chris meek 1 Posted September 29, 2016 Share Posted September 29, 2016 Has anyone ever made their own silencers for 2 stroke glow engines? I'm looking for hints or tips on how to do it for my dh mosquito build... Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted September 29, 2016 Share Posted September 29, 2016 i Have, For a super 60 2 stroke it is one of my Mustangs and sounds like a four stroke when it`s running and Cos it is all hidden under the cowl know one knows it`s a two stroke un till i show them . I`ll see i can take some pictures, The key is to use thick Ali as that will help dampen the noise . A thick walled tube blocked of at one end with a smaller tube with it . Better still i`ll let the pictures do the explaining . Pictures to follow then i`ll explain Steve Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted September 29, 2016 Share Posted September 29, 2016 Do you have machines Chris? On the Mossie I would checkn on the available space and then outlet angle. You should be able to make long silencers in those nacelles. If the angle is beyond my machine, I get Weston UK to build a silencer. If it is just a modification of the existing silencer, then tube is added to the middle,and a longer bolt put through, or a new exit box is fabricated from thick tube with a new outlet Quote Link to comment Share on other sites More sharing options...
Former Member Posted September 29, 2016 Share Posted September 29, 2016 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Former Member Posted September 29, 2016 Share Posted September 29, 2016 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
chris meek 1 Posted September 29, 2016 Author Share Posted September 29, 2016 Thanks folks, was thinking of using some copper pipe capped at the ends and strapped onto the cylinder head somehow - this is what the plan shows for dimensions to keep them inside the cowls Hopefully it won't effect power output too much. Quote Link to comment Share on other sites More sharing options...
Nigel R Posted September 30, 2016 Share Posted September 30, 2016 "The key is to use thick Ali as that will help dampen the noise . A thick walled tube blocked of at one end with a smaller tube with it ." My dad made a few simple expansion chamber types using thick wall ali tube, exactly like that. Ali discs were cut to block both ends. A flat was filed where the exhaust mounted on the tube. Mounting bolts went right through the thick wall tube. The outlet tube was stuck into the thick wall tube. IIRC the end inside the silencer was splayed slightly. The whole lot was sealed up with 24 hr epoxy. They long outlasted the original installation. Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted September 30, 2016 Share Posted September 30, 2016 What size motors Chris? As it is possible to modify the existing silencers. There are aluminium wheel repair garages, all around the country, who also repair cylinder heads, for a small fee will Ali weld small add ons Edited By Denis Watkins on 30/09/2016 07:43:27 Quote Link to comment Share on other sites More sharing options...
bert baker Posted September 30, 2016 Share Posted September 30, 2016 Copper pipe always seemed to give a crackle note to exhausts I have made in the past. Quote Link to comment Share on other sites More sharing options...
perttime Posted September 30, 2016 Share Posted September 30, 2016 Do you have space to put a Mousse Can Muffler inside the nacelle? Quote Link to comment Share on other sites More sharing options...
Jimbo565 Posted September 30, 2016 Share Posted September 30, 2016 This is one i did for my Sierra Super Sportster,bit of copper pipe sealed at both ends with a 2p piece and silver soldered,worked a treat. Quote Link to comment Share on other sites More sharing options...
kc Posted September 30, 2016 Share Posted September 30, 2016 Alex Whittaker did a series of articles called Bespoke Silencing in RCME Dec 2003 to April 2004. This was about fabricating your own silencer. My view is that unusual silencers can cause all sorts of engine problems and that is the last thing you need with a twin! Quote Link to comment Share on other sites More sharing options...
chris meek 1 Posted September 30, 2016 Author Share Posted September 30, 2016 That was the sort of thing I was planning Jim, was thinking copper as easier to work with for me than Ali!! Have heard a lot about engines not running properly with own made or after market silencers but worth a try as I don't want to ruin the outline with the silencers hanging out, and I don't understand electric!! Quote Link to comment Share on other sites More sharing options...
John Lee Posted September 30, 2016 Share Posted September 30, 2016 Good luck, but if your efforts are unsuccessful Weston UK can make you custom silencers. Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted September 30, 2016 Share Posted September 30, 2016 Blimey Jim this must have been a very important model to you if you were willing to use one of your two pence pieces on it... On a more serious note I'm with kc on this one.....exhaust back pressure is very important to a 2 stroke engine helping it to run correctly......do lots of testing at various revs before committing to flight to ensure all is well. A badly designed exhaust will cause rough running & possible over heating. I'm not saying it can't be done I'm just saying be sure it works before committing the model..... Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted September 30, 2016 Share Posted September 30, 2016 I tried a silencer using the fuselage with a box installed as per Brian Winches recommendations. It was quiet but on the second engine start up the model burst into flames. In fairness it was a four stroke motor which ran much hotter than the original two stroke design. Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted October 1, 2016 Share Posted October 1, 2016 Hi, Sorry for the late replay, I am not that sort of technical guy that works all kinds of formulas. So i find a simple approach to as many things as i can. So i filled the supplied exhaust that came with my engine with water by blocking the exhaust port with my finger . I then poured out the water from the filled exhaust into a measuring jug, that way i now know the internal volume of the exhaust. So that way i check my home made Exhaust using the same method and so long it equals the same or a little more than the volume of the original i know i will be ok. Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted October 1, 2016 Share Posted October 1, 2016 It is best to use silicon tube to connect the manifold to the Exhaust if the engine is mounted on a nylon engine mount as mine is. I used JP weld which is a hard epoxy, Steve Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted October 1, 2016 Share Posted October 1, 2016 My plane is under repair at the moment as you can see my cowl is being re-glassed. it is hard to see the Exhaust with the cowl on. Not sure how my idea would work on your plane, Steve Quote Link to comment Share on other sites More sharing options...
Jimbo565 Posted October 3, 2016 Share Posted October 3, 2016 Steve Still have 1 more 2p left and I have a new plastic fiver I'm slowly stretching into a tenner. never had any trouble with the copper silencer,maybe more good luck than good management. Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted October 3, 2016 Share Posted October 3, 2016 Hi Jim, The last part of yours and my Exhaust system are both secured to the fuselage while the engine is fixed to a nylon engine mount which will absorb any vibration from the engine. And as the rear exhaust is firmly fixed i fear cracks will appear somewhere along the exhaust system and that is why i have a silicon tube between the two parts. Steve. Quote Link to comment Share on other sites More sharing options...
bert baker Posted October 3, 2016 Share Posted October 3, 2016 Yep defo go for antivibration.. don't resrict it or ir will overheat the engine Quote Link to comment Share on other sites More sharing options...
Jimbo565 Posted October 4, 2016 Share Posted October 4, 2016 Steve Same here,this is one i made for a scaled up version of Peter Miller's Miss lizzy,it had to fit inside a Magnatilla cowl Quote Link to comment Share on other sites More sharing options...
Jimbo565 Posted October 4, 2016 Share Posted October 4, 2016 Finished job and it worked very well. Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted October 4, 2016 Share Posted October 4, 2016 Posted by Jim Carss on 04/10/2016 09:31:40: Steve Same here,this is one i made for a scaled up version of Peter Miller's Miss lizzy,it had to fit inside a Magnatilla cowl That looks good Jim, well thought out . Steve Quote Link to comment Share on other sites More sharing options...
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