Lister JP cooling

[Deard Pirate Roberts]

I’m working on a Lister JP3. I have removed the heads and noticed that some of the openings that pass from the head through the crank case are open and some are plugged. If this is for cooling why are they plugged? Head 1, 3 plugs heads 2and 3 no plugs. 

Regards Scott

[RLWP]

To balance the cooling water flow through the heads. With all of them open, the water favours one head over the others

[Deard Pirate Roberts]

I guess that’s why the head with the most plugs is the closest to the pump. I thought the others had corroded and dropped into the case. 

Thanks for the advice.