Portofino
Well-Known Member
All that would do is replace as it displaced it .This is gas a lot of gas emptying the close cooling .
Also did yours overheat .....as rapidly if at all ?
While weepy coolers have been mentioned although nothing to do with the OP problems .
Out of interest I see theses numbers running
The “seawater pump pressure“ on mine runs @ 2.4 bar
The coolant “ expansion tank pressure “ only 0..8 bar .........so you can see the Dir of travel if the HE core was breached .which is what Trevor reports
“Gearbox oil pressure “is a whopping 18 bar
The 2.4 bar of seawater remains from the main HE run through the GB cooler ....the Dir of travel is oil escaping rather quickly ...no biggie as the clutch plates will open and sensors alarm off etc + I have a analog dial as well as the digital screens .
Engine oil p is 5 bar running so a beached oil cooler will tip it all into the lower coolant circuit ....er very quickly unfortunately!
The learning here I hope is why it’s experienced sufficient thermal stress to blow a gasket or crack a head ,
Early on in #post 1 cavitation crossed my mind .This is thinning of the wet liners , porosity allowing gasses to pass into the closed cooling ...= bubbles .
Prevented by regular changes of coolant .....it’s reckons to contain additives to inhibit cavitation which go stale .
The bang / explosion of the firing inside the cylinder sends micro shock waves down the liners and the liquid on the other side ( the coolant ) in contact momentarily evaporates m micro bubbles millions are formed and suddenly condense back to liquid .The energy released as they turn from gas back to liquid if they are in contact with metal .....chips away , in this case increased porosity occurs .Eventually a breach occurs .Thats cavitation folks .
So in the wider subject folks ridicule solid blocks like the D6 and D4 , VP having done away with wet liners .....but you can see the method in the “ throw away blocks “ .
How ever as we know know wet liners are replaceable at rebuilds .
You will get a movement of fluid coolant into the cylinder with a porous wet liner as on the suck stroke coolant will enter the cylinder make smoke and some will get past the rings and contamination of oil will occur .
I suspect cavitation comes on with Hrs linked to zero coolant management/ maintenance .
Having thought about it and the clue for me “80 % “ and the initial silence on sterngear hygiene . With bubbles when stone cold in the first post ...I went with HG or other gas leak from a cracked something or other .
The OP then revelled the exhaust manifold ( VP s first choice base on his experience ) ....” is off “ and tested .
Its gonna need a strip to find the leak .
This involves a new HG any how ...
Close inspection of the head(s)
May as well pull the liners out and inspect .
When I was looking for a boat in 2014 I fancied a Riva which had Cummins K2 16 L derivatives.
Designed for NY dust cart lorries.
Dry liners .
Its an absolute must to do the gas test like the op brother in law has done ( refer to post #1 ) .
Even though no bubbles yet ! Its not cavitation with this motor it’s the dry liner seals .
The liners have seals at there bases .Again back to coolant history / changes .......if the additives go stake then theses with the cummins loose there sealing ability and gas starts to enter the coolant .A simple gas test tells you .Even though it May be asymptomatic at the time .
So you can get gas and oil mixing slowly .
The Ops is a rapid gassing up after running with fouled sterngear on 1200 hrs engines.
