bert baker Posted August 28, 2016 Share Posted August 28, 2016 So I have heard that there is a glow type of plug that can be used with petrol,with out the need for a ignition system. Basickly use petrol instead of glow fue. Anyone had a go with them. or should that be glow with them Quote Link to comment Share on other sites More sharing options...
Former Member Posted August 28, 2016 Share Posted August 28, 2016 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
bert baker Posted August 28, 2016 Author Share Posted August 28, 2016 I dont want to buy one, I want to know if any one other than shops have used them. Quote Link to comment Share on other sites More sharing options...
Former Member Posted August 28, 2016 Share Posted August 28, 2016 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
GrahamC Posted August 28, 2016 Share Posted August 28, 2016 Just Engines do sell a spark plug in the shape of a glow plug. I won't however work without an ignition module, and will require the mounting of a magnet and hall sensor on the front crank of the glow motor. There is also an old thread here discussing the viability of running a glow engine on neat petrol with a permanently lit glow plug, Quote Link to comment Share on other sites More sharing options...
flight1 Posted August 28, 2016 Share Posted August 28, 2016 You can buy a special glow plug for petrol i belive Enya developed one first see there site you can buy direct Here Os do one too G5 the plug is called . might be usefull for the smaller size engines but 20cc and above spark all the way . Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted August 29, 2016 Share Posted August 29, 2016 You will have more luck on the RC Groups website, I believe there was a discussion in the Engines forum. IIRC even some of those running the OS GGT(? I think that's the type) engines that come with the G5 gas glow plugs were reported as having issues with tuning and transition. But then again, you only tend to hear of problems (real or imagined) on the internet Quote Link to comment Share on other sites More sharing options...
Mike T Posted August 30, 2016 Share Posted August 30, 2016 I'm using one in a Moki 210 fitted to a H9 1/4 scale Cub. The Moki was converted to petrol by shimming the head (2 shims from JE) and fitting all the necessary Rxcel gubbins, plus a Walbro carb mounted via an adaptor spigot which I turned myself. I heard about the OS G5 plugs, so bought one (about 8 quid) and tried it. It works. Only problem is the idle which is not as low as I'd like - I'll maybe try another shim to lower the compression a bit more. One positive is that I have reverted to the 'reverse bounce' start that got the Moki going first time when it used to be a (messy) glow. Some pics: First 2 show engine running with ign cap clearly off. Remainder show installation with and without the Rxcel gear. HTH. Edited By Mike T on 30/08/2016 23:53:04 Quote Link to comment Share on other sites More sharing options...
Mike T Posted August 31, 2016 Share Posted August 31, 2016 I should add that while this plug clearly works, I am using an engine that's already optimised for petrol (shimmed head; walbro carb). However, as it was originally a glow engine, it shows that a bit of light engineering can make these plugs worth a punt. Next experiment is to try it on a spare fourstroke (glow; no adaptions) to see how it gets on in that... Quote Link to comment Share on other sites More sharing options...
bert baker Posted August 31, 2016 Author Share Posted August 31, 2016 Many thanks just the info I needed,, I wonder if a heavy prop would aid better idle. of perhaps a flywheel. Quote Link to comment Share on other sites More sharing options...
Mike T Posted August 31, 2016 Share Posted August 31, 2016 A massier prop would probably help. The wood prop in the pics is a Clark 20 x 8. The Moki will easily swing a 22" but I haven't the ground clearance (even with the "tundra" tyres...). I can live with the high idle, but may try a G-sonic prop at some point (or a Master if I'm really desperate!) Quote Link to comment Share on other sites More sharing options...
Anthony Scott 2 Posted August 31, 2016 Share Posted August 31, 2016 I bought a G5 recently & tried it initially in an old Leo 46, I was amazed at how easily the Leo started. It ran well at WOT but the idle was not very reliable, however I will persevere. I also have an OS 120AX with a Morris Minimotors petrol conversion, which runs as well as anyone could want. I tried this with the G5, again great at WOT but the idle needs adjustment to the carb which I do not want to do. For £7.99 & some 2 stroke mix the G5 has to be worth a try. Tony Quote Link to comment Share on other sites More sharing options...
PETER BRUCE - Eastchurch Gap Posted August 31, 2016 Share Posted August 31, 2016 The below maybe of help so others reading this thread... This is a simple way with SOME engines to get away from costly glo fuel. My friend Keith did this engine conversion for me and I was a bit sceptical at the time - but as usual he was right... On this Aviastar Av-150 R/C 25 cc only the glo plug was changed and the existing carb was re-tuned to run on petrol - that's it... Now I need to find a plane to put it in... This is one low cost engine that's very well made indeed. The tinkling noise is the camera NOT how the engine sounds. I have also tried the G5 plug on other engines however the needle taper pitch is too course on many engines so although you can get them to start the idle is not stable no matter how you ply with it. In short I have found that its down to what carb you have on the engine - if it will take petrol instead or nitro - the latter has a far thicker consistency which makes getting the right mixture over the throttle range with petrol "challenging" but as a plug the G5 does its job on 2 stoke and four stroke so give it a go. The other option is to change the carb to a Walbro and it will be fine then. Regards Peter Quote Link to comment Share on other sites More sharing options...
Mike T Posted September 1, 2016 Share Posted September 1, 2016 If someone did a range of petrol-optimised needles and jets for popular glow carbs, that would be ideal! Quote Link to comment Share on other sites More sharing options...
GONZO Posted September 1, 2016 Share Posted September 1, 2016 Any use? Quote Link to comment Share on other sites More sharing options...
