stu knowles Posted March 17, 2018 Share Posted March 17, 2018 Interesting Mercos? This is a petrol conversion from 'back in the day' - although when that would have been I have no idea. I have been around modelling since about 1972 and I have a very vague recollection of Dunham Engineering adverts in the mags. It has a very crude set of external points attached to the front and I believe it to be unrun (No surprise there!) Quote Link to comment Share on other sites More sharing options...
Cuban8 Posted March 17, 2018 Share Posted March 17, 2018 A friend bought one of the Merco petrols when they were on sale IIRC about 25 or so years ago. I remember going with him back to the shop where he bought it and he said something like "after forty years of running model engines, this so and so has defeated me". The chap in the shop said "I'm not surprised" and gave him a full refund! Quote Link to comment Share on other sites More sharing options...
TartanMac Posted March 17, 2018 Share Posted March 17, 2018 Great thread this Jeff2wings and very nice job on the mercos. Did you use anything special to clean the case with ? I usually just use soap powder boiling water and an ultrasonic cleaner. Quote Link to comment Share on other sites More sharing options...
stu knowles Posted March 18, 2018 Share Posted March 18, 2018 I can't imagine that a naked spark at the front of the engine did a world of good to the 27/35 meg radio either. Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted March 24, 2018 Author Share Posted March 24, 2018 Some interesting replies ! I vaguely remember Skyleader running an add with those target drones,think one of the mags did a feature on it ?? you can tell an "MOD" spec merco as they had no drilling for a silencer and a bit less well finished on the out side. Stu,Dunham eng. used to make rep engines ,such as the Orwick 64,Hornet 60 ,1/2 size DC Wildcat etc .Nice MERCO btw (better on glow though ) Here's Mercos factory effort It's on e-bay at the mo (not mine btw) nice compact ignition unit (not ) ! TM after years of faffing about with different boil n' bake methods,I got a blasting unit before and after ,one on left is unused. Quote Link to comment Share on other sites More sharing options...
Former Member Posted March 24, 2018 Share Posted March 24, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted March 25, 2018 Author Share Posted March 25, 2018 never seen or heard one in the flesh Well,it runs ! Must restore my one Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted March 25, 2018 Author Share Posted March 25, 2018 So the next one for rebuild will need a bit more work as at some time in it's life it's been face planted into mother earth with the result that it has a bent shaft and conrod Well a few deft blows with a (soft face) hammer sorted out the crank,but the conrod needed a bit more finesse ! yep,that's had a thump ! made some close fitting gauge pins,it looks worse than it is,very carefully bent straight.After that just a simple re-assemble Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted August 12, 2018 Author Share Posted August 12, 2018 Well,I think I must have merco-itus or something ,just got four more projects ! This looks like it's never run but has been left in a damp shed,will need new bearings most likely.Mk iv early '80's and just for a change,a 35&40.......and a twin plug 61 from mid late 70's this will need a bit of work... and it's not just mercos' that I mess about with......... Edited By jeff2wings on 12/08/2018 14:12:52 Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted August 18, 2018 Author Share Posted August 18, 2018 So did a few hours in the workshop to day on the 35&40 here's the 40 as brought striped and blasted ,new prop driver made and finned jacket and a coat of paint same for the 35 nice thing with these engines,no bearings to replace ! Quote Link to comment Share on other sites More sharing options...
SR 71 Posted August 18, 2018 Share Posted August 18, 2018 jVery nice job your doing on those Mercos Jeff, I used to fly stunt in comps in the 60 early 70s, I'm looking for another stunt engine to have a go again, if you come across one Tony Quote Link to comment Share on other sites More sharing options...
TartanMac Posted August 19, 2018 Share Posted August 19, 2018 Your engines look absolutely terrific. The 35 and that dual plug 49 look amazing really nice job 👍 great thread this. Quote Link to comment Share on other sites More sharing options...
