OSGGT15 TEST RUN

The latest innovation from O.S. - the GGT15 (.90) is the same as the GT15 but it has a special glow plug for ignition. Using 32:1 petrol to Coolpower oil, the engine performed flawlessly - excellent idle and steady maximum RPM. As an example - 11,312 RPM on a 13/8 propeller and 8,161 on a 16/6 with 1,650 reliable idle.This is the start of a different engine era in my opinion.
Note the card of the new OS G5 plugs (standard plug thread of 1/4" x 32 tpi) and the common type glow power at the start of the video - that's all it needs and, when it is started, just like a glow engine, the power is off. Interesting!

[@Anon.Emouse]

I have the spark ignition version of this engine and I gotta say the glow version looks all naked and weird to me :-). Seems like it runs very well and I can definitely see a few applications where the ignition module on the GT15 and accompanying battery would add too much weight and bulk so this glow version will be ideal.

[@AlpineWarren]

Wow really - Cool - Hey Brian 3/32" or 1/8" tubing to feed this engine?

[@growingupisoptional]

hello I was reading one of your reviews of the OS22 petrol engine and you were also showing two new type of oil. I couldn't find what your preferred oil is even though you mention it a lot. Could you please tell me your preferred oil for use in petrol engines?

[@BrianOilyEngines]

Yo Who? In want country do you live? This helps me answer your question as to the oil. Maybe better if you email me for an easy contact and I can assist you. [e-mail] Regards Brian Oily

[@tahevol]

Thanks Brian. I will get the gas/petrol engine. In the long run it makes sense. I bought the biggest trainer kit I could find. Its still a pile of wood. I notice OS makes both a sparkplug and glow plug version of this engine. The spark plug version is $50 less. Is there a significant benefit of one over the other?

[@BrianOilyEngines]

Yo Jeff, Really a toss of a coin in some respects. Glow plug might not be as reliable as a spark plug though either can 'die' in use but the spark plug is generally better in this respect. No batteries or CDI with the glow plug but...there is no automatic advance if you use heavier load propellers. Another consideration is that the spark plug version can have an on-board 'kill switch' which is a very nice accessory. Once a glow engine is in the air you cannot 'kill' the engine if there is a need but...as I am sure many will tell you, we have been putting up with that since 1947 (the development of the glow plug in model engines). Not a valid argument for me but...as I said, you make the choice considering my simple input. Regards - Brian Oily

[@tahevol]

Thanks so much. I read your technical review in the magazine. I am re-entering RC flight after a 30 year hiatus. I'm starting from scratch and am building a .60 trainer. To me it makes sense to just buy a good gas (petrol as you say) engine and leave glow behind. I live in Alaska, and getting glow fuel is a pain. Any thoughts?

[@BrianOilyEngines]

Yo Jeff, Thank you for your interest in my reviews and videos. I really cannot think how hard it would be in winter to start glow engines on methanol in Alaska as methanol is so reticent to vapourise in cold weather and...as to cold weather...I think you have cornered the market in your area of the world. Petrol (gas) is so much easier to use, purchase and store and...a lot less costly. As to the trainer - for sure, go as big as you can - large models are easier to fly, slower and look better in the air. I have quite a few modern petrol engines now and a methanol engine is becoming a rarity in my workshop. Errr - do you want to buy a hundred litres or so of methanol? (Ho Ho) Let me know how you go with the trainer. Regards Brian Oily (Email : [e-mail])

[@davelowets]

I wonder if this plug would work in smaller nitro engines (.25-.30) to allow them to run on gasoline?? 🤷🏻 Would be nice..

