Oil pressure, enough? - Team Camaro Tech
Engine General Engine Discussion.

 
LinkBack Thread Tools Display Modes
post #1 of 9 (permalink) Old Jan 8th, 06, 06:54 PM Thread Starter
Senior Tech
SS
 
Join Date: Jun 2002
Location: U.S.
Posts: 535
Unhappy Oil pressure, enough?

Background:
When the machine shop built my 406 they used a m77 standard volume pump. I needed to use a BB pump due to the .75" p/u.

I know that the clearances were correct when the engine was assembled. The pressure really hasn't changed from when I first got it running last winter.

Pan is 7qts plus the filter!

Hot at idle it has 20-16psi, 35-38psi at 2000rpm going down the highway. At WOT it goes to 40+psi, and thats it.

The problem I believed is somewhat based on the fact that we used direct lube/cool run solid lifters. each has .020" hole which equates to something like a 3/8" hole, or internal oil leak.

the last engine/pump was an Hv and went 55psi at 3000rpm, but the clearances in that 383 were big and idle was equally as bad and that was w/o the direct lube style lifters.

My question is; how much is enough? I have heard some factory manuals state 9psi at idle for stock sbc, which this really isn't.

I am considering putting in a HV/HP milodon 18760 BB pump. But of course this entails major surgery of removing the entire engine and the car is running nearly perfect!

Any info or suggestions are appreciated. SS

406, TKO 600 and 12 bolt posi.
railing68 is offline  
Sponsored Links
Advertisement
 
post #2 of 9 (permalink) Old Jan 8th, 06, 07:55 PM
Senior Tech
 
Join Date: Feb 2004
Location: Shalimar, Florida
Posts: 151
Re: Oil pressure, enough?

I've always heard you need 10 psi per 1000 rpm. This is from professional engine builders, not my cousin Bubba Ray.

First thing I'd do is verify the accuracy of your oil pressure gauge. I've had them go bad on me before.
Sporter is offline  
post #3 of 9 (permalink) Old Jan 8th, 06, 08:02 PM
Gold Lifetime Member
Robert
 
Join Date: Oct 2000
Location: Simpsonville, SC
Posts: 3,359
Re: Oil pressure, enough?

It looks good except for the WOT part, that might be a little low. My' 69 is below 15 at idle hot. With all you've done I hate to ask but has the gauge been verified to be accurate. My '67 has a HP pump and shows it on the guage and the '69 has a HV pump which seems to show it in terms of leaks. I'll go stock pump next time for sure.

Robert

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
355ci 10:1, 64cc Edelbrocks, Comp Mag 280H, Performer RPM, 700r4 (2000 stall), 3.55 posi A/C PS PDB Hotchkis

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
369ci 10.3:1, 64cc Edelbrocks, Voodoo 276/284, Performer RPM, Holley 650DP ...T56 Magnum, 3.73 Moser 12 bolt
TC member #18
rojo is offline  
 
post #4 of 9 (permalink) Old Jan 8th, 06, 09:21 PM Thread Starter
Senior Tech
SS
 
Join Date: Jun 2002
Location: U.S.
Posts: 535
Re: Oil pressure, enough?

I put a pro comp guage on when I primed it on the stand, and it read only 34psi from my craftsman 1/2 drill. So to answer the question not in the car as a direct comparison.

It would be easy enough to do though since it is a -3 braided line, a good idea that I will probably try however, I think the auto-meter mech guage is good that is in the car. From what I was told the spring in the pump could be the reason that it won't exceed around 44psi. Not sure but either way pan needs to come off.

I have considerered trying the swap in the car but, with a scattershield and a block plate, I don't know if that is even possible. Probably less of a headache to remove the whole thing. Total PITA, and of course there are no gurantee that pressure will increase dramatically. As far as oil pressure goes it seems to be a curse for me!
SS

406, TKO 600 and 12 bolt posi.
railing68 is offline  
post #5 of 9 (permalink) Old Jan 8th, 06, 09:47 PM
Senior Tech
Chris
 
Join Date: Jun 2005
Location: Wichita Falls, Texas
Posts: 537
Re: Oil pressure, enough?

I don't understand why you used a big block pump.

That is very old school and is OVERKILL oiling on a small block Chevy.

A good M55 pump, hardened pump shaft, a good oil pan with the matching pick up and proper bearing clearances should be more than adequate.

You can over oil a small block Chevy.

Advances in oil technology have come a long way since the 60's, 70's and 80's with new racing blends ans synthetics.

JMO

1967 Chevelle 496BB/TH400/Dana-60 (Show and Go)
1967 El Camino 388SB/700R4/12-bolt posi (Daily Driver)
1967 C10 Short-Wide 496BB/TH400/12-bolt (The Shop Truck)
2008 Harley Davidson Dyna Low Rider


Chris @
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Motorhead62 is offline  
post #6 of 9 (permalink) Old Jan 8th, 06, 10:10 PM Thread Starter
Senior Tech
SS
 
Join Date: Jun 2002
Location: U.S.
Posts: 535
Re: Oil pressure, enough?

I needed to use a BB pump due to the .75" p/u

Milodon road race pan uses a specific p/u that has a .75" inlet and bolts to the pump, if memory serves the body of the small block pump differs.

You can over oil a small block Chevy!


That is why the machinist/builder decided to use the standard volume M77 was worried about too much pressure and volume, something to the effect of washing the bearings.

I guess this is the real meat of my question, at lower pressures are the internal parts getting the appropriate volume(amount of oil) regardless of the pressure?

From what I have been told, BB pump is better in terms of pressure variances and distribution but that seems to almost be opposite in my case.

SS

406, TKO 600 and 12 bolt posi.
railing68 is offline  
post #7 of 9 (permalink) Old Jan 8th, 06, 10:24 PM
Senior Tech
Chris
 
Join Date: Jun 2005
Location: Wichita Falls, Texas
Posts: 537
Re: Oil pressure, enough?

There are stock volumn pumps available with the .75 diameter inlet.

What are your bearing clearances and rod side clearances?

1967 Chevelle 496BB/TH400/Dana-60 (Show and Go)
1967 El Camino 388SB/700R4/12-bolt posi (Daily Driver)
1967 C10 Short-Wide 496BB/TH400/12-bolt (The Shop Truck)
2008 Harley Davidson Dyna Low Rider


Chris @
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Motorhead62 is offline  
post #8 of 9 (permalink) Old Jan 9th, 06, 04:40 AM
Banned
 
Join Date: Dec 2003
Location: NORTH EAST
Posts: 938
Re: Oil pressure, enough?

Quote:
Originally Posted by Motorhead62
There are stock volumn pumps available with the .75 diameter inlet.

What are your bearing clearances and rod side clearances?
Side clearance does not regulate the oil flow its the bearing clearance as we run some piston guided rod engines with almost .100 side clearance and these engine run the same oil pressure as the rest of the engines we build.

I would maybe look at a cam bearing issue some times the rear cam bearing does not get put in correctly or even may have spun cam bearing as we have seen both of these problems brfore and we have run lifters with EDM holes in them before M55HV pumps and no problems and the pump your uising is HV type pump.
CNC BLOCKS N/E is offline  
post #9 of 9 (permalink) Old Jan 9th, 06, 09:53 PM
Senior Tech
 
Join Date: Jul 2005
Location: California
Posts: 2,353
Re: Oil pressure, enough?

not to try and give stupid input
but i switched from 10w-30 to 20w-50
and the oil pressure went up from 5 at idle to 25 and 40 max to 55-60 max
might help
400bird is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome