Have an 02 Z06.. Still sbe ls6, but pretty healthy setup and changed that this winter. Went to TFS 220s from TEA Stage2 243s. LS3 hollow stems, etc, BTR shaft mount, Johnson ST2126lsr's, Manton 11/32 120 wall rods... That all being said, I replaced the oil pump back when I originally did the heads and cam back in 2017. I put a Hubbard high volume in the car back then, oil pressure with Amsoil Dominator 10w-30 is around 33-36 hot. Now with the axle oiling on the Johnsons, should I worry about changing the pump? (Melling 10295 most likely)... If the pressure only drops 3-5psi as from what I have seen from others, then a hot oil pressure of 28-31 doesn't worry me realistically.. But just wondering what others suggest.

 

Melling has proven itself in many of builds

 

Thanks, and yes I know.. But that doesn't answer my question.

 

I would check the oil pickup tube oring.

 

What would you like me to check the oring for?

 

It can be common for the oring on the pickup tube to become brittle over time and crack, leading to the pump (no matter which one you have) sucking air and reducing the ability of the pump to correctly pull oil from the pickup. Or, it could have been not seated correctly, or someone could have chosen the wrong size oring. Any one of those scenarios would result in a cause of low oil pressure.

Imagine trying to drink water from a straw with a hole in it.

 

What I meant was, there is no reason to check the pump pickup oring when I'm asking about replacing the pump to a higher pressure unit due to me changing to lifters with axle oiling, which will more than likely cause a pressure drop. The car isn't running currently. I don't have an oil pressure problem currently either.

 

Ahh, I see, your original post wasn't clear what the situation was. Sorry if I misread, If you had 33 PSI hot oil pressure, I would just off the top of my head say thats on the low side, hence why we all jumped to solving that problem first. I plan on running the Melling 10296, just my .02 there.

 

I'm fine with the pressure where it's at now. Still gains 10psi per 1k. I've seen perfectly healthy engines run at low to mid 20s for years. I was going to look at the 355 as well

 

With the axle-oiling lifters you now have an extra 16 holes in your engine for the oil to leak from. I’d go with the Melling 10296 for more volume to account for this and I’d have it ported by Tony Mamo if you can’t port it yourself. Porting the pump entrance and exit drastically reduces cavitation in the oil. I run the 10296 ported by Tony with axle-oiling lifters along with a big cooler setup and it works great.

 

I do have the ported Hubbard high volume. Can't recall the difference of that versus stock. The 296 is high pressure/high volume right?

 

Correct. HV+HP

 

Okay, I'll think that one over. I'm really debating it since I'll be building a 408 for it over the next year.. So I'll be buying a new pump for that anyway. I just have the steering rack out currently, so pulling the balancer and water pump wouldn't be much more at this point

 

Scott

The 296 is actually only high volume....however while it comes with a standard pressure spring installed, it also comes with an optional red high pressure spring in a small parts bag that a customer could install.

My opinion on this situation is you don't really want pressure......you want volume.

"Standard" pressure is more than enough.....higher peak pressures drive the pump harder, costs you a little more power to drive it harder, and sprays engine oil from the bearings all over your cylinders giving your oil rings a much harder time of clearing the cylinder walls. Also more oil spraying in the crankcase and everywhere else creates more windage issues as well (and more drainback from the top end). There is just alot of excess oil and that will cost you a little power. One of the reasons a dry sump engine makes more power is the engine has less oil flying everywhere.

I see no need to have more than standard pressure especially with thinner higher quality synthetic oils and all the pumps I port and send to my customers are usually high volume but they always ship from me with the standard pressure spring installed (blue in color).

That said at lower engine speeds a higher volume pump will create more pressure (idle and low RPM cruising) because at lower speeds the pump isn't moving as much oil so in this situation volume dictates the pressure created. At much higher engine speeds the pump is moving ALOT of oil and creating more pressure so the bypass valve opens up capping the peak pressure of the pump.

The stouter red spring supplied by Melling (and installed from them in their higher pressure model pumps) is stiffer and it delays the opening of the internal bypass creating higher peak pressure (not lower RPM pressure) but I see very little benefit in that situation for all the reasons stated

Im sure you will get other opinions out there but that's mine.....LOL

Hope this helps

-Tony

 

Tony,

Thanks for the detailed response. As I mentioned in the OP, the car currently has a Hubbard ported pump on it. I think it sounds like I will be fine here for this next season. Now when I do my 408, then I will purchase a new pump and most likely go with the 296.

 

There are ported pumps and ported pumps.

I wont name names but I have seen some of the internals of "ported" pumps by big name companies. Most don't even touch the inside.....they just port the inlet area which does very little in moving more oil but is the obvious thing most people see (most don't disassemble them).

We hit that area also but that's not where the big improvements are found.

The largest gains are found opening up the internal pressure passages and radiusing all the brutal sharp square edge entry points made by end mills and drills etc. at the manufacturer and creating a short turn in the exit of the pressure side as well (also a brutal sharp edge turn from the factory)

Just to be clear, I have no idea how good or bad Hubbard's oil pump porting is.....I never seen one of their pumps apart.

Im just letting you know that ported oil pumps in general are like ported intakes and ported heads. They all sound and read the same on paper but in the real world there can be vast differences in how they perform.

Seems some guys never figure that out while others figure it out right away or certainly after they get burned a few times

Automotive performance is like every other technical "hobby".....99 out of 100 times you get what you pay for.

-Tony

 

Your current pump is fine and your pressure is fine. I don't start to worry about oil pressure until it gets down into single digits at idle. Even that is acceptable in some applications. You'd be surprised how little oil pressure you actually need.

 

This is correct though the same can happen with higher volume through wider clearances. The issue I look for the most with high oil pressure >70 psi is aeration. The capacity of entrained air in the oil increases exponentially as pressure increases. There's been cases of bearing cavitation due to excessive aeration 80-90 psi oil pressure.

 

Poly, what would be the max pressure you would run in a LS up to 8500rpm? 70psi?

 

70 psi is plenty.