Mr1 oil tank / cooler operation

[Jgorm]

I'm working on better understanding on the oil tank off my non ho mr1. I have oil water contamination and low compression. Part of my investigation has taken my to places where oil and water are in close connect. It's an impressive casting that was well thought out!
The side plates hold the cooling water and route it through channels around the central oil tank. There are 3 port of the cooling water, 2 on the bottom and one at the thermostat. They all connect to different areas on the cooling jacket. I haven't figured out the flow direction because it doesn't really matter for me now.

I haven't figured out the oil flow yet. It seems to return into the top side of the tank through a complicated baffle system to return oil to the center of the tank. The center vent on the top seems to be a vent similar to the pcv on a car. There are two holes on the bottom that attach to the engine block. The one on the right goes into the stand pipe channel on the side of the oil tank. I really can't explain that. Anybody have any insight?

The good news is that I pressured tested the cooling side and it holds 20psi, and that the meal is in excellent condition. Does anyone know what the operational pressure is for the cooling system?
Here are some pictures. It would be fairly easy to pressure test it in the boat if you think you might have a problem. Hope this helps someone.

 

[buckbuck]

Here is some readings I pulled on my boat several years ago. https://jetboaters.net/posts/52533/
Does it appear that water sits in the bottom of the tank in this picture?

 

[Jgorm]

Thanks a ton @buckbuck looks like it should never see 30psi and my test at 20 should be sufficient considering the water spits off that line multiple times for the different areas that require cooling.

Yeah, it looked like water collects and causes corrosion at the oil tank bottom. Both sides had crud and I took the pictures after I cleaned a bunch of it off. I always blast the shit out of it multiple times at the end of the day until no water comes out. Revving to about 5-6 k then hold for 5 seconds, then a wot punch seems to work best. If its going to be a while before I drive it again, I do out again after at least 30m. Sometimes once the next day. I realized how much water stays in the system when I fired my fx140 after a few weeks with 115+ temps and it still shot out a bunch of water. Raising the nose seems to help too.

 

[buckbuck]

Be careful @Jgorm . The guys here have been talking about reving an unloaded engine and causing damage. I have changed my approach to just letting it idle for 1/2 a minute. Just something for you to consider.

 

[Jgorm]

Be careful @Jgorm . The guys here have been talking about reving an unloaded engine and causing damage. I have changed my approach to just letting it idle for 1/2 a minute. Just something for you to consider.

Don't hold it at wot and you'll be fine. The only risk of revving an unloaded engine is if it's accelerating so quickly the rev limiter can't catch it and you over rev. 30sec at idle will leave massive quantities of water inn the system. You could idle until it overheats and not remove half the water.

 

[Jgorm]

I figured I probably should check the screen while I'm at it. Looked clean.

 

[itsdgm]

Fwiw, revving the engine won't remove any water from the oil cooler cooling system. All that revving the engine does is remove water from the exhaust system by "blowing it out" with exhaust pressure. Gravity is the only thing that will remove the water from that area.

I have torn down an engine completely. But I haven't opened up an oil cooler before. So it's great to see the pics of what's actually in that heat exchanger. From what I can remember, the two main lines at the bottom of the cooler were the main feed in to the oil pump and I thought the second was the main return to the oil cooler. I'd have to physically see it in place to go over the cooling lines in (from below) and out.

 

[Jgorm]

The main oil feed from the tank has to be the middle hole because of the filter and that the other hole has a stand pipe that would not feed oil unless it was super full. I still think the main return is at the top because of all the extensive baffle work. I hinted around the manual but couldn't focus that out.

 

[itsdgm]

Im pretty sure that the second hole on the bottom that has the pipe that runs to the top of the tank would be the return.

 

[itsdgm]

Going from memory, There is a breather hose that goes from the valve cover to the top of the oil cooler.

 

[Jgorm]

I looked at the ski and snapped a could pics. The top center is the breather / crank case vent to the valve covers. The top side with the major baffles connects to the oil separator box. I'm not really sure what that does either. Separate oil from air?

 

[Jgorm]

I now might understand why oil gets in the intake when over filled. It flows out the breather, straight into the valve covers, pressurises in the head, then overcomes the valve stem seals to spatter out the intake ports during reverberation. I could feel the intake ports blowing out more air than I expected, but I don't normally play with individual throttle body engines with no intake manifold.

 

[Beachbummer]

So, On Which line does the oil return to the cooler?

Is it the one at the top?

 

[Trevor Shipman]

Kinda off topic but should I rev the engine a few times once’s she’s out of the water or do I just look like a dick?

 

[BigAbe75]

I think most do that to blow some water out the exhaust. That’s what I was told to do, so have followed suit. Was there a concern that a couple short blasts is harmful?