Oil Pressure
05-26-2011, 04:12 PM
#3
2nd Gear Member
Join Date: Jan 2011
Location: Missouri
Posts: 263
My oil pressure runs about 45-50 when fully warmed up and about 70-80 when cold.
It seems kind of high when cold but I've had it only a few months and I think the last owner may have used a thicker oil so it runs a little higher when cold.
It seems kind of high when cold but I've had it only a few months and I think the last owner may have used a thicker oil so it runs a little higher when cold.
05-26-2011, 08:25 PM
#5
6th Gear Member
Join Date: Apr 2007
Location: California
Posts: 10,468
Depends on clearances, oil viscosity and use. General rule of thumb is 10psi per 1k rpm. So 8-10psi at idle, 20psi at 2k etc.
Engines with turbos and positive displacement blowers, you generally want more oil sooner. Keeps the oil wedge intact at lower rpm where the cylinder pressures are much higher than a n/a or centri engine. So 20-30psi at idle, and 30-40psi by 2k. But that typically requires a high volume pump, and isn't always necessary but is a good safety margin yardstick.
Engines with turbos and positive displacement blowers, you generally want more oil sooner. Keeps the oil wedge intact at lower rpm where the cylinder pressures are much higher than a n/a or centri engine. So 20-30psi at idle, and 30-40psi by 2k. But that typically requires a high volume pump, and isn't always necessary but is a good safety margin yardstick.
05-26-2011, 11:57 PM
#8
4th Gear Member
Join Date: Jul 2008
Location: alabama
Posts: 1,812
It sucks the pan dry, it pumps so much more oil it dosent drain back to the bottom of the pan fast enough! (under wot)
A friend of mines experience was add a 7quart pan and dont worry anymore ofcourse after new bearings! He spoke with moroso after the fact and that what they told him.
A friend of mines experience was add a 7quart pan and dont worry anymore ofcourse after new bearings! He spoke with moroso after the fact and that what they told him.
05-27-2011, 03:20 AM
#9
6th Gear Member
Join Date: Apr 2007
Location: California
Posts: 10,468
That's complete nonsense that continues to be perpetuated(usually by companies or shops that want to sell you a more expensive pan). I ran a HV pump with a 5qt stock oiling setup for years and never ran the pan dry. If your bearings are worn out then you might run the pan dry, but that's because the clearance lets a lot more oil through due to a worn engine.
The oil pump simply CAN NOT pump more oil than the engine clearance will allow. Period. If it tries to, the pressure goes up...once it hits the relief valve pressure the relief valve opens and bypasses the oil before it ever leaves the pump. All a HV pump does is TRY to pump a larger volume of oil(due to a larger rotor)...which just results in higher pressure SOONER. It won't pump a larger volume of oil unless the engine clearances will let it through.
And running a pan dry because oil can't return to the pan quickly enough isn't an oil pump problem, it's an oil return pathway problem.
That said, it's usually a good idea to run a larger pan anyway on performance setups, since wet sump performance applications are a lot more prone to uncover the pickup under high cornering/braking/acceleration forces. There's a reason Canton's road race pans have a 9qt capacity, crank scrapers and a trap door baffle system.
http://www.mellingengine.com/Portals...lume-pumps.pdf Not that this is actually from a company that makes oil pumps, not a customer service rep from a company that doesn't make oil pumps.
The oil pump simply CAN NOT pump more oil than the engine clearance will allow. Period. If it tries to, the pressure goes up...once it hits the relief valve pressure the relief valve opens and bypasses the oil before it ever leaves the pump. All a HV pump does is TRY to pump a larger volume of oil(due to a larger rotor)...which just results in higher pressure SOONER. It won't pump a larger volume of oil unless the engine clearances will let it through.
And running a pan dry because oil can't return to the pan quickly enough isn't an oil pump problem, it's an oil return pathway problem.
That said, it's usually a good idea to run a larger pan anyway on performance setups, since wet sump performance applications are a lot more prone to uncover the pickup under high cornering/braking/acceleration forces. There's a reason Canton's road race pans have a 9qt capacity, crank scrapers and a trap door baffle system.
http://www.mellingengine.com/Portals...lume-pumps.pdf Not that this is actually from a company that makes oil pumps, not a customer service rep from a company that doesn't make oil pumps.
05-27-2011, 12:02 PM
#10
4th Gear Member
Join Date: Jul 2008
Location: alabama
Posts: 1,812
Well his was a fresh engine! lasted about a month and a half. I thought it to be a weird result but hey i`ve HEARD of stranger things lol.
I have a 5 quart on mine but have a standard pump.
The pump wasnt damaged, nor the shaft broken.
It didnt make a noise he drove home one night and the next day he tried starting it and it was seized!
the bearings wear mangled.
I have a 5 quart on mine but have a standard pump.
The pump wasnt damaged, nor the shaft broken.
It didnt make a noise he drove home one night and the next day he tried starting it and it was seized!
the bearings wear mangled.