The bypass moved up and down like to basically where the threads started in the pump basically. I feel like I should pop a rod cap off to inspect but don’t want to let the magic out. Cam bearings looked alittle worn when I did the cam but that’s also how LS motors look so…

I ended up getting a M355HV and thinking about slapping that on and hoping for the best.

 

I agree you should pull a rod cap off and take a look at the bearing before continuing.

 

I’d pull a rod cap off and have a look. Put it back on at 47 ft lbs if the bearing looks ok.

 

Not sure if sludge/crap can just make a pump clog up and cause low oil pressure, but old buzzard is probably right and the pump was a problem and may have done damage to bearings too. Too bad not more of a smoking gun there.

Can you put it back on that stand with a new oil pump? I don't own a stand and don't know how big an effort that is. If it were me I'd do that and if oil pressure is back I'd run it, since it's just a junkyard motor.

Otherwise yea I guess the clues hint damage may have been done so probably pull a rod cap and inspect to make sure.

 

Update, put it all back together and oil pressure is highhhhhh haha. Kind of expected with the HV pump but it has 75psi cold and warmed up to about 60psi. Alittle worried about overall pressure now though… 111psi I saw before the gauges maxed out oof at around 2500rpms. Thoughts on this high of pressure? I didn’t even really rev it that high so I have no idea what the overall pressure would be but i can’t say I’m comfortable with this High of pressure.

 

Now you see why many here don't believe in HV pumps in stock apps. It's simply not needed.

 

Did you pull a cap to inspect or just the HV pump and reassemble?

 

^^^^THIS ABSOLUTELY!^^^^
OP-I'd pull 1 rod cap and one main cap. If they both look good, the other 7 rod caps and 4 main caps should be good. If one is bad, time to pull it apart completely. You'll know when ya see it. If it has a few radial lines, but the rod and crank journals look good, I'd put it back together as is. I kinda agree with the other.guys on the O-ring sucking some wind. It's like a straw. If there's a small leak, the straw is junk. When the oil is cold (thickest), the O-ring may seal. When the oil is hot (thinnest), and the parts have expanded, the leak appears. A LOT of these engines have been ruined by mismatched, or slightly cut O-rings when the builder installs them. Unless you have piston squirters, you shouldn't really need more oil volume/pressure. Also, IDK all the details of the vehicle or motor, but one thing I do not like is the 2 bolt pickup tube. Speaking from experience on a C5 Corvette, there'd be no way to change the oil pump with the 2 bolt setup, unless you drop the front cradle and pull the oil pan, all just because of that second pickup tube bolt. Maybe your setup allows access by removing just the pan. But that 2nd bolt isn't really necessary, and can be a real PITA on some setups, like mine!!! Good luck, brother, and keep us in the loop.....


UPDATE!! I see you installed the REALLY Hi volume pump. There's no problem with a 10296 Melling@stock pressure. But that's not what you installed. You have a Hi volume AND Hi pressure pump. With the pressure you're seeing, you're aerating the oil, and taking unnecessary power from the engine to drive it. Not only that, but increasing the pressure to that degree will increase the oil temp. A lose/lose/lose proposition. If you plan on high speed events like the 1 mile top speed runs, you may pump the pan dry. Hi volume pumps like the Melling are fine, as they're pumping only about 20% more volume. High volume at stock 60lbs of pressure is fine. The problems start when you shim the relief spring, install the Hi pressure spring, or shim the Hi pressure spring on the Hi volume pump. My .02, and I've been wrong before......

 

yea, but given the low pressure I figured it could have been loose bearing tolerances as the car has never really Been warmed up long enough to get the oil good and hot and when I did I had zero pressure. What are the cons of 100+ psi on the street? Besides blowing up a filter or pushing past a gasket? I could run a 20wt oil to help with the pressure and I left the spring that it came with which is the medium pressure. Lower pressure spring should knock off 10psi.

 

I did not pull a cap. Thought for a while on it but I saw no copper/bronze in the oil so said F it and didn’t want to let the magic out. I just stuck the HV pump in and and let it eat.

 

I’ve l heard the single bolt setups can put the oring at an angle and cause a leak. The double with a brace is so you get the flange flush with the tube and get a better seal.

engine is back together and didn’t pull a cap, 111psi of oil pressure with M355HV pump at 2500rpms with 5w30 conventional.

 

You will have problems, eventually, running that high of oil pressure. Please read my entire post. You've basically swapped oil pressure problems.......