Matt Theron Posted August 19, 2018 Share Posted August 19, 2018 Hi Jeff2wings, Where are these blasters purchased and at what price please? Cheers Matt Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted August 19, 2018 Share Posted August 19, 2018 I've acquired a Merco 61 twin plug, quite clean, good compression and turns over smooth, tempted to put it in a Flair Astro Hog, hopefully would be a good combination. Just got to sort out a silencer as it came with a small home made exhaust defector. Would it be best to use exhaust pressure for the tank or not? Edited By Frank Skilbeck on 19/08/2018 08:24:51 Edited By Frank Skilbeck on 19/08/2018 08:25:34 Quote Link to comment Share on other sites More sharing options...
Former Member Posted August 19, 2018 Share Posted August 19, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted August 19, 2018 Author Share Posted August 19, 2018 Well Percy,that depends on the kind of spares you need ! If like every one else back in the day,you used castor fuel the engines will be in good condition under all the crud,however,50% of the 49&61's I've brought the bearings have been toast from the congealed castor.I have used Model fixings for replacement bearings for the Mercos and other engine projects,not the cheapest but they more often than not arrive the next day .Things like piston rings can be had from gaviscool on e-bay,and I make gaskets from thick brown parcel wrapping ,as for any thing else,I make ! Frank,as Percy says,however,that said,if it's a small case mk II from '66 on, the carb choke was smaller so suction would be fine,should make for a nice retro combination with the astro hog.Try and get a P&R strap on silencer,I may have one going spare in my box of bits ! SR71 ,the 29&35's come up on e-bay ,sometimes for little money you can of course convert an r/c to stunt by locking the throttle open or fit a stunt venturi. some more pics of the 35 Quote Link to comment Share on other sites More sharing options...
Former Member Posted August 19, 2018 Share Posted August 19, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted September 3, 2018 Author Share Posted September 3, 2018 Just a few more finished engines.................... and this is one of my Ltd 'Black edition' 49 Mk 1 made from leftover bits ! next will be a Mk 111 and another bitza Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted September 11, 2018 Author Share Posted September 11, 2018 Well this is the last of the Merco restorations ,I still have plenty of others to build/restore that will be in my other thread,I may even build a (retro)model or two for them! Mk III with micro-flow carb bit of a rarity (for a merco that is lol !) MkII with Enya carb from the bits box Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted September 11, 2018 Share Posted September 11, 2018 Jeff, the Mk111 with micro-flow is what I've got. I tried running it but was getting a very severe leak from the cylinder head joint, took the head off and there is no gasket, so it looks like I will have to address that. Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted September 12, 2018 Author Share Posted September 12, 2018 Frank,mercos never had head gaskets the head sits directly on the liner,I would suggest you try lapping them together,if that dose not work I will look in my spares box ,might have a twin plug ? Quote Link to comment Share on other sites More sharing options...
Frank Skilbeck Posted September 12, 2018 Share Posted September 12, 2018 Jeff, thanks, I will investigate further. The engine has been cleaned up by a previous owner so I will have a look at the head/cylinder joint to see if there is any problem there. It looks like it has newish head screws, 3 short and 3 long, just wondering if these might be slightly too long and are bottoming out, do you know what length they should be. Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted September 12, 2018 Share Posted September 12, 2018 hello Jeff, I admire your work on the engines....well done ken anderson...ne..1.... admiration dept. Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted September 12, 2018 Author Share Posted September 12, 2018 Thanks Ken,it' a bit like restoring a car or motorcycle,but quicker and not so expensive (as I keep telling the wife!) Frank,short screws are 3/8 long(threaded part) and are 1/8 whit ,have found the test report by Peter Chinn in the Sept '68 RM and no head gasket,however looking at the pictures it looks like the cylinder head has been machined to leave a band around the combustion chamber,my guess to size would be 1 1/8 o/d x.020-30 thou high .The head on my Mk III is also flat but I think at some point in the last 50 (!!) years it's been ' got at' as it had a non-Merco con rod in it so may not be the original head? as received,no gap at head you may just be able to see the raised band on the head Edited By jeff2wings on 12/09/2018 22:31:10 Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted September 13, 2018 Author Share Posted September 13, 2018 So had a go at a spare head on the lathe std head just visible witness mark from liner 30 thou step smaller contact area will give better seal Quote Link to comment Share on other sites More sharing options...
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