dbs1

Just had to build a new LS3 based 416 to replace one that went boom, and I used a new engine builder that comes highly recommended.

Oil pressure on new engine is around 28 psi at idle but doesn't go over 46 psi at full rev when warm. The installer called the engine builder and he assured him it will be just fine. The other couple of engines I've had built over the years would show 55-60 psi at 6000 rpm.

Should I be concerned? Using 0-50w Mobil 1 racing oil.

07NBSChevy

iTrader: (1)

20-40 psi at hot idle is normal. The AFM/DOD motors idle around 22 PSI.
40-60 psi at rpm is also normal. Some LS engines have a relief that goes off at 55 PSI.
I think GM Recommends 10 psi per 1,000 RPM with a minimum of 10 or 15 idle psi, with a pressure relief to monitor max psi.

You were definitely in the correct range.

Not saying you used the wrong oil, but was there any reason you did not use 5w-30 in your engine? I have always been told on a new engine/built engine or an engine with tighter tolerances you should use the recommended 5w-30.

kingtal0n

iTrader: (1)

10psi per 1k rpm is 60psi at 6000rpm. How can anyone say 46psi is good at 6k rpm? What is "full rev" because for some that is 5k and others it is 9k.

I think if I saw 45psi at 6k I would freak out and rip the engine out of the car to change the oil pump and inspect everything.

Motor oil selection is generally based on clearance, If the engine was rebuilt using OEM clearances then it would probably desire 10-30 or similar (depends on climate also). a 50W oil in a stock clearance engine is asking for trouble, especially in cold climates. also, 0w anything just flat out scares me in an engine from 2000's era, unless is absolutely freezing cold and I mean frozen. In which case you need an oil pre-warmer not a lighter weight oil. and my final perturbation is the wide range between 0 and 50, the bigger the split the more viscosity adjusting molecules (forget exactly what they are called) the oil has in it which typically leads to a less effective oil.

07NBSChevy

iTrader: (1)

When I say GM, I am referring to Stock engines, not 9k rpm engines. Most GM LS engines rev to 5,600-6,000 with a pressure relief in the pump and some in the pan as well.

The 07-13 Silverados idled at 22-25 psi and maxed at at around 45-50. So it varies as well. But GM recommends the 10 psi per 1k rpm as a rule of thumb. You do not need 75 psi in an engine, anything around 50 is fine. Unless your running a race engine.

Even with a Melling 10295 Pump in my engine, I max out at 55 psi due to the relief in the pan. I really didn't feel it necessary to remove the relief for 6,200 rpm shift points and was happy with 55 psi. Hot idle is 35 psi.

Like mentioned above, the heavier weight oil may be a cause to your lower pressure. If the tolerances are tighter, which it should be, I would use a 5w-30 oil.

KCS

iTrader: (20)

The 10psi per 1k RPM rule is BS. You don't need that much oil pressure.

kingtal0n

iTrader: (1)

Well thanks, but it wasn't me that suggested it. I only posted in response to the original idea where it was presented. I neither agree nor disagree since i have no knowledge of LS oiling system behavior specifics.

That said, you can't just say that it is complete BS, because that is a blanket statement which you seem to be applying to all engines at once. I am sure some engines out there would take offense at 6k rpm to 40psi of oil pressure (or less). Maybe not LS variety, but some do. So for starters, lets be specific. You are saying specifically that LS engines, ALL of them, do not need 10psi/1k rpm rule then? I am not sure, would you like to clear that up?

Next, I think of these "rules" as sort of guidelines, not 'hard fast' rules. In other words, someone says "10psi/1k rpm" and I see 9.5psi/1k rpm and wouldn't freak out just because I was 4psi short at 8k rpm, because I am within a fair range of the original "guideline". This particular guideline is there for us to generalize the idea that oil pressure gradually increases with RPM, and if the reverse should happen, that something could be wrong.

spy2520

iTrader: (3)

Pretty sure GM spec is 6psi per 1k rpm.

07NBSChevy

iTrader: (1)

Gm states 6psi per 1,000 is the absolute minimum, 10psi per 1,000 rpm is the recommended rule of thumb according to the GM Service Manual.

GM also states each engine/model has its min/max psi's which should be accounted for.

This is not saying an engine should have 60 psi at 6k rpm. Which most engines have around 55 before the relief lets off the pressure. It is a rule of thumb and should be taken as that.

Also Kingtal, GM does not have an engine that Revs to 8-9k rpm, so I do not understand why you keep referring to a engine that revs crazy high? GM references are obviously for stock oiling systems. If you have an engine that revs to 8-9k rpm, then your oil system will be very different. I did put in the second post the normal oil pressures, that is what you should go by. 45 psi at 6k rpm is no reason to tear down an engine to inspect it, that is considered normal.

pdxmotorhead

Sprint car dry sump 9500 rpm 120 PSI Small block chevy... Just for the Effect..

0-50 oils are typically highly stable, they are usually J spec oils for high shear engines, for instance motorcycles. They typically stay more consistent on pressure in my bike than a 20-50 does for instance..

When I redid the engine in my jeep, (4squirrels) We reset the full relief to 75lbs, and the engine sits at about 55 at cruise and 25 at idle which I like. SInce it shares its pump with the 6cyl engine its a bit oversized..

KCS

iTrader: (20)

You posted a question, and I answered. You're welcome.

