[B767capt]

Well I couldn't leave well enough alone after I installed my digital oil pressure gauge. My next project that I've done is an oil prelube system. Sends oil under pressure to the main and rod journals before the crank turns. Will it help with our rod bearing problem on cold starts? Who knows but for the price of a sprint booster, I bought one to play with. Looking around it seems like large industrial engines and some race engines use this. After a search I found one that has several size bottles to hold the precharged oil under pressure. The problem with our cars is where to install it. I bought the 3rd largest kit which has a bottle that is 4.25" x 11.0". The only port I know of to install it into is the oil pressure port on top of the oil filter.

This system has a timer on it so when you turn the ignition on (foot off the brake so the motor won't start) a solenoid opens and the bottle that has 2 quarts of oil in it under pressure, discharges this oil into the engine. The timer leaves the valve open for 30 seconds then closes and only allows oil now to flow back wards into the bottle under normal oil pressure and maintains the highest pressure achieved during the engine run. In our case that's almost 90 psi while the cold start is running. IOW the solenoid valve turns into a one way check valve. The next time you start, it opens and discharges the oil. I hit the start button about 5-7 seconds after discharge to start the motor.

A perfect place for the bottle is on top of the chin bubble that's under the car. There is a ton of room in that area and the bottle doesn't hit or touch anything. If the bottle is to be mounted horizontally like I have it, there is a rubber hose you install in the tank so it will push all of the oil out during discharge. This system requires you to add 2 extra quarts of oil. That's been verified with my oil level indicator reset. When you go to change the oil, you just discharge the bottle without starting the engine so it will go to the oil pan to be drained.

I mounted the solenoid under the right wheel brake cool duct.

I verified operation with an oil pressure test gauge mounted on the bottle side of the solenoid. I trapped 83 psi in the bottle and it stayed in there for several hours without losing any psi. I turn on the ignition and the bottle pressure drops to 15 psi quickly. Will this help? Who knows but it was fun.

The last 2 pictures show the oil psi with the car at a cold idle. The blue test gauge stayed at 83 psi for several hours with the car shut off. Works as advertised.

 

[FastHackem]

Freaking AWESOME idea Capt! I love BMW forums man. We just traded our E46 and got a Hyundai Santa Fe, the forums SUCK for Hyundai!! Would NEVER see something like this on there.

 

[talbotmick]

Brilliant. DIY please!

 

[jcolley]

I wondered when you'd take the wraps off this project Bill. Well done.

Let me know if you're interested in being the guinea pig for my VANOS redesign.

 

[Hasan Shaikh]

I don't understand how this would help. Throwing oil at the bearings would not help. We need something to make the oil flow through them.

Or have I misunderstood the concept.

 

[Braheem24]

I have questions to pose,

Do most people feel most bearing wear happens at low or high rpms? If High RPMs, This I would assume would not help since this is a foreplay lube.

I'm under the assumption the bearing wear happens at 8K. The only way to know for sure is to look up other cars with the same clearance as ours that have a 5-6K redline and examine their bearings.

 

[Hasan Shaikh]

In my opinion most of the wear occurs on cold starts.

For a fair comparison we would also need to consider the oil viscosity.

 

[Braheem24]

This is a question as much as it is a reply.

If it is cold starts, 0W-40 would have resolved all the issues, therefore no need for this device, Correct?

 

[Hasan Shaikh]

This is what I said in my earlier post. Oil sitting in the engine will not do anything. It has to flow, and for that it needs to be the right viscosity.

 

[Hasan Shaikh]

0W-40 will help on cold starts. But will it have the film strength at over 8000 rpm.

 

[ticat928]

A pre-lube / acumulator oiler has just as many benefits at 8,000 rpm.

You understand that when driving around a track the reality is the crank does not constantly see 80 psi at 8000-rpm it fluctuates a lot if your tire alignment combo is capable over 1.2 G's in turns. These kind of G's trap oil in the heads since the lateral loading exceed the gravity that normally drains the heads. To deal with this BMW installs pumps in the head that actively force oil back to the pan.

Meanwhile at 8000-rpms there is hurricane going in the crankcase; spray from piston coolers and oil squirting out the sides of rod bearings creates a lot of oil mist and aerated oil in the pan, if the remaining oil level in the pan is not sufficient some aerated oil will reach the oil pump pick up.
this causes pressure drops and intermittent loss of hydrodynamic lubrication.

It also causes the cavitation damage I have seen in bearing pictures (where a portion of a bearing material is peeled or blown away by the imploding air bubbles).

The pre-luber accumulator would provide 80-psi oil pressure directly to the pump when pressure drops occur, thus if you have a data logger instead of wild swings in oil pressure spiking up and down on a graph you would see a near constant pressure proportional to engine speed.

This is also how it is done on a fuel rail an accumulator takes the fuel pump pulsations right out of the eqation allowing accurate measured injection cycles.

Of course a proper dry sump system would make oiling issues during track days a non event, one typically has a 3 to 5-stage vacuum pump that practically eliminates all airiated oil and mist from the crankcase. a 12-gal tank allows time for airiated oil to settle out trapped air such that the oil sent back to the pump is completely clean of any trapped gasses.

I would get a 3+ quart pre-oiler / accumulator install it horizontally but tilt up the non feed end of the pressure vessel to accumulated any oil/air mix, there should be a purge valve at that end as well to release any air after track session.

 

[Hasan Shaikh]

Thanks for sharing the information. I thought it worked only before the engine started.

What effect will it have on oil temps. Especially while cruising on highway.

 

[ticat928]

The accusump accumulator and pre-oiler Canton Racing Products has no effect till oil supply is interrupted.

A lighter weight oil is much more efficient at removing heat from the crankcase and pistons vs a heavy oil.

However if you have an M6 that had maximum oil change intervals by the first owner, the bearing clearances are likely to be twice the factory spec.

Thus need 10-60w to attain any kind of oil pressure.

If you are the original owner and have miles on the bearings stick with 10-60w as well

Only use 0-40w with brand new bearing replacement.

 

[sjsuM5]

This is great. How long did the install take, how much for the parts?

 

[B767capt]

Engine Pre Lube System Insta-Lube Kit

I got the C kit. Fred is the point of contact with email and phone. Great support and easy install. Could do it inside an hour once you know where the tank will go.

 

[Tortuga]

I like this, really like this BUT:

If the hose ruptures will you lose oil? The solonoid only opens pre-start? Only opens for a pre-determined time after powering up? So you get in power it all the way up without touching brake, oil primes, then hit brake and start? And if somebody drives it who doesn't know about the system guess its fine it will discharge until engine oil press overcomes bottle pressure?

I also wonder about the location, chesse that chin plastic and 2qt mess?

BUT the concept is brilliant, a mod i can get behind!