Engine Doctor Posted January 17, 2021 Share Posted January 17, 2021 Hi Mick . I look into it when my current build is finished and the bench is cleared . I have a few candidate engines to choose from. will post results as and when . E.D. Quote Link to comment Share on other sites More sharing options...
Michael Linacre Posted January 18, 2021 Share Posted January 18, 2021 Hi ED thought you might like some pics of Glens engine,fitted to a Buzzard Bombshell. Quote Link to comment Share on other sites More sharing options...
Peter Jones 21 Posted January 18, 2021 Share Posted January 18, 2021 Posted by Alan Gorham_ on 12/01/2021 14:17:58: Posted by Michael Kulagin on 11/01/2021 23:15:11: I have spent the majority of my working life overhauling aircraft landing gear and hydraulic components. Any repairs involving plating of any kind in bores was always problematic. Difficult to jig the component to be plated and awkward to get the pre-cleaning of the area to be plated right. Chrome plate does not take to steel very well and should have an 'undercoat' of copper to aid adhesion. Nickel, if anything is worse. The plating in question here is being applied to a brass liner. Hence the "ABC" term used in several posts above. It represents "Aluminium piston running in a Brass, Chromed liner". The OS company developed or licensed (can't remember which) a proprietary Nickel based plating know as "Nikasil". However, it seemed rather more fragile when compared to a true chrome plated brass liner as used by other manufacturers. OS do not use Nikasil which is a Mahle process. OS nickel plate liners (electroless nickel plating), this is done for expediency of production rather than Japanese laws, think about it the Japenese splash a lot of chrome around on other goods so that is unlikely to be the reason. When chroming a cylinder each cylinder needs a mask around it to prevent chroming the OD and needs an electrode accurately aligned inside the cylinder, if the electrode is misplaced it allows an uneven chrome build up. All that faffing around is why OS liked to Nickel plate as the process is applied all over the cylinder with no masks or central electrode. Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted February 14, 2021 Share Posted February 14, 2021 (edited) Hello Michael . Nice pics . I am still messing about with a model on the bench that seems to go on and on but have done a bit of head-scratching re the diesel head conversion. I am thinking of making an steel insert that fits into the top of the cylinder incorporating a squish band that is clamped in place by the head . Why ? I dont like diesels that have loose compression screws that come loose in flight and need a locking lever . This system can then use a conventional interference fit contra-piston . Might be a while but will post here when I get sorted. Regards E.D. Ps I see you have sleeved the carb mouth and not the barrel . Does this work ok and is transition from idle to WOT smooth ? Edited February 14, 2021 by Engine Doctor Quote Link to comment Share on other sites More sharing options...
Stuphedd Posted March 13, 2021 Share Posted March 13, 2021 I made a head for an Irvine 20 last weekend , "O" ring type contra piston , there was an article somewhere ( fly RC) ?? anyway today it got an outing ! The smell is amazingly memorable ! 2 Quote Link to comment Share on other sites More sharing options...
Kevin Fairgrieve Posted March 13, 2021 Share Posted March 13, 2021 Similar. This was in an OS40FX that I got cheap on that well known auction site. Quote Link to comment Share on other sites More sharing options...
Gary Manuel Posted March 13, 2021 Share Posted March 13, 2021 Can anyone smell Victory Vs? Quote Link to comment Share on other sites More sharing options...
conrad taggart Posted March 13, 2021 Share Posted March 13, 2021 On 12/01/2021 at 15:19, Bob Cotsford said: Nikasil has been commonly used in Japanese motorcycles from the likes of Kawasaki and Yamaha since the '80s so I doubt very much whether it was an OS invention. Even found its way into Jaguar Cars - again with poor results !https://buy.motorious.com/articles/features/349111/nikasil-cylinder-linings-jaguar-xk8-xkr Quote Link to comment Share on other sites More sharing options...
