Why a knowledgeable mechanic is key on our LT5s....

[-=Jeff=-]

Originally Posted by XfireZ51

I have a Low Oil light that tells me when I should be concerned.

1990 does not have that luxury.. 1991 and newer got some cool addons..

[Dynomite]

If you have good oil pressure (sucking no air) no matter the oil level.....
As long as the oil pick up screen is fully below the oil level at all times.
you should be good to go (Just that less oil means the oil heats up a bit more and wears out a bit faster).
That would be my guess

There IS an Oil Level Sensor on the 91'-95' ZR-1 Oil Pan.

The Oil Pan for 1990, 91 & 92 are interchangable with the only difference being, the 1990 LT5 engine was not equipped with a Low Oil Level Sensor. The extra material was cast into the pan but not machined for the screw-in sensor. As such, the oil level indicator would not be functional if the 1990 oil pan is used for 1991 & 1992 applications. Oil Level Sensor TIPS

[fred]

Originally Posted by Dynomite

If you have good oil pressure (sucking no air) no matter the oil level.....
As long as the oil pick up screen is fully below the oil level at all times.
you should be good to go (Just that less oil means the oil heats up a bit more and wears out a bit faster).
That would be my guess

Yeah, I think it has more to do with 212k miles than 3 qts low. Maybe if he really ran the piss out of it with it cold.... I wonder if that's Ron's old car.

[d15b7]

if he was cornering hard with 3 qts low it would probably starve for oil really badly. zero oil press for seconds at a time on high speed large radius turns.

on my road race cars (Lotus Super Seven and K24 powered Honda) we run 1/2 qt over full at all times to protect against starvation. at 1/2 qt low both starve very badly (and that's with baffled race pans). I'm positive that 3 qts low on an LT5 and she'd starve bad if driven hard

[Paul Workman]

Originally Posted by fred

Yeah, I think it has more to do with 212k miles than 3 qts low. Maybe if he really ran the piss out of it with it cold.... I wonder if that's Ron's old car.

Marc Haibeck had an LT5 torn down that was sent to him for a refresh after 175k miles - much of it on the track.

We were both a little astonished to learn that the bearings, tho worn, were actually within spec; could have gone some more before overhaul!

Testimony to good maintenance, no doubt. And, the Lotus LT5

[DRM500RUBYZR-1]

Originally Posted by efnfast

Seems odd that 3 quarts low out of 12 would cost you an engine. Something else is going on here.

You can bet the farm on that!

Marty

[Dynomite]

The Oil pump flow at Idle is 1.6 gpm and the Oil pump flow at 7,000 rpm is 9.1 gpm. That is 34.6 quarts per minute or about an oil pan full in 15 seconds.

I would take another guess.....if you rev the LT5 up to 7,000 rpm for a bit, the oil is pumped to where it is needed at relatively high flow rates but only gravity brings it back to the oil pan. What I am saying is that under high rpm oil is prolly pooled topside in the heads and elsewhere lowering even further the oil level in the oil pan.


d15b7 and fred seem to concur

Originally Posted by d15b7

I'm positive that 3 qts low on an LT5 and she'd starve bad if driven hard

Originally Posted by fred

Maybe if he really ran the piss out of it with it cold.

Engine Lubrication System Functional Discussion

I repeat myself here
If you have good oil pressure (sucking no air) no matter the oil level.....
As long as the oil pick up screen is fully below the oil level at all times.
you should be good to go (Just that less oil means the oil heats up a bit more and wears out a bit faster).
That would be my guess

There IS an Oil Level Sensor on the 91'-95' ZR-1 Oil Pan.

The Oil Pan for 1990, 91 & 92 are interchangable with the only difference being, the 1990 LT5 engine was not equipped with a Low Oil Level Sensor. The extra material was cast into the pan but not machined for the screw-in sensor. As such, the oil level indicator would not be functional if the 1990 oil pan is used for 1991 & 1992 applications. Oil Level Sensor TIPS

[Z51JEFF]

Doesn’t the system shut down if there is no oil pressure to prevent damage?

[Dynomite]

Originally Posted by Z51JEFF

Doesn’t the system shut down if there is no oil pressure to prevent damage?

Now that is a great question and would mean low oil would NOT damage the engine because that would be prevented with a fail safe low oil pressure system if that exists.....but would risk damaging the whole car if this happened in traffic....

Oil pressure on starting is zero so is a bit complicated....do other vehicles have a low oil pressure engine shutdown. That would be dangerous on the freeway just in case you forgot to check your oil for a long while or had an oil leak. But then again if you ran with zero oil pressure for a few seconds you would shut down anyway but with a lot of noise and smoke giving you a chance to move to the side or at least giving others a chance to see all the smoke

Some google Comments......

The oil pressure switch to the fuel pump is a safety feature. If the vehicle is in an accident that causes the engine to shut off or if the vehicle lands on it's side/top there's no oil pressure, so the switch opens turning the fuel pump off.

Ford uses an inertia switch for this safety feature.

A 1998 Oldsmobile had an oil level monitor and would shut down the engine if it decided it had no oil. And yes it was a very dangerous feature. I was driving rather energetically on a curving expressly ramp and plastered all the oil against the right side of the pan and it shut off the engine in the middle of the curve. Fortunately my arms were still used to driving tractor- trailers w/o power steering.

For liability reason's the OEM would rather replace the odd engine under warranty due to oil system failure than risk getting sued for the consequences of automatically shutting off the engine when the driver, for example, is about to cross a railway track with a train approaching.

[Ccmano]

It sold for $6500. Some else’s problem... errr... project now. Makes me feel good about the one I got with 180k miles for $6800 in fantastic condition! Ultimately they are all projects to one degree of anther.
H