--- In [email protected], "Michael Askin" <[EMAIL PROTECTED]> wrote: > > On 5/17/07, dave hearnden <[EMAIL PROTECTED]> wrote: > > Can anyone help, our neighbour in our boat yard has a SR3 Lister engine in > > his Narrow Boat. > > > > The problem is, its smokes and no comments about its a lister. This one is > > very bad. > > > > The owner has just had the bores honed, heads off and decoked, etc but its > > still as bad. > > > > One question what would be the best engine oil to run in this engine? > > I use the oil that Marine Engine Services in Uxbridge sell. It is > 10W40, but HD30 is also recommended. Unless someone has really put > some funny stuff in the engine it's unlikely to be the oil. > > Unlikely - but it may be oil dilution where diesel leaks internally > into the sump. It might be that it just isn't working hard enough and > a good run down a big river might help. > > Even after a really big service my SR3 (1964) still smokes well, but > after it has warmed up well, it isn't to bad at tick over! :-) > > Where's Tony Brooks when you need him? > >
Reading this set of posts - and wondering what colour the smoke is. Unless I am very wrong the SR range is air cooled with a flywheel come fan, so whoever at Lister (if it was at Lister) said fit a thermostat needs to seek a second oppinion. You can fit theromostatic coolingb shutters to air cooled engines , but it would likley cost more than an SR is worth. I note the words really big service - did this include having the injectors overhauled by a specialist? If not that would be a good first step. I think these injectors have a tiny metal "tit" known as a pintle sticking out of the end. If anyone snapped one off it would not make a fuel spray - more like jets, and this would cause smoking. Next, one needs to be sure the ports in the head and the backs of the valves were properly decarbonised - I expect they were. Does it have hot air trunking directing the hot cooling air right out of the hull? I have seen loaas of NBs venting the hot air straight into the engine room. If not, or if the trunking is in bad condition this may cause smoking because the ambient air temperature will cause the air to expand so less oxygen(for burning the fuel) will be drawn into the engine. It may be easier to trunk cool air from the cockpit area straight into the air intake. This sounds daft, but try it without the exhaust connected. It will make a hell of a din and will blow oily smutts all over the place, but a partially blocked exhaust will cause smoking because the back pressure (mainly at higher speeds) will prevent all the exhaust gasses leaving the cylinder, so you get less air drawn in and less air means less oxygen to burn the fuel = smoke, usually black. Many olders boats suffer blocked silencers I hope the person who did the service checked the oil for dilution, but it is worth watchinmg the dip stick level, feeling the oil and smelling it. If the level is rising, the oil feels "thin" and it smells of unburnt diesel change the oil urgently and get it loked at without delay. Then internal crankcase breather system (if it like the SL range)will eventually feed oil mist to the inlet (bluish smoke) and if left the engien could suddenly rev to self destruction. However it will probably partially sieze up at low speed first. I also hope they checked the valve stems and guides for wear. Very badly worn diesel ones may cause bluish smoke, but it is far less likley than on a petrol engine. If none of that helps the side cover needs to come off and the injector pump timing and phasing be set. Unless you have a manual and fully understand this I would advise that you seek expert help - it involves possessing assorted shims and a swan neck (ask the engineer about these to judge his competence on Listers. The SL range required the clearance between the piston crown and cylinder head to be adjuted by shims under the cylinder barrel or head, I expect the SRs are similar. As the barrels were taken off was this reset upon re-assembly. If not the compression ration may be wrong, again giving problems. As far as oil is concerned I seem to recall they once recomended a straight 20 grade oil in winter, so I doubt that anything you buy today would make a significant contributioin to smoking as long as the cylinders and pistons/rings are in good condition. If you have convinced yourself it is the oil try some SAE 20W50 in API CC or CD. I bet it still smokes. Lastly it has long beeen accepted that direct injected diesels (no glowplugs) in small engien sizes are likley to smoke at low speeds. This is realted to lack of swirl inside teh cylinder, so I think the Lister (and my Bukh) will always smoke a bit at idle and low speed, but it is a question of degree. Note, Computer simulation in engien design has done much to address this issue on modern engines. I bet you wish you never asked. Tony Brooks