 

Ive read from a few places that High oil pressure isn’t bad unless you cavitate, aerate or suck the pan dry (plus not blow up the filter). Some stock LS7 engine run at 100+ psi oil pressure.

what I don’t understand is how I’m getting so much pressure as the relief valve should Open. I’m running the standard spring too and not even the high pressure. Oil temps also aren’t up, this is just idling in my garage for 15-20min. I suspect oil pressure will drop a good bit once it gets warm. I can also always swap to a lower pressure spring and drop oil weight to 5w20 or even 0w20. I actually run 0w40 in my other car that has a turbo 5.3 with the LS6 “GM hv pump”.

anyways here is one thread I pulled from.


“the Simple answer is...as long as you dont collapse/blow up the oil filter, and as long as you dont cavitate the oil, or suck the pan dry.... you can never have too much

the low side all depends on the use....
of course you already know the 10psi per 1000 rpm rule...
but some engines dont even need that much...
I know some diesels spec out at 2psi minimum at idle.....because that is all it takes to float the crank and prevent bearing damage because of how well they are built and how much tighter their machining tolerances have to be to support the power they make.

on my setup... at idle I have 75-80 psi cold, and 60-65 psi hot.
at WOT, I have 130-135 psi Hot (I dont know about cold because I dont go WOT until all Fluids are warmed up

I know some promod guys, and they all have 70-90 at idle and 130-150+psi at WOT(some have more than that)


again.. they key is that you dont suck the pan dry, and you dont cavitate the oil or froth it up...

other than the oil filter, there is nothing you can hurt from high oil pressure
so just be sure to use a Wix or K&N filter that have been tested to over 300 psi with no issues.

if you have turbos or an oil fed supercharger, you may need to restrict the feed line to keep too much oil from going into it and overflowing it.

get a high flowing oil pump like the Schumanns Race pumps, and you will see a rise in pressure because of the rise in flow(you can only flow so much fluid thru the passageways, so pressure goes up because flow cannot increase without a pressure increase if the oil passage stays the same size)“

 

the relief can only relive so much. if a hoss pump can out perform the relief... psi goes up, oil gets aerated, and cavitation happens with more rpm.

 

having said that, get the oil up to 200* and see what the pressures look like.

 

Idling for 15-20 minutes there and the oil is hot. It will get a bit warmer at rpm under load, but it was already at 180 after 15 minutes. Too much pressure/volume in the crankcase and you’ve got windage issues. Windage both in the crankcase and under the valve covers. Windage causes power loss and oil frothing. Frothing is foam and along with cavitation, puts air bubbles in the oil. Problem with air in the oil is that air is compressible and doesn’t show up on the oil pressure gauge. As Grinder said above, you’ve went from one oil problem, to an extreme other oil problem. 100 lbs cold and dropping to 50-60 at temp is acceptable, but if it’s staying at 100 when hot, you’ll have problems. If your running the factory PCV setup, you’ll be sucking a ton of this mess into the intake, causing more problems.
The Pro-mod guys are running dry sumps. A dry sump setup can allow an engine to survive with extreme pressures because the vacuum pulled on the engine from the dry sump removes the “atmosphere” from inside the engine. All splash oil from the bearings and associated windage is pulled out the bottom very quickly with a dry sump setup, so there isn’t time for cavitation or frothing. I’ve never seen an Oem ls7 with 100 lbs of pressure personally. I have the Melling 10296 pump in my 434, with middle of the road bearing clearances. I have 75 lbs at cold start and I will jump to 100 if I touch the throttle. It goes down to 40 at hot idle and 50-52 at cruise.

 

On my other car I have a 5.3 with a single turbo with a temp sensor in the oil level port. On that car I need to be driving for 30+ min to see any real oil temp. I drive it to work during the summer and by the time I get to work the oil temps might be 140ish degrees. On that car the oil only gets to 180 ish according to the gauge and it’s a backroad slower speed kinda drive. I’m not sure how long it takes the oil to get Up to temp but even the radiator doesn’t really budget temp wise in 15-20min and that’s with the trans cooler in the rad being used.

yours sounds similar to mine with the touching of the throttle. I have no idea what hot oil idle and throttle is yet so I will have to see. I’m also aware I might have to
remove this and maybe do a M2095 style pump depending on what the numbers look like.

 

Wow, that’s odd to me. My C5Z and my Chevelle have an oil temp gauge. Both have 180 degree oil after 15 minutes, as well as 2 other C5’s I’ve had. Doesn’t matter if it’s winter or summer either. 30w oil here. Doesn’t matter really. Do what it takes to get your oil hot, and then see where your pressure is. Hopefully It’s fine and your golden.

 

The one side worry, many automotive oil filters don't handle 100PSI well , especially the cheaper ones.
I've seen a couple blow the can off at about 120.....

 

Lots of suggestions and now comes the "ya, but" responses.
I'm done.