Corvax Posted March 14, 2021 Share Posted March 14, 2021 Fellow modellers, Are you aware of this production run about to start soon? Open to all. https://www.rcgroups.com/forums/showthread.php?3795139-OS-61-FSR-VF-ABC-Replacement-Piston-Liner-Sets Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted March 20, 2021 Share Posted March 20, 2021 (edited) On 13/03/2021 at 17:08, Stuphedd said: I made a head for an Irvine 20 last weekend , "O" ring type contra piston , there was an article somewhere ( fly RC) ?? anyway today it got an outing ! The smell is amazingly memorable ! Hi Stuphedd. Great conversion well done . Cant understand hy we dont do more of this sort of thing ? Perhaps with the no shortage of engine manufacturers and the cost of OS engines etc more of us will be d ing these sort of projects. Dont forget that the diesel fuel will eventually make the silicon fuel tubing swell up, go soft and fall off . I'm in the process of converting a Magnum GP 40. It has now run on prime and starts very easily. Its now been stripped down for a thorough clean and for the prop driver and new Cylinder head to be anodised . Will post pics when its done . I chose to make a steel insert with steel contra-piston to fit inside the alloy head . This took some time to get a good CP fit . I will try the "O" ring method on the next one . Can you let us know if the "O" rings last ok and ist the contra-piston a firm fit ? I chose the Magnum as it has good compression, came very cheap in a bundle of engines and if it works OK the new parts can later be sapped to an OS 40 FP. Edited March 20, 2021 by Engine Doctor Quote Link to comment Share on other sites More sharing options...
Stuphedd Posted March 20, 2021 Share Posted March 20, 2021 Hi ED, The conversion actually only took half a day ,I had plenty of material lying about so I just set to , the Contra piston is 1/2 a thou smaller than the bore it runs in and the O rings are Viton , I think , as I had some in the junk box that appeared to be the right size . I ,like you, suspect the "O" ring life factor , only time will tell. The real problem is "What is it going into ??" I really have not a clue ??!! I just wanted to see if it was possible to do a conversion . I did do a baby Cox years ago , it would run on a prime but not continue , I might revisit that project if I can find it !! cheers Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted March 21, 2021 Share Posted March 21, 2021 On 13/03/2021 at 18:23, Kevin Fairgrieve said: Similar. This was in an OS40FX that I got cheap on that well known auction site. That's the trouble with auctions or bought unseen . Caveat emptor and all that. Did you manage to fix it up ? I will only bid scrap value for engines etc on " the well knownauction site" as some folk see it as a way of disposing of junk at higher price than scrap. All engines I have bought apart from one on " the WKAS" site have needed work not declared by the seller but bought with that in mind . The last one I bought was an ED baby with a MK 1 head very well and honestly described by the seller . I wish they were all that honest . Quote Link to comment Share on other sites More sharing options...
Kevin Fairgrieve Posted March 21, 2021 Share Posted March 21, 2021 I knew the risk`s when I purchased it, as the FX are notorious for the sleeve peeling issue. I put out a "wanted" request on this forum to see if any one had an old crashed dead example with no joy. I found a retailer who had stock of the equivalent SC piston and liner in stock, and replaced them. Fitted new bearings as a matter of course. So I have a basically new engine for just under £60.00 As an added bonus a member who saw my request offered me a .46FX for a good price, so two good engine`s to go into my stock for future use. Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted March 21, 2021 Share Posted March 21, 2021 (edited) Excellent outcome Kevin ?. My finished diesel conversion of a Magnum 40 GP . Iv'e only run on a prime so far so dont know whether the carb will need sleeving. The second pic is the head before being anodised . Third pic is the insert for the head that the contra-piston sits in . I made this all out of scrap but the steel parts ie , the sleeve was turned from the head of a large High tensile steel bolt and the contra piston from the shank . It was a so and so to turn to a finish as its a very springy steel . Got there in the end and conta-piston re-sets with a nice click when slackening it off. Comp screw is made from a M5 cap screw with the head cut off and filed to the shape in the lathe then heated and blackened in oil Edited March 21, 2021 by Engine Doctor Quote Link to comment Share on other sites More sharing options...
Stuphedd Posted March 21, 2021 Share Posted March 21, 2021 Hi ED Nice you are an "Artist". The comp screw is brilliant ! You can "cold" anodise some alums using fabric dyes . I used to do it when I made my own carbs , Involves a quick dip in caustic to clean the surfaces and then boiling the object up in the dye . It tends not to be an option on magnesium? and when the wife is watching !! Cheers 1 Quote Link to comment Share on other sites More sharing options...