[@SKYPUP]

Brian....I lost some info you sent me last year. I am just now getting to running my engine. I will be using Klotz R/C Modellube Gas Burner Synthetic Techniplate 2-stroke 32:1 to 50:1 oil. What is your recommendation for amount of oil i.e. mix ratio? Thanks in advance. Regards Bob USA

[@BrianOilyEngines]

Yo Bob, I don't use that particular Klotz oil as it is for two strokes only - can cause carbon in four strokes so I stay with KL200 Original Techniplate - that is - if I ever run out of Morgans Coolpower (not likely). However, that particular Klotz can be used at 32:1 down to 50:1. If you mix 20 ml (or cc - both the same) with 1 litre of petrol you will be on the mark. Let me know how you go with that engine...just remembered - I advise you don't use a power panel for the OS G5 plug as there is a very high chance it will burn out as it cannot take anymore than 2.5A. Contact me on my email as it is easier for me to reply rather than all the folderol of going through my You Tube URL. [e-mail]. Regards Brian Oily

[@Anon.Emouse]

Hi Brian, I just started my own GGT15 for the first time tonight. It starts easily and runs really well. I'm impressed. When i removed the prop up i noticed 1-2mm of bac-and-forth play in the crankshaft. I have never noticed this on any of my engines and don't recall my GT15 being having any play there. Is it normal?

[@BrianOilyEngines]

Yo Michael, !00% correct! Advanced engineering techniques have shown that a slightly loose fit of a shaft as in these applications leads to greatly reduced bearing load which means greatly reduced bearing wear. If you think about it - the propeller pulls the crankshaft forward when the engine is running so there is no movement to and fro. I have been doing this for some years now on all bearing replacement jobs I get and the owners of the engines report that the bearings now never seem to wear out. You can expect the same with that very nice engine. Thank you for your interest in my videos. Regards Brian Oily

[@Twin_Flyer]

Its been year since you posted this, any updates? Have you used the engine much? How long have the glow plugs lasted? How is the power vs a standard glow engine? I'm guessing for the same amount of fuel it will run longer then a glow engine. Thanks!

[@BrianOilyEngines]

Yo Bill, Thank you for your interest. I have a network of modellers world wide who report to me on their use of the various engines I review and this is extremely valuable to me as I could never use an engine to the amount they are used by so many modellers. With regards to this engine it is all good news - all the modellers in my network who have one report great satisfaction and many glowing reports. There does not appear to be an issue with plug life as this would very quickly come to the fore. As well, the Australian distributors told me they have not sold many plugs at all for replacement purposes but...have sold many for experimental jobs where modellers are converting existing petrol engines to glow operation with one example being a great success converting a Zenoah 38 and that's a surprise. Just as a warning, the replacement plug issues all stemmed from modelers using a power panel and O.S. have addressed this issue in the instructions for the latest 10 cc engine wherein they instruct that the maximum current is 2.5 Amperes and this can be well exceeded by many power panels. I use and suggest the Rcats glow driver - I have 5 of them (I test and review many multi cylinder engines) and I would suggest that they are the 'El Supremo' of glow drivers. (my opinion) Regards Brian Oily

[@BrianOilyEngines]

Yo Warren Allred, The last section of tube to the engine is 3/32" black neoprene - I use this for all testing. Regards, Brian Oily

[@drlade007]

Hello Brian , Dan here from Texas , I'm very interested in this GGT15 engine .How does it compare to the GT15 Spark plug engine power wise ? and have you installed it on a airplane yet ?

[@BrianOilyEngines]

Yo Dan, Nice to hear from you. It was a little surprise to me that the GGT returned slightly higher RPM on the identical props and fuel than the GT. It certainly ran very well and reliably as you would expect an O.S. to do. The plugs are about the same price as the OS F plugs so no surprises when you got to get a spare plug. If you would like a bit more information, I can be contacted at [e-mail]- always pleased to hear from readers. Regards Brian Oily

[@aquinter17]

Hello Brian, I own one of this engines and I was tunning it but then the lock down restrictions do not allow me to continue. I was able to running and fly five times, trying to follow the instructions but I could not get an stable engine, I have always touch the nedle for every fly (which not make sense for me). From your experience with this guy, would you please recommend me some tips for tunning (I just want to have a reliable engine)? I am using 13x8 and 25:1 redline oil mix with Killer Chaos airplane, and I plan to build another patter ship in this lock down and use same engine. Thanks for sharing,

[@direktorpresident]

Andres I am very sorry to say Brian has passed away, he would certainly have helped you out with your query.

[@aquinter17]

I am sorry to hear that, thanks for reply.

