spf8298

I'm doing a cam install on my '99 vette and need a little input as to which oil pump to go with. I know the ported will give me a boost in pressure, but what are the pros and cons of more oil pressure?
Thanks for any help you can provide.

Shaun

Blacked Out

Heres a bump for you. I couldnt get an idea of the big difference it would make in my car so I went with a LS6 stocker. It was a bit cheaper and no one could tell me definitively that it would be better to have it or not so I elected not.

Bandit28

iTrader: (28)

As long as your stock oil pump is young and does not have to many miles on it, you should not need a ported oil pump at all. I have great oil pressure with my 402 on a stock ls1 pump

A-Dub

iTrader: (6)

I just replaced mine...bought a stock LS6 oil pump, ported it myself with my dremel and a couple bits. Picked up a solid 15 psi across the board, which was crucial for me, I was hot idling in the 25-30 range. Haven't had the car drop below 40psi since the swap.

If you are happy with your stock pressure, you could just port it while doing the swap. I didn't see what all the fuss was about with the Oring. It was so easy, I thought I did it wrong.

michael402z06

iTrader: (15)

you wouldn't really need a ported ls6 pump with just the cam install. but they aren't that expensive either. i have a stock ls6 oil pump off my z06 if you need one.

DaddySS

The ported pump will give more volume which may be important at higher RPM operation but not more pressure. Pressure is determined by the relief spring. Some pumps have a higher relief pressure spring and if you are concerned about low pressure may be a way to go. The LS6 pump is higher pressure than the LS1 to begin with ( I believe I read somehwere) so in most cases a stock LS6 pump will be more than enough for reliable operation and good pressure.

Insanekamel

i asked my tuner and he said a ported ls6 is a WASTE of money for that same amount you can but a melling 10296 or 10295 which is a hi-volume oil pump for the ls1.

its going to be installed this weekend hopefully. i will let you know the diff over stock

A-Dub

iTrader: (6)

Bullshit the ported pump doesn't increase pressure....I just did it myself, didn't shim the spring and I picked up a solid 15 psi.

67Firebird455

iTrader: (27)

Strange, theoretically it wouldn't increase pressure that much since you're removing casting flaws, and more or less, that's it... The added volume shouldn't make an increase that much, but who knows, great for those who increased 15# by grinding some casting flaws! =)

A-Dub

iTrader: (6)

Theoretically it shouldn't increase flow either. The amount of flow would be dictated by the smallest cross sectional area, and that area is where the pump meets the block, which isn't ported. The gains come in because you smooth the entryway for pressurized oil to exit the pump and enter the block....this reduces the frictional losses and (I think) changes the actual flow pattern which allows for an increase in both volume and pressure.

DrkPhx

iTrader: (15)

Not everyone see's big gains with ported oil pumps; especially 15 psi. On my old setup I ported my stock pump and maybe saw a couple psi increase. For my 402 I just installed a new stock pump and oil pressure is 40 psi at hot idle and 60 when cruising.

Charlie@LsXperts

iTrader: (12)

im at 101k with my stock oil pump 1999 camaro btw... and i have great oil pressure, it has times when the gauge jumps around a little but thats mainly on HOT *** days and when i have the air on but i think its just hot *** days because thats the only way you will get me to turn the air on so......... but other than that i dont see the need in changing it, i watch it like a hawk so if it goes bad ill swap it out

DaddySS

Hmmm, a little agressive there? The LS6 pump makes more pressure than a stock LS1 pump, how can you be sure your porting had anything to do with the increase you saw?

Studytime

iTrader: (15)

Guys, I'm not a PUMP ENGINEER, but I stayed at a Holiday Inn Express last night...

J/J, The LS1/LS6 pump is a positive displacement pump. The special "LS6" is just an updated LSx oil pump. It's nothing special just an improved version of the LS1 pump as it [LS1 pump] is no longer offered.

"Porting" one these pumps WILL NOT increase pressure. It will simply reduce the efford required to spin the pump. Once ported it takes less power to spin the pump. That's where the advantage is. You don't port the pump for more pressure, you shim the relief spring in the assembly. You port the pump for than extra 2hp you'll see (just picked arbitrary number, point is it's low) .

Ben T.

98A4LS1

iTrader: (1)

Just buy a stock GM LS6 oil pump. When you look at the oil pump, it will be obvious where you can remove a little metal with a dremel or just leave it as is and you will be fine. I only saw a 6-8 psi gain when I replaced the stock '98 oil pump (45K miles) with a GM LS6 oil pump I ported.

A-Dub

iTrader: (6)

I am an engineer and I am very familiar with flow. Porting the outlet section does not change the amount of pressure generated at the rotor itself, but it reduces the head loss in the system, which increases the amount of pressure present at the outlet.

I had 25-30 psi hot idle before on my 98. Could have easily been a weak pump.

Studytime

iTrader: (15)

...hey wait a minute. I thought that a positive displacment pump (as opposed to a centrifugal) has constant pressure regardless of head. At least it did in Fluid Dynamics. Porting or eliminating losses would not have an impact on pressure it would only impact the amount of the work into the pump.

In may, I'll finally be an engineer too.

What you described would be a centrifugal pump.

Ben T.

SS_bnoon_SS

iTrader: (3)

Porting the pump also reduces the possiblity of internal cavitation, helping to maintain even pressure at a given RPM (especially the higher RPM's).

ShevrolayZ28

iTrader: (4)

But I think only the inlet is ported. And also, having a larger outlet than inlet will increase the likelihood of cavitation at the positive pressure side of the pump, if I'm not mistaken.

And I'm pretty sure that the increased pressure you saw when you went to the LS6 pump was due to it have a stiffer relief spring than your 98 pump had and not because of a larger inlet or outlet size.

No offense to anyone, but I like Studytime's take on this topic.

A-Dub

iTrader: (6)

Correct it is a positive displacement pump, but you are getting confused.

I realize the pump sits in a cast housing, but the pump itself is the rotors. You are correct, porting the pump casting does not change the pressure output at the rotors. The outlet for the casting is not related to the rotors, it is downstream as is the sending unit for the oil pressure gauge. Removing the casting flash removes losses in the system between the pump and the pressure gauge, allowing the system to see more of the pressure that the pump was already creating.

Think of it as porting the passages, not porting the pump. The pump itself is not changing, the system is. So porting the system increases volume and pressure.