Sr2 advice

[Lee willis]

My lovely 1972 two pot, starts ok and runs fine, it's a bit tappity tho ? it's now started pumping out (white smoke) a lot more than it always has or should be. I've fitted new injecters and fuel filters, checked the fuel and lines. 

 

[Tracy D'arth]

Oil dilution?  If you burn lube oil its blue smoke but if it has a significant diesel content it turns white.

Edited August 12, 2023 by Tracy D'arth

[Lee willis]

That makes sense, the oil level was over the top mark on the dip stick, I thought it was odd and very thin, so how can diesel be getting into the oil.  

[nicknorman]

From the engine driven fuel lift pump, iirc. Bust diaphragm I think.

[Tony Brooks]

2 minutes ago, nicknorman said:

From the engine driven fuel lift pump, iirc. Bust diaphragm I think.

 

Possibly, but more likely a broken or loose internal fuel pipe. All those engines have the fuel lines inside the engine. It has been known for the bleed screws on the internal injection pumps to come loose.

[Lee willis]

Thanks.  The lift pump seems to working ok but I'll check those ideas out tomorrow. 👍

[Stilllearning]

There are a pair of plates below the heads, the injection pumps are behind them, it is fairly common fault for a pipe to work loose. Take off the plates and have a look,  push the pipes onto their mounts, and if you can push them, that may well be the problem.

You will also need to drain the engine oil and replace with new. A raising oil level is diagnostic of the fuel leaking inside the engine.

[Lee willis]

1 minute ago, Stilllearning said:

There are a pair of plates below the heads, the injection pumps are behind them, it is fairly common fault for a pipe to work loose. Take off the plates and have a look,  push the pipes onto their mounts, and if you can push them, that may well be the problem.

You will also need to drain the engine oil and replace with new. A raising oil level is diagnostic of the fuel leaking inside the engine.

So I need to take the heads off I'm guessing first. 

[Tracy D'arth]

Attend to the dilution ASAP as your engine is at risk.

 

The fuel lift pump will continue work with a perforated diaphragm but willl dump fuel into the sump as will cracked copper pipes and loose bleed nipples.

Have the copper pipes been annealed whilst you have owned the boat? It is a service requirement to prevent cracking.

 

They can be brazed up.

7 minutes ago, Lee willis said:

So I need to take the heads off I'm guessing first. 

No, they stay on. Take the lower side covers and the rocker covers off.

Edited August 12, 2023 by Tracy D'arth

[Tony Brooks]

13 minutes ago, Lee willis said:

So I need to take the heads off I'm guessing first. 

 

On no account take the actual heads off but take the two rocker covers off so you can run the engine and check for fuel leaks close to the injectors that are below the rocker covers.

 

I think that on a two cylinder it is just one side cover.

 

[nicknorman]

15 minutes ago, Lee willis said:

So I need to take the heads off I'm guessing first. 

No, the cover plate is below the head. Here is a pic giving the general idea…

 

[alan_fincher]

There is actually a whole host of ways with air-cooled Listers that diesel can end up in the lubricating oil.

 

Somewhere there is an excellent article by Lister specialist Peter Thompson that takes you through a series of steps to diagnose, but a quick Google failed to find it for me - someone else will, I am sure find it.

 

I don't know if anybody has yet spelt it out, but as the contents if the sump build up an ever increasing percentage of diesel, there is a possibility of the engine running away in uncontrolled manner which, in extremis, could result in a catastrophic failure.

[Lee willis]

That's a great help thank you nick, I'll let you no how things turn out. 

[Tony Brooks]

Lee, for information, Nick's photo is for an engine equipped for self bleeding, yours may not have the two small pipes running up vertically from the injector pumps' bleed screws.

[Lee willis]

4 minutes ago, alan_fincher said:

There is actually a whole host of ways with air-cooled Listers that diesel can end up in the lubricating oil.

 

Somewhere there is an excellent article by Lister specialist Peter Thompson that takes you through a series of steps to diagnose, but a quick Google failed to find it for me - someone else will, I am sure find it.

