Gardner issues

[Neil Corbett]

We recently looked at a boat with a Gardner 2L2, and a couple of things concerned me. First, the engine( which ran very smoothly and started well) appeared to be running very cool. I didn't see any temperature gauges, but after a couple of hours idling I could still hold my hand on the top of the head, and the water from the calorifier was only tepid. I don't know what thermostat, if any, is fitted.

 

Secondly the engine was prone to stall if brought back to idle in neutral.

 

Thirdly the engine was installed so that the gearbox was on the opposite end from the flywheel. I know this is supposed to be a threat to the crankshaft if the prop is suddenly stopped, but has anyone actually heard of that happening in such an engine?

 

The engine otherwise looked and sounded very good and had been regularly serviced etc.

 

Would you regard any of these faults as show stoppers to a purchase?

[scrumpylurcher]

Sounds like it is one of Danny Williamsons rebuilds, if so there should be records of it that he supplied at the time. It does not do an engine any good to run cold, I have a 2L2 rebuilt by Danny 13 years ago, you cant really bare your hands on the rocker cover after it has got up to temperature. I cant give you an actual figure, just it always runs in the middle of the gauge. It sounds possible that your thermostat is missing or stuck open.

I have heard stories of possible problems with reversed engines but never an actual instance.

[Timleech]

We recently looked at a boat with a Gardner 2L2, and a couple of things concerned me. First, the engine( which ran very smoothly and started well) appeared to be running very cool. I didn't see any temperature gauges, but after a couple of hours idling I could still hold my hand on the top of the head, and the water from the calorifier was only tepid. I don't know what thermostat, if any, is fitted.

 

Secondly the engine was prone to stall if brought back to idle in neutral.

 

 

 

The stalling is probably just an adjustment issue. I can't remember off the top of my head whether the L2 has a buffer spring on the end of the fuel rack like other Gardners, I think it does. Probably just a matter of setting this properly, although it could be an indication of stiffness in the linkages.

Gardners don't like running at 'modern' temperatures, but it should be warmer than that. If there is at least a thermostat housing incorporated in the system, again it should be a fairly minor issue to resolve.

 

Re the crankshaft thing, it seems that the makers did produce some (not necessarily marine) units arranged for drive from the 'wrong' end, but it's not something I would choose to do if it could be avoided. At the very least I'd want to be sure that everything is perfectly aligned.

 

Tim

[Proper Job]

The stalling when bought back to idle might be because the engine isn't getting warm.

 

My JP sometimes stalls when bought back to idle when cold. Once it's up to temperature it's fine.

[Neil Corbett]

The engine is off centre anyway, certainly vertically and perhaps horizontally too, so the shaft has universal joints. So alignment isn't straight through. I sense no vibration when in gear. Maybe the UJ would fail first if the prop was stopped.

 

 

 

Re the crankshaft thing, it seems that the makers did produce some (not necessarily marine) units arranged for drive from the 'wrong' end, but it's not something I would choose to do if it could be avoided. At the very least I'd want to be sure that everything is perfectly aligned.

 

Tim

[Proper Job]

How much of a risk is snapping the crank on a Gardner?

 

I know the JP2 had a tendency to snap cranks if stopped abruptly, but this was because there was no main bearing to support the crank between the two big ends. JP3's, 4's & 6's all had intermediate main bearings.

 

What's the arrangement on Gardner twin pots?

[Timleech]

How much of a risk is snapping the crank on a Gardner?

 

I know the JP2 had a tendency to snap cranks if stopped abruptly, but this was because there was no main bearing to support the crank between the two big ends. JP3's, 4's & 6's all had intermediate main bearings.

 

What's the arrangement on Gardner twin pots?

 

They're a 'proper' engine with mains where they should be.

There is quite a long unsupported distance between the 'front' main bearing and the 'front' of the crank/timing case, though.

 

Tim

[martyn 1]

The Gardner general directions for the L2 series engines state a normal running temperature of 60 Deg C. This isnt very hot even for a Gardner as the stated for an LW is 72 Deg C. The full general directions book can be found Here but you will need to log in. Might make some useful reading.

