Jon H Posted October 4, 2017 Share Posted October 4, 2017 Good to hear the engine landed safely Ron, im just sorry it took so long! we dont supply plugs as we dont make them ourselves and it gets all complicated if we choose a brand to supply with the engine. As a modeller though, i use the OS F in my Lasers and never have trouble. I would not recommend using standoffs as they lack torsional rigidity and even the V will vibrate if you use them. Half the reason petrol engines flap about so much is the use of standoff mounts. Its really not a good way of retaining an engine. Ply disks cut with a hole saw and epoxied together are the best way. You can then fit long bolts into captive nuts on the back of the original firewall for a simple and solid install. As the engine is completely consumed by the cowling you will have to create baffles to make sure the cooling air is directed where it is needed. Its not difficult, but something often overlooked. Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted October 4, 2017 Share Posted October 4, 2017 The 160 has a circular engine mounting so I need to make a ply ring for it. I did think about the standoffs but have been advised not to go down that route by Jon. Nearly finished the Sbach repairs so may be able to get into it this weekend as we're flying next Monday! Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted October 4, 2017 Share Posted October 4, 2017 Looks like posts crossed! Take your point about cooling Jon and on all of my gassers (and the 1 glow!) I make an effort to direct air to the cylinder and work on the basis of 1 in 4 out! A cursory look at the cowl leads me to think that I may need to have 2 deflectors from the intake to the cylinders, pack out the back of the cowl (useless airspace) and then form an opening in the underside near the rear. I need to do that anyway to gain access to the carbs, how else can I choke the engine or could I just prime them instead? Exhaust outlets are going to be interesting! Quote Link to comment Share on other sites More sharing options...
Jon H Posted October 4, 2017 Share Posted October 4, 2017 That all sounds pretty good Ron. Just make sure the hole under the cowl has a little lip at the front as air may not flow out otherwise. The exhaust gas temperature on the 160 is not too high so silicone should work to extend the exhausts. How far do they need to go? If you are electric starting you dont usually need to prime the engine. If its really stubborn you can force fuel through with the fuel pump when filling the tank. Once the tank is full, open the throttle fully and with you finger blocking the tank vent pipe just run the fuel pump for a second or two and it will force fuel into the carbs. I do this with my sea fury in the winter as it is stored in such a way that oil sometimes blocks the jets in the carbs. if its cold this oil can be quite solid so a quick blast with the pump clears it before the first flight of the day. Once run i never prime it and just go with the starter. For the glow, i use a 2.4v battery and run the plugs in series. This means that if one plug dies the circuit is broken and the engine wont fire at all. This is easier to troubleshoot than having one cylinder light and the other not Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted October 4, 2017 Share Posted October 4, 2017 Not too sure yet about the exhausts but when I had a quick look I think the problem is more one of the correct angle for the exhausts rather than length but will know more once it's all mounted correctly. Am rather into reverse flick starting at the moment, just twisting the spinner in the reverse direction looks and feels 'cool'. But to be honest in haven't tried that method on any of my gassers, for those it's the good old gloved flick. Having said that, one of my gassers doesn't like starting that way so I have to resort to the electric wrist so no problem doing that with the 160. I'm planning to use glow drivers for the plugs (not on board glow) but do take your point about fault diagnosing. Quote Link to comment Share on other sites More sharing options...
Rich too Posted October 4, 2017 Share Posted October 4, 2017 I agree using the correct standoffs for the application ( and not in this case) but there's nothing wrong with them on petrol motors. Quote Link to comment Share on other sites More sharing options...
Jon H Posted October 4, 2017 Share Posted October 4, 2017 You can start the 160 with a backflick but as its fully enclosed in a cowling its not really worth the effort. On board glow is definitely not required. As for the standoffs, they lack torsional strength irrespective of what motor they are used on. Beam or radial mounting is a much stronger solution and will reduce vibration on any engine. Large displacement single cylinder engines will see the greatest improvement if the mounting method is changed. Not really sure why standoffs have become so universal, its likely cost driven, but unless they have diagonal bracing they really aren't a great solution for mounting an engine. Quote Link to comment Share on other sites More sharing options...