The question asked in the OP is about a 416ci LS engine. This is an LS based forum. My experience is based mostly on domestic V8 engines. Let's not be so absurd to assume anything said here applies to every single engine to include some oddball Datsun engine that needs incredible oil pressure to overcome poor oiling. There are always exceptions to every rule.

Anyone who states that they wouldn't freak out if their brand new engine had less than 10psi of oil pressure at idle is full of it. No offense.

kingtal0n

iTrader: (1)

weeel my only question was, what is "full rev". I already knew (no offense) that engine oil pressure should climb with RPM.

As to the rest, you are right this is an LS forum sometimes i forget that. I am only being careful with clarity and word intent. It goes against my wording-judgement to make blanketstatements just because I assume everybody knows I am talking about LS engines on an LS forum- because I don't just discuss those engines.

Annd last, I wasn't even thinking about idle conditions, at all, until you brought it up. Yes I completely agree 10psi at idle is iffy depending on the kind of gauge and engine in question. Thats is actually a great example of a time when I was not careful with word intent and got it mixed up so that one of the conditions was against intended meaning- which further emphasizes the reason I try to be careful.

tech@WS6store

iTrader: (2)

Gm trucks normally operate at 40psi to a tad under on the gauge. I went out last night amd checked 4 nbs and 2 nnbs. They had miles ranging from 50k to 170k. Thats hot idle. Anything less than actual 25 at idle and id be a bit concerned. Of course running snake oil is a common problem also.
If you are within spec with bearings and a std pump id say 25 - 40 would be hot range.

The 10psi per 1k seems like bs and gets thrown around alot.

That being said, ive seen some engines run on 10psi verified on a mechanical gauge and not make any noise and run for 60k more miles so far. i wouldnt do that, but you can.

kingtal0n

iTrader: (1)

it looks like these guys think that over +10psi/1k rpm is good for an "LS". See what I mean about guidelines? This company, the next company, the FSM, and the guys on the internet, and the OEM manufacturer, all have different things to say sometimes. Then you call the oil company and they have yet more interesting things to say. it goes round and round. In one thread, the above is an "authority" that sells oil system parts. In this thread, they are complete BS because they believe in the rule of 10psi/1k, or that it is "good".
IMO: Application dependency is not a blanket theory.

G Atsma

Saccity Corvette says NOTHING about the 10psi/1K rule in the above quote you cite. So they are NOT "complete BS" in this thread, as you state. You are getting good at flaming people who know a LOT more about this stuff than you do. You just want to pick info bits apart and use them against each other, instead of reading between the lines and forming good info out of all of it. Chill, dude....

kingtal0n

iTrader: (1)

Nothing has been taken out of context. It says right there 90psi at 7000rpm. According to the mod, that is complete BS for ls engines. My point was only that you can't make a blanket statement like that.

get mad

tech@WS6store

iTrader: (2)

You are trying to imply what is not there and seems that you arent aware what actually causes or meters pressure let alone in an ls engine.
Every time someone says something diff or tells you you are wrong immediately you fly off the handle and start flaming.
Obviously that engine is not the norm and would require more than a billet barbell and bypass delete to make that pressure let alone maintain it. That example was clearly showing the capability of the parts...kinda like flowing an ls1 head on a 4.125 bore.

KCS

iTrader: (20)

Last I checked, a question mark designates a question...

That's why I commented that your premise is BS. Most engines run just fine with less than that over 2kRPM. Below 2k, you usually need more just to keep the hydraulic lifters from collapsing.

There's a difference between what you want to have for oil pressure and what you actually need for oil pressure. Many builders run higher oil pressures because otherwise, people such as yourself, would freak out if the pressure isn't where you think it should be, despite your lack of knowledge on LS oiling systems.

G Atsma

^^^^^THIS^^^^^^
Well put, KCS!

kingtal0n

iTrader: (1)

you misunderstood what i wrote, I see why now. I will re-do it for you, so you can follow better.

I started with:
"10psi per 1k rpm is 60psi at 6000rpm. "

That is in response to the above post which originally mentioned the 10psi/1k rule. For all intents and purposes I've never heard of that rule (we all have heard of it but I would never have mentioned or quoted it because its the exact kind of blanket statement I would never make and suggest others avoid making)

He said:
Thus, I follow it up with the question based on the previous sentence:
"How can anyone say 46psi is good at 6k rpm?"

In other words, "he" says "in the correct range". But instead of pointing my finger and quoting his post, I wanted to kind of nudge the info without being a douche bag. I don't like talking down to anyone.

I probably should have used the word, 'therefore'. So it would have read like this:
10psi per 1k rpm is 60psi at 6000rpm. Therefore, How can anyone say 46psi is good at 6k rpm?

Notice I keep it going with another question based on the previous post:
"What is "full rev" because for some that is 5k and others it is 9k. "

So the whole thing went like this: [previous post re-statement, question that helps us think about it, question that helps us think about that].

Does it make more sense now?


And yet, neither one of us knows how much oil pressure is necessary. Nobody can tell from engine to engine because every engine example is different, even two of the same models. Another great reason why I avoid making blanket statements, and would never quote or expect any of those to hold without some qualification.

kingtal0n

iTrader: (1)

And one more thing. In my first LS 5.3 2002 model engine with 150k (unknown miles assumed to be approx 150k), a hot idle gives me 36psi at 550rpm, and i get 55psi at 900rpm or so. Thus, this is why I said that I would freak out if i suddenly noted 45psi at 6k. It would mean oil pressure dropped 10psi from 900rpm to 6000rpm, which is clearly a problem (I would think it was). So far, logic wins.