jeff2wings Posted August 16, 2020 Author Share Posted August 16, 2020 Here's my latest and most ambitious,it' based on the 1947 Micron/Owat 5 cc fixed comp engines,but my one is adjustable Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted December 14, 2021 Author Share Posted December 14, 2021 So a bit of an update on my engine(ering) projects, the micron/owat adjustable head didn't work out as well as I hoped so a conventional one was made but I now need to make a new piston, after an hours running it's a little on the slack side. 1 Quote Link to comment Share on other sites More sharing options...
J D 8 - Moderator Posted December 14, 2021 Share Posted December 14, 2021 Interesting stuff, how did you make compression adjustable with out a contra piston ? Was the whole head screwing in/out and why did it not work ? Quote Link to comment Share on other sites More sharing options...
Robin Colbourne Posted December 14, 2021 Share Posted December 14, 2021 jeff2wings, Firstly, let me say I'm in awe of the various engine project you have restored, modified and made. You must have the patience of a saint! Secondly, with reference to your Micron/Owat-type engine, I wondered if you have seen the article on piston/cylinder finishing by Ken Croft, published on Adrian Duncan's modelaeroengines.com website? Quite by chance I was only reading it last night. Ken makes some interesting points about tapered bores and how to achieve them.Ken Croft on Piston/Cylinder finishing Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted December 19, 2021 Author Share Posted December 19, 2021 Oh,hello,thought it was just me here, lol ! Robin, yes I know of Ken Croft from the model engine news website, in fact it was the motor boys plans handbook that Ken made available on the outerzone website that provided the necessary information to build the engine, although I have visited Adrian's website I had not seen that article, it would seem that I was doing all the right things, but not necessarily in the right order! Hopefully the next set of pistons will be better, thanks for the link. Before makeing a new piston I thought it would be worth attempting to salvage the old one by "cherry bombing "it and lapping back to the size it should be. Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted December 19, 2021 Author Share Posted December 19, 2021 Did a few more bits on some of my other projects, made some screws, a bit of welding and made a new backplate Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted December 31, 2021 Author Share Posted December 31, 2021 (edited) Refurbished a couple of Merco carbs today need a couple of needle valves made,knurling not that good, but it will do.also did a bit more on the marine to aero conversion MDS 46 Edited December 31, 2021 by jeff2wings 1 Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted January 5, 2022 Share Posted January 5, 2022 Hi Jeff did the " cherry bombing" work on your diesel ? E D Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted January 5, 2022 Author Share Posted January 5, 2022 Yes,to the tune of .0025" that will allow me to bring it to size and lightly hone the bore to a good fit,for a 'do or die' attempt I quenched in water, normally when I have done this before it's done in oil. Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted January 5, 2022 Share Posted January 5, 2022 (edited) Hi Jeff I have always used oil . It obviously earned gor you this time but any known issues when using water that you know of ? Edited January 5, 2022 by Engine Doctor Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted January 9, 2022 Author Share Posted January 9, 2022 Well there is a possibility of enbritellment or micro cracking,will see how it goes when it's back together and running but that won't be for a while until I finished this lot off Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted January 13, 2022 Author Share Posted January 13, 2022 MDS aero conversion 1 Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted January 15, 2022 Author Share Posted January 15, 2022 So my latest victim is this innocent PAW 15 nothing wrong with it mechanically, justa bit boring to look at ?! 2 Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted January 16, 2022 Share Posted January 16, 2022 (edited) Very nice Jeff. Very ED Baby ish ? Ps. Love the old True-Flex prop ? Edited January 16, 2022 by Engine Doctor Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted January 16, 2022 Author Share Posted January 16, 2022 Yes I suppose it does, probably because of the drilled ex ports,and funny how something with flex in the name can be considered true lol,obviously it's just for display purposes only! Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted February 8, 2022 Author Share Posted February 8, 2022 So I have been working my way through my pile of rebuilds,PB engines are simple to do,no pesky ball bearings to replace.The next repair is a Webra speed 61 with a cracked front housing and head minus some fins. 2 Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted February 8, 2022 Share Posted February 8, 2022 Will have to read all this interesting thread... Anyone got a frog 150 R ? With or without a fitted silencer ? Would you know the actual diameter of the cylinder base threaded area, where it screws into the c/ case please ? Anyone happen to know if the silencer similar to the circular Cox 09 type was fitted "alloy up" or alloy down please. Been hunting for a picture to clarify orientation, but no luck. ED, if I were to email you with description and pictures, would you give me the benefit of your opinion.please ? Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted February 8, 2022 Author Share Posted February 8, 2022 Funny you asking that as I had my 150r in the test stand the other day after freeing the stuck contra piston, wouldn't start though because of low compression so I will be stripping it down to fix that, so I can measure it then. Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted February 8, 2022 Author Share Posted February 8, 2022 Exhaust port belt is .844 threaded part of liner is. 743 1 Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted February 8, 2022 Author Share Posted February 8, 2022 Webra speed 61 back together apart from running out of 3.5 capheads ! The other three will have to wait, replacing the bearings is a bit much for my pocket at the moment! 5 Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted February 9, 2022 Share Posted February 9, 2022 (edited) Frog 150 R Thanks Jeff much appreciated. Mine doesn't have the "bee hive" shaped cooling jacket, it has verticaly parallel sided find. It came with silencer ring fitted, label on box and gaurantee slip confirms engine number, 150R w/s, with silencer, slip not dated. Gaurantee slip and engine number tally at approx 1200, so may be an early-ish one ? How easy was it for you to remove the cylinder, c spanner and some heat ? Will measure up in a few days... Suspect either silencer up side down ( the back plate was ) or washer missing. Tiny contact area spigot on cooling jacket to nip alloy ring in place. The spigot does not fit in the alloy exhaust ring, looks wrong to me. Thanks for the dimensions and sorry to hijack your thread which I will read from the begining. Edited February 9, 2022 by Rich Griff Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted February 9, 2022 Share Posted February 9, 2022 (edited) Rich If your Frog has strait sided fins then it's a later Mk2 version from the early to mid sixties I think. All the early models had the round or beehive shaped head. Really early ones were plain silver and later we're anodised blue. The frog silencer muffler fits alloy side up. I have one with a set of the instructions somewhere . If I find them I'll scan and print them here. If the piston is not scored then "cherry bombing" the piston could get its compression back. Start another thread for the frog ? Jeff2Wings. Brilliant repair to the Webra front housing. What alloy rods did you use ? Obviously better alloy used on Webra cases than on the CS Boddo I melted ! Excellent work .? E.D. Edited February 9, 2022 by Engine Doctor Quote Link to comment Share on other sites More sharing options...
Rich Griff Posted February 9, 2022 Share Posted February 9, 2022 Cool, nice to have it confirmed as alloy up. Will start a thread on it... Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted May 29, 2022 Author Share Posted May 29, 2022 Rebuilt webra 61R & 61F with all its screws! And I've actually attached one to an aeroplane!! 4 Quote Link to comment Share on other sites More sharing options...
jeff2wings Posted November 2, 2022 Author Share Posted November 2, 2022 Back to some more metal mangling! Time to resurrect one of my scratch builds, so just made a conrod,piston, contra piston and prop driver (took three attempts to make the conrod) Next up will be the intake tube, needle valve and fuel tank 3 1 Quote Link to comment Share on other sites More sharing options...
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