Hot Rods "New" small block oil pressure

Air in the line will not change the pressure reading on the gauge it will only cause the gauge to react to the pressure slower, but not to an extent that it would be a problem. Were talking fraction of a second. Dampening the movement of the gauge is not a bad thing, probably make the gauge last longer. After all if you look at the fitting where the oil line screws onto the back of the gauge there is probably a tiny hole where the pressure enters the gauge, that is also designed to dampen the movement.

 

Doesn't sound right to me. I just did a 'Krylon Rebuild' one an untouched '69 300 HP 350 I pulled out of a wrecked Impala. I pre-lubed it on the test stand, not because it was a fresh motor cause its not, but to fill the oil filter and purge the air from the oil passages. I got almost 40 psi with the drill. Motor idles at around 30 psi with 20-50 Valvoline racing oil. Pressure maxes out at 40 psi but probably due to the pressure regulator built into the pump.

 

I change the pump, do I need a new oil pan gasket even though I just replaced it and talk to properly? Candidly, if this was my daily driver, the answer would be no, but since it's occasional use, might as well do it right

 

If the gasket is glued on the Engine Block and not damaged it should be fine.
If it is a 1 piece moulded gasket it will be for sure OK to re-use.
I hope that the Oil Pump replacement takes care of your problem, a sticking pressure relief valve could be the culprit here.
If the builder brased the pick up tube to the pump body without taking the pump apart it could cause that problem.

 

depends if the pan gasket is the reuseable one piece rubber type, or the original 4 piece style. If it's the one peice, you can re use it.

I still don't know if you had an oil pressure problem, since you didn't run the engine much.

 

Well damn. Kinda anti-climactic. It seems to me that both parties are absolutely correct.

 

That's a great point, the shearing of the oil as it passes through the relief valve will cause a lot of heat from the internal friction (the oil molecules being torn apart from each other), the more viscous the oil (somebody mentioned using 20W-50) the greater the heat buildup. Also, the heavier the viscosity, the slower it releases heat.

 

If you drop the pan, consider getting one of the new Fel-Pro one piece gaskets. They are super easy to install and no leaks. I generally agree with what Don (Don's Hot Rods) says, but in this case I'll have to disagree with him about a high volume pump. I had all kinds of problems because somebody put a high volume/high pressure pump in my '67 Corvette 327 when it was rebuilt. it would peg the gauge and flooded the rocker arm covers with oil at high engine speeds. Those pumps are completely unnecessary in non-racing engines. I had to swap it out to solve my oil consumption problems. That is how I found out about the Fel-Pro gaskets. You should also know that all Mellings pumps come equipped with high pressure relief springs (I think they are painted yellow). I called Mellings and they sent me a standard spring gratis.

If you really want a high volume/high pressure pump, I have the one I pulled out of the Corvette with less than 3000 miles on it. You can have it for shipping costs.

 

It also gets recirculated through the gears in the pump again, and the oil that is passed through the bypass goes right back into the inlet of the pump, and theres no provision in a stock pump for the oil that has been through the by-pass to be separated from the fresh oil being sucked up the pick-up from the pan, so some of that oil keeps cycling through the by-pass and gears over and over, this is what really raises the oil temp.
Most savvy endurance racers modify the pump so the oil that goes through the by-pass dumps directly back into the pan instead of re-cycling in the pump, but then you also need to use a larger pick-up, because that quantity of oil that was being re-cycled is now being dumped back in the pan, and the pump has to pull more oil straight from the pan.

 

Look at orifice in the back of a Stewart Warner oil pressure gauge when you size your line.

 

I have... As the Smoke once said "You can lead a horse to water, but sittin' on his head wont make him drink"

 

My thoughts exactly. But the HAMB loves chasing unicorns...
And if the engine was broken in on the dyno, and you THINK you have an oil pressure problem, you need to talk to the ENGINE BUILDER.

