Left the exhaust cap off and it rained (3LW)

[bigoltubosteel]

So I am an idiot and forgot to put the cap on the exhaust. There was no rain scheduled so I was planning to go back to the boat and put it on in the morning, however there was a massive downpour and it rained for about an hour overnight.  I am obviously now worried about water in the engine and don't want to risk starting it until I can be sure there isn't any, or at least none has made it into the exhaust valves.  The layout of the exhaust and manifold means it would realistically need quite a lot of water to hit the valves (I calculated about 2L would be required) and the hole is only 80mm in diameter.

 

There is what looks like a convenient drain hole but this happened:

 

 

I guess my questions are; how likely would there have been enough water to reach up to the level of the exhaust valves and water to have got into the engine? Is there anything else I can do to check other than removing the manifold (and potentially shearing more bolts....)?

[matty40s]

Start her up, it will all come out swiftly...

[rogher]

I'm sure you're not the first to have done this and I've not heard of any dire consequences.

But that doesn't mean to say that there haven't been any, of course.

Any rain (surely only a couple of inches?) would be caught in the baffles within the silencer and not have chance to reach the innards of the engine.

Gardners are robust. I'd start her up and let her get hot. I'm sure that would remove any moisture before any harm can develop.

Having said that, it's not my engine so i've nothing to lose...

[Chris G]

I'd be worried trying to start any engine that might have water in the cylinders.  Water is incompressible, but something has to give - a con rod perhaps!

[David Mack]

Does your engine have manual decompressors? If so open them up and spin the engine on the starter. That will throw any water in the cylinders out into the exhaust. Then close the decompressors again and start normally.

[bigoltubosteel]

If I have done my maths correct, it would have needed 99mm of rain to create 2L over an 80mm hole, which is all the rain we had for the whole month of January 😂

 

2 minutes ago, David Mack said:

Does your engine have manual decompressors? If so open them up and spin the engine on the starter. That will throw any water in the cylinders out into the exhaust. Then close the decompressors again and start normally.

 

It does indeed, well it has one lever which I assume opens all of them. How long would you suggest?

[David Mack]

25 minutes ago, bigoltubosteel said:

 

It does indeed, well it has one lever which I assume opens all of them. How long would you suggest?

A few seconds will empty the cylinder(s) of any water which may have got in. Then start her up and run for long enough to get the whole exhaust system hot to dry out the silencer - leave water in there and it may start to rust.

And if there was any water in there, expect a roof like Matty's.

[Kingdom Isambard Brunel]

Either decompress and spin on the starter or wind it by hand through 2 complete revolutions before starting or turn it backwards 2 revs. All will expel water safely.

If when turning it by hand either way you feel any solid resistance STOP.

[jonesthenuke]

FWIW I always turn our 3LW over a few times with decompressor on if its been left for more than a few days. Our engine's exhaust manifold points down at 45 degrees, then has a bend back to the vertical, so more room to accumulate water below the valve inlets.

 

Edited May 13 by jonesthenuke

[agg221]

If starter button and decompression lever position allow, once you have it spinning decompressed so are confident of having expelled the water, just keep the button pressed and move the decompression lever. It doesn't matter if you stop, compress, start, but if you can do it all in one then the engine is already spinning so less current required to get it moving. A very minor point, but you might as well if you're doing it anyway.

 

Alec

[MtB]

15 hours ago, jonesthenuke said:

FWIW I always turn our 3LW over a few times with decompressor on if its been left for more than a few days. Our engine's exhaust manifold points down at 45 degrees, then has a bend back to the vertical, so more room to accumulate water below the valve inlets.

 

 

I think it is always good practice to spin up a vintage diesel decompressed, before disengaging the decompressors to start it. 

 

Much kinder on the starter motor than making it turn the engine over against full compression from stationary.

 

 

 

 

 

Edited May 14 by MtB
Grammar!

[bigoltubosteel]

When I first got her I was doing that because (I later discovered) the starter battery was basically dead and opening the decompressor sometimes allowed it to start. Since the new battery though, she turns over after just a few turns. BUT the lever is easily reachable from the starter so I can do that as a matter of course if it's better all round.

 

There was a few times I had compression lever in one hand, key in the other and a blow torch down the air intake with a third arm....

[Tam & Di]

38 minutes ago, bigoltubosteel said:

There was a few times I had compression lever in one hand, key in the other and a blow torch down the air intake with a third arm....