[@oudeiseimi2724]

How does it handle different tank pressures, and tank placement? This is the big down side of glow engines, in my opinion.

[@BrianOilyEngines]

Yo Oudeis, The engine is fitted with a O.S. P8 fuel pump so pressure is not an issue. For any petrol engine that has a fuel pump or a Walbro carburettor it is best to mount the tank as high as possible for easy fuel feed and first starts - a gravity feed such as is used for motorcycles. Thank you for your interst. Regards, Brian Oily

[@DanielGonzalez-bb2cr]

Hello Brian. This video was made some time ago, but I have one question: my math model says that on the 16/6 you are using takes 893 Watts at 8161 rpm, but for the 13/8 at 11312 rpm you would need 2122 Watts. The engine specs say the max power is 2.3 BHP, 1691 Watts. Is it posible that the speed was 10312 instead of 11312?. At 10312 using that propeller, the power would be 1614 Watts or 2.2 BHP

[@BrianOilyEngines]

Yo Daniel, My RPM readings are very precise as I use two tachometers - one of which is accurate to 5 decimal places and records down to 1 RPM. You must consider I was using the smallest propeller in the range suggested and this would record the maximum RPM for that load. In my opinion, I think many modellers get too tied up with engine output performance with the quoted BHP and it was for this reason that O.S. started referring to the power as so much PS (pferdestarke) which is equivalent to (UK) 0.986320071 HP and that confused all but the German modellers and stopped a lot of arguments about the power. In many cases the stated output power comes from one of several graphs wherein you can calculate the supposed HP but...why bother? Just enjoy the magnificent model engines on offer and if you think the power is inadequate - simply go for a larger capacity engine. Remember the old USA saying, 'you can't beat horses under the bonnet' which refers more to the number of cylinders and capacity of the engine. Look up Sir Isaac Newton's formula which he used to calculate horsepower and then tell me a, say, 2.5 HP model engine has the pulling power of 2.5 horses. All a figure to use as a guide in most cases (and to sell motor cars to those of whom it is a concern). Thank you for your interest. Brian Oily

[@DanielGonzalez-bb2cr]

Thank you very much for your answer, Brian. I have heard not so good comments about OS gas 15 cc heli engine, but your plane engine sounds great!. I am looking for a good gas small engine for a drone, and this ngine will be a good alternative, as I can see.

[@pumatraca]

Hello!, For breakin what oil recommend ? Thank you!

[@BrianOilyEngines]

Yo Puma, No break in oil - never a good idea. The oil you use for the fuel is the oil to use from the start. If a 'break in oil' (an oil that rapidly wears the engine parts????) is used, you then have to condition the engine again (break in) when a new oil is used due to running temperature, viscosity and lubrication friction (Lubricity drag). For about 35 years I have used Morgans Coolpower oils for running in, testing engines, running engines I repair and for my own engine use and....never had a problem of any type and....I run an awful lot of engines every year. If you cannot get Coolpower, my second choice is Klotz Original Techniplate KL200. You might also consider the new oil from Deluxe Materials (Power Model 2T-S) in the UK. I have tested it and it does an excellent job but only for petrol fuel. Regards Brian Oily

[@jmarismendi]

Hi, Mr. Brian. I have an OS GGT10cc and GGT15CC not work well with the original pump , buy 2 perry pumps and now work perfect. It happens with bombs OS that bring these engines ? I have tried everything possible but do not work with the OS that comes with original pump motor, pump perry has been my solution , someone has an explanation , thanks.

[@alegutie]

Hello Brian, I´m alejandro Gutierrez. I see your video on youtube and need your help. I have the same engine, and lost the original factory settings, Can you explain to me how to set up the engine correctly?

[@nikolayrykov]

What is the gas mileage of this engine per hour? And what is the thrust at maximum engine speed?

[@oudeiseimi2724]

Twitchy fuel feed is THE big gripe that I have with nitro engines with no fuel pump. It's good to hear that OS has fixed this with a fuel pump. But the wonderful idle (without loading up) of gas engines is also a huge advantage over nitro engines. I was surprised to see a pull test of 20.2 lbs for the OS 33cc gas engine. If that claim is true, then the OS gas engines have more thrust than the DLE ones.