 

I am not a huge fan of the one-piece gaskets, they tend to squirm around a lot when you install the pan, but if you use one, silicon the gasket down to the block, and grease the end rails on the pan, it helps prevent the pan from "grabbing" the gasket and pulling it.

 

Squirrel, I guess I misread your post, sounded like both of you were talking about the V8 in the car now.

"You should not be able to turn a fresh Chevy V8 by hand by only holding the damper, especially with the plugs in. When assembling an engine, I find that after I install about half the pistons, I can no longer turn the crank by just pushing on it, I need a lever".

 

I would definitely compare to a known good gauge before I tore things apart, 10 psi at Idle is minimum for a sbc they will survive with that, Keep in mind that besides the oil pump, pressure is also determined by Main bearing clearances, I would try and find out what they set bearing clearance at,,If you can't find out I would suggest dropping some main caps and see what you have,, If the clearances are on the high side or over the max limit what you have for press may be what you are going to have without redoing the bearing clearance,, For what it is worth I have driven quite a few sbc that made 10-12 psi at idle ,as long as the lifters aren't noisy and the rocker arms arm getting enough oil , I would drive it...

 

How many of us have suggested trying another gauge that is known to be accurate, or at least a brand name gauge, rather than the cheap Chinese stuff from Auto Zone??

 

No, hell no. Why would you TALK TO THE ENGINE BUILDER when you can get 40 different opinions on the internet, based on a brief reading on a junk chinese oil pressure gauge? Right?? RIGHT??!! Throwing up my hands in disgust and walking away...

 

I like to START with basics and the easiest, maybe I'm just a lazy old man, I'm done!!!!

 

I can't stand phones. Seriously can't stand them. It autocorrected and said "I changed the pump" but it was supposed to say "IF i change the pump"

I didn't change it yet

 

Wish I had $5 for every SBC that had oil pressure problems chased where none existed in the first place. The real key is flow more then pressure.

Gary

 

Junk oil pump or filter . Use a wics filter .

 

I'm with George, I've had enough of this thread. The guy asks for help and then won't do a Fucking thing we ask him to do.

 

AMEN

 

Man don't our parents tell us at like 3 "if you don't have anything nice to say don't say anything at all?" My goodness. To go out of your way to post something like that is just unnecessary.

As for the rest of you who have contributed CONSTRUCTIVE help, I appreciate it. I have not had a chance to do anything yet and will pick up a pump first.

Noticed the pan is slightly dented - or the flat bottom is some what concaved in and I am wondering if perhaps I pushed it into the pickup screen. Going to check that out when in there.

 

The dent is slight and i was thinking it could be blocking the screen

 

Drew, as you can tell, the guys on here are more than willing to help another member, but at some point you have to do some very obvious things yourself...........LIKE PICKING UP THE DAMN PHONE AND TALKING TO THE GUYS WHO BUILT THE MOTOR !!! That lame excuse about you hating to talk on the phone is just dumb. You need to either call the guy or go over there and have a serious discussion with him.

We don't mind helping, but at some point it feels like one of our shoes are nailed to the floor.....we keep going around in circles on the very same subject. Now the ball is in your court.

Don

 

No no I hate TYPING on the phone. I have an iPhone and it automatically corrects words to what it "thinks" I wanted to say and it looked like I said I changed the pump already but I didn't - it was auto spell correct. I did talk to the guy; didn't get (didn't know to ask for) too much detailed info other than it should run 40 at high idle (which I don't know what my carb does but it's all automatic and SO easy compared to my old fully manual Rochester 1bbl) and that a spring was changed in the pump to correct an initial problem and that did solve it.

 

I would think you could pull the valve covers off and start it. If you have oil to the rockers drive it, if not I'd say the galley plugs were left out.
I bought a 327 long block from a RACE CAR BUILDER years ago. Threw my intake on it, installed and pre oiled it, and it had 5 PSI on the gauge, so I pulled the motor, pulled the pan and timing cover pushed in the soft plugs put it back together and had it running in the time this thread got to this point.....Just saying!
Good luck!

 

I don't have anything to compare this to. Is it normal?