Low oil pressure.
#1
Registered
Thread Starter
Join Date: Jul 2001
Location: Melbourne, Florida
Posts: 81
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
I have twin Mercruiser 350 custom built to 425hp. This winter my old man and me rebuit one. New crank, bearings, rings, lifters, Melling high volume oil pump, carb ect. Kept the same pistons cause the block was already 60 over. Question is, I'm only getting 25psi hot idle and 42-45 psi at 3500. The other engine is getting 45psi idle and over 55 at 3500. What the heck is going on. Any ideas. Am I about to blow this engine ........again. When looking through the oil cap there seems to be quite a bit of oil splashing around. I also just put 2 new oil senders on.
Chris
Chris
#2
Registered User
![Default](/forums/images/icons/icon1.gif)
Too much bearing clearance or a bad oil pump are common causes. Once I did a motor and neglected to tighten the oil pump bolt. I learned never to allow yourself to be interrupted when doing something important.
#3
Registered
Join Date: Nov 2001
Location: Pennsylvania
Posts: 3,385
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
Buy a mech gage with copper line and make sure of your readings. I have one engine that reads low continuously but in actually is too high with a mechanical gage (80+ cold). I know this engine is tight because I built them both. Check it with a mechanical gage before jumping to conclusions. If I didn't know how my engines were built I would guess this one is weak and it is not.
#4
VIP Member
![](https://www.offshoreonly.com/forums/images/icons/prop.gif)
![Default](/forums/images/icons/icon1.gif)
I have twin Mercruiser 350 custom built to 425hp. This winter my old man and me rebuit one. New crank, bearings, rings, lifters, Melling high volume oil pump, carb ect. Kept the same pistons cause the block was already 60 over. Question is, I'm only getting 25psi hot idle and 42-45 psi at 3500. The other engine is getting 45psi idle and over 55 at 3500. What the heck is going on. Any ideas. Am I about to blow this engine ........again. When looking through the oil cap there seems to be quite a bit of oil splashing around. I also just put 2 new oil senders on.
Chris
Chris
Larry
#6
Registered
Join Date: Feb 2008
Location: Michigan
Posts: 715
Likes: 0
Received 0 Likes
on
0 Posts
![Default](/forums/images/icons/icon1.gif)
I wouldn't be concerned either. Oil pressure is not really what you want anyway, you want oil volume, big difference. Just because oil pressure is high, doesn't necessarily mean you're getting good lubrication.
Thread
Thread Starter
Forum
Replies
Last Post
FlyFast
General Q & A
13
05-10-2004 11:39 PM