Sbc very low oil pressure. Use thicker oil? - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 01-29-2013, 03:53 PM
bigdog7373's Avatar
Of course it's fast
 
Last photo:
Join Date: May 2010
Location: florida
Posts: 2,673
Wiki Edits: 0

Thanks: 13
Thanked 49 Times in 49 Posts
Sbc very low oil pressure. Use thicker oil?

Hey guys the 350 in my car has very very low oil pressure at hot idle. Cold idle its very good. Hot idle in gear is literally sitting just over 0 on the gauge. In neutral it comes up to like 4 or 5psi, then when cruising it looks ok. Just slightly under 20psi. The annoying thing is that it doesn't have many miles since rebuilt. I was thinking maybe the filter is clogged, but I didn't think that it will affect oil pressure, at least not this much. I was thinking of getting a fresh filter and some thicker oil and seeing what that does for it. What would be a good oil to get? I would think 20w50 is too thick. It has 10w30 in it now. I don't know if 10w40 is a big enough jump to make any difference. Any help is awesome. Thanks

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 01-29-2013, 04:30 PM
How fast is fast enough?
 
Last photo:
Join Date: Jun 2005
Location: St. Louis, MO
Age: 29
Posts: 9,193
Wiki Edits: 0

Thanks: 17
Thanked 338 Times in 318 Posts
10W40 will make a difference, hell just throwing in 1qt of 60w into what is currently in there will probably bring it up in about 30 seconds. Since its just rebuilt y9ou may be running large clearances and need a thicker oil, just go thick enough to get good idle pressure though (10psi) and leave it at that, too thick of oil can cause other problems too, especially on a street car that can see short trips where the oil doesn't get hot enough.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 01-29-2013, 04:55 PM
delawarebill's Avatar
Registered User
 
Last photo:
Join Date: Mar 2009
Location: delaware
Posts: 1,296
Wiki Edits: 0

Thanks: 19
Thanked 69 Times in 69 Posts
pressure

pressure is good but flow is MORE better.. (thats gooder english)
ck the filter for sure. i'd stick with the 10/30. have u ck'd it with a good gage at the dizzy port area ?? there are others on here of more knowledge then me..
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 01-29-2013, 04:58 PM
LATECH's Avatar
Hotrodders.com Moderator
 

Last journal entry: Motor - vator
Last photo:
Join Date: Jul 2010
Location: Northeast Pennsylvania
Posts: 5,294
Wiki Edits: 0

Thanks: 220
Thanked 268 Times in 248 Posts
20 psi at cruise is too low. 0 is also too low. chances are it wont last long before
I would tear it down Dog. Something aint right, and you risk damaging some parts pretty seriously if not taken care of.
A newly built motor should be resting at 40 ish at Idle when warm.
__________________
Fact is stranger than Fiction
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 01-29-2013, 05:33 PM
bigdog7373's Avatar
Of course it's fast
 
Last photo:
Join Date: May 2010
Location: florida
Posts: 2,673
Wiki Edits: 0

Thanks: 13
Thanked 49 Times in 49 Posts
I thought a rebuilt sbc goes by the 10psi per 1000rpm rule.
I can't tear it down either, Im living in a rental house in a community that hates my car. No joke they yell at me for it being too loud and "unsightly". I'm 100% sure they wont be happy if I rip the engine out in my driveway. I'm going to exhaust all my options before I do anything like that. I'll try the heavier oil and new filter first and see how it goes. 10w40 will be enough?
Hopefully that will get it up to an acceptable pressure. If not then Im not sure what I'll do with it. I've been wanting to drop an ls in there for a while now.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 01-29-2013, 05:48 PM
LATECH's Avatar
Hotrodders.com Moderator
 

Last journal entry: Motor - vator
Last photo:
Join Date: Jul 2010
Location: Northeast Pennsylvania
Posts: 5,294
Wiki Edits: 0

Thanks: 220
Thanked 268 Times in 248 Posts
Lots of places like that in florida , so I understand.
10 lbs per 1000 is a general rule.
All of the 350 SBCs I have ever built have carried 40-45 PSI , fully warm on 10w30 at Idle.
Sounds like You have a clearance problem somewhere. JMHO
__________________
Fact is stranger than Fiction
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 01-29-2013, 05:48 PM
How fast is fast enough?
 
Last photo:
Join Date: Jun 2005
Location: St. Louis, MO
Age: 29
Posts: 9,193
Wiki Edits: 0

Thanks: 17
Thanked 338 Times in 318 Posts
Instead of swapping out all the oil just add a qt of 60w first and see what happens.

and yes, 10psi per 1000rpm when hot.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 01-29-2013, 07:00 PM
Jake_Dragon's Avatar
Member
 

Last journal entry: New Carb
Last photo:
Join Date: Jul 2005
Location: Central Florida
Age: 49
Posts: 772
Wiki Edits: 0

Thanks: 2
Thanked 2 Times in 2 Posts
20w40 in the summer and I have great oil pressure. 50000 miles later I am still running the same oil and have the same oil pressure.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 01-29-2013, 07:10 PM
bigdog7373's Avatar
Of course it's fast
 
Last photo:
Join Date: May 2010
Location: florida
Posts: 2,673
Wiki Edits: 0

Thanks: 13
Thanked 49 Times in 49 Posts
Quote:
Originally Posted by ap72 View Post
Instead of swapping out all the oil just add a qt of 60w first and see what happens.

and yes, 10psi per 1000rpm when hot.
Ive been meaning to change it for a few weeks, might as well do it now.
Quote:
Originally Posted by Jake_Dragon View Post
20w40 in the summer and I have great oil pressure. 50000 miles later I am still running the same oil and have the same oil pressure.
Thanks. I was gonna try 10w40 with some w60 mixed in and a zinc additive for the flat tappet.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 01-29-2013, 08:04 PM
carolinacustoms's Avatar
Automotive Extraordinaire
 
