ZR-1 Oil Change

[mlipmd]

You guys are inventing and trying to solve a problem that doesn't exist.
Fill vs. no fill.
It probably and practically makes very little difference.

If you watch this video (https://www.youtube.com/watch?v=zLBgIve1YzY) by the same guy, increased engine wear with having an unfilled vs. a filled filter in startup only happens with lower viscosity oils and does not happen with higher viscosity oils. And it would only happen for a few seconds anyway on the first startup after an oil change.

Either way, your choice, hopefully the anti-drain valve in whatever filter you choose, if you fill it first, will work, and you won't dump a large amount of oil all over the engine and the flloor.

[tf95ZR1]

I agree.
But some have even installed pre-oil systems.
In medicine the question is: "Is it really clinically
significant?" I think not.
That is one benefit of Z ownership. You can do
WHATEVER you want to YOUR car.
Unless you are in California.

T

[Dynomite]

There is also a lot of debate on Anti Drain Back capability in the oil filter.
Oil flows from the outside filter media to the center core.
In an oil filter review it is shown how much oil remains in the oil filter after 8 hrs.
I would ask "How much oil will the oil filter hold when new and saturated" to calculate a Drain Back efficiency.....

I am guessing....but after a week or 168 hours the oil filter will be empty......except for the saturated filter elements. I would guess that after 24 hours most oil filters will probably be empty or in such a condition that no oil will drip out of the filter when removed...... I use Mobil 1 M1-207 Oil Filters for that and other reasons......Obviously since drain back is by gravity the rate of drain back will decrease as the filter empties.

I assume the center core drains immediately and the anti drain function is related to the filter elements between the center core and outer part of the filter.

The Anti Drain Back valve is most often in the form of a rubber membrane adhering to the inner side of the spin-on filter cover. This membrane obscures the holes through which oil gets into the outside filter elements of the filter and returning to the oil pan through the center open core of the oil filter. The purpose of the anti-drainback valve is to prevent the oil from escaping from the filter when the engine is switched off..

I always let my ZR1 sit over night so that I do not have a mess when changing M1-207 oil filters. The LT5 engine can sit for a very long time without loosing oil where it matters (crank shaft, rod ends, rings).....

See.....Long sit before starting
By A26B 👍

I use AMSOIL 10W-40 Engine oil.

[A26B]

An empirical observation with unknown parameters.
About 20 years ago, I acquired about 25 LT5 engines. The engines were left over from development for production, testing & active handling. Most were complete, several had some degree of disassembly. None were properly protected or stored, just dropped into crates of various styles & condition. About 1995, the engines were shipped to GM in MI and unceremoniously put in a big warehouse.

I disassembled a number of the engines for inspection of rod bearings. All still retained ample oil in the crankshaft/bearing interface, to suffice for startup, after +- 10 years.

To the best of my knowledge, synthetic oil was not used during development. I mention this only in reference to the difference in cohesion or surface tension that may exist between oil types & viscosity parameters.

In my personal opinion, bearing lubrication is not detrimentally affected to any significant degree at startup.

Bleed down of hydraulic secondary chain tensioners results in some rattle at startup, but has not been found to cause any damage in the long run. GM did make a 2nd design Tensioner Housing to help alleviate the chain rattle. Whether it significantly affects rattle, is best answered by those who have installed the 2nd design Housing. Following, is a link to the 2nd Design Housing manufactured by and available through Jerrys Gaskets.

https://www.jerrysgaskets.com/housin...ign-90-95-1g3/

[Dynomite]

Thank you Jerry......I specifically cited that in my post above

See.....Long sit before starting

That is great information from EXPERIENCE

[Dynomite]

Originally Posted by tf95ZR1

I agree.
But some have even installed pre-oil systems.
In medicine the question is: "Is it really clinically
significant?" I think not.
That is one benefit of Z ownership. You can do
WHATEVER you want to YOUR car.
Unless you are in California.

T

See......California Law On Modifying Engines

[Great White]

I've always thought that starting a cold engine before an oil change to "stirr the gunk around" was a silly idea...

If you must do an oil change on an engine that must run before changing the oil (for example to move the vehicle onto a lift,) get the oil up to operating temp first. When I say that, I don't mean idle it up to temp. Starting a cold engine, running it for a few minutes till the coolant has some heat in it, and shutting it back off is pointless. It won't burn off any of the contaminants in the oil! If you are worried about junk in the bottom of the pan, pour a new "chaser" quart of oil in after draining but before you put the plug back in.

Secondly, it takes forever for an LT-5 to 'drain back' after it has ran (I'm not talking about the filter.) This means more used oil will be circulating after the oil change if you don't give it enough time to drain. The engineers clearly didn't want anything starved for oil.

Filling up a filter right before you tip it upside down is counter intuitive. 99% of Mazda wankels have vertically challenged oil filters just like our LT-5. Among the issues they are known for, bearing failure actually isn't one of them. Neither is oil pump failure. Nowhere in any oil change instructions for those engines is there any inclination that the filter must be filled before installing. It doesn't matter in this case. If you want to pre-fill your filter, knock yourself out... Have fun cleaning up the mess afterwards! If you still can't stand it, relocate the filter.

Last... If you really want to do yourself a favor and go the extra mile on your LT-5 oil change, don't forget to drain the cooler. A filter magnet might be a good idea too.

Sorry for writing a book.