Martin Rowe 1 Posted February 15, 2015 Share Posted February 15, 2015 Hi stupid question time! I am fitting a IC engine for the first time. All my others are electric. coming from the fuel tank I have three lines. One is angled down in the tank with a hose and a weight. The middle line I believe goes to exhaust. My question is where do I connect the last line. Quote Link to comment Share on other sites More sharing options...
Marc Osbourne Posted February 15, 2015 Share Posted February 15, 2015 Hi Martin, usually there are three pipes as you say. One is usually central in the tank and like you say, has the pipe with the clunk (weight) on the end of it, this is your fuel feed/pick up. The other two, depending on the tank are used for exhaust pressure (to the nipple on the exhaust itself) and the third is for filling the tank (usually blanked with a bung after filling so as the exhaust pressure stays within the tank!). Marc Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted February 15, 2015 Share Posted February 15, 2015 It's the filler and just exits to somewhere accessible. The vent (exhaust) tube should come from the top of the tank so that fuel escapes to let you know the tank is full, the filler is plugged once the tank has been filled so that the exhaust can pressurise the tank when the engine is running. Quote Link to comment Share on other sites More sharing options...
bert baker Posted February 15, 2015 Share Posted February 15, 2015 You need to vent the tank during filling or else you will force the fuel out through the carburetor during filling, that is if the carb is open, filing that you may over pressurize the tank and pipes. Quote Link to comment Share on other sites More sharing options...
Martin Rowe 1 Posted February 15, 2015 Author Share Posted February 15, 2015 Ok. so,the vent is not connected when I pump the fuel in and I use th carb line to fill? then I plug the vent line so the tank can pressurise from the exhaust line? Quote Link to comment Share on other sites More sharing options...
cymaz Posted February 15, 2015 Share Posted February 15, 2015 Some pictures here. With my 3 line set up ...the fill and pressure go to the top of the tank. The lower pipe has the clunk and will feed the carb. Make sure the clunk does not sit right at the end of the tank but is 5mm off the end. this allows a bit of wiggle room. When the tank is filling through the fill pipe, fuel will exit out from the pressure pipe when the tank is full. Quote Link to comment Share on other sites More sharing options...
Levanter Posted February 15, 2015 Share Posted February 15, 2015 Many people use a colour code in the fuel tubes to differentiate the functions. When working in tight spaces or removing hoses for access / cleaning it is easy to get them muddles up. I use clear inside the tank a that is what they are normally supplied with if pre-assembled. Red for the tube leading to the silencer (red + hot) and blue for the filler. The weight inside the tank is called the clunk and keeps the fuel delivery tube in the fuel when flying inverted. Make sure this does not hit the back of the tank and get stuck. There are some excellent books out there with all sorts of advice about engines, tanks and installations. By the way welcome to the I.C. club. You won't regret it. I have I.C. mainly but a number of electric which I am very happy with. Another facet of this brilliant hobby and sport. Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted February 15, 2015 Share Posted February 15, 2015 Posted by Bob Cotsford on 15/02/2015 21:29:47: It's the filler and just exits to somewhere accessible. The vent (exhaust) tube should come from the top of the tank so that fuel escapes to let you know the tank is full, the filler is plugged once the tank has been filled so that the exhaust can pressurise the tank when the engine is running. During filling the tank vents through the line to the exhaust. These days I like to take the filler tube to the bottom of the tank so that I can use it to empty the tank after a days flying, saves any remaining fuel dribbling out in storage. Edited By Bob Cotsford on 15/02/2015 21:49:21 Quote Link to comment Share on other sites More sharing options...
Martin Rowe 1 Posted February 15, 2015 Author Share Posted February 15, 2015 Thanks for the welcome! I used to be a mechanical engineer up until I got promoted. I miss the smell, my wife thinks I am mad. I have been messing around with small models but I have three big ic models in the pipeline. I am considering converting my asp four stroke to petrol but not made my mind up. I like my planes big as I can store and slow.... that picture was great, it should be mandatory in AFT anyway, what I don't get know is the vent.surely it will allow out the positive pressure from the exhaust? Whilst you are all helping, the model I am building (blackhorse chipmonk) is covered in film. Should I be treating it to fuel prove? What's best for cleaning? Quote Link to comment Share on other sites More sharing options...
cymaz Posted February 15, 2015 Share Posted February 15, 2015 Your fill line will be plugged when the tank is full. With a clamp or plug or small bolt if your really tight. The pressure line takes some of the pressure created by the exhaust gasses off the silencer and feeds it into the tank. This puts the tank under positive pressure helping to force out the fuel to aid the carb and keeping a constant supply no matter what orientation the plane/tank is. If its the smaller version, the Blackhorse Chipmunk is a great plane. No vices. Flaps make the plane pitch up a little but nothing that can't be mixed out on the Tx with some down elevator. Edited By cymaz on 15/02/2015 22:00:57 Quote Link to comment Share on other sites More sharing options...
bert baker Posted February 15, 2015 Share Posted February 15, 2015 You put a bung it the vent pipe after filling the tank, Quote Link to comment Share on other sites More sharing options...
Martin Rowe 1 Posted February 15, 2015 Author Share Posted February 15, 2015 Got it! Thanks all Quote Link to comment Share on other sites More sharing options...
PatMc Posted February 15, 2015 Share Posted February 15, 2015 Basic method I used before I saw the light & went all electric - from the Irvine 40 instructions. It's also a good idea to route the feed line so that it is above the tank level at some point. This means that after a flight, with the engine cut, you can raise the nose to break the syphon. Which stops any fuel that's left dribbling into the carb & potentialy choking the engine on the next start up or overflowing to waste. Quote Link to comment Share on other sites More sharing options...
