Team Camaro Tech banner
1 - 16 of 16 Posts

·
Registered
Joined
·
620 Posts
Discussion Starter · #1 ·
My 67 camaro has a 74 or 75, 350 in it that was just rebuilt last year. I bought it after the rebuild so I dont know what exactly he put in it.. It runs very well and hard but my question is that it will start out at 75 psi oil pressure or so (cold) and then gradualy drop to around 60 where it stays after it warms up. Is this normal for a new rebuilt engine? I this what high volume pressure pumps run at? Ive only got about 3000 miles on it.
 

·
Registered
Joined
·
567 Posts
Too much oil pressure is when you blow the oil filter off. Don't ask how I know!

------------------
------------------
Mark

1992 Firebird 355/Six Speed (Soon to be LT1)
1991 RS 350 / 700-R4
1987 Toyota Pickup 383 / 500 + HP 10.963 @ 119.95 Slicks / 11.997 @ 114.23 Radials
"Speed KILLS, so drive a FORD and live forever!"
http://personal.lig.bellsouth.net/~racer383/

Member of the "unwanted" 3rd Gen group.
 
  • Like
Reactions: jcabuilder

·
Registered
Joined
·
6,138 Posts
And too high flow (high volume) oil pump can suck the pan dry at high rpms (and fill the valve covers).
That's why Lingenfelter says to use the standard oil pumps.

Kurt
 

·
Registered
Joined
·
52 Posts
I agree your oil pressure doesn't sound too high and I wouldn't be concerned, but it is above average in my opinion with the engine hot. Anyway, like the other reply indicated too much oil pressure can drain the oil pan, blow off filters and gaskets, a std oil pump is all you need for a street machine. The racers, like NASCAR use hi volume pumps, but then they have 20 times as much oil in their system too. Also, keep in mind that if your oil is circulating too fast it won't tranfer its share of heat from the engine and lubrication films might be thinner than desired. In this case you'll be working the raditor/water cooling system overtime. Lots of people that have hot running engines just assume their raditor is too small or thermostat setting is too high, when in actuallity their oil system isn't flowing at the right speed or an inadequate amount is available. If you notice, all race cars have oil temperature gauges to monitor this critical parameter in hi performance engines. My 2 cents worth..

------------------
George Thomas
1969 Camaro Z28 X77
[email protected]
http://members.aol.com/gthomas917/private/gt.htm
 

·
Registered
Joined
·
448 Posts
I'm going to put a high volume pump and a 7 quart pan on my 330 hp crate motor for my 69. Do you think this will be the wrong thing to do?

------------------
Black 69 camaro
 

·
Moderator
Joined
·
11,631 Posts
My engine builder changed something on the pump to turn a high pressure/high volume pump to a high pressure/standard volume pump. Maybe a spring or something. Kevin

------------------
69' SS-350 ragtop, M20, 3.55 posi. Totally Disassembled & in boxes (I'm working on it!)
69' Hugger Orange Z-21 ragtop 327/PG, Driver
 

·
Registered
Joined
·
622 Posts
Yep, it's a simple spring change, the heavier, the more pressure I have stretched stock springs and have had no problems
John
 

·
Registered
Joined
·
301 Posts
Just to clarify some things that have been said here:

High oil pressure will not necessarily drain the pan, but high volume can at high rpms. Volume and pressure are two different issues. A high volume pump will not necessarily produce any higher pressure over a stock pump, just a high amount of oil. A standard volume/high pressure pump will pump about the same amount of oil as a stock pump, but at a higher pressure.

The idea that high volume/high pressure pumps will blow gaskets is a myth (with the exception of the oil filter gasket). This is because no gaskets (that I can think of) in a small block or big block chevy engine are in contact with pressurized oil, they just keep oil splash controlled and inside the engine. If your oil pump produces 60 psi of oil pressure, the only parts of the engine that see this pressure are the crank and rod bearings, the cam bearings, and lifters (Hence, no gaskets). Think about it: your rockers are lubricated by oil simply splashing around in the valve covers and the timing chain is lubricated by oil splash from the front drain holes in the lifter valley and oil splash from the oil pan.

