Cam variator oil system, pre lubing?

[boomerang]

As my Gransport only very rarely runs, (last year due to circumstances not ONE mile) i was wondering if it would be wise to add a pre lubing system to the engine.
Especially, while the cam variators made some noise for 1-2 seconds, when i started her for the last time, more then a year ago.

Plan is to add a small 12 V hydraulic pump, surging from the oiltank, priming the oil lines at the accumulator of the variator circuit.
Off course there wil have to be a check valve added to the oil line, to prevent oil flowing back through the pump when the engine is running.
I removed the right hand oil line from the cilinder head and not one drop of oil could be found there.
So, certainly after a year not being used, these lines drie up completely.....

I am thinking of adding a second line to the oilfilter housing, this way priming the main oilcircuit via the oil filter, at the same time.
The oil pressure regulation valve in the existing oilpump, will top of maximum pressure to ca. 5 bar, as it allways does, thus preventing oil pressure in the variator circuit going up to high at the same time.

What do you guys think of this plan?
As some people state, it are especially the cars that are standing for longer periods, that tend to suffer variator problems at a lower milage...
Apart from that; it seems quite nice, to see the oil gauge rise up to 5 bar, before you even start the engine.

Interested to see your thoughts!

 

[mjheathcote]

http://www.accusump.com/

However isn't it not possible to start her every couple of weeks/monthly and allow to idle to working temperature, even if not driving her?

 

[boomerang]

Thanks, interesting website!

There are a lot of technicians that do not advise starting/idling an engine, only running to normal temperature without any load.
And indeed, everyone allso knows, that wear is at its max, starting a cold engine.
But maybe its still the best of two bad situations indeed.
Till now, i only started an engine if there was an opportunity to run it on the road for at least half an hour.

 

[boomerang]

Ok, at this moment i am testing the prelube system on my car.

The engine did not run for nearly a year now and after the first test, promissing results can be mentioned!
I primed the pump with a temporary external 12 v power supply.
Ignition on; the needle of the oil pressure gauge wandered towards 3 bar.
I then started the engine and it was quiet from the first moment on!
(New oil and a new filter of course)

The oil line enters the cam circuit at the RH oil line into the cilinder head.
I added a 0.5 bar checkvalve in this supply line, preventing (the higher) oil pressure from the secundairy pump, leacking back to the electric pump when the engine starts running.

A second input was made at the oil pump housing, at the oil filter input.
By doing this, max pressure is topped of by the pressure regulator valve inside the main oilpump, preventing over pressurizing the cam circuit.

Some pics:







As you can see, there is a dot of toilet paper under the new oil input.
It was there to suck spilled oil;
I was very curious to find out, how much time it would take, to fill the accumulator circuit.
Allready after 3 or 4 seconds, oil dripped out of the slightly loosened oil line from the accumulator.

Filling the main oil lines of the engine, brought there by the second oil line, takes about 15 seconds or more, depending on the oil temperature/viscosity.

All in all, my goal is achieved; even a "dried" cam variator (and main engine) oil circuit, can be filled and pre pressurised in less then 30 seconds, just by pressing a button!

 

[alfatwo]

That's a very good idea for any engine.. lots of race cars use similar system's

As you obviously know the veriator's rattle due to no oil pressure..

Dave

 

[metorical]

I'm very interested in this, as my GS has a rattle more often than not on start, even when warm. Occasionally it will start without a peep. Is the electric pump onboard? or do you only plan to prime the system externally?

 

[boomerang]

Yes, the electric pump is on board.
It is placed very near the bottom of the oil tank.
At this moment i am placing a small relay and a fused powerline from the starter motor.
I am thinking of taking the unused starter contact in the Gransport ignition switch for activating the relay/pump. (As the Gransport uses the start button at the center console)
You could then turn the key as if you would start the engine, but in fact just activate the electrical oil pump.
Immediately after priming the oil line, you could start the engine as usual.
i will take a picture later on, to give you an idea how i mounted things.

 

[boomerang]

For those of you who had some questions;

Here you can see where the oil is taken from the sump, an existing plug was taken out and replaced by a fitting 90 degrees hose pillar.

Here you can see the front of the oilpump, mounted with small rubber studs under the oil tank.

The unused contact, used for activating the startermotor in 3200/normal 4200, was taken for activating the oil pump relais.
The relay and its fuse had plenty of space in the existing relay box at RH wing side.

 

[hladun]

A few points

It's not the variators you want to pre lube it's the shell bearings on the crankshaft and cams.

The sump may or may not have enough oil in it to pre lube the engine. This is a dry sump engine so very little oil in sump.

You have to be careful that the pre lube system doesn't become a bleed once the main oil pump kicks in. You can be lowering the engine oil pressure.

The cold start knocking is most probably the hydraulic lifters. They drain when the engine sits but there's no harm.

 

[boomerang]

A few comments to that:
It realy are the variators that i want to provide with oil before starting the engine, because the cam variator oil circuit, looses oil quite quickly.
Oil certainly is lost there after a few months standing.

The sump has more oil available than one would presume; it is the main oil pump that is taking oil from it as well, via the three suction filters, items 5,6.
( http://www.eurospares.co.uk/parts/maserati/4200-gransport-2005/cooling-heating/water-oil-pump-28170 )
You can see one of them here:

It became clear that the electrical pump was able to empty the tank quite fast, filling the engine sump with way too much oil.
(Circulation over the oil tank only starts when the engine is running!)
So if you would suck form the tank and would prime the pump too long, the complete oil tank would be emptied in the engine, without flowing back to the oil tank!
This is why i moved the input for the pump to the lowest point of the engine sump.
When i primed the pump for a longer period, just for testing, i could hear the oil dripping down in the sump again, then being sucked up again etc.etc.


There are checkvalves integrated in the oil lines, so no oil pressure is lost when the engine starts running.

The cold start rattle, after a long period standing, is definitely not the lifters (i know how they sound), it is clearly audible at the variator housings for one or two seconds.

 

[hladun]

It's your engine, good luck. But do you know what a scavenge pump is?

 

[boomerang]

Indeed, thanks and yes, i know.
Don´t worry; there is oil pressure before i even start the engine, Variator rattle is gone, oil pressure warm at idle 2.5-3 bar.
All is fine.

 

[conaero]

We watch with interest Boomerang.