Damage from cranking engine?

[andrejsv]

I bought a 48ft boat (Samson Ferrocement) with a Leyland/Thornycroft 25V engine that has not been run in years, and I was told it was 'pickled' due to 'water in the oil'. I have tried to find info on the engine but so far not much luck.. other than it could be a marinized BMC 2.52 engine (which does not tell me much except that I was able to order a manual for it.. not here yet). What happened is:
I was trying to figure out if the engine was salvageable and bought a large wrech to turn the motor main nut by hand. After applying quite a bit of pressure (wrench is about 18 inches) I was able to get it to turn counter clock wise as seen from the front (I am calling the rear the side that has the propeller shaft). I was so happy it moved I continued for about 1/4 turn until I heard a loud 'clank' from inside the engine. I got worried and moved it back 1/4 turn clock wise, it seems to move without much effort now. My questions are:

1) Do engines get damaged if you turn them in the 'wrong' direction? (I dont know which way the engine is supposed to turn.. cw or ccw?)

2) Can the strength of a guy times 18 inches produce sufficient torque to bust something inside the engine?

3) I have not opened any glow plugs or anything.. is it possible if fluid was inside the cylinder that I may have broken something by fluid compression?

4) The transmission control was frozen all the way forwards (towards the front of the ship) while the above happened, so afterwardsI took a mallet and a wrench and banged it until it was vertical, hoping that means neutral. Could being in gear have been part of the noise?

I dont know much about engines.. how do you recommend I proceed? Take the glow plugs out? (I didnt really wanted to open the engine), take the valve cover off (and look if everything still moves?), just connect power to the started and give it a go?

I really want to try to get the engine started (mainly since the local re-power shop told me a Yanmar re-power is typically 11K for the engine and another 11K to put it in). Any advice in to what to start replacing first (starter,generator, belts, fuel fileter, water pump">raw water pump, etc) and in what specific order recommended would be greatly appreciated.

Thanks
P.S. And if anyone has information on Leyland Thornycroft 25V engines.. (like a manual) please share it with me.

[Chief Engineer]

Take out the glow plugs or injectors.

Liberally dose the cylinders with a mix of diesel fuel and oil 50/50.

(It is cheaper than wd-40 or PB)

Let it sit a coupla days...then try to turn the engine over by hand.

If there was water in the oil..something may be rusted up.

The main downside of turning an engine in the opposite direction is you may loosen the nut.

After you get the engine turning freely by hand. Use the starter to turn it over.
Put some rags over the holes where the injectors were so as not to make a mess.

Listen.....report back to us.

[Inthewind]

You said the engine was pickled, that means it was fill completely up with diesel. With the diesel in the cylinders, it will lock up and sound like a thump. Take the injectors out and then try turning the engine over therby letting the diesel out of the cylinders.

[Alan Wheeler]

I have never heard the term Pickled in regards to fuel in the cylinders before. If the cylinder was full of anything, he would not be able to turn the engine.
Andre, no you won't damage anything if the engine was all working internally OK. The only possible thing that could be damaged is the camshaft if by some chance it was seized or out of time. But lets not worry about that as a possible yet.
Here is the operators manual. It gives a little info that may help till the service manual arrives.
http://www.lionfam.nl/files/operator...ions%20154.pdf

[GordMay]

Thornycroft 90 and 108 Marine Engines:
http://www.bluestarsurveys.co.uk/Thornycroft90-108.pdf