[@Realitygetreal]

+Oudeis Eimi I have now seen both the DLE 30 and the OS 33CC run the OS does have more pull, but the % of cost more than the DLE is not the % more pull :)

[@logangreenlee]

Brian, nice review. Do you have any idea how much fuel uses in OZ/min at full throttle?

[@BrianOilyEngines]

Yo Logan, Pleased you liked my little review - I certainly enjoyed running the engine, it runs extremely well and I gave it a good review in my magazine articles. On test I recorded 11 minutes on 200 cc of fuel with varying RPM settings - much the same as when you would be flying a model. It is important that you use 95 RON petrol in all our model engines as the 90 and 91 RON grades are not suitable and will give constant problems and overheating. I used Morgans blue Coolpower oil with 95 RON petrol for excellent results. Regards Brian Oily

[@amiraldz1970]

HELLO Brian Winch this is what worries me me that's life span of the candle, osg5 after 2 liters of fuel the scrolling of the candle is lit almost. you have an idea how to preserve it thank you

[@BrianOilyEngines]

Yo Yacine, Don't worry so much - it is bad for your health and, most of the things we worry about never happen. So ends today's sermon. Now, the glow plug. The plug is on all the time exactly the same as a glow plug in a methanol engine and it will last a long time provided you don't run the engine lean. The power you use to heat the plug is important as the maximum current it will tolerate is 2.5 Amps. Anything more than this will kill or shorten the life of the plug. Power panels are not recommended as they are a known plug killer (generally) - a Nistarter is okay but they don't last long. I use and recommend the Rcats glow driver - certainly a little expensive but they last forever with reasonable care, need charging only about once in 18 months and have a slow warm up for the plug which is excellent. They will not shorten the life of any glow plug. Nothing worse than a burnt out glow plug as was put by Monty Python, "Minnie, the wick in the engine has gone out." Regards Brian Oily

[@amiraldz1970]

Hello Thank you for your response and your Board I use a socket 4000mha, I think it helped deteriorated candle, I thought also use a power panel. So I have to change my battery for a 2500 mha

[@Gavs_rc_hobbies]

Hi Brian, im thinking of getting one of these. How have you found yours to be? Also i have an OS GT33, could i run this GGT15 on the same 25:1 mix as i run my GT33? Cheers.

[@BrianOilyEngines]

Yo XRAYRACER 1 I have had many comments from modellers worldwide about how much they enjoy this engine and I have not had any problems with mine or the GGT10 but I do not fiddle with the mixture controls and I use only 95RON grade petrol with a high grade lubricant. Your 25:1 mix will be okay if it is a good drop. Thank you for your interest. Regards, Brian Oily

[@Gavs_rc_hobbies]

Brian Winch thanks for the info mate. With my GT33 i run 95RON and use Castrol 2T oil. Cheers.

[@jangisgand6140]

Hey Brian, How much does this engine cost? And what engine has the best performance? This engine or an os methanol (glow) engine? Regards

[@BrianOilyEngines]

Yo Bobba, Cost depends on where you live - what country etc. Check up at a model outlet for the current price. The engine is a petrol engine but it has a glow plug for ignition - a very good combination and, as you can see, it runs very well. As to what engine has the best performance - a question too hard to answer as I don't know what you are thinking as far as brands and size and...what you mean by 'performance'? Regards Brian Oily

[@jangisgand6140]

Brian Winch Well by performance I mean throttle performance, rpm and also reliability like easy starting, tuning,...