 

I don't know if anybody has yet spelt it out, but as the contents if the sump build up an ever increasing percentage of diesel, there is a possibility of the engine running away in uncontrolled manner which, in extremis, could result in a catastrophic failure.

 

[Lee willis]

2 minutes ago, Tony Brooks said:

Lee, for information, Nick's photo is for an engine equipped for self bleeding, yours may not have the two small pipes running up vertically from the injector pumps' bleed screws.

 

[Lee willis]

Ok I'll check to see if it has. Whatc this space 👍

[Stilllearning]

32 minutes ago, Lee willis said:

So I need to take the heads off I'm guessing first. 

No, the side plates are entirely separate and accessible. Listers are lovely and simple.

[David Mack]

1 minute ago, Stilllearning said:

Listers are lovely and simple.

Apart from the fact that leaking fuel ends up in the sump, rather than in the bilges.

[alan_fincher]

Found it!

Credited to, and copyright of, Peter Thomson

LUBRICATING OIL DILUTION IN LISTER ENGINES
Introduction
The range of Lister engines including LD, SL, LR, SR, HSR, ST, HA, HB, HR & their water-cooled variants
all have the fuel equipment contained within the engine.
Any leakage on this equipment will result in the lubricating oil being contaminated by fuel oil causing
increasing levels in the engine - possibly with serious consequences.
Although it was generally accepted that the engines would survive running with 65% dilution, the possible
result of this could be that the crankshaft would dip into the increased level of oil causing excessive
crankcase pressures, erratic running, stalling on tick-over and, in extreme cases, possibility of the engine
running on its own lubricating oil and becoming uncontrollable.
There are three main areas where leakage can occur:
1 Low pressure feed sources
2 High pressure sources
3 Low pressure leak-off sources
Section 1 - Low pressure feed sources
1:1 Leak on fuel pump diaphragm
1:2 Damage to fuel feed rail
1:3 Leaking dowty washer between fuel feed rail and fuel injection pump
1:4 Leaking bleed valve on fuel injection pump
1:5 Loose element securing screw at rear of injection pump
Section 2 - High pressure sources
2:1 Worn fuel pump element - in bad cases manifested by fuel spraying from pump rack
2:2 Loose delivery valve holder
2:3 Damaged delivery valve holder seal
2:4 Loose or damaged injector pipe union to top of injector pump
2:5 Fractured injector feed pipe
2:6 Loose or damaged injector pipe union to injector
2:7 Loose or damaged union on injector
2:8 Cracked injector body
2:9 Leakage from injector nozzle cap nut
Section 3 - Low pressure leak-off sources
3:1 Injector cap nut
3:2 Loose or damaged leak-off union on injector
3:3 Loose or damaged cap nut or nipple on spill rail assembly - often caused by over-tightening
3:4 Fractured or damaged pipe on spill rail assembly - also includes automatic bleed pipe extension
to fuel injection pump & associated union (if fitted)
Section 4 - Recommended Investigation Procedure to determine source of leakage
All the above can usually be diagnosed as follows, with the exception of the lift pump - this is covered under
section 5.
4:1 Reduce level of oil to mark on dipstick
4:2 Remove air ducting, cylinder head covers and fuel pump housing door.
4:3 Check that fuel pumps are correctly tightened down - do not tighten fuel unions at this stage.
4:4 Observe whether any fuel pipes are being chaffed by pushrods etc - bend to provide adequate
clearance if necessary.
4:5 Locate & disconnect oil feed pipe from crankcase to valve rocker pedestals. This is located within
the fuel pump housing and comprises a single small pipe connecting to a tee-piece.
Place a piece of flexible tubing c. 1/8" ID over this pipe and redirect through convenient hole back
into crankcase.
4:6 Thoroughly dry with tissue or cloth all potential sources of leakage as detailed above.
4:7 Operate fuel lift pump by hand & inspect all sources covered in Section 1.
4:8 Start engine & inspect all potential sources.
Section 5 - Fuel Lift Pump
5:1 Remove pump from engine
5:2 Plug outlet from pump (usually 1/2"unf)
5:3 Connect inlet to pipe & container providing fuel at pressure - c. 3ft head should be sufficient
5:4 Leave for sufficient period to determine whether leakage is apparent.
Section 6 - Rectification Procedures
In most cases the cure will be obvious, i.e. tightening, repair or replacement of part at point of leakage.
However, the following comments should be noted:
6:1 Do not assume that leakage will only come from one source - check all points as above.
6:2 Looseness of parts or abrasion will often give guidance to possible sources.
6:3 If delivery valve holder is loose (2:2), do not just tighten as this can introduce a 'twist' to the
injector pipe.
Disconnect injector pipe from Injector and loosen union to fuel pump.
Tighten delivery valve holder - 35 ft.lb
Align fuel pipe to injector & tighten to delivery valve holder - use two spanners to avoid applying
torque to pump.
Check alignment again and reconnect fuel pipe to injector.
If this does not cure leakage between holder & pump, assume damage to sealing washer. This will
require specialist attention - also applies to 2:1
6:4 When faults are located and rectified, reassemble engine using new joints etc if required, pump out
contaminated oil & replenish with fresh oil of the correct grade & viscosity.
BEWARE OF OVER TIGHTENING !
THIS CAN INTRODUCE FURTHER PROBLEMS
Peter Thompson
Marine Engine Services Ltd, Unit 3 / 549 Eskdale Road, Uxbridge, Middlesex UB8 2RT
Tel: 01895-236246. Fax: 01895-813322. e-mail: Peter@marineengine.co.uk
© Peter Thompson 2005

