Hot Rods Oil pressure/ viscosity

What's up my brother Tommy? Yeah i saw the conversation but i didn't see the original post, just the answers. Thought i had switched dimensions yet again. Caught my eye due to my recent issue and concoction of lubrication weights and additives, trying to make one last show lol. And I'm proud to say i made it. Seems to me that "cold oil" serves as a restriction in those p***ages, mimicking a tighter tolerance, and in turn, giving false hope of "acceptable oil pressure". Up to the point it gets warm and starts moving with the rest of the oil, then you're **** out of luck again. You can't replace wear with thicker oil. (These statements have not been evaluated, and are only the opinion of Lloyd, who is a painter, and shouldn't even be sticking his nose into this conversation)

 

LoL,,,,it’s going good Lloyd ,
I have only a limited experience on this .
Back when my 440 was fresh,,,,,it was a peculiar start up ritual .
I had to start it and warm the engine at a fast idle,,,,,until 100 degrees on the gauge .
Summer or winter,,,,,hot or cold weather,,,,,it would not run right until temp was at a 100 .
The oil pressure,,,,,the engine,,,,,just didn’t want to run,,,,,,20-50 Pennzoil at the time ,,,,,35 years ago .
After a little heat,,,,,it was a different engine,,,,I guess the clearances and the oil would co habitate after that .
But,,,,I never really saw any discernible pressure change from different weight oils .
I never used any ultra thin stuff in it either,,,that was before the 0 weight stuff .
I’m certain I’m behind the times in that as well,,,,LoL .

Tommy

 

I thought the relieve valve limits pressure, when it gets too high...and doesn't do anything when it's below the limit. How would shimming the spring do anything to increase oil pressure at idle?

 

I've never (had to) tried it, but I've heard many many times people using "Motor Honey" and STP and similar stuff all the way up to 90 wt gear oil in old, high mileage no oil pressure smokers. You're right, it ain't supposed to work. But.

The stories usually go something along the lines of "I drove it that way for a long time, I sold it, the guy immediately changed the oil to 10w40 and it threw a rod out of the block the next day." LOL

 

Oh yeah, i know what you're saying. It's all theory. I put 20w-50 in mine, along with a bottle of something like stp, it was in a plastic bottle, motor medic? Something like that, but it did raise my pressure, and the bottom line was that my lifters weren't pissed off. Win win. Now I'm about to put a new engine together for my car. It's on the stand. I'm curious what the main bearing clearance is on my current engine

 

Little trivia tid bit for the guys that get bamboozled by C temperature specs, 0C = 32F, 100C = 212F.

 

My OCD would never allow for that. But then I never had to, see a lot of guys back in the day just drove stuff till it fell apart. They couldn't afford new cars, or even used cars, or much of anything else, and they made do.

I remember first seeing STP - that stuff is unreal, it doesn't even pour out of the bottle LOL. You want me to put that in my engine!? Mein Gott, noooooo!! ... That'll never do.

 

I drove my Valiant with an old worn out 318 for years, made about 2 psi at idle maybe 30 when cold revels up, I abused that poor thing until it developed a rod knock. I ran all different concoctions trying to get more oil pressure, finally I quit worrying about it…

 

You will see a little higher oil pressure with a “ thicker” oil at all speeds. . Even at relief pressure, because it is a little harder to push the thicker oil through the relief than thinner oil! That is also why you see higher oil pressures than the relief setting at high rpm. There is some resistance to push the oil through the relief ports, and that results an increase in “oil pressure “. But it will not be much of an increase, I have experienced around 5 PSIG increase going from 30 to 40 weight.








Bones

 

Blues4U ,
Didn’t mean anything by it,,,,,,Celsius is just not my bag man,,,,,LoL.
And yeah,,,,,,I was probably being disingenuous when I stated I wasn’t up to tabs on the C versus F scale,,,,,LoL.
Sorry man,,,,,and I realize that most of the world uses that scale ,,,,,,again,,,,I’m sorry .
But,,,that’s just me,,,,,,this is a website about American hot rods,,,,,I just choose to keep it old school .
No problem with anybody,,,,,like I said earlier,,,,I guess I’m just a renegade ,,,,,LoL.

Tommy

 

Its somewhat less than re***uring when a question is asked , & , I guess, because no one knows the answer your query is met with such comments as (paraphrasing)" why do you need to know that " or " what are you trying to do" or " it really doesn't matter" , or the best one ," its just not important " ( I'm glad you felt duly empowered to decide that for me. )Things would be decidedly better ,IMO , with either no answer or a simple , " I don't know"
It was a simple question.

 

I don't know.

 

Sure, though sometimes there aren't simple answers.

Why don't you take one for the Team and perform the necessary routine so we can get a data point?

I say about 5 psi. Get the engine good and warmed up, on the highway, under load. Just idling in neutral won't really get oil Temp up where it needs to be for an accurate measurement.

And it's now July, or near enough, so that's perfect, too. Use a mechanical or ****og pressure gauge plumbed into the sending unit fitting. Then, check it at 2000 RPM in neutral. Do this same routine for both viscosities.

In the interests of the Furtherance of Human Knowledge, and the H.A.M.B. Thanks!

 

Boneyard's reply is spot on. "Pressure is resistance to flow". To put it into context...think about someone with plugged up blood vessels and arteries. The flow of blood is reduced and consequently their blood pressure is off the clock.