Kevin Fairgrieve Posted March 21, 2021 Share Posted March 21, 2021 49 minutes ago, Engine Doctor said: Excellent outcome Kevin ?. My finished diesel conversion of a Magnum 40 GP . Iv'e only run on a prime so far so dont know whether the carb will need sleeving. The second pic is the head before being anodised . Third pic is the insert for the head that the contra-piston sits in . I made this all out of scrap but the steel parts ie , the sleeve was turned from the head of a large High tensile steel bolt and the contra piston from the shank . It was a so and so to turn to a finish as its a very springy steel . Got there in the end and conta-piston re-sets with a nice click when slackening it off. Comp screw is made from a M5 cap screw with the head cut off and filed to the shape in the lathe then heated and blackened in oil A good result indeed, for the same forumite who sent me the .46 also sent me this! It has been many many years since I ran a Diesel, and I have never had one with a throttle!! 1 Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted March 22, 2021 Share Posted March 22, 2021 On 18/01/2021 at 19:40, Michael Linacre said: /sites/3/images/member_albums/136340/886837.jpgHi ED thought you might like some pics of Glens engine,fitted to a Buzzard Bombshell. Hello Michael nice machining. Is the engine a OS FP ? How does it run , what is fuel consumption like and what prop is it swinging ? Is the carb sleeving really needed ? E.D. 16 hours ago, Kevin Fairgrieve said: A good result indeed, for the same forumite who sent me the .46 also sent me this! It has been many many years since I ran a Diesel, and I have never had one with a throttle!! Hi Kevin . I remember the Irvine 40 diesel . They were short production run for Ovine as diesel was only for the " oily hand brigade" ? They also produced the 20 size in a diesel . Great little engines and quite sought after now. I'll look at converting some smaller engines later on but want to get some flying in if possible ? With the idiots rioting in Bristol last night ( Sky news) I wouldn't be surprised if lock down measures are kept a bit longer. They have made the case for it ! Quote Link to comment Share on other sites More sharing options...
Stuphedd Posted March 22, 2021 Share Posted March 22, 2021 I would be interested in any OS 40 fp conversion , because according to my son, ? Thats my next project ! Engine already obtained , cheers Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted March 22, 2021 Share Posted March 22, 2021 Hi Stuhedd . The conversion I did on the magnum is exactly the same as would be for an OS 40 FP as they are almost identical . Cylinder liner ,piston etc all fit the FP and are IMO better quality and outlasted the OS parts . Pics above tell it all really . The head could have been made a bit lower but I couldn't be bothered as it would only save a few grams . E.D. Quote Link to comment Share on other sites More sharing options...
Michael Linacre Posted March 24, 2021 Share Posted March 24, 2021 On 22/03/2021 at 10:17, Engine Doctor said: Hello Michael nice machining. Is the engine a OS FP ? How does it run , what is fuel consumption like and what prop is it swinging ? Is the carb sleeving really needed ? E.D. Hi , ED Made a really nice job of your conversion. Yes it's a 35 FP. Spoke to Glen yesterday he's running an apc 12x6. Fuel consumption is very good.Not been run for ages cos of lockdown,he fueled it up primed and 3rd flick start.When i first tied it ran ok but was a bit stuttery picking up,tried a 2mm smaller sleeve and now it is almost instant like a glow. Let us know the results when you have tried yours. Cheers Mick Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted March 25, 2021 Share Posted March 25, 2021 Thanks for the update will test sometime before fitting in a model and let you know the outcome . E.D. PS I think this has gone off topic for original post . Will start a new thread for next post . Quote Link to comment Share on other sites More sharing options...
Stuphedd Posted March 25, 2021 Share Posted March 25, 2021 Hi ED yes we need a new thread !!On conversions or something ?? Then I may "copy " your contra piston method ( Thanks ) and even do an O ring one to and see the difference ! cheers Quote Link to comment Share on other sites More sharing options...
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