Ross Clarkson Posted April 28, 2010 Share Posted April 28, 2010 Hi all, I will be fitting a SC61A MkII Series engine in my VMAR Bulldog which i am currently putting together. This will be the first time i have installed an engine in an aeroplane so i was just wondering whether anybody has some general tips so i hopefully get it right first time? What would be best, sideways or inverted or does it not make much diffeence? Also, i am sure my engine with silencer on may not fit as the silencer is too long. If so, how would i overcome this? Cheers, Quote Link to comment Share on other sites More sharing options...
Paul Gauci Posted April 28, 2010 Share Posted April 28, 2010 not having installed an inverted set up I can't really comment on that, but I have a sideways mounted OS-61FX in a groovy 50 3A and it works perfectly, except I had lateral balance issues, nothing a bit of lead on the left wingtip didn't fix though. Inverted would have been neater in my plane, but I went the "safer" route of a sideways mount after a few people mentioned inverted might be an issue with relative carb to fuel tank height and flooding etc so I just went with what I knew wouldn't be a problem for my particular plane design. Edited By Paul Gauci on 28/04/2010 01:20:27 Quote Link to comment Share on other sites More sharing options...
Aslan Posted April 28, 2010 Share Posted April 28, 2010 Sideways would be a neater fit Ross,with the silencer exiting the bottom. Quote Link to comment Share on other sites More sharing options...
John Privett Posted April 28, 2010 Share Posted April 28, 2010 Quite a few of my models have the engine mounted so the silencer exits along the bottom of the fuselage. This means the engine is mounted "sideways plus a bit" so it's somewhere between sideways and inverted. Hope that description makes sense! Quote Link to comment Share on other sites More sharing options...
Lee Smalley Posted April 28, 2010 Share Posted April 28, 2010 sideways or inverted make no difference as long as you insure the tank position is still fractionally below the carb line Quote Link to comment Share on other sites More sharing options...
Ross Clarkson Posted April 28, 2010 Author Share Posted April 28, 2010 The silencer just seems too big with my SC61A MkII Series and fouls the bulkhead and will be very visible if i fit this one. Does anybody know if i can change the silencer for this type of engine to a more compact one? Quote Link to comment Share on other sites More sharing options...
Rob Posted April 28, 2010 Share Posted April 28, 2010 just engines do a great range of after market silencers including a pitts style one that sounds like it could be the answer to the problem. Quote Link to comment Share on other sites More sharing options...
Ross Clarkson Posted April 28, 2010 Author Share Posted April 28, 2010 You are a genius Rob, just the stuff, Cheers. Quote Link to comment Share on other sites More sharing options...
Stephen Grigg Posted April 28, 2010 Share Posted April 28, 2010 Is it 2 stroke or 4 stroke Ross Quote Link to comment Share on other sites More sharing options...
i12fly Posted April 28, 2010 Share Posted April 28, 2010 My SC61 is sideways, starts and runs beautifully. To resolve the interference you could an extension piece between engine and silencer (I think Just Engine sell them) Quote Link to comment Share on other sites More sharing options...
Ross Clarkson Posted April 28, 2010 Author Share Posted April 28, 2010 2 stroke Stephen. I dont think a 4 stroke would have had the same problem as thier silencers are much smaller aren't they? Cheers i12fly, i have contacted Justengines and they will be getting me a BCM Pitts muffler which looks awesome. I don't really want the the big traditional silencer sticking way out underneath. Quote Link to comment Share on other sites More sharing options...
Guest Posted April 29, 2010 Share Posted April 29, 2010 only problem I have experienced with inverted is damage to the engine if taildraggers nose over on landing - our field is concrete/tarmac pad Quote Link to comment Share on other sites More sharing options...
Steve Hargreaves - Moderator Posted April 29, 2010 Share Posted April 29, 2010 Pitts silencers can be a bit loud in my experience.....I had to fit an extra box as an "after Silencer" to mine to keep the noise down which kind of negated the reason for fitting it in the first place!!! Quote Link to comment Share on other sites More sharing options...
mothy Posted May 12, 2010 Share Posted May 12, 2010 Sideways or inverted is not a problem. Whatever fits and is consistent with getting a match between tank fuel level and needle valve level. In my experience (30 yrs) needle valve level needs to be about two thirds up from bottom of tank level. Do be aware that inverted engines, if flooded, can lock up and a powerful starter might bend the con rod. The 45 degree mounting which puts the silencer along the bottom centre line is a good way to go but still prone to flooding lock up. Quote Link to comment Share on other sites More sharing options...
Ross Clarkson Posted May 12, 2010 Author Share Posted May 12, 2010 Cheers Tim and thanks for the tips, I have mounted it sideways and levels should be fine. Just on too installing tank tomorrow. Cheers, Ross. Quote Link to comment Share on other sites More sharing options...
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