 

The staling when brought back to idle will 90% certainly be related to mal-adjustment of one of the many links/buffers etc on the fuel pump rods.

 

As for the gearbox installation as previously mentioned by Tim, this configuration is not ideal and IMO not one i would choose to do personally. but there are many engines around that have been installed like this and some that are like it when built by the manufacturer. the proper marine Lister JP's for a start. flywheel one end, gearbox the other. I would probably go with an old wives tale. because if not properly aligned engine to gearbox then these loads could do damage.

 

The only issue here that I would be overly concerned about would be the coolant temp as running too cold will not do it much good in the long term but as previously mentioned this is probably nothing more than a missing or faulty thermostat. the stalling can be sorted by checking through all the settings and correcting I expect.

 

 

Martyn

 

We recently looked at a boat with a Gardner 2L2, and a couple of things concerned me. First, the engine( which ran very smoothly and started well) appeared to be running very cool. I didn't see any temperature gauges, but after a couple of hours idling I could still hold my hand on the top of the head, and the water from the calorifier was only tepid. I don't know what thermostat, if any, is fitted.

 

Secondly the engine was prone to stall if brought back to idle in neutral.

 

Thirdly the engine was installed so that the gearbox was on the opposite end from the flywheel. I know this is supposed to be a threat to the crankshaft if the prop is suddenly stopped, but has anyone actually heard of that happening in such an engine?

 

The engine otherwise looked and sounded very good and had been regularly serviced etc.

 

Would you regard any of these faults as show stoppers to a purchase?

[mattlad]

A lot of vintage diesels run at 60 Deg C.

 

As far as cutting out is concerned it is probably adjustment to either the fuel rack or the governor.

 

There should be a shear-pin fitted somewhere between the gearbox and the propeller to prevent any damage to the engine or the gearbox in the event of the prop stopping dead.

[Split Pin]

Depending on which type of water pump is fitted there may not be a thermostat fitted

If it has a ram pump then the engine temp is controlled by tweaking a valve in the by pass pipe.

Thermostats are normally fitted with centrafugal type pumps.

 

The stalling may be that the current owner has set the tickover to low or as others have commented

the linkage is incorrectly set up, there is as Tim suggests a rack buffer spring unit fitted which

is intended to prevent the rack dwelling to far shut when reducing the speed of the engine.

a little bit of tweaking should certainly cure this problem

 

Steve

[Neil Corbett]

Thanks guys for all the useful information. That gives me a few good leads. Any further comments still welcome.

 

Neil

[RLWP]

<snip>

 

Thermostats are normally fitted with centrafugal type pumps.

 

<snip>

 

Steve

 

Often, but not always. Is you comment a general observation or a specific piece of knowledge about Gardners?

 

Richard

[Split Pin]

Richard

 

My comments are Gardner specific, section from L2 manual on temperature control

 

79· 2. Water TempeRtan Control-Marine engines and all engines which draw their cooling water from large or unlimited supplies of water at or about atmospheric temperature are fitted with. a temperature control which " Shunts " or " by-passes " warm water from the discharge pipe to the suction pipe of the circulation pump. thus raising the temperature of the water going into the cylinder jackets. It will be readily understood that the by-pass cock serves as a means of controlling, within limits, the temperature of the water in the cylinder jackets and at the point of discharge. which is of special utility when the engine is running light loads d~ which the temperature of the discharged water

should be maintained at about ISO" or 140"F .. that is, when it is just about as hot as the hand can

momentarily bear' .

Note.-When. starting the engine, it is important that the control cock be closed. otherwise air may get into the circulation pump and interfere with its opera.tion.

On engines fitted with centrifugal water pumps the water temperature is controlled by a thermostat arangement, which automatically maintains the water at or about 140°F. (60DC.)

(provided. the radiator, pipes and ventilation are adequate).