[Arthur Marshall]

My SR2 has dumped diesel into the oil at least three times in the past thirty years. In every case it was a break in the leak off pipes and replacing this solved the problem... at least until the next time. I'd look at that before anything more expensive, they're only about seventy quid. I now carry a spare...

I think the vibration busts the joints, which are pretty shoddily made. In one case they rubbed against the moving parts which wore a hole in one. You have to bend them to get them to fit under the rocker covers so they can easily abrade if you get the angle wrong.

One new one, about to be fitted by the engineer, fell to bits even as he took it out of the box .

 

 

[magnetman]

My first narrow boat (1994) had an SR2 and the fuel leaked into the sump. I didn't know anything about it as did not check then one day going under a railway bridge near Rugely it suddenly revved up out of control  produced prodigious amounts of smoke and got very noisy. Basically running on its own lube oil/diesel mix. 

 

Speed control not working, stop cable not working so I lifted the boards and pushed across the decompressors. 

 

This obviously did stop the engine. 

 

In the absence of decompressors (broken or missing) I believe one has to block the air intake with a rag or use a CO2 fire extinguisher to deprive the engine of oxygen. 

 

It was mad. Never seen so much smoke. 

 

Good engines designed to be running for endless hours in the open air / poor weather so the side cover. makes sense but for boat use one would rather have it all exposed with fuel leaks remaining external..

 

 

 

I'm pretty sure that engine is still going nearly 30 yars later so it didn't seem to be too serious. I had it sorted out by a boatyard. 

[Arthur Marshall]

Listers can run happily with a fairly high proportion of oil dilution. I used to wait till the level had gone an inch up on the stick, take half of it out and replace to the max mark. Do that a couple of times and then do a proper complete change.

When my engine overheats it just stops, much better than anything else. But as above, after all the advice at looking at complicated stuff, mine has always just been either a split, hole or fracture in the leakoff pipes.

[Tony Brooks]

20 minutes ago, Arthur Marshall said:

Listers can run happily with a fairly high proportion of oil dilution. I used to wait till the level had gone an inch up on the stick, take half of it out and replace to the max mark. Do that a couple of times and then do a proper complete change.

When my engine overheats it just stops, much better than anything else. But as above, after all the advice at looking at complicated stuff, mine has always just been either a split, hole or fracture in the leakoff pipes.

 

I think that is what everyone is telling the OP, except if it is not a leaking pipe or pipe union he will need to look at other possibilities.