------------------
Justin
-1967 Camaro SS350

www-student.furman.edu/users/j/jtrauner
 

·
Registered
Joined
·
6,513 Posts
You can't change the flow characteristics of an oil pump by changing the relief spring in the pump. Volume produced by the pump is a function of the diameter of the pump body and the shape of the gear teeth in the pump. If someone changed your spring to modify a high volume pump to a standard volume pump they did it by lowering the pressure at which the relief valve opens thereby dumping the extra oil into the sump. The pump continues to pump the same amount of oil through the pump gears you are just bleeding off some portion of it before it gets to the engine. You now have a standard volume, lower pressure pump in the car.


------------------
Mark Canning
1969 Indy Pace Car
350/300HP RPO Z11
 

·
Registered
Joined
·
1,553 Posts
Many times simply using a less viscous oil, e.g. 20 w 50 to 5 w. 30. can lower the oil pressure, especially when the engine comes up to operating temp.
 

·
Registered
Joined
·
312 Posts
<BLOCKQUOTE>quote:</font><HR>Originally posted by HOTROD69CAMARO:
I'm going to put a high volume pump and a 7 quart pan on my 330 hp crate motor for my 69. Do you think this will be the wrong thing to do?

<HR></BLOCKQUOTE>

the stock pump is a good pump no need to change it out. just change the pick-up tude if needed for the new pan.

a high volume pump take's more hourse power to run then it is worth. all the racer's i know that run a wet sump use a stock pump and have no problem's running at 6 grand all day long.

oil pressure is made by the cam bearing's and crank bearing's not the pump. if your motor is "tight" you will have high oil pressure.

by tight i mean at the perfect spec for clearance or on the tightest alowed spec.

a high volume pump will not make more pressure then a stock pump, it just move's more oil per second then a stock one.

IMHO they are a waste of money, they do not give you much for what you give away for it, meaning hourse power. i belive it take's around 3 to 5 more hourses to run a high volume pump.

[This message has been edited by ilbl8 (edited 03-15-2001).]
 

·
Registered
Joined
·
6,138 Posts
I agree with 'ilbl8'.

What problem are you trying to solve? There aren't any design issues with the stock oil system.
And the higher whatever pumps suck more power.
Read Lingenfelter's book.

I disagree that high volume pumps can't suck the pan dry. My brother put a hi volume one in a 69 stock Vette. Had knocking at rpm. Pulled the fresh rebuild apart, all the clearances were fine. Put it back together, still knocked. Someone suggested the pump, swapped in a stock one, ran great, no knocking.

------------------
Kurt S.
www.camaros.org
 

·
Premium Member
Joined
·
7,728 Posts
Don't forget what drives the pump - it's the distributor shaft; high-volume pumps take more power to drive, which increases the load and wear on the distributor drive gear, especially bad scene if you have a roller cam and a bronze gear on the distributor gear, which wear out prematurely anyway WITHOUT the added load of a high-volume oil pump. Also, surging and cavitation in a high-volume pump can affect your timing at high rpm ("spark scatter") due to shaft oscillation. Stick with the stock pump, it'll last longer than you will.

------------------
JohnZ
'69 Z28 Fathom Green
 

·
Registered
Joined
·
8,097 Posts
OK another opinion here. I agree that most do not need a high volume oil pump especially for a street ride. But - I think having a spring with a higher set point is important if you rev your motor higher than designed RPm's (most V8's weren't intended to run past, say 5500 RPM). What happens when RPM's increase - pressure increases and flow increases until the spring unseats, then pressure and flow stay about the same regardless of rpm. 40 psi may be OK at 5000 RPM's but if you rev to 6500 or 7500 RPM, I personally like the assurance that I've got a little extra pressure. I've always run High volume / High pressure oil pumps and never ran a pan dry in a 1/4 mile blast, running stock 4 quart oil pans. I can see how the circle track guys might run into trouble though. Maybe it's not that big a deal . . .
 
1 - 16 of 16 Posts
Top