 

Having made the above comments I have seen one L2 with a ram pump and thermostart combination which is aparently sucessful,

I currently have involvement with a 4L2 on which the owner has tried to go the same route but so far has be unsucesfull due to a build up of air which then blows the water out of the header tank, others who have tried it have also not been succesfull

 

Steve

[Timleech]

 

 

Having made the above comments I have seen one L2 with a ram pump and thermostart combination which is aparently sucessful,

I currently have involvement with a 4L2 on which the owner has tried to go the same route but so far has be unsucesfull due to a build up of air which then blows the water out of the header tank, others who have tried it have also not been succesfull

 

Steve

 

 

I'm sure you meant thermostat, thermostart is something else altogether

 

Another approach, which I've used successfully with a JP with ram pump, is to have a 'hot well' arrangement, essentially an open-topped skin tank with enugh volume to give a reserve for expansion/contraction and losses. The one I made was against the sides and bottom of the boat, roughly square section. It'll need a bigger surface area against the hull than a thin skin tank with baffles, and will be more expensive in antifreeze, but no worries with header tanks overflowing, trapped air, etc. Admittedly there was no thermostat, just relied on the JP bypass cock for temperature control.

 

Listers used to do a thermostat arrangement specially designed for raw water systems, but I think they could be a bit troublesome.

 

Tim

[Split Pin]

I'm sure you meant thermostat, thermostart is something else altogether

 

Yes Tim I did mean thermostat! fingers are to big for the keys

Thermostarts arn't that common now,Ive only come across those on Perkins units circa 1970's,

no doubt they were fitted to others.

 

Did you sort that altenator mounting?

 

Steve

[RLWP]

Richard

 

My comments are Gardner specific, section from L2 manual on temperature control

 

<snip>

 

Steve

 

Thanks Steve, good stuff

 

Richard

[Timleech]

I'm sure you meant thermostat, thermostart is something else altogether

 

Yes Tim I did mean thermostat! fingers are to big for the keys

Thermostarts arn't that common now,Ive only come across those on Perkins units circa 1970's,

no doubt they were fitted to others.

 

Did you sort that altenator mounting?

 

Steve

 

 

The AC7?

 

I've opened out the cradle on the crankcase, very pleased with my method & results. Waiting for the alternator to come back from testing.

 

Might post a couple of pics when the job is finished.

 

Tim

[Gibbo]

Richard

 

My comments are Gardner specific, section from L2 manual on temperature control

 

I've got a 4LW with ram pump that I modifed to use a thermostat because I got tired of manually controlling the temperature. It's not a straight-forward job but it now works very well after the intial meddling. I could take photos if anyone's interested.

[flatplane8]

I've got a 4LW with ram pump that I modifed to use a thermostat because I got tired of manually controlling the temperature. It's not a straight-forward job but it now works very well after the intial meddling. I could take photos if anyone's interested.

 

Yes, I'm interested

[Gibbo]

Yes, I'm interested

 

I haven't been to the boat since. I'll take some next time I'm there. In the meantime, if you can make out the ropey picture quality there are a couple here...

 

http://www.smartgauge.co.uk/engine.html

[Athy]

A very enjoyable read, Gibbo - though perhaps your bank manager would not agree.

[Gibbo]

A very enjoyable read, Gibbo - though perhaps your bank manager would not agree.

 

Ta. I don't think my bank manager ever agreed with anything I ever did.

[Gibbo]

Yes, I'm interested

 

Right...

 

 

1. I had to make these as the original alloy ones were knackered.

 

2. Just a flange soldered on the end. Local engineering shop made it.

 

3. Thermostat housing with bypass before the thermostat (has to be before instead of after otherwise the ram pump just smashes the 'stat to pieces).

 

4. Thermostat housing off a Ford Fiesta. Got it from the scrap yard, then had the other bits made to fit it.

 

5. Manual bleed valve. To let the air out.

 

6. Manual bypass valve. This is in addition to the natural bypass through the calorifier. If it's closed off fully the ramp pump smashes the 'stat.