Last photo:
Join Date: Dec 2012
Location: Connelly Springs NC
Age: 32
Posts: 1,041
Wiki Edits: 0

Thanks: 391
Thanked 262 Times in 221 Posts
If I had to take a guess, I'd say someone did not change the cam bearings OR installed them turned wrong (it's easy to do, been there myself), and I also had a guy bring an engine by that was a fresh rebuild with less than 1,000 miles NO oil pressure. The builder (who was supposed to know what he was doing,) did not use any assembly lube. Needless to say the bearings were all junk. But I am completely guessing. I have had good luck with "Hi-tach" and Lucas products for quieting down noises and increasing pressures a bit. I run one or the other in all my high mileage engines, but just my input on it. Either way you most likely have an internal problem and will eventually have to pull the engine, however the thicker oil or additive will buy you sometime. Again ALL of this is JMHO, Best of luck with it

Kelly
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 01-29-2013, 08:27 PM
vinniekq2's Avatar
Registered User
 
Join Date: Jun 2012
Location: BC,Canada
Age: 56
Posts: 8,305
Wiki Edits: 0

Thanks: 342
Thanked 812 Times in 778 Posts
I use heavy oil all year.
Just for your information,some of the older BMWs have almost no oil pressure at idle when new.Just the design. what brand of oil filter do you use?
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 01-29-2013, 08:40 PM
GMCTRUCKS's Avatar
Registered User
 
Join Date: Dec 2006
Location: Texas, Coast
Age: 54
Posts: 327
Wiki Edits: 0

Thanks: 0
Thanked 5 Times in 5 Posts
Many of people rebuilt engines but don't do them correct to me building is if the factory would have done with all there specs not just replacing the rings and head work one needs to do all the bearings.

Try Castrol High Mileage oil oh im not saying you didn't do it correct im thinking you had someone do the work for you. Good luck my friend.

Many moons ago a friend of mine rebuilt a 455 HD engine well he had so much blow by he had a water hose atteched to valve cover going under the car that was sad since he had all HD parts he just didn't put it together correct.
Reply With Quote Quick reply to this message
  #13 (permalink)  
Old 01-29-2013, 09:01 PM
bigdog7373's Avatar
Of course it's fast
 
Last photo:
Join Date: May 2010
Location: florida
Posts: 2,673
Wiki Edits: 0

Thanks: 13
Thanked 49 Times in 49 Posts
Its an stp filter. I run them on all my cars. I don't know how long its been on there though, definitely gonna change it.
I'm not going to doubt that there are large bearing clearances, but the block checked out ok and the cam bearing looked faily new so I left them alone. No blowby or anything. It runs great and no noises. Could the pickup be clogged? Maybe from debris during breakin?
Reply With Quote Quick reply to this message
  #14 (permalink)  
Old 01-29-2013, 09:18 PM
carolinacustoms's Avatar
Automotive Extraordinaire
 
Last photo:
Join Date: Dec 2012
Location: Connelly Springs NC
Age: 32
Posts: 1,041
Wiki Edits: 0

Thanks: 391
Thanked 262 Times in 221 Posts
Quote:
Originally Posted by bigdog7373 View Post
Its an stp filter. I run them on all my cars. I don't know how long its been on there though, definitely gonna change it.
I'm not going to doubt that there are large bearing clearances, but the block checked out ok and the cam bearing looked faily new so I left them alone. No blowby or anything. It runs great and no noises. Could the pickup be clogged? Maybe from debris during breakin?

That is a possiblity, not sure break in would have caused enough to clog it, but something may have. And for the record I wasn't saying you built the engine wrong just giving ideas of what may be the cause. After I read my post it did not read the way I intended. Sorry if I came across wrong.

Kelly
Reply With Quote Quick reply to this message
  #15 (permalink)  
Old 01-29-2013, 09:19 PM
lg1969's Avatar
Google "Tunnel Ram 406"
 
Last photo:
Join Date: Oct 2007
Location: Bohemia, L.I.N.Y.
Age: 64
Posts: 1,059
Wiki Edits: 0

Thanks: 1
Thanked 21 Times in 18 Posts
Quote:
Originally Posted by bigdog7373 View Post
Hey guys the 350 in my car has very very low oil pressure at hot idle. Cold idle its very good. Hot idle in gear is literally sitting just over 0 on the gauge. In neutral it comes up to like 4 or 5psi, then when cruising it looks ok. Just slightly under 20psi. The annoying thing is that it doesn't have many miles since rebuilt. I was thinking maybe the filter is clogged, but I didn't think that it will affect oil pressure, at least not this much. I was thinking of getting a fresh filter and some thicker oil and seeing what that does for it. What would be a good oil to get? I would think 20w50 is too thick. It has 10w30 in it now. I don't know if 10w40 is a big enough jump to make any difference. Any help is awesome. Thanks
There are two areas you should check. A defective oil pump or the distributor itself. The housing itself may not be sealed causing the oil passage to leak back in the oil pan. I had to replace my distributor twice. Once on a 307 and most resent my 406. Hope this helps ya.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last 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 for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Low oil pressure on SBC lg1969 Engine 30 05-30-2013 05:00 PM
Low oil pressure sbc 350 Lightspeed Engine 2 10-16-2011 01:25 PM
sbc low oil pressure 1967chevelle454 Engine 5 02-27-2009 06:02 PM
SBC HVP oil pump, low pressure tnsmith10 Engine 14 01-12-2009 05:28 PM
305 sbc with low oil pressure??? Help 91olds305 Engine 17 10-14-2002 06:57 PM


All times are GMT -6. The time now is 10:16 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.