oil pressure

[Elmolino]

I have a 72 GTV that seems to have too much oil pressure. With a mechanical gauge, it has 50psi at idle (hot) and 75psi at revs. I took the oil pump out and checked the relief valve, and it was not stuck and seemed to be in good condition. Is there a problem with this amount of oil pressure?

[alfazagato]

Sounds very good and similar to what I have on my 2000 Spyder on a mechanical gauge. On the car's instrument the pressure shows the needle thickness over 57 lbs at revs and just under at about 40 at tick-over.

[Elmolino]

well, at least the oil pressure is not too low! Should I worry about it or drive it and forget about it?

[Peter]

sounds fine to me

[han]

the alfa guages are not the best there are, if you whant too know for sure let it be measerd by a garage.


that is the only way and so long your oilwarning light is working ok than you now that you are not running too low.

wenn you use a veglica sender on a yaeger guages you get also very strange
readings and the ather way around, one is high and the ather low


.

[Mick Westwood]

Indicated 50 at idle and 70 at higher revs on my 1750 GTV. Can't be all wrong and after recent engine rebuild the garage was very happy with it, so just be pleased it is not too low!

[George Willet]

What is the weight of the oil you are using?

[Elmolino]

I am using 20/50w. I tried using 10/40 with this car, but it burned too much oil (clouds of smoke!). The pressure was taken on a new after-market mechanical gauge.

[George Willet]

You must have another problem with 10w40 oil causing smoking. We race with 10w30 oil, and no smoke.

The engines were designed to run on 10w40 oil from the factory. with 7 quarts of 20w50 in an aluminum engine you are way to thick on viscosity, thus high indicated oil pressure.

And what is the ambient temperture when you are taking these tests? I note you don't give us all the info that might be necessary to make a reasoned diagnosis, like where you live and what the temps are there.

[Elmolino]

The engine has good compression and runs strong but seems to need valve guides/seals and or rings because it burns tons of oil. I live in Northern California and the ambient temp was around 70 degrees. I was hoping that some of the oil burning was a result of high oil pressure, thats why I took the pump out to check the relief valve.

[alfazagato]

George,
As a matter of interest my '76 Spyder factory handbook gives 10w50 as the oil viscosity, my '71 GTV book 20w50. My GTA handbook is silent on the subject of oil but my GTA registers 75 lbs plus at speed on its mechanical gauge and on 20w50. I am using 20w50 in the Spyder in temperate London and in driving to the heat of the South of France there is no appreciable change in indicated pressure.
In London ,especially, traffic is such that oil temperature quickly rises and immediately drops off the gauge when running at even low speed outside town!

[Mick Westwood]

Elmolino

The oil I use is HPX Synthetic 20W-50 (Italian). Before the engine rebuild it burnt oil at a prodigous rate and it was fundamentally new pistons and rings that were required. Now burns very little oil and steady pressure.

[Martin Schuler]

Hello guys!
On the inside of the bonnet of my 1972 GT1300 Junior there`s the original sticker from the factory that says I have to use 20W50 in this car...

Regards, Martin

[italiansedanman]

Here in Australia, i've always been advised to run 20/50 in my twin cams - our temps range from about 7 to 35 degrees CELCIOUS so never VERY cold, but sometimes very, very hot.

My question re oil pressure, is that occasionally on long runs (and the car does use a bit of oil) the pressure seems to drop slightly at revs, after long distances. Is this because of the loss of oil due to burning and therefore less oil in the engine? Or does the oil level not have an effect on pressure?