Numbers on oil pressure gauge

[Huib Geurink]

Does anybody know what the numbers on the oil pressure meter mean?
Some of my Fulvia have 0 - 25 - 50. Some have 0 - 30 - 60. I think my S3 coupe even has 0 - 35 - 70.
Are these psi? Then 50 would be 3,5 bar. A bit low I would say.
Are the figures bars? If true the oil filter would be blown off.
Or tenths of a bar?

I hope someone can solve the mystery.

Note: Fram oil filters get blown off occasionally anyway

[Leonard Zapala]

YOUR OIL FILTER BLOWS OFF!!!! That must be exciting at 120-130 kph! I have used a FRAM HP-1 for years. (it is my understanding the FRAM made these filters for Ford's SHO V-8 which ran at higher pressures) They are larger than the filters listed on the web page's Fulvia tech information. I have never had the "drama" of one blowing off.

[Jan Vos]

Hallo Huib,

It is a very interesting question, and I hope to hear the answer.
I have looked into some manuals, and a standard off oil pressure is kPa ore kg/cm2
Which means minimum pressure ( when the oil pressure light is burning) about ƒ¬ 15-45 kPa (0,15-0,45 kg/cm2.
At 2000 min-1 the pressure is at least 200 Kpa ( 2.0 kg/cm2)
These figures are from VW

A table of pressure is:

Bar mbar Pa kPa Mpa kg/cm2 psi

Bar = 1 1000 100.000 100 0,1 1.01972 14.5038

None of these pressures seems to match with the numbers of the oil pressure instrument.
Only psi but in those days we have metric as far as I know and only in England and America they worked with Pound/Square Inch

Greetings

Jan Vos

[Andreas]

Dear Huib,

there is a popoff valve inside of the oil filter block (Alu part ) as you sure know.
Maybe it is (was) blocked.

best regard

Andreas

[Huib Geurink]

Do you mean the maximum oil pressure valve screwd in from the side?
I have never understood how that could work. Do you?

BTW, I have the story of the FRAM filter being blown off from hearsay

[giancarlo]

Fulvia prescriptions for oil pressure at 90° temperature say: at least 0.4 to 0.5 kg/cm2 at 800 rpm and at least 4-5 kg/cm2 at 4500 rpm. From this, one may deduct that the meter indications are kg/cm2 /10, that is, hg/cm2.
This is my guess.

[Leonard]

In Wim H. J. Oude Weernink's A COLLECTOR'S GUIDE: LANCIA FULVIA & FLAVIA, he states in chapter nine, "The mark "35" means 3.5kg/cm2 (squared) (50 psi) pressure..."

[Huib Geurink]

Thanks Giancarlo and Leonard!

[Andreas]

Yes this is it, what i mean !

If I understand this valve well, the spring inside gives the force to close the by-pass with a disc
under the sping.If the pressure is higher then the force (" => pressure " ), it open and the oil goes
bag in the oil-sumpf directly.
That´s all.

If you use a wrong oilfilter or you use an old one to long, the resistance for the oil to pass the
filter get´s to high.The pressure will be increase then for sure.And in this case this valve should
open to aviod a blowoff of the filter.
And who know´s whats going on the spareparts selling it would be not a surprise
to have a wrong filter with to high resistance undepent what´s written on the box.
They trying alway the unification of parts to save variants and money.


bye and best regards
Andreas

[Huib Geurink]

Andreas,

I figured that myself. There is a small cilinder under the spring.
However the whole regulator is screwed into a hole with a rather large diameter. Wouldn't the oil just flow around it instead of pushing against the spring loaded valve?

At the bottom of the hole there is a seat. The distance from the top of the hole to the seat is equal to the distance between the mounting base of the regulator and its tip. However when the 2mm thick fibre washer is put under the mounting base the tip of the regulator remains 2mm short of the seat.

When I look again into the hole, I notice it has a smaller diameter at the lower half. Unfortunately I do not have the tools to compare this smaller diameter with the diameter of the collar around the tip of the valve. Since we do all sorts of efforts te reduce the clearances of the oil pump to microns to have good flow and pressure, I wonder what the clearance is between the collar of the regulator and the bush down in the hole.