[@BrianOilyEngines]

Yo Boba, I'm pleased to read you are aware of what performance means. To many modellers it means one thing only - the RPM speed of the engine - not the overall performance which is the correct meaning. Now, for your information, based on my 70 odd years of experience and having tested and reviewed over 350 engines, this engine gets a big tick from me in all aspects of performance. I have received quite a lot of feedback from readers of my articles to tell me how pleased they are with this engine and it is particularly popular for twin engine models due to its reliability. Buy yourself one for your birthday - your wife's birthday or any day you can use for the excuse...you need one for sure. Regards Brain Oily

[@bobair43]

Hi all engines at my feild so far are glow .Someone brought a gas engine I believe it was the ggt15 and was told he couldnt fly it at our field the DB level was way over the limit. Is there a good way to quiet them down

[@BrianOilyEngines]

Yo bobair, Somebody is having a lend of themselves here. The O.S. GGT15 is a glow engine running on petrol and the exhaust note is, if anything, slightly lower than the methanol version. I wonder it the reading was taken by ear (most unreliable) or a dB meter by somebody who knew how to use it correctly. The exhaust sound is a little different but no louder than an equivalent methanol engine. Anyway, if you want to reduce the exhaust sound it can be done as a petrol engine is more tolerant of muffling than a methanol engine. If you extend the stinger (muffler outlet) with tubing and suitable silicone tubing will do the job you will find the sound is considerably reduced. Regards Brian Oily

[@bobair43]

Im defenetly interested in the gas engines now that they are comming down in weight. Thanks for the reply

[@b1jxvk89]

Hi Brian Engine looks like it runs well! I tried a o's g5 plug in my eve gx10 ran great!

[@BrianOilyEngines]

Yo Shaun, Yep, I did also and recorded 14,000 RPM on a 10 x 6 prop but I am not telling anybody yet (HO HO HO) in case they want to buy engines without the CDI systems and drive the dealers mad. Seriously, the glow plug is good but the disadvantage is that you do not have the auto timing (14º advance) you have with the RCexl CDI which is really good for large propellers. In my opinion, a spark plug is more reliable than a glow plug which would be really important for modelers who build scale multi engine aircraft in which reliability is most important. Thank you for your interest in my tests. Regards Brian Oily

[@b1jxvk89]

Brian Winch Hi Brian I think in smaller aircraft (40 size ) getting away without the cdi box and still running gas is very appealing for just saving space and simplicity of it all. My gx10 runs as good if not better with the g5 plug over the cdi box. Just bought the ggt15 and evo gx20 to play some more lol.

[@BrianOilyEngines]

Yo Shaun, I am interested to hear how the 15 and 20 engines go with the plug. I have used one in several engines to date and all tests have been very positive. Thanks for keeping me posted Brian Oily

[@b1jxvk89]

Brian Winch hi Brian Ya ill let you know how they run! I'll probably break the gx20 in using cdi then try the g5 plug. Have you tried any engines larger like a dle30 with a adapter?

[@BrianOilyEngines]

Yo Shaun, I set up a hard to start Zenoah for a friend and he is delighted as it starts first flick now and runs better than it ever did. I have had good success with a couple of large two and four strokes, an O.S. 160 for example so there is plenty of scope for experiment. Regards Brian Oily

[@BrianOilyEngines]

Rafael Marmolejo Leyva 1 day ago (edited) Been Reading that this engine waste a lot of G5 plugs...is that true? how long this plugs lasts? Yo Rafael, The OSG5 plugs have a very good life - much like the OSF plugs. The problems stem from the plug power used by some modellers. The worst is a power panel as these can really kill plugs when the current is too high and when they are first switched on as they pulse a good load of power for a second or so and this kills the G5 plugs (and many others). The G5 plugs need a maximum of 2.5 Amps current...that's MAXIMUM..no more. Any higher and the plugs have a short life. I use Rcats plug drivers and my plugs last....and last. You don't want these G5 plugs to glow bright - a deep red glow is ideal. Regards Brian Oily

[@rondoschiavoni8840]

can you use 97 octane or higher for better running

[@BrianOilyEngines]

Yo Ronald, HaHa! You must be a 'rev head' if you want more. O.S. engines already run better and at maximum RPM for the engine and its type. By increasing RPM you increase propeller speed and, thus, more noise which we can do without. What benefit would there be if you gained, say, 500 RPM? For common flying activity you would not even notice it but...you would be stressing the engine unnecessarily. The engine is designed for low RON petrol and, in my opinion, 95 RON is as high as you should go. Thank you for your interest in my videos. Brian Oily

