High oil pressure after oil/ filter change...cause?

[chevyconvert]

Hello everyone,
Been a long time, but you know how it is sometimes....life gets in the way!

Anyways, last week I changed the '70 440 6pak oil and filter.
For the 1st time I "upgraded" to Lucas 10-40 hot rod oil from summit that has all the zinc etc missing from modern auto part store oils.
I also install a K&N oil filter for the 1st time. (I've been using those for years on my newer v8 cars).
 So I warm her up a little and start on my cruise and I notice the oil pressure gauge (orig. Rallye) is at the top mark (like full if it was fuel).
Now she's always had good oil pressure,but not this high. Alarmed me some. Babied her around the neighborhood and the pressure did come down some, but still seems higher than with the old regular oil and cheaper filter.
I do not believe she's overfilled....running about 5-3/4 quarts to the full mark on the dip stick.
Didn't seem to cause any problems.
Appreciate your input on this one.
 

[brads70]

I've had bad experiences with Fram oil filters loosing all or low oil pressure.
https://www.youtube.com/watch?v=XRRgw4B7R-I

[Chryco Psycho]

No problem just better oil & flow through the filter

[cudabob496]

so, its 10-40 dino oil?

I use 5-30 full synthetic.  You could add a zinc additive.

[DocMel]

Have to ask:  Why 10-40?

[chevyconvert]

 Thanks for the replies.
Cuda Bob: yep Dino oil. already has the zinc, some tests suggest to much. I do run Mobil one in my newer cars.
Just thought this might be the way to go. Less than a 1000 miles between changes...sometimes way less.

And why 10-40 vs. 10-30? I was thinking (there I go doin that again ! that when it's cold (start-up) it's 10 weight either way. I live in a hot area and I thought it would be good to have the little extra thickness when it's hot.
What the downside? I'm not an oil expert.

Chryco's answer aside, the pegged oil pressure still bothers me a little. Do you think 10-30 would read lower on the gauge when the engine is cold?

[Chryco Psycho]

Maybe a little but not enough to notice , my 440 had a 100 psi mechanical gauge on it & cold it would push the needle past 100 psi , it would drop to 85-90 once it was warm . you could always swap the bypass spring inside the pump , you probably have the black high pressure spring in there or grind it a bit shorter .
 I never worried about it .

[cudabob496]

the same weight sythetic flows about twice as fast as the same weight dino.
Also lubricates better, and can stand up to about 700 degrees before breaking down, while
dino is about 450 I think. Engine will run cooler.  Lotta wear is at startup, especially at the valve train, when you want the oil to flow quick.
Synthetic is just far superior, but that will be argued by some forever.

Give you an idea, I replaced my mechnical fuel pump rod after 15 years of full synthetic.
The about 4 inch rod only decreased in lenght 5/100 of an inch.  If I had used dino, probably would have been a lot
more wear. I use full syn in engine, tranny, and rearend. Gives 20 more RWHP.

Also, last 10 years, rarely have to adjust valve lash on my solid roller. If I do, its just to snug it a little bit more.

[moper]

If it were me I'd replace the filter. It's not the oil doing that. Possibly a defective filter. I run exclusively Wix filters sold by Car Quest or Napa and I've never had a bad one, nor crazy oil fluctuations like others do from time to time.
Too much pressure is a drag on the engine, a potential source of heat, and can be a source of breakage of the oil pump drive if it's not the hardened tip and pinned gear version (meaning not a factory one). Enough is enough. Too much is bad.

[cudabob496]

Wix are good, but these filter better


http://www.summitracing.com/parts/knn-hp-3002/overview/

[roadman5312]

Wix are good, but these filter better


http://www.summitracing.com/parts/knn-hp-3002/overview/

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[73440]

10 microns K&N vs 19 microns Wix

[Chryco Psycho]

if the filter was restrictive the pressure would be higher between the pump & filter where it s not measured , if the filter is less restrictive the higher pressure would be in the engine passages where the pressure is measured , so you are suggesting using a more restrictive filter ?

[73440]

if the filter was restrictive the pressure would be higher between the pump & filter where it s not measured , if the filter is less restrictive the higher pressure would be in the engine passages where the pressure is measured , so you are suggesting using a more restrictive filter ?

No, just making note of the difference in the two filters in that aspect.

[Chryco Psycho]

I was actually reffering to the post higher up , but good to know the WIX has finer filtration