Tim Flyer Posted October 4, 2017 Share Posted October 4, 2017 Agreed Jon.i think standoffs are popular as they are an "instant fix"with and most put them in ARTFS. As you say lateral rigidity is poor plus I have seen quite a lot damage firewalls on nose overs. They must transit more vibration than a beam mount . I think they are best on electric planes . Obviously they do work but in my opinion are not good engineering unless the posts are very short and thick. Quote Link to comment Share on other sites More sharing options...
Jon H Posted October 4, 2017 Share Posted October 4, 2017 Strangely Tim they aren't much cop for electric either due to the high instant torque of modern electric motors. Clearly small ones are fine, but i have heard of large jobbies twisting themselves off their mounts. We are getting a little off topic though Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted October 4, 2017 Share Posted October 4, 2017 I'm away tomorrow and flying on Friday so won't get chance to do any more work on it until the weekend. Hopefully then I'll be able to see the challenge of the cowl installation and all that that entails. Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted October 7, 2017 Share Posted October 7, 2017 Standoff ring made: Quote Link to comment Share on other sites More sharing options...
cymaz Posted October 7, 2017 Share Posted October 7, 2017 Neat but when the holes are drilled, ( I assume that's what the markings are for) won't they be very close to the edge of the ring? Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted October 7, 2017 Share Posted October 7, 2017 I don't think that will be a problem as it is only a spacer with the fixing bolts passing through it and the bulkhead to T nuts located behind. Arguably I could just have grooves in the ring for the bolts to rest in, at the end of the day the full engine mounting ring is supported by the ply ring and any direct loads will be transmitted back through it. To negate torsional loads I will epoxy the ring to the bulkhead. Quote Link to comment Share on other sites More sharing options...
Rich too Posted October 7, 2017 Share Posted October 7, 2017 Nice job Ron, that will do the trick. Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted October 7, 2017 Share Posted October 7, 2017 First time i saw motors/engines on standoffs, i gave em a funny look n thought "I don't like that" years later, i've never seen a problem n i've seen some big stuff fixed to em. Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted October 7, 2017 Share Posted October 7, 2017 I agree John, all my gassers have them, albeit the largest are powered by DLE55s, and they don't appear to have a problem. But I did take on board what Jon said hence the ply ring. I was going to make an alloy one but when I checked my stock the only lump I had was 25mm thick so would have fallen short by 5mm. I also thought about making one to go between the engine and its mounting ring, as that would be a smaller diameter and I have plenty of bar stock from which to turn it, but have shied away from that. Doing some gardening today so won't be able to get back onto it until later on this afternoon but will hopefully have holes drilled and have it fuel proofed by early evening giving me a bit of time to sort out the tank fixing and plumbing. Quote Link to comment Share on other sites More sharing options...
Gordon Whitehead 1 Posted October 7, 2017 Share Posted October 7, 2017 Hi Guys, can anyone tell me the weight of their WotsWot XL please? I've seen one post earlier in the thread quoting 15lb 8oz, admittedly with a 3lb wt 4-stroke, and wondered if that would be about in the ballpark for this model. Thanks Gordon Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted October 7, 2017 Share Posted October 7, 2017 Not knocking what you've done Ron. Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted October 7, 2017 Share Posted October 7, 2017 Didn't think you were John and I was tempted to make some standoffs as per the gassers, after all, it would have a lot easier and quicker! Threatening rain has curtailed garden duties so infernal management has let me back into the workshop! Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted October 7, 2017 Share Posted October 7, 2017 I do gardens for a living Ron, any excuse to down tools gets my vote. Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted October 7, 2017 Share Posted October 7, 2017 More progress tonight. Standoff ring fitted and fuel proofed Tank bearers with integral zip ties fitted Tank fitted Fuel filler fitted Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted October 7, 2017 Share Posted October 7, 2017 And finally, for tonight Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted October 7, 2017 Share Posted October 7, 2017 Quote Link to comment Share on other sites More sharing options...
Tim Flyer Posted October 7, 2017 Share Posted October 7, 2017 Great job Ron . Re bolts near edge no problem as long as they are bolted in and not loose. Load is spread around entire ring so the structure is massively strong. Much better than four aluminium rod standoff’s . Quality work. Well done🙂 Quote Link to comment Share on other sites More sharing options...
Tim Flyer Posted October 7, 2017 Share Posted October 7, 2017 Will try to weigh my Wots Wot tomorrow 😊 Quote Link to comment Share on other sites More sharing options...
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