460 oil pressure issue starting at 4600 RPMs

I went up very very very slowly on the throttle on glass smooth water. When it got near 4500 rpm the pressure drops. It also drops punching the throttle to come up on plane. When the rpm's are up there the pressure drops.
With the windage tray in this pan I don't think the oil is being sucked up from the crank on plane cruising 4500 rpms do you? The stock pan had no problem at that rpm so I can't see why this one would.
I'm at my wits end. I'm starting to lean towards air being sucked in through the tube, maybe the gasket end has a flaw??
The oil pan sloshing makes complete sense but in this case we have been nearly alone on a glass smooth lake. It does the pressure drop back ANYTIME the rpms get up there.
I'm not saying it does it exactly the same rpm every time but just that it is so near 45 to 4600 you can't really tell the differance on the tach.

Wow, do look for a pinhole or maybe a faulty gauge then...

Paul, thanks for the info. I got a LOT out of that! Thanks!

FE

Originally Posted by electrowoman

...The oil pan sloshing makes complete sense but in this case we have been nearly alone on a glass smooth lake....I went up very very very slowly on the throttle on glass smooth water. When it got near 4500 rpm the pressure drops. It also drops punching the throttle to come up on plane. When the rpm's are up there the pressure drops.

With the windage tray in this pan I don't think the oil is being sucked up from the crank on plane cruising 4500 rpms do you?

Yes, I do. Nevermind the "sloshing" I mentioned in my second post; as I stated back then, it was just an example of one of the characteristics of these oil pans...I didn't say that this was the reason for your oiling issues.

Truth is that if you put your particular engine on a dyno with that particular oil pan, and tilt the engine to the same angle as it sits in your boat, you will have the same oiling issue...yes, even when the engine is completely still and unwavering, and whether you inch up the rpms or hit wide open throttle. Not to sound rude or insensitive, but you don't seem to undestand the forces at work in your crankcase relative to the design, shape, and internal configuration of this pan. Nevemind the sloshing. Most oil pans have the sloshing issue to some extent (but it is usually more controlled indeed).

If you are going through the trouble of pulling the engine for the sake of changing the oil pump, then by all means change the pan while you are in there. The oil pump has been suspected in the past and changing out several proved nothing other than the problem wasn't with any of the oil pumps.

Paul

p.s.: search this website: Armando's Racing Oil Pans

Does it happen when the boat is on the trailer, or have you only tried it in the water? I just assumed that you were testing this out of the water and so slosh would have nothing to do with it, but maybe my assumption was wrong.

I don't run it out of the water other than to set timing or just make sure it will start.

I'm wondering why I didn't have this issue with the stock front sump pan with no windage tray??

You ran your engine above 2000 rpm not in the water? Even with the garden hose hooked to the water intake you are risking serious damage to your pump as there is not enough supply, and are risking serious damage to your engine.

No, I do NOT run the boat out of water other than to set the base timing and see if it will start.
All of this has been IN the water free on the lake.

Looks GOOD there Lady! Show us the whole boat



FE

Here's the boat at 7 points Raystown Lake Huntingdon Pa

Sounds like Paul has the answer to the problem.