ChevyRacer

Ok guys i think i have a problem. It is confirmed. My oil pressure is 60psi at idle. Showing maxed out on stock electrical gauge, and 60psi on my mechanical guage.

Its a stock flow oil pump. Yet i have 40psi while just cranking with the starter, and 60psi at idle. Revving it maxes put all my guages.

Now i thought maybe that was kinda cool, more oil pressure the better right?

but today i decided to make sure valve lash was correct with the engine running method. Well, i couldn't even do it. Oil was actually shooting out of my pushrod ends like 6 inches. It got everywhere. I'm talking a steady steam here guys, not a little bit of oil, i lost a 1/2 a quart in the 15 seconds until i turned the car off. This is now starting to scare me. I've been around engines for a long time. Why does mine have such high pressure, and streams of flowing oil coming from my pushrods?


Is this bad, or just extra good?

8Mike9

Fresh motor? If so, what pump did you use?

Or did this just start happening?...could be the bypass in the pump is clogged?

pellmanm

iTrader: (1)

What weight oil are you running, is that 60 psi when the engine is warm. If it idles with 60 psi on the guage when the motor is warm something must be wrong, either you have way too thick of oil, or your bearing clearances are too tight.

R1UK

Bypass [pressure relief valve] valve, would be a good starting point, 60 at idle is a bit un-nerving.

pellmanm

iTrader: (1)

The bypass valve allows unfiltered oil to pass by the oil filter if the oil pressure gets too great. Many people block the bypass to not allow any unfiltered oil into their engine, and have to remember to take it easy on the rpms when the motor is cold.

So enen if the bypass is clogged, there is another problem causing the pressure to be that high in the first place.

ChevyRacer

umm... i got the summit oil filter mount that bypassed pressure reliefe. Thats my problem then?


hmm...

yes it is a fresh motor. Its only been run maybe 27 minutes total at this point.

But it just gets weird. And for the breakin, i am using Walmart Supertech 10W-30 Oil then afterwards using mobile 1. I've changed the oil twice already.

But the wierd thing, when i ran her in for breakin for the 25 minutes, she still had close to 45 psi at idle. Is that bad?

pellmanm

iTrader: (1)

Were all the bearing clearances in tolerance?

8Mike9

Good point, plugging the bypass or using the adapter shouldn't affect the oil pressure.

KnightWarrior

Maybe the sending unit went bad. My '97 Firebird did that, maxed out on the guage, got a new sender and it went back to 45 LBS. Either you have a high-flow oil-pump in there, a bad sender or cam break-in lube has clogged your oil-filter and you are bypassing.

ChevyRacer

all clearances are in tolerance. I dotn remmeber the numbers but they are ok.

Oil pump is a standard flow melling oil pump. as far as i know its standard flow. But flow wont increase pressure. Not a bit.

I do have the bypass blocker.

Oil is 10w30, and filter was changed yesterda with the oil after breakin.

kevinc

Maybe on your planet that's the case, but here on Earth PV=nRT and volume (flow) is directly proportionate to pressure.

stealthhit

Do you have the part number for your melling pump? IF you do go to http://www.advanceautoparts.com/ and do a search and is will tell you if its a high volume pump or a stocker.

Apeiron

Oil is an ideal gas?

kevinc

Yup, brain fart this morning, but pressure and volume are still directly proportional in fluid dynamics given the same flow path characteristics and fluid viscosity.

ChevyRacer

theoritically yes pressure and volume are directly proportionate.


Butwhen the pressure will bleed past the pump vane assembly there is no added pressure. Its like trying to inflate a soda can with a straw as compared to your mouth. It will take less time with your mouth, but there is still no manner of force behind the flow to truely pressuize an aluminum can.


but i got the oil pump from http://www.partsdinosaur.com/ , i get a 20% discount there from connections. but i ma sure its an M55,

here's the add

anesthes

iTrader: (12)

My cold idle pressure is around 80psi, 55-60psi hot idle.

They sell little clips to go over the rocker to adjust them and keep it from spraying oil 6 inches, however, I'd recommend you check your rockers and pushrod ball mating.. The oil should be spraying more down than up.. What kind of rockers?

-- Joe

MrDude_1

id stop driving your car and fix it.

at idle, assuming you idle around 800 or less, you shouldnt be able to make 60PSI.

so what would make it go that high? a restriction. most likely, the full volume of oil isnt getting to one or more bearings... its hitting a restriction, making the pressure sky-high, and dumping oil out its bypass....



