So far the oil on the dipsticks and what can be seen flowing over the rockers through the filler caps looks clean. When the engines arrived I pulled the pans to take a peak inside and both engines were absolutely spotless with no signs of water ingress anywhere. Compression tests were all approx 180psi, oil pressure 60psi cranking. One drive has been replaced with a Bravo 1 dual water pickup and that engine seems to be running even cooler than the standard pickup drive and the condensation is worse in that one🤷‍♂️. I know that the oil temps are low and so its an issue that needs sorting, however, I also appreciate that things can go wrong at anytime and if the thermostats don't solve it I'll pull the engines (again🤦‍♂️) and open them up. Most likely intake manifold gaskets? Intake manifolds are Weiand Team G's with Mighty Demon 850cfm's and heads are Merlin 1043-B's. Cheers for your time fellas 👌 not got much transom or bulkhead space left so just need to work out the best thermostat kits I can fit in 🙈. I'll keep you all posted 👍

Pcv valves can work wonders pulling moisture out (make sure wherever you put it is baffled so not to suck any oil) but with your description of how much milk and getting on flame arrestors, I have a feeling Icdeadpeople is right.

😫. My heads telling me there's a strong possibility of a larger problem at play. But the Low oil temps has highlighted an issue that has to be sorted either now or later. Might as well sort it and if it doesn't work I'll pull the units again to delve deeper. Shame, coz I spent countless hours polishing and painting them up before the install 🙈. I'll look into PCV valves, are they whats installed on the valve covers/breathers of HP500s? Thanks again 👍

THe blue 502 motors put the pcv into intake manifold bottom to lifter valley. These motors also had the GM lifter vslley shield. Kept oil from getting thrown to and sucked out pcv.

Few older OSO posts note the HP500 uses the following PCV: ACDELCO CV856C

Hmm, OK I'll look into those, though I'm not sure I've got the option of installing in the intake manifold above the lifter Valley. Well, not without surgery, can they be installed in the rocker covers?

Yes, valve cover pcv hole must be baffled or will suck oil.

And I'd run one in each cover. Not required, but if one fails, the other picks up the slack.

I have never seen white good on the cap or in the engine like that. Usually with water in the oil it would look like coffee with a shot of creamer in it :ack:

Also, what does the fuel look like in fuel/water separator? Yeah, that's separate from the oiling system, but just makes me curious.

Hate to say it though, but like said before, those power plants probably have to come out and get a thorough going over. Check the gaskets while installing the other sensors and wot not and just get it out of the way for peace of mind.

Hi Bill,

The fuel is fresh, the boat has just enjoyed a complete, 2 year, bow to stern restoration, tank was completely drained and filled with fresh fuel and 2 new fuel filter housings and new lines were fitted.

like I've said before, I feel from what I'm seeing that there is probably a larger issue than oil temp/ internal air flow at play and as you say a thorough going through is probably on the cards. Only thing stopping me at this point is that both engines have the same issue. Upon arrival and removal of oil pans the insides were like brand new, absolutely spotless, no signs of surface rust as you would expect if engines had had moisture in them, particularly over the months it took for them to arrive from the States. Oil was dark, used, required changing, not brand new like it had just been changed. If it was one engine, absolutely would have been convinced that there was a more serious issue and would have opened it up by now. But both seems to give the indication that its possible 🙏🤞its an install or usage issue rather than an internal problem.

In response to an earlier comment I checked out a HP500 intake manifold I have and there's no PCV in it. The breather pipes have 2 large silver domes that push into the rocker covers though? Is it those?

I do have facility on the side of the demon carb for pcv pipe connection. Am I right that I could baffle the rocker on one side, fit one pcv and pipe it to the carb, and then fit a small breather filter to the other side rocker cover breather hole?

Oil Stats and PCV it seems are changes that i should add to the engines anyway regardless of what the cause of the moisture turns out to be so might as set them up ready.

Thanks again everyone.

Heads up, THe BG carbs have pcv nipple in rear base of carb. The small ones in the side will not work for that.

Had a look on parts diagram for the Mighty Demon and I think it was that pipe that has a rubber cap on that was listed as the PCV pipe location 👍

Thanks 👌