Richard Acland Posted January 11, 2021 Share Posted January 11, 2021 I have a passion for OS 40 FSR engines. I spend a bit of time buying and refurbing them. I recently bought a nice looking example on a well known auction site. I stripped it down and was amazed to see the state of the cylinder liner. I have rebuilt several ABC 40 FSR models, some of which had seen a lot of use and have never come across a liner that had peeled like this one. Fortunately I have some spares so it wasn't a real problem. It goes to show you never know what is lurking underneath. Another thing with this engine is the prop driver is machined opposite to all my other engines. The engine on the right is what I call normal the one on the left is different. I wonder why. Richard Quote Link to comment Share on other sites More sharing options...
DaveyP Posted January 11, 2021 Share Posted January 11, 2021 Don't know but guessing it might have been used as a pusher.... Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted January 11, 2021 Share Posted January 11, 2021 I'm not sure about the 40 FSR but that sort of damage is certainly not uncommon on OS engines of a certain age. I believe that at one time OS were replacing parts FOC but a common mod. was to use ASP/SC 46 parts to repair failed 46 FX engines. Quote Link to comment Share on other sites More sharing options...
Michael Linacre Posted January 11, 2021 Share Posted January 11, 2021 Had the same with an os 46 fx,replaced with ASP parts and converted to diesel,runs great. Quote Link to comment Share on other sites More sharing options...
SIMON CRAGG Posted January 11, 2021 Share Posted January 11, 2021 Been there and worn the T shirt. How OS ever got away with "peeling liner" fiasco I will never know. OS prices have always been silly, one of the reasons I ditched them and went ASP!. Quote Link to comment Share on other sites More sharing options...
Andy Stephenson Posted January 11, 2021 Share Posted January 11, 2021 I lost patience with OS because I had stripped liners on OS46FX and OS61RF twice on each. OS thought nickel plating would be a good replacement for chrome due to the pollution chrome plating causes but it seems they never got it quite right. A. Edited By Andy Stephenson on 11/01/2021 22:12:42 Edited By Andy Stephenson on 11/01/2021 22:13:20 Quote Link to comment Share on other sites More sharing options...
Michael Kulagin Posted January 11, 2021 Share Posted January 11, 2021 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. Quote Link to comment Share on other sites More sharing options...
Brian Cooper Posted January 12, 2021 Share Posted January 12, 2021 I too became thoroughly disenchanted with OS engines and the "peel-o-matic" chrome plating on their liners. . The engines failed with monotonous regularity. To be fair, it was several decades ago when their engines were going through this disastrous era, but the damage to confidence was done. . . . This was a time when I discovered superb MVVS engines, and never looked back. Quote Link to comment Share on other sites More sharing options...
Nigel R Posted January 12, 2021 Share Posted January 12, 2021 "The engine on the right is what I call normal the one on the left is different." Reverse rotation crank? Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted January 12, 2021 Share Posted January 12, 2021 We all go on about the OS quality but I have never had a liner peel on a SC/ASP etc engine , they really got that right. Even the AAC engines from Bluebird back inc the 1980's with chrome plated aluminium cylinders never peeled and aluminium is notoriously difficult to plate successfully OS seem better with other parts like crankshafts etc especially on the four-strokes but the peeling cylinders really let them down . Edited By Engine Doctor on 12/01/2021 14:25:06 Quote Link to comment Share on other sites More sharing options...
Alan Gorham_ Posted January 12, 2021 Share Posted January 12, 2021 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. Quote Link to comment Share on other sites More sharing options...
Michael Kulagin Posted January 12, 2021 Share Posted January 12, 2021 To be fair to OS the peeling cylinders could all be down to a change of operator in the plating company or a change of company. The chrome plating process has to be followed meticulously or failure results. Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted January 12, 2021 Share Posted January 12, 2021 I thought Nikasil was nickel silicon carbide plating directly to aluminium? I believe this may be the process used by Laser - perhaps Jon will confirm this? Did OS use ABN (aluminium brass nickel) in their troublesome engines? Edited By Martin Harris - Moderator on 12/01/2021 14:27:10 Quote Link to comment Share on other sites More sharing options...
