[heavyhaulerss]

Originally Posted by YerDaddy

All you guys worry yourself bald about oil and samples and miles and filters but... how many of you have made your own prelube system like me to fill the oil galleys with oil at positive pressure before cranking the engine?
Synthetic or dino when you crank that engine with zero oil pressure you are giving it the most wear it will have all day.

can you elaborate? what is a prelube sys? how is it made? how is it applied? thank you.

[YerDaddy]

Originally Posted by heavyhaulerss

can you elaborate? what is a prelube sys? how is it made? how is it applied? thank you.

I bought a 12V pump made for circulating hot oil. It sucks oil out the pan and pumps it into the oil galleys. I have a toggle switch on the dash to turn it on/off. Inline between the pump and engine I installed a "T" fitting with a ball valve, another ball valve, a one way valve and a 100 micron screen. For line I just used braided fuel line 3/8" ID and Parker fittings. I want to buy a stronger pump and will have to use larger lines. Not in the budget right now.

No more does the engine start running before the oil makes it's way to the top end.

As a plus, the ball valve that runs off the "T" is what I attach a hose to when I do oil changes. Shut the ball valve going to the engine, open the valve on the "T" and turn on the pump and neatly fill 8-1/2 gallons of used oil into jugs. Then remove oil pan drain plug and drain what's left below the prelube pick up fitting level.

[Musicman]

You can buy systems that do the same thing... they are called "Pre-Oilers" and the majority I know of use a spring loaded plunger to inject a few (or maybe a couple) of quarts of oil into the system just prior to start-up.

I'm not knocking them, and certainly not knocking YerDaddy for his ingenuity in making his own; but I've often wondered just how much wear really takes place in those very brief few seconds at start-up where there is (theoretically) no oil pumping through the system. My thinking is that the oil pumps are gear driven, and since they are placed at the lowest point in the oil pathway, they should keep oil "loaded" on the pressure side of the pump when the engine is shut off, and start pumping oil with the first revolution the engine makes. Therefore, the moment that you begin cranking your engine, that oil should begin pumping through the system and lubricating all those expensive parts. Keep in mind that when you are cranking your engine, it isn't under load and it isn’t being cranked at high rpms where real friction and heat would build up. I'm sure there is some (on a microscopic) level of wear, but really how much is the question. I have considered installing a pre-oiler but I just couldn’t convince myself that I would see any ROI.

On a different note, I switched from Rotella T dino oil to Valvoline Premium Blue Extreme Full Synthetic and my economy has gone from 6.8mpg to 7.29 over the last 30k miles… no kidding. I’m really kicking myself for not trying this before. I knew you were supposed to see a small increase in economy, but I never expected what I’ve been seeing. Anybody else out there experience that big a jump in economy after switching to a full synthetic oil?

[YerDaddy]

I've heard my whole life that most wear takes place on start-up before oil pressure builds. From experts and non-experts alike. It makes perfect sense to me.

I have a mechanical CAT and it fires in less than a second (in the summer) when you crank the starter. It will run about two seconds before the oil pressure gauge jumps into action and the engine rpm drops as the oil pump meets resistance when the oil galleys are full and at pressure. When I run the pre lube pump for a minute first, there is no two second interval of no pressure; pressure is immediate.

Think about a garden hose at full blast. That is a good comparison to how much oil flows inside the engine.
Now think about the engine sitting all night, oil dripping into the pan. How dry do you think the bearings are? If you had a choice would you want to grind metal against metal for 2 seconds every day or would you take steps to minimize this situation? Personally, I chose to limit the damage. I should mention those days were we start and stop the truck 20 times while waiting in a moving line. Lots of wear.

CATs are designed to pump oil directly from the pan, bypassing the filter until oil pressure closes the spring valve and oil starts to flow through the filter. It would take precious seconds to wait for the oil to make it through the filter if there were no bypass valve. Obviously, the guys who designed these engines know that immediate pressure is more important than filtering every drop of oil.

Just stating my reasons for doing what I do. Everyone else is free to treat their equipment as they see fit. Not my problem.

[Musicman]

Originally Posted by YerDaddy

Just stating my reasons for doing what I do. Everyone else is free to treat their equipment as they see fit. Not my problem.

As I stated before, I’m certainly NOT knocking you for your ingenuity or initiative. I simply said that in my research (and admittedly I’ve not put tons of time into it, but I have looked into the matter a little) I couldn’t convince myself that a pre-oiler or a bypass filter would give me enough ROI to make the investment worth it. If somebody gave me a pre-oiler would I put it on? Sure… why not… it couldn’t hurt, right? I’m just not convinced that spending money on either of the two systems is worth it to me.

My ’06 ISX shows oil pressure the very instant I start cranking it, and at those very low rpms, and over such a short time, I’m just not convinced that a pre-oiler is needed. Look, all of the oil doesn’t drip away anyway. There is still a very thin film of lubricant left even if the engine sits for a month. Couldn’t that be enough to keep my engine from committing Hara Kari in a second or two at startup?

Now let me really get things stirred up by saying that IMHO both pre-oilers and bypass filters make more sense than running wide bias tires.

[Copperhead]

The pre-oiler idea sounds neat, but not sure it would be that good of an ROI for me either. I took a '96 N-14 to 1.4 million without opening it up and it still got 7 mpg average and used only a gallon per 8,000 miles. The pre-oiler concept is probably a good idea, but there are a LOT of factors that go into engine wear. One could have a pre-oiler and still need an inframe at 600,000 miles if they beat the engine to death. A good bypass or a centrifuge will probably do more to decrease wear in the long run than a pre-oiler, as will replacing the crankshaft dampner at roughly 500,000 miles like Bruce at PP suggests. Even with a pre-oiler, I would replace the dampner.