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Discussion Starter · #1 ·
My oil pressure is dropping right at 4000 rpm. What might cause this? It is going from 60 down to about 25-30 :mad: Also checked with mech gauge...

It's a BBC 468, melling oil pump and milodon 10qt jetboat pan, 20-50 Kendall oil

When the R's go below 4000 the oil pressure comes back. It drops back to about 30 at idle when it warmed up. Anything over idle and it's back at 55-60 until I hit 4000 rpm. Even gradually increasing, so I dont thin k it's from sloshing. I have tried running the full 10 quarts down to about 7 qts with no changes in this condition...

Any ideas??
 

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Discussion Starter · #3 ·
Thanks. While we are on the subject, what is a good pan for a budget? I've heard of a few good pans while reading the forum, but they all seem to be $1000 or more...my budget is pretty well dried up at the moment...
 

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Sit N' Spin
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I've been running Canton's 9qt marine pan and have had no oil pressure issues. Comes with a windage tray and double trap doors. I think they're around $300-$400.
 

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While you have the pan off check the pick up, check the distance off the bottom. Try for 3/8" but no more! 5/16" is better than 7/16. The bfurther it is off the bottom, the harder it is to maintain pressure at Rs. For some reason, 4000 seems to be the magic number for this to happen. And make sure it is FLAT AND PARALEL to the bottom.



 

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Thanks. While we are on the subject, what is a good pan for a budget? I've heard of a few good pans while reading the forum, but they all seem to be $1000 or more...my budget is pretty well dried up at the moment...
Check with REX marine on our B&B Pan. Mike stocks them on the "Left Coast" an they have become very popular with the Jet crowd....

10 Qt pan including filter
Removeable Windage tray and crank scraper
8" Depth
Acceleration ledge to keep oil from climbing up the back of the pan
Comes with matching pick up and 12 bolt kit for easy installation
Uses OEM GM dipstick
Will clear up to 4.250" Stroke
 

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Discussion Starter · #8 ·
Thanks for the input. Things were all running fine for most of last season (engine being fresh as well) If I end up pulling the engine out, I may just switch pans at the same time...

Naturally, I start hearing bad things about the Milodon pan after I had everything together, but it did seem to be working fine for awhile...
 

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Discussion Starter · #11 ·
Got the engine pulled and everything looked good underneath. No issues with the pump or the pickup at all. I am wondering what the main differences are between the Milodon pan and the B&B pan. Does the B&B pan have a kickout?
 

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You may have too much oil "trapped" in the valve covers and valley and after a while at speed you are running the pan low.

Valley screens, Jesel drive, certain heads can all cause restrictions in the oils ability to return quickly to the pan.

Many BBC run external oil return lines from the corner of the heads to the pan.
 

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Discussion Starter · #15 ·
Filter is a system 1. I'm pretty sure it's the oil pan that is causing the issue. Just wondering what the differences are with the different pans. I dont really like the windage tray in the Milodon pan. Looking towards something with a screen type tray and a kickout...
 

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Sit N' Spin
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My oil pressure is dropping right at 4000 rpm. What might cause this? It is going from 60 down to about 25-30 :mad: Also checked with mech gauge...

It's a BBC 468, melling oil pump and milodon 10qt jetboat pan, 20-50 Kendall oil

When the R's go below 4000 the oil pressure comes back. It drops back to about 30 at idle when it warmed up. Anything over idle and it's back at 55-60 until I hit 4000 rpm. Even gradually increasing, so I dont thin k it's from sloshing. I have tried running the full 10 quarts down to about 7 qts with no changes in this condition...

Any ideas??
Does it instantly drop when you hammer it to 4000? Or is it a gradual drop?

Also, what brand oil are you running and what weight?
 

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I changed from a 14 quart dooley pan to a 10quart B&B. Here are a few pics of the B&B pan. Cant really say if the pans better or not.









i'm running this same pan and I've got the pressure drop thing happening too. 50+ psi hot until I get on the pedal and then starts dropping to around 25psi. I've got the 10quart B&B pan, and I'm running 10 quarts total in the pan/filter. I'm gonna suck a quart out of it next weekend and see what that does. I'm running 10W-40 conventional in it now.
 

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i'm running this same pan and I've got the pressure drop thing happening too. 50+ psi hot until I get on the pedal and then starts dropping to around 25psi. I've got the 10quart B&B pan, and I'm running 10 quarts total in the pan/filter. I'm gonna suck a quart out of it next weekend and see what that does. I'm running 10W-40 conventional in it now.

Wait... wasnt it you in my other thread saying that you had this pan and didnt have a oil pressure problem so look else where? ( http://performanceboats.com//showthread.php?t=40896&highlight=dyno POST NUMBER 23 )

My oil pressure hasnt been figured out yet. We removed oil from the pan and the drop changed and followed a different pattern. At that point we figured that we were actually sucking the pan dry that time and they though that maybe my original oil pressure drop was the pump pressure bypass opening up. We ran a 10 second 5800 RPM blast to see what the pressure looked like and it was stable around 60 PSI if i remember correctly. I'm going to try a baldwin filter with a bypass but with out a data logger it's kinda hard to keep a eye on oil pressure at WOT... especially since right now the boats wild when i mash the gas.
 
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