The Classic Machinery Network

Thanks Fred
What you say makes perfect sense ....so it doesn't matter if its blocked off or left open sucking air in as there are no brakes on the boat
I will go today to see what is on the plate and will let you know
Thanks again
Jeff

Hi all i have a boat with a jcb leyland thorneycroft 4/98 NV normally aspirated engine.. just forward of the DPA pump is a box that appear to be some kind of diaphragm ,and it has a threaded hole below one of the nuts that is sucking in air ..my question is ..what is it (see pictures attached , ? sh...

Hi all i have a boat with a jcb leyland thorneycroft 4/98 NV normally aspirated engine.. just forward of the DPA pump is a box that appear to be some kind of diaphragm ,and it has a threaded hole below one of the nuts that is sucking in air ..my question is ..what is it (see pictures attached , ? sh...

Thanks pete I agree. I dont want to coke up the cylinders in the event of a surge of oil mist..There is a lot of oil pumping around the valves and rockers . Its a different matter on a boat when the engine dies or wont start when you,re a few miles offshore . Its been really helpful reading all the ...

Hi Fred that makes a lot of sense , and i didn't want to feed oil saturated air into the inlet manifold . There is no non return valve in the pipe to the dipstick from the forward breather in the rocker cover ...I think i will take your advice though and leave thing alone . it just doesn't look very...

Thanks for the reply It seems the local "experts" seem to think there is some valve or suchlike that for positive crankcasepressure ...i cant see anywhere this would be !! they seem to think that that because there is such a saturated mist of oil in the rocker cover, that the oil would poo...

hi ...i have a leyland 4/98 normally aspirated thorneycroft diesel in my boat .i think it was a jcb engine back in the day. It has two breathers on the rocker cover . the forard breather has a pipe that connects to the dipstick tube . the rear breather has a pipe that runs down to a plastic bottle, ...

thanks for that .i havent checked the throttle at the helm..i wll have a look
thanks again ..jeff

hi thanks paul I think its going to be a recalibration of the dpa pump....ive done everything else ,all new ...if that don't do it,i guess it aint gonna speed up ever ....thanks for your input...by the way ,no black smoke or any smoke except a puff of blue on initial crankover ans start...probably v...

hi essexpete this is indeed a thorneycfoft leyland 4/98 . i am beginniing to wonder if this 1400rpm is as much as i will ever get out of this engine ...when i said underload, i meant in forward on the velvet drive 1:1 borg warner ...with throttle at halfway it does 8 knots as you said ...but it just...