Starting a diesel on the bench !

[Colin K]

Hello,
Wondered if anyone could give me some advise. I bought a newer Watermota engine for my old Kingfisher after the old one went pop. Well actually bang !
The engineer that I bought it off said it was all going great but the diesel pump had packed up. I got it home and put my spare on and its all ready to be fitted.
I have decided that its wise to start it up on my patio when SWMBO isn't watching ! To make sure it works ok and I have not been sold a dud.
Debating this with helpful sailing colleagues every one of them pointed me to the humorous youtube video of the runaway diesel that we have all seen. Not entirely helpful !
I intend to have a water butt full and fed by a hose to feed the raw water inlet. The 2m long flexi exhaust connected and run down the garden feeding into a 3m length of rain water pipe i have to get the noise and cooling water away. Most important thing in my mind is a proper kill cable which goes to the diesel pump so I can stop it. Throttle I don't know what to do to be honest Id prefer not to have to rip the morse control off the boat as thats a lot of work. Thought that I could put a spring on to hold it closed and rev it by hand on the lever? If I dare get close enough ha ha .
Diesel fed from a can which will be at high level to feed the lift pump by gravity.
Oil pressure and charge systems are electrical and I think I will not bother. To start it I was simply going to run a jump lead from earth to neg and the starter solenoid to pos and brave the spark.
I am going to mount the engine on a pallet and fix it pretty much as she will be on board using the mounts.
I wondered if I had missed anything ? If anyone else has done this? Or if anyone thinks i'm nuts??

Thanks for any help. Cheers, Colin.

 

[Jcorstorphine]

I would put on a simple oil pressure gauge and you need to remove the alternator belt as it will be damaged unless it is connected to the battery. Have the exact size spanner to slacken the injector couplings in case of a runaway or have a plug to cut of the air inlet. Also watch out for flooding the exhaust so keep the cooling water off until the engine fires. Last make sure you have no loose clothing like sleaves which can be caught on the engine. I would also suggest you only try to start the engine with an able bodied friend to help.

 

[ripvan1]

j - could you explain this bit

I would put on a simple oil pressure gauge and you need to remove the alternator belt as it will be damaged unless it is connected to the battery.

I'm doing exact same thing tomorrow and 1 of the flywheels attached to the alternator by belt runs the water pump - how does not having alternator attached to battery cause problems ?

 

[Avocet]

Wherever the oil pressure sender is, just unscrew it and screw in an adapter of the same thread, connected to the mechanical oil pressure gauge that JC referred to. That'll tell you more about the health of the bottom end of the engine than anything else.

I'm sure you'll be fine with it bolted to a pallet.

I'd be inclined not to use the water butt in case the head of pressure floods anything. Let the water but feed into a bucket and get the engine raw water inlet to suck out of the bucket (at about waterline height). Just work throttle level manually - keep hand away from air inlet though. As has been said, there's a risk of alternator damage if not connected to a battery when turning.

What are you going to do for the exhaust, just run on an open pipe? It'll be noisy!

 

[PCUK]

The alternator won't be damaged unless it is energised, which it won't be so leave the belt on.

 

[Colin K]

Hello Thanks for the tips so far. Blimey just realised that the belt needs to be on as it powers the water pump. But if I leave the electrical plug out of the alternator think that will be ok ???

Exhaust on the boat is a flexible that does a loop in its length and then goes overboard. So was going to do that and slip it in a length of drain pipe too.

Fair comment about learning a lot from seeing how the oil pressure is at start up so I will try and rig up an old pressure one.

Thanks chaps. Colin.

 

[TQA]

I have done this a number of times usually with the engine just sitting on its sump with a couple of big guys holding it. No coolant no belts and usually no silencer just the exhaust manifold. A mechanical oil pressure is a useful diagnostic tool.

These were big old cast iron lumps and running them for three or four minutes sans coolant would do no harm. No raw water impellers were involved.

Make sure you can plug the air intake just in case a rag is not really good enough.

I would turn the engine over two full revolutions by hand before trying the starter to check for anything stuck.

Crack each injector pipe nut with the engine running and listen to the engine note change. The governor will adjust to keep the revs constant but the other cylinders will work a little harder. List to see if you have a 'lazy' cylinder that gives no change.

 

[penfold]

Most important thing in my mind is a proper kill cable which goes to the diesel pump so I can stop it.

No need, just use the stop lever on the injector pump; pretty much all engines of this size will have one, but make sure you know which it is before starting!

Thought that I could put a spring on to hold it closed and rev it by hand on the lever? If I dare get close enough ha ha .

It will already have a closing spring, most likely internally or possibly externally; you may have to arrange a means of holding the throttle at idle or a start position. Bolted to a pallet it's not going anywhere so while minding out for rotating pulleys and moving belts just get in amongst it.

To start it I was simply going to run a jump lead from earth to neg and the starter solenoid to pos and brave the spark.

Sounds fine; I have done this many times to bypass defective ignition switches.

I would put on a simple oil pressure gauge and you need to remove the alternator belt as it will be damaged unless it is connected to the battery. Have the exact size spanner to slacken the injector couplings in case of a runaway or have a plug to cut of the air inlet. Also watch out for flooding the exhaust so keep the cooling water off until the engine fires. Last make sure you have no loose clothing like sleaves which can be caught on the engine. I would also suggest you only try to start the engine with an able bodied friend to help.

There's no means for a non-turbo engine to run away unless it's completely knackered, in which case the OP won't mind it blowing up, although making a plug to block the air inlet is not a bad idea generally as you can use it when the boat's ashore or out of use for long periods. There's no danger of flooding the engine unless there's a watertrap in the exhaust line, so just attaching the garden hose and turning it on a low flow is fine. Having some help handy is a good idea if you've not done it before, in case of disaster.

j
I'm doing exact same thing tomorrow and 1 of the flywheels attached to the alternator by belt runs the water pump - how does not having alternator attached to battery cause problems ?

It won't; it's possible to damage an alternator if you disconnect it while running and charging, but starting an engine with the alternator disconnected will cause no harm.

Hello Thanks for the tips so far. Blimey just realised that the belt needs to be on as it powers the water pump. But if I leave the electrical plug out of the alternator think that will be ok ???

It will be fine.

Exhaust on the boat is a flexible that does a loop in its length and then goes overboard. So was going to do that and slip it in a length of drain pipe too.

Do you mean the flexy hose is in a swan neck or riser loop? That's just to avoid waves against your transom filling up the exhaust and engine with water, like a water trap but somewhat less effective; you don't need that to run ashore, just run the exhaust hose to a convenient drain. If you do run with a loop or swan neck then what I wrote above about the water does not apply and it would be better to get the engine SW pump to suck from a bucket.

 

[john_morris_uk]

Agree with all the above notes about it being fine. How do I know?

Because I ran up our Volvo 2040 several times when it was sitting on a pallet on the floor of our garage. I connected a battery and fuel and fuel return lines, bled the diesel pump and injector pump etc and it started first time after the rebuild. (I used a screwdriver to short across the starter terminals.) It was full of coolant and wasn't even that noisy. I took the impeller out of the raw water pump and didn't bother with raw water supply. If you only run it for a few minutes it won't overheat; in fact it will barely warm up…

It ran so sweetly I started it several times to show it off to anyone who would come and watch. It wasn't that noisy either.

 

[Jcorstorphine]

If you run the engine with no electrical connections to the alternator, you will burn out the rectifiers as the alternator will generate a high voltage if not tied to a battery. Use a temp smallerbeltr