OR

the bypass thats BUILT INTO THE PUMP is broken (this has nothing to do with the FILTER bypass thats on the block)... now if you're getting 60 PSI at idle, this is unlikely since the engine should only be making 30psi or possibly less at idle... because thats less then the spring pressure, the bypass would be100% closed..


as a first check, id just replace the pump with another one... you could take off the pump, and disassemble the buypass, but they're cheap enough that its a better idea to get another one... try it... THEN if it still does it, tear the engine down.

ChevyRacer

ok first off, the car is not ready to be street driven yet. I have yet to connect the trany up and all.

There are no restrictions, i can assure you of that.

Myidle isn't 800 opr even in that range,m my idle is 1100-1200. High idle i know, but that comes from a 305 tune with everything 350. Plus a aftermarket cam.

The oil doesn't spray up 6inches, it sprays like completely sideways. almost at 110* from the pushrod tip. It shoots on the fenderwell directly.

And they are standard stamped rockers, and Summit Pushrods. I may son upgrade to roller rockers, but didn't see justifying $200 for maybe 1-2hp, and a couple of minutes of adjusting later on.

There shouldn't be a blockage, the block is fresh, bearings are as well. Everything is new.

However today, i decided to let her run for a while just idling, and her oil pressure dropped dramatically after she fully warmed up. I'm talking 45PSi at an 1100-1200rpm idle. Which is great.

Cold she still has a high oil pressure. I'm sure it will wear off one day. But for now this seems to be ok.

Now about those clips you were talking about for the rocker arms. Where can i get them? Can i make some?

Apeiron

The bearings may be new, but what are the clearances?

Any parts store should have the oil deflector clips.

ChevyRacer

i dont exactly know the clearances. I asked the machine shop guy, to make them better then stock. He installed Clevite 77 Bearings, and honed all of them. He is a buddy of mine's friend. and works at a very reputable machine shop called "Fox Machine Service." They've been in business now for 57 years. And that a long time when we are tlaking about this area.

I have no clue what the clearances are. But i'm sure they are pretty tight. Isn't tighter better? With tighter clearances do i need a highflow pump?

I was told not to use a high flow opump with my stock 5 quart oil pan, because it would drain empty at times.

Confuzed1

iTrader: (4)

I know I installed a high volume pump on both my 305 and 400, and both will read around 60-65 PSI at cold idle, but as it warms up, it'll settle out at 45-50 at idle.

Tighter is not better when it comes to bearings. You still need clearance to provide oil flow and lubrication through the bearing, so you want to be "not to loose, and not too tight".

I've heard of a few claiming there oil pumps actually sucked up 5 plus qts. of oil out of the pan, and put it on top of the engine faster than it could drain back to the pan......uh - never had that problem.

MrDude_1

good.. if your idle is that high, 60psi is possible with a bad bypass.

assuming you're using a normal weight oil that should be at a normal PSI all the time..... its probly the bypass sticking.
pull the pump and swap it for another one... or pull the pump, tap the rollpin out, and pull the spring and piston out.... make sure it all can move smoothly, no casting flash in the way, no sticking of the piston, ect.. and make sure its the "stock" pressure spring, not a "high pressure" one.

ChevyRacer

pull the pump? doent i need to like pull the engine again todo that? I mean i've heard of lifting it up with 2x4's on the mounts but ummm.... cant i get away with not doing that? I'd hate to have to pull all that fun stuff again.



I'll get back to all ya'll. I am gonna go out there and see what i can do now.

8Mike9

1100-1200 RPMs isn't idle for the pump...in fact your pressure may be okay at that RPM.

Check with melling on your pump vs RPM on a fresh block...you may be in the right range...I know when I set the valves on a stock 350 a few months ago with the covers off, the owner revved it up and oil spurted all over the place. No idea of pressure he had (only an idiot light).

But back to changing the pump...I've heard of guys dropping the pan in these cars without lifting the engine...they had to rotate the crank to index it against the pan while sliding out...I dunno....might be okay removing it, but make it tough to get the gaskets in place when reinstalling....but if you have to, maybe the 1-pc pan gasket makes it easier?

ChevyRacer

i do have a couple extra oil pan gaskets. I have a few extra of a bunch of gaskets. I bought 3 complete gasket sets for this engine. Cause i kept having to redo a couple things.

But if i get to it, i will have to pull the pan, and i guess i'll just do it the more easy way, and lift it 6 inches and put blocks there. I dont want to make it harder in anyway for the future.

Cavedog5663

I run a 355 All new it took between 3 and 400 miles and when it warms up now it drops to 30lbs at idle. Its much easier to adjust the Valves if they are Hydraulic lifters when the engine is not running.