Marshall 802 engine rebuild

[Andy1971]

Hello in the process of rebuilding a 4/98TT Marshall 802 engine the Turbo has been taken off and run with out up to now engine is now having new pistons and liners fitted because of water in the oil would any one no the big end torque figure,i have found 2 answers 1 is 60lbt-feet anougher 70-75lbs-feet am i correct in that if big ends don't have locking tabs that the later is correct? also Head bolts are used not studs so the figure i have found for studs is 110lbs-feet would this be same for Head bolts? Thanks in advance.

[T P]

Torque figures as below. Make sure you have fitted the correct liners as there are several variations and it won't last a month if you have the wrong one's in.

https://imagizer.imageshack.com/img922/7039/SY8dwf.png

https://imagizer.imageshack.com/img923/6171/raw4eI.png

http://farmingforum.co.uk/forums/sho...hlight=leyland

If it's a true Marshall engine it should not have the keywed shrouded non rotating inlet valves. Lot of stuff has been swopped around over the years.

Sometimes water in the oil is caused by one of several threaded bungs on top of the head working loose so check that too before re-assembling.

[Andy1971]

Thanks for the info T P most helpful the head will be going to have new injector sleeves fitted as they came out with the injectors.

[ACE]

Thanks for the info T P most helpful the head will be going to have new injector sleeves fitted as they came out with the injectors.

Make sure to check the liner standing height and shim as required or you will be blowing head gasket and doing it all again

[T P]

If it's a genuine Marshall era block it's rare to need shims as they had the machining tolerances sorted by then .None of the Marshall's I ever did needed shims Of course unless you owned it from new or know the history the block could be out of anything at this stage so as ACE said best to check the liner standout. The counterbore in the block needs to be scrupulously clean otherwise a bit of crud will create a stress point and the liner will crack horizontally below the lip a few months down the line. Seen that a few times after slap dash in the tractor jobs. You could even get externally chrome plated liners at one point in time for the naturally aspirated version which didn't rust in contact with the water but i doubt they are available any more, I only ever fitted one set and the local supplier is gone now. There were quite a few naturally aspirated engines fitted to small boats and if it was a cowboy installation they used the river water to cool the engine without a heat exchanger and coolant then the liners ate through in short order probably hence the chrome idea.