 

Gardners deserve better than that.  😦

[bigoltubosteel]

I'll take a blowtorch down the 'ole over letting start spray get anywhere near it 🤷

[bigoltubosteel]

She's alive and as well as she's ever been.

 

 

 

Edited May 14 by bigoltubosteel

[agg221]

Do you have any photos that show the starter motor? I have a suspicion…

 

Alec

[MtB]

That motor is labouring really badly, and possibly drawing far too much current. 

 

Does turn over that slow with fully charged batteries?

 

P.S. Not so trendy but I LURVE the sound of three cylinder lumps...

 

 

 

[agg221]

10 minutes ago, MtB said:

That motor is labouring really badly, and possibly drawing far too much current. 

 

Does turn over that slow with fully charged batteries?

 

P.S. Not so trendy but I LURVE the sound of three cylinder lumps...

 

 

 

I think it might be something else but I need a photo.

 

Alec

[bigoltubosteel]

I certainly do have photos of the starter as it's the next thing to look at on the engine, I have been told it doesn't sound right.

 

The battery is brand new and fully charged, it was even more laboured on the old battery. Since getting the new battery she does start straight off without the decompressor under normal circumstances so I was hoping that was all there was.....

[agg221]

The photos confirmed what I thought. That is a CAV BS5 starter motor, which is exactly what should be on there. However, these come in two variants - 12V and 24V and I strongly suspect that you have a 24V starter motor fitted and are running it with a single 12V battery. I know this because someone had done the same to ours. It will start on a well charged battery with a good engine but you only have a few attempts before the surface charge depletes too far and you have to wait 10mins before you can have another go.

 

The main advantage of the 24V starter motor is that you need much thinner cables (I do have the recommended diameters for these somewhere, posted on another thread). However, it does require space for two batteries and some more complicated wiring to charge at 12V but discharge at 24V (don't ask me how to do it!)

 

In the end, I found a 12V starter motor and swapped it over - works much better!

 

Alec

[bigoltubosteel]

Wow, that's hugely useful information.

 

Funny thing is I just had the rest of the electrics bumped up to 24V and a 24/12V charger installed..... They also moved the three leisure batteries that were next to it so there's a bunch of space.

 

How would I confirm this is a 24V model? Other than what you described about having to wait 10 minutes being EXACTLY what I've experienced. The above video was 6 and half minutes before being cut.

 

Presumably I could add a second battery and change out to a 24/24 charger? (I'll consult the electrician before doing anything of course)

[MtB]

You could well be bang on the money there. I had this motor on my K1 in 24V format and it spun the engine over faster than tickover once started!

 

 

 

[agg221]

19 minutes ago, bigoltubosteel said:

How would I confirm this is a 24V model?

 

Presumably I could add a second battery and change out to a 24/24 charger? (I'll consult the electrician before doing anything of course)

Ref. confirming 12V vs. 24V, sometimes there is a data plate on the starter motor, on the same face as the connecting terminals. Mine was missing. My approach to confirming it was 24V wasn't very scientific. I borrowed a second starter battery and a wire and temporarily wired it in series. My reckoning was that I knew the engine was good, so it was either a faulty starter motor, in which case cooking it at 24V wouldn't make it much worse as it would need to go off for repair anyway; or it would work properly and prove the point. It did the latter.

 

No idea on the electrical charging side I'm afraid. @Ben Jameson has a 24V starter and may be able to comment on the wiring.

 

These starter motors are capable of delivering around 15hp, which is 930amps at 12V. I have a 900CCA battery fitted which means in reality the limiting factor is the wires, but in practice it draws a lot less than that, even at full compression. It does explain why they will spin the engine faster than tickover when properly set up!

 

You may find this thread useful: 

 

 

Alec

Edited May 14 by agg221

[bigoltubosteel]

Thanks, I was just reading that thread when the notification of your edit came up!

 

At the moment she does start so I have no need to rush into anything, might have the back off the starter to see if there is any identification on it anywhere. If it is 24V, I'm the opposite of that other thread's poster; I'd rather fiddle with the electrics than the mechanical bits.

 

It's very probable she's been set up this way for nearly 30 years!

[David Mack]

Could 12V on a 24V starter motor also mean the solenoid which pushes the pinion into gear doesn't push it all the way, hence the teeth not engaging every time?