Shaunie Posted February 15, 2015 Share Posted February 15, 2015 Welcome to the oily side Martin. On the downside you get to practice your deadsticks if the engine isn't behaving. On the upside, you get full power to the last drop! Enjoy. Shaunie. Quote Link to comment Share on other sites More sharing options...
bert baker Posted February 15, 2015 Share Posted February 15, 2015 Oh boy you will have some fun with clunks in the tanks. if the clunk pipe is to long the clunk can vacuum itself to the back of the tank. If you have a hard landing or sudden stop the clunk can jam itself forward giving al sorts of issues I prefer to have fill and vent at the top and turn the plane over to fully empty the tank. If you go down the petrol route it is best to leave some petrol in the tank, they normally have a felt filter for petrol,if it dries out fine fibre particles clog up a fine filter in the carb. Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted February 15, 2015 Share Posted February 15, 2015 I fit an extra "clunk" to the fill line.....I can then fill & empty the tank via the one tube.... Oh & as the others have said...welcome to oily side....we are becoming a minority I fear.... Quote Link to comment Share on other sites More sharing options...
Simon P Posted February 15, 2015 Share Posted February 15, 2015 Posted by Steve Hargreaves - Moderator on 15/02/2015 22:23:48: welcome to oily side....we are becoming a minority I fear.... That is what my LHS proprietor keeps telling me. He also said balsa was on it's way out and that small model aircraft have gone the way of the dodo. I have taken his derision of my interests as a challenge to get on and try out these aspects of the hobby before they are truly gone. I have, rather painfully, put an addiction to discus launch gliding aside and slowly collected some of the kits and plans that I used to gawk at as a kid but couldn't afford and have a handful of engines for them. You'll be seeing some oil soaked questions and build logs from me soon as a result. Quote Link to comment Share on other sites More sharing options...
Jon H Posted February 15, 2015 Share Posted February 15, 2015 Balsa and small models are on the way out? that man is a fool , look at all the tiny models from eflite etc. As for the balsa bit, there is a growing trend towards building at my club, and seagull have released kit build versions of their ARTF's so I don't think balsa bashing is done just yet Quote Link to comment Share on other sites More sharing options...
bert baker Posted February 15, 2015 Share Posted February 15, 2015 Yeah does make you wonder where it is all going, how long before covering is unavailable. Quote Link to comment Share on other sites More sharing options...
cymaz Posted February 16, 2015 Share Posted February 16, 2015 Posted by Simon P on 15/02/2015 22:45:08: Posted by Steve Hargreaves - Moderator on 15/02/2015 22:23:48: welcome to oily side....we are becoming a minority I fear.... That is what my LHS proprietor keeps telling me. He also said balsa was on it's way out and that small model aircraft have gone the way of the dodo. I have taken his derision of my interests as a challenge to get on and try out these aspects of the hobby before they are truly gone. I have, rather painfully, put an addiction to discus launch gliding aside and slowly collected some of the kits and plans that I used to gawk at as a kid but couldn't afford and have a handful of engines for them. You'll be seeing some oil soaked questions and build logs from me soon as a result. Oh, Seagull have just launched a balsa kit. They are not going to do that unless they think there is a market for it....though mainly in the US I suspect. Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted February 16, 2015 Share Posted February 16, 2015 Posted by PatMc on 15/02/2015 22:00:36: Basic method I used before I saw the light & went all electric - from the Irvine 40 instructions. It's also a good idea to route the feed line so that it is above the tank level at some point. This means that after a flight, with the engine cut, you can raise the nose to break the syphon. Which stops any fuel that's left dribbling into the carb & potentialy choking the engine on the next start up or overflowing to waste. Nice diagram PatMac . Just an add on . If you extend the pipe marked "sealed filler pipe into a bottom corner or center bottom of tank.you can also drain the tank if you don't fly it dry at the end of the days flying. Fuel left in a tank will find its way into the engine either by syphoning or through temp change causing the vapour to expand and push the fuel along the pipes. This fuel will then absorb moisture from the air and before you know it your engine will have rusty bearings. Once the tank is emptied run your engine dry to remove all the methanol. If you don't intent to use it for a couple of weeks add some two stroke oil or similar into the carb and spin the engine over to spread it around the internals. Good luck and enjoy IC. E.D. Quote Link to comment Share on other sites More sharing options...
Martin Rowe 1 Posted February 16, 2015 Author Share Posted February 16, 2015 Bad day. I managed to put a small hole in my fuel,tank. Will 30 minute epox be ok with glow fuel? Quote Link to comment Share on other sites More sharing options...
cymaz Posted February 16, 2015 Share Posted February 16, 2015 I wouldn't ....chances are it will fail at the most awkward moment, down wind, leaving you no where to go but into trees or the ground at a 1,000,000 mph. For the few £'s for a new one don't risk a model. Quote Link to comment Share on other sites More sharing options...
Keith Evans 3 Posted February 16, 2015 Share Posted February 16, 2015 You could try to seal the hole with a soldering iron . This was how we used to repair those red plastic footballs that were so popular in the "60's".It was also the recommended way as suggested by the manufacturers and you could buy a small tool which you heated in a flame to carry out the task . I have repaired a couple of tanks this way with success--you will need to give it a really good pressure test afterwards to make sure though . Quote Link to comment Share on other sites More sharing options...
Martin Rowe 1 Posted February 16, 2015 Author Share Posted February 16, 2015 I am going to get a two dollar one from HK. I won't be able to start it until I have bought a starter. i did buy one of the simple ones from china but the bush holder melted and it no longer works. Buy cheap buy twice according to my dad! Quote Link to comment Share on other sites More sharing options...
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