Link to comment Share on other sites More sharing options...
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