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[kiwimodeller]

Greetings all, I have repaired a vintage engine acquired some time ago (http://www.modelboatmayhem.co.uk/forum/index.php?topic=18582.msg196432#msg196432) and got the old boat up and running but the one thing that concerns me is the lubrication of the bottom end of the engine. It is similar to a Sun or Sirius in that it is twin cylinder, single acting, with an enclosed sump. In this case the engine had a hole in the bottom of the sump with what looked like the remains of a thread so I tapped it out and made a sump plug. I oiled the bottom end, assembled the engine and gave it a brief run on steam. When I took the sump off again there was a small amount of water in it so there must be some blow by of steam past the pistons but I do not think the steam oil in that steam (from the displacement lubricator) would be enough to lube the crankshaft. I have therefore drilled and tapped the crankcase and fitted an elbow and pipe to allow me to put oil in to the sump. There was no way to do this previously. Having done this my question is what type of oil do I use in the sump? It cannot be steam oill as that would be too heavy. If I use ordinary lubricating oils I would expect them to emulsify when any steam that blows past the pistons condenses in the sump. Is there an oil which will lube the crank and big end bearings but not mix with steam/water? What do Stuart reccomend for their enclosed sump engines? As the boat is a Straight Runner it will not do long runs and I am prepared to change the oil (even though it means removing the engine) after each days running. Any ideas welcome. Thanks, Ian.

[Underpressure]

Ian, take a look at this thread. Different engine, but the same issues with oiling.
http://www.modelboatmayhem.co.uk/forum/index.php?topic=21332.0

[SteamboatPhil]

Hi Ian
(sorry long time no chat) The best oil to use is the oil you get for car gear boxes or differental's (over here its called Hypoy90), it is thick enough so thet when it gets hot it doesn't thin down too much. I have used this ( as did my father) in the crank cases of all of my enclosed engines and never had a problem. With regard to getting water in the crank, you will never really stop this and it will mix with the oil, but this is not a real problem as long as you clean and flush the engine through ( I use petrol) at the end of the days running. Yes there would have been a sump drain plug, and your engine being a very early example I don't think had a filler (which on the sun is on the top corner of the crankcase) and you are right to have fitted a one, you should also have a breather hole. Another good tip (bit late now as you have re-asemabled the engine) is to paint the inside of the crankcase (I did that with with both my sun engines).
In the early days of flash steam tethered hydroplanes, they used the sun engine and normal engine oil in the sump, and it worked (along with a displacement lubricator for the cylinders) and they did not suffer (too much) wear and tear.
Hope this helps
Isn't straight running fun  

[gondolier88]

Don't want to disagree with you Phil, you are the enclosed expert, but wouldn't a proper emulsifying oil that lubricates with a water content be a better option, also wouldn't have to be drained and cleaned every run?

Greg

[SteamboatPhil]

Hi Greg
Yes it would, but its one of those things passed down via family, that type of oil was unavailable way back when (Grandad et al were running high speed plants) they went for what was available and I have sort of followed (must catch up) Not sure of the cost of that sort of oil either (what a cheapskate I am). I do drain and fush out at the end of a days running, which I think I would also do even if I were using a emulsifying oil ( I don't really like the idea of leaving anything they may contain water inside my engines)
 

[kiwimodeller]

Thanks for the good advice (as usual) guys. Phil, I am happy to use Hypoy 90 for now as I have it in the garage to top up the gearbox and diff on my Sunbeam Talbot, a fine example of a British motorcar which is guaranteed not to rust as it regularly gets coated underneath with Hypoy 90. As for the breather I was thinking that I would just put a long piece of tube on to the elbow and use that as both filler and breather and end it above the engine? As for Straight Running being fun I am hoping it will be. Any advice on how to do it well will be appreciated. The boat does have a vernier adjustment on the rudder so that should help.
Greg, I would like to investigate modern oils at some stage, do you have any reccomendations of specific types and grades? I take it that by "proper emulsifying oils" you are not meaning the cutting oils used with water in lathes, power hacksaws etc? Cheers, Ian.

