oil starvation issue on lm7

Reply Subscribe

Thread Tools

Search this Thread

Oct 19, 2017 | 05:06 PM

chejos13ls1

Thread Starter

Staging Lane

iTrader: (4)

Joined: Jul 2009

Posts: 81

Likes: 0

From: el paso tx

oil starvation issue on lm7

Hello, i have an 05 lm7 swapped into a 93 300zx with a turbo in the car. At first i just installed the stock engine into the car to see what i'll do, ended up with a spun bearing after a couple of weeks of beating the car. I figured it happened because of the unknown milleage of the engine plus the stress from the turbo. So based on that, i did new clevite bearings, new meilling pump and not so new but std size crank. So i did about a week of tunning/testing at about 8 psi and i just heard a bearing again. Is there anything that im missing on this set up for a propper lubrication? I always have at least a quarter of extra oil in the pan and the return for the turbo is on the front timing cover if it matters. Thanks

Oct 19, 2017 | 06:20 PM

G Atsma

TECH Senior Member

Joined: Jun 2016

Posts: 22,295

Likes: 3,617

From: Central Cal.

It bears repeating- Was the oil pump pickup O-ring properly installed?
ALSO all gallery plugs in the block?

Oct 19, 2017 | 06:32 PM

chejos13ls1

Thread Starter

Staging Lane

iTrader: (4)

Joined: Jul 2009

Posts: 81

Likes: 0

From: el paso tx

I'm going to do the disassembly on the weekend, i want to know what to look for. I'll get some pictures.

Oct 19, 2017 | 06:39 PM

G Atsma

TECH Senior Member

Joined: Jun 2016

Posts: 22,295

Likes: 3,617

From: Central Cal.

Yeah if you had 8psi max, there IS a problem. Likely something I mentioned above, would be surprised if different. BUT you never really know until you KNOW.

Oct 19, 2017 | 06:56 PM

Old Geezer

TECH Senior Member

iTrader: (3)

Joined: Jun 2004

Posts: 5,639

Likes: 71

From: GA, USA

Quote:

Originally Posted by G Atsma

Yeah if you had 8psi max, there IS a problem. Likely something I mentioned above, would be surprised if different. BUT you never really know until you KNOW.

I think the 8 psi may be reference to boost?
I am wondering what the oil psi was, before the last failure.

Oct 19, 2017 | 09:21 PM

G Atsma

TECH Senior Member

Joined: Jun 2016

Posts: 22,295

Likes: 3,617

From: Central Cal.

Quote:

Originally Posted by Old Geezer

I think the 8 psi may be reference to boost?
I am wondering what the oil psi was, before the last failure.

On second thought, you are probably right! Had the blinders on....
But yeah, a note about where the OIL pressure was would have been nice.

Oct 19, 2017 | 09:55 PM

chejos13ls1

Thread Starter

Staging Lane

iTrader: (4)

Joined: Jul 2009

Posts: 81

Likes: 0

From: el paso tx

Yeah im talking about the turbo psi, my oil pressure was right at 40 on start up and about 65-70 on light cruising. As far as i know that about average for a gen 3 engine.

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Verdad Gallardo

6 Common C5 Corvette Failures and What's Involved In Repairing Them

Pouria Savadkouei

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Verdad Gallardo

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Pouria Savadkouei

Top 10 Most Powerful Chevy Trucks Ever Made!

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Verdad Gallardo

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Verdad Gallardo

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Verdad Gallardo

10 Camaros You Should Never Buy

10 LS Engine Myths That Refuse to Die

Verdad Gallardo

Oct 20, 2017 | 09:14 AM

chejos13ls1

Thread Starter

Staging Lane

iTrader: (4)

Joined: Jul 2009

Posts: 81

Likes: 0

From: el paso tx

I had a local machine shop do the short block and i just did the top end. im going to open it up in saturday to see what's up.

Oct 21, 2017 | 07:10 AM

#10

Old Geezer

TECH Senior Member

iTrader: (3)

Joined: Jun 2004

Posts: 5,639

Likes: 71

From: GA, USA

" right at 40 on start up and about 65-70 on light cruising. As far as i know that about average for a gen 3 engine. "

Not close, unless the system has been modified.

Oct 22, 2017 | 09:57 PM

#11

chejos13ls1

Thread Starter

Staging Lane

iTrader: (4)

Joined: Jul 2009

Posts: 81

Likes: 0

From: el paso tx

Quote:

Originally Posted by Old Geezer

" right at 40 on start up and about 65-70 on light cruising. As far as i know that about average for a gen 3 engine. "

Not close, unless the system has been modified.

when you say not close, do you mean that it should be higher or lower?

Oct 23, 2017 | 08:32 AM

#12

moekluse

TECH Enthusiast

iTrader: (2)

Joined: Nov 2015

Posts: 543

Likes: 4

From: Nc

Quote:

Originally Posted by chejos13ls1

when you say not close, do you mean that it should be higher or lower?

those pressures sound very good. My newly rebuilt ls6 with a SLP ported pump runs about 49 psi idle

Oct 24, 2017 | 09:20 AM

#13

RockinWs6

TECH Addict

Joined: Mar 2013

Posts: 2,628

Likes: 30

Who put the bottom end together? What were the clearances? Was everything checked with mics? A lot of people use plastic gauge then wonder why the bottom spins a bearing.

Oct 24, 2017 | 12:30 PM

#14

BlwnLs1GTO

TECH Enthusiast

iTrader: (12)

Joined: Mar 2006

Posts: 577

Likes: 8

Quote:

Originally Posted by chejos13ls1

So based on that, i did new clevite bearings, new meilling pump and not so new but std size crank.

This raises a flag for me. What do you mean by this? Was it machined at all? Polished or anything? I'm curious if it's the same cylinder that spun. A spun bearing can ruin your main caps and bore. Did he check this or line hone the bottom end?