ported ls6 pump only 48 psi wot!

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Jun 1, 2009 | 06:47 PM

STAR

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ported ls6 pump only 48 psi wot!

Hey guys, need some suggestions and opinions on what I should do. I have a fully built forged motor and I'm using a ported and shimmed ls6 oil pump. At cold idle I see 49 psi pressure and 220 degrees hot I see 24 psi at idle. Problem is oil pressure does build with rpms, but maxes out at 48 psi at anything over 5000 rpms. This scares me as I want to pull the motor to 6500-6800 rpms. Why does the pressure not increase anymore? Any suggestions?

Jun 1, 2009 | 07:09 PM

dre2013

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o-ring seated properly? and have you verified these numbers on a mechanical gauge? my stock oil pump with 140k on it holds 40psi warm idle..

Jun 1, 2009 | 08:43 PM

Marc 85Z28

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From: MD

While you may still have a problem, 48psi is plenty of pressure for 7000rpm. 24psi at idle is also more than adequate.

Jun 1, 2009 | 08:57 PM

bigboykilroy

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I use the old rule of 10 psi per 1000.
I love my meling pump.

Jun 1, 2009 | 09:14 PM

98Aggie

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Is this a new motor - never run before?
What are your bearing clearance set at?

Jun 1, 2009 | 10:06 PM

STAR

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Quote:

Originally Posted by 98Aggie

Is this a new motor - never run before?
What are your bearing clearance set at?

Yes its a new motor that has about 600 miles and everything seems fine. I think the mains are at .002 and the rods at .0025 if memory serves me corrrect.
Considering upgrading to a melling 296 pump.

Jun 1, 2009 | 10:07 PM

05 GSXR 1XXX

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pinched o ring?

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Jun 1, 2009 | 10:30 PM

STAR

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Don't know if the o-ring is pinched until I take it apart, but I doubt it. It seems like I'm bleeding off pressure somewhere? Or just simply the oil pump is not providing enough volume?

Jun 1, 2009 | 10:33 PM

#10

bigboykilroy

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I wouldnt run an engine at 7000 with 48psi, go with the Melling 10296 Oil Pump.
also make sure the oil pressure sending unit isnt damaged, test the pressure with a mecanial reader to be sure of the pressure.

Last edited by bigboykilroy; Jun 1, 2009 at 10:45 PM.

Jun 1, 2009 | 10:39 PM

#11

bigboykilroy

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actually after thinking,,,,,if it wont build pressure over 48 psi i bet the pressure blead off spring is defective (in the oil pump)
mechanical test then order a Melling 10296 Oil Pump to replace it.

Last edited by bigboykilroy; Jun 1, 2009 at 10:46 PM.

Jun 2, 2009 | 09:43 AM

#12

muayyadf1

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try to change oil + filter

Jun 2, 2009 | 10:03 AM

#13

bigboykilroy

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Quote:

Originally Posted by muayyadf1

try to change oil + filter

Yes I forgot about that as well, if its a fram get rid of it !!

I only use Napa gold (Wix)

Jun 2, 2009 | 07:47 PM

#14

SweetS10V8

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Quote:

Originally Posted by bigboykilroy

I wouldnt run an engine at 7000 with 48psi

You would be surprised how bad things have to be for an engine to die. 3v fords only have about 35psi at 7000 RPM.

Ive also run ZZ4s to 7000RPM at 25psi and never had a problem, even tore apart the bottom end and all the bearings looked perfect.

I would find out if indeed it is possible to have a mechanical bleed off, or if something is wrong causing it to bleed.

Jun 2, 2009 | 07:58 PM

#15

Super Speed

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Try running a thicker oil if you want more PSI...

Jun 2, 2009 | 08:01 PM

#16

Breathing Fire

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Try the easy stuff first. Change oil and filter. I used a fram once because my usual ac delco was out of stock that day. Lost 15psi of oil pressure. Fram=****!