[@giuseppeborgia4226]

good morning friend, the problem is that I can not make it carbureted engine does not maintain the minimum, I do not get a transition from low to high perfect rpm and lost to the factory setting and have many bubbles in the fuel pump which already replace a new one and still the same. And check the fuel tank pipes and everything is fine (excuse the translation)

[@BrianOilyEngines]

Yo GIUSEPPE, Nice to meet you. One piece of advice I give to so many - do not adjust the idle screw on a new engine or an engine giving a problem unless you definitely know it needs adjustment and then no more than about 45° as this adjustment, once set, does not need any other further adjustment unless you have a really radical fuel change. The adjustment on this engine is a mixture control valve and, as it is turned, it actually moves the fuel jet and that adjustment affects both high and low speed running. Again, once this is set - it does not need further adjustment EVER! The simple setting is to have the slotted head of the adjuster just level with the bottom of the cup in which it is fitted - no further in. This should get you very close to the mark but...if you need further information, email me from your email address (not through you tube) and I will give more precise instructions. As to the air bubbles - a simple fact of life. Not a problem and, according to O.S., they are caused by the varying pressures of the pump and the equalising of atmospheric pressure and, as such, will not cause a running problem. My email address is - [e-mail] Are you a descendant of Lucrezia Borgia - famous noble woman - daughter of the future Pope of many years back? Regards Brian Oily

[@giuseppeborgia4226]

Buenas noches yo tengo un os ggt15 que no puedo carburar no consigo que me mentega el minimo del motor ni que la transicion de baja a alta rpm sean perfectas tambien tengo muchas burbujas en la bonba de gasolina y ya la remplace por otra y sigue igual ya no se que hacer alguna sugerencia please ....

[@BrianOilyEngines]

Yo GIUSEPPE BORGIA, Greetings to you too but that is as far as I can get as I speak and read only Australian which is close enough to English. If you can translate your comment to English I will be pleased to make further contact with you. Regards Brian Oily

[@MHuslin]

Hello. I believe that the engine had to be started with a starter.. How would you rate the engine over all ?

[@BrianOilyEngines]

Yo MHuslin, You watched the video and saw I flick started the engine didn't you? According to the instructions the engine needs to be started with a starter and it is easier but I am a 'flicker' of many years and I found I could flick start it quite well after it had been run a bit. As to the engine - it is - in my opinion, an excellent choice for a 15 cc engine. Being an O.S. it is of excellent quality and the performance is superb. My review will be in two magazines - RCMN Australia and RCM&E in the UK. Thank you for your interest. Brian Oily

[@MHuslin]

Thanks for you quick reply.. Thanks you so much.. But what about the fact that fuel has to be left in the carb..? i am some what new to the gas engine world, i got myself a evo 10cc an it was a waste of my money, that evo engine dead stick so many times that it cost me two planes an broke the engine in one of the crash.. I am looking a good reliable gas engine that tunes easy an stay tuned.. I dont want a 20cc DLE the people keeps talking about, i just want a small little gaser that can work with my 60 size plane.

[@BrianOilyEngines]

Yo MHuslin, Rather than using KZbin for questions and assistance, you can email me on [e-mail] and I can provide whatever assistance I can to help you. When you contact me, include the country where you live as this often helps with the reply or information I can supply. Regards Brian Oily

[@MHuslin]

email sent.. Thanks..!

[@specialized29er86]

love the idea of only paying 1.30 a litre for fuel instead of the 20.00 a litre for the nitro.

[@guerrillaradio9953]

Jesus Christ, I thought $20/gallon was crazy! That side of the Atlantic robs people blind. I understand for full sized car fuel (taxing it to pay for government services), but how much model fuel is honestly used? Pettiness personified. I'm sure the US will get there one day. We always do, eventually. Better enjoy it while it lasts, I suppose.

[@hudsonornelasribeiro5246]

Os novos agora estao vindo com iguiniçao e vela cm6

[@BrianOilyEngines]

Yo Hudson, Sorry my friend - I speak only Australian which is close to English. If you can translate your request to English I will see if I can provide an answer for you. Regards Brian Oily

[@drlade007]

Yes Email sent