Tim Flyer Posted September 1, 2016 Share Posted September 1, 2016 Sorry to douse the petrol flame. But surely mass small engine motor manufactures would use glow plugs on petrol engines if they were reliable. It would save them a huge amount of money. The idle and low end throttling on a model aero engine is one of the most important features especially as we use fixed pitch props and do not want sudden dead stick on landing. Agricultural engine manufacturers also require steady idle settings on their motors but I cannot see Stihl using glow plugs. I mostly use glow fuel in four stroke engines of 13-26cc which are also very economical. I don't have the hazardous handling and ignition/tuning problems of petrol. I fully understand use of petrol in 30cc plus engines , but have not been that impressed with the small petrol engines I have seen. Unless I wanted hours in the air with my models I don't feel persuaded to change. Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted September 1, 2016 Share Posted September 1, 2016 There again, utility units usually use magnetos to avoid the need for a battery and associated charging circuit while glow ignition would mean fitting a battery just for starting - not helpful! Quote Link to comment Share on other sites More sharing options...
Mike T Posted September 1, 2016 Share Posted September 1, 2016 Posted by GONZO on 01/09/2016 12:25:48: Any use? Yup! Go on - turn some up Quote Link to comment Share on other sites More sharing options...
Mike T Posted September 1, 2016 Share Posted September 1, 2016 Re Timothy Harris 1's points, more manufacturers do seem to be going for smaller petrols. OS is already producing 'model' petrol carbs (instead of using Walbros). And if OS are selling a petrol plug they must have a degree of confidence in it. (They know dabblers will try it in lash-ups, so they'll have made it robust so it doesn't get a poor reputation.) Re the industrial engines - in their intended use they get a far harder time than in any model installation, so they have to be bullet-proof. Hence they use a virtually unbreakable ignition system, burning readily available fuel. Moreover, it is the system used since their inception and has been proved to work, so I suspect their market would be quite resistant to change (a bit like the 'model' market, in fact!)>> AFAIC petrol is no more hazardous than glow, if handled correctly, and surely one of the main selling points of petrol/spark is the 'fit and forget' nature - i.e. no more fiddling with needles. The main motivators for me to convert my Moki from glow in the first place were firstly mess and secondly fuel cost - the Moki was a thirsty beast on glow! The fact that I had the tools and materials to do it also helped. It was a simple step from there towards trying the G5 plug.>> Quote Link to comment Share on other sites More sharing options...
chris larkins Posted September 1, 2016 Share Posted September 1, 2016 I test ran my SC 1.20 4 stroke this afternoon on the O.S G5 plug, see video below. This engine was converted to electronic ignition using an ignition unit from hobbyking and a magnet ring/sensor bracket from Morris Mini Motors and it ran beautifully...........Today's engine run was a first test using an O.S G5 glow plug, the magnet ring and sensor bracket are still fitted to the engine but have been disconnected. With a small amount of tuning we got the engine to idle reliably at 2500 rpm and peak at 8050 rpm with a smooth transition using an evolution 16 x 6 prop. The engine sounds pretty loud in the video but the exhaust was aiming directly at the camera and in reality didn't sound much different from when it ran on glow fuel.......the major advantage was that it literally sips fuel as the main needle was only open 1/2 turn and it ran so clean that there was no exhaust residue whatsoever...........so far so good. Quote Link to comment Share on other sites More sharing options...
Mike T Posted September 1, 2016 Share Posted September 1, 2016 Nice! I'm going to try the plug in a 'stock' SC65 F/s, just to see how usable an unmodified engine is. Quote Link to comment Share on other sites More sharing options...
chris larkins Posted September 1, 2016 Share Posted September 1, 2016 Posted by Mike T on 01/09/2016 21:18:01: Nice! I'm going to try the plug in a 'stock' SC65 F/s, just to see how usable an unmodified engine is. My SC 1.20 is totally stock, no head shims or any other mods. The only thing I found, as have many others, is that the main needle is extremely sensitive with just one click either way making a big difference. I have read on another thread (similar to the diagram on page 1) that giving the needle a finer taper helps to make it far less sensitive and I will be trying this next Quote Link to comment Share on other sites More sharing options...
AndyD Posted September 1, 2016 Share Posted September 1, 2016 does any one produce adapter to fit walbros as that seems to work well with the g5 what ive seen on the tube any way. Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted September 1, 2016 Share Posted September 1, 2016 Posted by chris larkins on 01/09/2016 21:38:01: Posted by Mike T on 01/09/2016 21:18:01: Nice! I'm going to try the plug in a 'stock' SC65 F/s, just to see how usable an unmodified engine is. My SC 1.20 is totally stock, no head shims or any other mods. The only thing I found, as have many others, is that the main needle is extremely sensitive with just one click either way making a big difference. I have read on another thread (similar to the diagram on page 1) that giving the needle a finer taper helps to make it far less sensitive and I will be trying this next What I found interesting (I was at the field when Chris was running his engine) was that a small adjustment on the bottom end needle affected the top end quite substantially while we were attempting some fine tuning. This might relate to the much smaller volumes of fuel being handled by the carb than it was designed for and possibly throw some light on difficulties experienced by others? The engine ran and throttled pretty well but could be stalled by snapping the throttle open after prolonged idling - which was cured by a tiny adjustment. Quote Link to comment Share on other sites More sharing options...
Mike T Posted September 3, 2016 Share Posted September 3, 2016 Re needles, adaptors, carbs, etc., this is the sort of guy who I'd hope would take an interest: **LINK** Quote Link to comment Share on other sites More sharing options...
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