 

7. Main outlet to the skin tank.

 

8. Feed to calorifier.

 

You can see the return pipes at the bottom to the right of the pump.

[flatplane8]

Thanks!

[Timleech]

 

 

Did you sort that altenator mounting?

 

Steve

 

Yes.

It got quite involved.

 

I'll start at the beginning.

 

The dynamo mounting cradle on my (late 1930s) 4LW was made for 6.5" diameter machines. I'd fitted the (6.25" dia) AC5 alternator which came with the engine when I bought it, but even with the small 15 tooth sprocket that I had fitted on the dynamo drive it was only putting out about 15A (24V) at any reasonable engine revs.

Following on from suggestions from SirNibble, I decided to look into fitting an AC7 alternator (7" dia) which I had available. This is a 60A/24V machine specifically designed for low speeds. I'd initially thought the mounts were for 7" dia, which apparently they are on later versions of the 4LW, but I didn't let that deter me.

 

How to open out the cradle from 6.5" to 7", with the engine in situ?

After a bit of thought, I decided a biscuit jointer was the tool to use!

For the benefit of non-woodworkers, this is essentially a small angle grinder modified to take a special carbide-tipped saw blade and with a retracting 'table' and adjustable fence, used for cutting slots in the edges of timber to accept compressed hardwood 'biscuits' for glued joints. I removed the fence arrangements, and turned up a block of acetal (Delrin) to the right radius (3.25") to fit snugly against the existing cradle. Then I set it up on the jointing machine so that it would plunge just enough for 1/4" of blade to be exposed:-

 

 

 

(Edit - the top handle was removed for the operation)

 

This was used to cut a whole series of slots into the existing cradle:-

 

 

The remaining pieces were easily knocked off, and the surface smoothed, first with flap wheels & then finished with a wooden disc, turned to just under 7" dia & with coarse emery tape tacked to the periphery.

This is before final finishing:-

 

 

Next the alternator itself. The cradle mounted AC7 which I had lying around turned out to be unserviceable, beyond economic repair (leakage to frame on both rotor and stator). I dropped lucky on an ex-MOD unit for a good price, sold as used but turned out to be New VeryOld Stock. Snag was, it was the lug mounted version rather than the strap/cradle mount type. I thought, no problem, I'll just hack off the lugs, tidy them up in the lathe if required. It wasn't quite that simple, the whole frame on the lug mounted version is slightly bigger so had to be turned down:-

 

 

Then I had to modify the intermediate drive shaft. The AC7 uses a bigger diameter drive collar than the AC5, so the intermediate shaft had to be shortened and a bigger boss fitted. It consists of a stainless steel tube with aluminium bosses pressed on at either end, to take the rubber hose couplings. The tube was cut to length, and a new 2.25" diameter boss turned up to fit, with a knurled outer rim. The end of the tube was also knurled, and the boss pressed on to the stainless tube with Loctite retainer.

 

 

Then a new strap had to be made, I found some thin stainless sheet in the 'almost scrap' bin, cut it to size, wrapped the ends around and TIG welded them together, then all that was needed was a bit of wiring:-

 

 

And, hey presto, it works!

 

 

 

One day, I'll get it all painted! There wasn't time when building the engine to do it properly, ie painting the individual parts, I was working against a very tight deadline as well as trying to earn a living.

 

The ammeter is using the 25sqmm negative lead between alternator and starter motor as a shunt. It still has to be tweaked because it's reading a bit high, just waiting for a couple of small resistors to arrive. (The spare hole in the panel is waiting for a second ammeter, eventually there will be a second, belt driven, alternator)

 

Relevance of all this to most Gardner owners on this forum is perhaps limited, but some might find it of interest anyway.

So far as I know the AC7 was only made in 24V and 36V versions. Even if the cradle on the smaller LW versions will allow similar modification, you might struggle to physically fit that size of alternator into the space on a 3 or especially a 2-cylinder.

Edited November 18, 2012 by Timleech