[gondolier88]

Hi Ian,

Well if you've already got some 'stuff' then at least you can get running straight away.

These are the guys you need to talk to- www.morrislubricants.co.uk/scripts/prodview.asp?idcat=113&idProduct=250- sorry I havn't done my research properly- the oil doesn't run emulsified, it's designed NOT to emulsify at high temperatures. I knew it was specially designed to do something in the crankcase!!!!

As for physically buying the stuff- it's not cheap at £75 a barrel, however I'm sure there are a couple of Sentinel lorries in NZ and perhaps they would allow you to buy a couple of pints off them?

Greg

[BarryM]

Don't want to disagree with you Phil, you are the enclosed expert, but wouldn't a proper emulsifying oil that lubricates with a water content be a better option, also wouldn't have to be drained and cleaned every run?

Greg

What's an "enclosed expert"? Is this one of those boffins who are so way out that they have to be kept permanently locked up? (Or should be?    )

[gondolier88]

Phil's forefathers were probably enclosed on the prison ship we packed them off in.........

Greg

[kiwimodeller]

Geoff, I already deal with the Morris Lubricants people in this country and they are very good about supplying steam oil 680 in small quantities so perhaps I can be lucky with the Sentinel Oil too. Also I have come across a light steam oil which was labelled "Steam and Turbine Oil". The person who got it for me thought it was a B P product so I will do some searching to see if it has the right sort of properties. Thanks again, Ian.

[kiwimodeller]

Well I gave it the first run today on the water and the engine appears to go well however I can now offer the following advice to anyone else with an enclosed sump engine - Do Not Overfill the Sump! Especially if the breather is a piece of tube pointing straight up at your face when you turn the steam valve on. Everyone else thought it was funny, I was not amused. I guess I am either going to have to install a dipstick or use a measured quantity of oil. On the good side of things I do not think it blew all the oil out so there must be a happy medium to be found between no lubrication and overfull. The engine seemed to put out reasonable power with the valve just cracked open on 40PSI and although I did not let the boat run free it seems like it will move along quite well. The other problem still to be solved is how to stop a long narrow straight runner from listing at about 45 degrees at the slightest provocation. I did not have any ballast with me small enough to fit in the hull so I guess it is a matter of going back to the lake with some smaller pieces of lead next Sunday. Cheers, Ian.

[Underpressure]

Ian, if it makes you feel any better, I was one of the team involved in the 24 hour race in Taunton in 1995/6, when we set a new record for distance travelled of 44 miles. We brought the boat in every 45 minutes or so, to top up the boiler with hot water, change the receiver batteries and lubricate the engine (a Puffin).

At the first 'pit stop', my job was the battery and engine lube, which included the displacement lubricator. The steam valve was shut at the boiler and the engine stopped, I unscrewed the top of the lubricator and POP, the contents emptied themselves right into my face  None of us had thought that the lubricator would still contain steam at (low) pressure, obvious when you think about it, but we found out the hard way. I was unhurt and we had the boat back on the water in about 5 minutes.

As for ballast, I always have some lead shot and a few re-sealable plastic bags in the bottom of my tool box, for just such occasions.

Neil

[SteamboatPhil]

Argh the world of straight running,  as you have quite a very narrow hull, I can see why you are getting a little propellor torque, but as you say a little wieight  should solve problem. When I built mine I did end up putting a dipstck in, I also made a note of how much oil to put in (can I fid it now---of cours not), I also ended up taking a pipe from the breather to a small "sludge" tank, as I had the same as you (funny all at pondside thought it amusing too !!)
Keep going   

[gondolier88]

I know a full size 45ft steam launch that has a 100hp triple that also lists at around 80deg- very impressive!!! Well done on your first run- any pics of her on the water?

Greg