Andy Stephenson Posted January 12, 2021 Share Posted January 12, 2021 AFAIK Nikasil plating can only be used with a ringed piston, Correct me if I'm wrong! Laser announced the use of Nikasil decades ago, I bought one of the first 150s to use this process. A. Edited By Andy Stephenson on 12/01/2021 14:33:58 Quote Link to comment Share on other sites More sharing options...
Alan Gorham_ Posted January 12, 2021 Share Posted January 12, 2021 I have probably read the term Nikasil in one of the magazines of the period and it is possible it was misreported as Nikasil when they meant ABN. I am sure I also recall reading one of the engine columninsts reporting that OS denied that the coating they used was nickel based. Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted January 12, 2021 Share Posted January 12, 2021 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. Quote Link to comment Share on other sites More sharing options...
Nigel R Posted January 12, 2021 Share Posted January 12, 2021 Did the other Japanese manufacturers use Chrome or Nickel at that time? Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted January 12, 2021 Share Posted January 12, 2021 Posted by Michael Linacre on 11/01/2021 19:30:12: Had the same with an os 46 fx,replaced with ASP parts and converted to diesel,runs great. Nice diesel conversion . Did you do it Michael ? If you did an article would be good ? Quote Link to comment Share on other sites More sharing options...
DaveyP Posted January 12, 2021 Share Posted January 12, 2021 Yep I'd be interested in seeing how it was done Quote Link to comment Share on other sites More sharing options...
Michael Linacre Posted January 12, 2021 Share Posted January 12, 2021 Hi Engine Doctor and DaveyP, I followed this tutorial that I found on the internet. I have always loved diesel engines and when I got myself a lathe decided to have a go at one, found I needed to sleeve the carb down for good transition. Have also done a OS35FP for a friend and he flew his regularly until lockdown. http://www.flyrc.com/make-your-own-diesel-conversion-head/ Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted January 12, 2021 Share Posted January 12, 2021 OS had to stop using chrome because Japanese law forbids stocking over a certain amount. I still have a couple of 25FXs which used to get a lot of use and were regularly sent back to Ripmax for new liners, they even replaced the bearings for free and I got them back almost by return post with no charge at all. Anyone know if this service is still available because OS stated that because of the problem it would continue for the life of the rest of the engine? Quote Link to comment Share on other sites More sharing options...
FlyinBrian Posted January 13, 2021 Share Posted January 13, 2021 I bought an OS 40 or 46 FX in the early 90's, at that time they were distributed by Irvine. It suffered from the peely liner problem so as I worked in London at the time I took it to Irvine Engines. Firstly they disputed there was a problem and claimed some foreign body must have got into the engine then they agreed to replace the piston and liner however they said the bearings were damaged and this was unrelated to the liner problem - After a long and meaningful discussion it was agreed the bearings would be replaced FOC. However due to the problem with the liners they had no spares and could not say when they were expecting any. Fortunately it was only a couple of days wait before my motor was fixed. Quote Link to comment Share on other sites More sharing options...
Glen Tennant Posted January 15, 2021 Share Posted January 15, 2021 Hello Mick Linacre, just read your article on converting OS 46 & OS 35FP, to Diesel ! great job- just wish I had your skills, I can confirm the OS35FP runs so smooth at all power settings, in my Buzzard Bombshell. Always starts 2nd or 3rd flick Amazing, thanks Mick Quote Link to comment Share on other sites More sharing options...
Engine Doctor Posted January 17, 2021 Share Posted January 17, 2021 Hi Micheal Thanks for the link . I may have a go at this while the lockdown is on and try Anodising the head as well for effect . Quote Link to comment Share on other sites More sharing options...
Michael Linacre Posted January 17, 2021 Share Posted January 17, 2021 That would be good. The 35 fp i did for Glen i took a bit more time over after mine worked successfully. Cooling fins counter bored head screws and even etched his initials onto head. Hope you have success. Mick Quote Link to comment Share on other sites More sharing options...
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