Raven97

like the title says what is your oil pressure at idle and how many rpms are you turning at idle? (especially guys with CC306)

I just got my car running again and the idle is around 600-700 rpms but the oil pressure there is around 15psi if I bring the revs up to 900-1000 the pressure comes up to around 30-40psi and when cruising the pressure stays between 45-60 psi.

I was thinking of having the tune adjusted to pring the idle up to around 900, but I just wanted to see what you guys had on your motors.

TABBED 5.3

iTrader: (1)

I'm running a fairly large cam (236/242) and thats about where my oil pressure is. my idle is set to 950 though.

Wicked94Z

iTrader: (26)

15 is plenty for an lt1 at idle. we've got roller cams man, don't need much lubrication. I dunno mine sits about right on the 1st line at idle, comes up to a little above 1/2 when the revs go up. I don't trust these gauges anyway, I've been running my car to 6800 rpm for over 23k miles (97k on it now) and its doing fine with supposedly only 40 lbs of oil pressure.

JB_97ws6TA

iTrader: (6)

sitting around 25 at idle 40-50 on revs and cruising I just got a baby cam tho

Raven97

Thanks guys I think I may just get a mechanical oil pressure gauge to help keep an eye on it.

Jditlfm

iTrader: (26)

Ya know i read a lot of people say that online. But I checked my stock electric gauge with a auto meter mechanical and it was dead on. Car even has 154,000 on it to so its not like its brand new either. I have a melling m155 st volume with a high pressure spring and have 60-70 psi cold idle 35-40 psi hot and 60-70 at anything above idle. That was with 10w-30 oil and .03" bearing clearance on my mains an .02 on the rods. I will be switching to Valvoline vr1 20w-50 this year tho.

Raven97

high pressure spring? tell me about it. please

bombebomb

40psi~ at idle if I recall. 80psi when I get into it.
Idles at 1000~ rpms, when its in drive it idles at around 800.
New engine so take it for whats its worth.

Bowtie_Aaron

iTrader: (3)

a SBC needs 7psi per 1k rpms. if you have more than that, you are good. as long as it goes up when you give it gas.

cammed has nothing to do with pressure. depend son what pump. if you have a stock spring, or a high pressure spring. high pressure oil pumps can rob as much as 7hp from the motor. what you want is a stock pressure, high volume pump.

i have a stock lt1 pump in my 355 in the chevelle. it pulls 60 cold, around 35/40 idle, and 50+ cruising. with 10/40 oil. it is cammed with 231/239 duration. idle is around 900


aaron

Jditlfm

iTrader: (26)

Most people just run a standard volume pump with a high pressure relief spring. Its pretty easy to change on a new pump while its out. A lot of people will use a stock replacement pump and the "GM WHITE SPRING" Its like $3 so most feel its worth the extra insurance while some recommend stock pressure and say your just fine with that. While others like to follow the old rule of 10psi for every 1,000 rpms. I would do what ever your engine builder recommends. Me personally i like the high pressure. Gm part number on that spring is 3848911. You really can get into a huge discussion on oil pressure there are a lot of interesting concepts.

Edit: after reading the post above 7psi per 1,000 rpm's sounds right also

Raven97

Well I this is a new motor, and I trust my engine builder (he is a "builder" not a "machiner") and as soon as it comes off idle the pressure shoots up. You guys have eased my mind a bit, but I will get another gauge just to watch it with ( redundancy is a good thing ).

Thanks guys.

Bowtie_Aaron

iTrader: (3)

lower the rpm, the lower the oil pressure will be..

remember the oil pump on a chevy v8 (non lsx because i am unsure about those) is run off the cam. on a typical chevy v8 and even 4.3 v6, the distributor is run off the cam, and at the bottom of the dizzy is a notch in the gear that fits over top of the oil pump shaft, that slides inside part of the oil pump. on an LTx there is no rear mounted distributor, but they have a gear that is bolted to the lifter valley of the block, that has teeth just like a regular dizzy gear that rides off the cam, which is attached the same way the regular dizzy attaches to the oil pump. so depending on rpm will depend on how much pressure you have, hence why you see 15 at 700, but 40 at 1000.

my stock pump in my bird is the same way, idle about 600 oil is below the 1/4 mark, and bring to 1k,its up around 40.

if you are that worried, just throw a good autometer mechanical gauge in there. but i wouldnt worry about it. only time to worry is when the gauge doesnt go up when you give it more gas.


aaron

ss.slp.ls1

iTrader: (36)

CC503
New stock shortblock
Idle is set to 750rpm

Hot idle: 30psi
WOT: ~60psi

Wicked94Z

iTrader: (26)

nascar guys only run 45 lbs of oil pressure at 10k rpm. then again their oil systems are optimised, give priority to the crank, and limit flow up top. I thought i read somewhere that a factory spec for oil pressure at idle was anything >7lbs

ss.slp.ls1

iTrader: (36)

Yeah, I too have read that GM spec is 7psi at idle.

blkm6formula

iTrader: (2)

7psi is correct! high pressure spring is cheap insurance, but I wouldn't worry, as long as it moves up and is above 7psi at idle!

And a st. Pressure with a high volum is NOT the way to go, for one, most people do not add the extra windage protection needed to prevent the pan from going dry! st. volume with a high pressure spring is the best for most people, if you are an ace engine builder, or had it proffesionally built, you are much more likely to tear it up with a high vol. pump!

if you don't mind me asking why will you be switching to 20w 50? jd??? unless you had your oil gallery drilled, that is not the best thing to do!

Jditlfm

iTrader: (26)

I will be switching for a couple reasons. I have been a long supporter of mobile 1 synthetic for a while. But with this new engine the oil seems to break down real quick and basically turns to water when it gets hot. I feel it prematurely breaking down is a brand problem. So I have been doing a lot of searching and from my research in 2004 they removed a lot if not all of the zdp and phosphorus. Long story short those are very important ingredients to oil that prevent a lot of wear while at the same time providing optimum lubrication and allowing new motors to break in properly. Zdp and phosphorus are found in Gm assembly lubricant (EOS) They removed those ingredients from off the shelf engine oil even diesel oil because they were found to cause long term catalytic converter damage and the epa is not going to have that.

I found texas speed recommend Valvoline Vr1 racing oil in all there short and long blocks for break in and long term use. Speed inc also agrees with this oil choice. Vr1 has the necessary % of zdp and phosphorus. Obviously it is a off road use oil, but I don't have cats any ways. Another upside is it is a non synthetic oil (mobile 1 syn is very leak ****) and its $4.99 a quart vs mobile 1's $7

I choose the 20W50 as i was researching oil and I found that either texas speed or speed inc recommended anyone with Clevite H main and rod bearings run a 20w50. They said because the clevite's usually run a little lose on bearing clearances. My Motor has .030" on the first mains and .04" clearance on the one with the oil pump. My rods are .030" with chamfered bearings (little narrower) and a chamfered and micro polished crank. Like i said when the motor got hot that 5w-30 turned to water. I also called the valvoline tech line and had them recommend me a oil weight. He said he would recommend the 20w50 also due to my high pressure pump.

Im going to give it a shot, because i get a little nitrous happy sometimes and that's how I spun my rod bearings in the old motor. So i will take any extra insurance i can get with this new motor. Even if its a long shot, cost a little more money(which it wont), or cost a little hp pumping loss running a high pressure pump. The current engine i'm building is a bastard engine I got screwed on it money wise (long story) So im going to try and give it a chance at lasting before i start dumping nitrous down its throat.

riceburnerZ28

iTrader: (20)

At idle my oil pressure is a bit above 40psi, but that's cause of a hv oil pump. For stock engines at idle it should be around 7 or 8 psi !

gen 3 bu

iTrader: (2)

i have seen a 28 rwwhp drop by changing to 10w40 from 5w30. i have also seen plenty of cam gear and pump drivshaft damage due to high volume/high pressure pump use. either one exerts a lot more force on the cam to "distributor" gear. if you set the bearing clearances properly you can run 5w20 with out issues. i have made 930 rwhp on 5w20 at 7000 rpm. 10,000 miles later the bearings still look new.

Jditlfm

iTrader: (26)

What were your bearing clearances? Is that damage you have seen from a high pressure high volume pump or just a high pressure st volume, high volume st pressure pump. I cant see a 28hp drop on my application from switching oil weights but we will see. Everyone has there own preference like i stated earlier. I dont even want to open that can of worms.