The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1947 - 1959 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 04-14-2018, 08:30 PM   #1
Fred n' Ethel
Registered User
 
Fred n' Ethel's Avatar
 
Join Date: Feb 2018
Location: Eastern WV
Posts: 161
Question Oil pressure

Hi folks.
In your experience, what does the following info indicate regarding the condition of my stock 1954, 235.
Outside temp 85f, 20 mile warm up city and highway.
Coolant temp never up to the midpoint.

Following oil pressures are est. from the stock 0-60 gauge.
At idle - 5 ish psi.
In 3rd gear, 25 to 30 in town - 10 to 14 psi.
Highway speed (50 to 55) 30 to maybe 32 psi.
Using straight 30W oil (100 mi. old)

Changing the oil soon, what would you recommend ?

Thanks
Fred n' Ethel is offline   Reply With Quote
Old 04-14-2018, 08:43 PM   #2
Black_Sheep
Registered User
 
Black_Sheep's Avatar
 
Join Date: Jun 2017
Location: upper midwest
Posts: 1,129
Re: Oil pressure

Quote:
Originally Posted by Fred n' Ethel View Post
Hi folks.
In your experience, what does the following info indicate regarding the condition of my stock 1954, 235.
Outside temp 85f, 20 mile warm up city and highway.
Coolant temp never up to the midpoint.

Following oil pressures are est. from the stock 0-60 gauge.
At idle - 5 ish psi.
In 3rd gear, 25 to 30 in town - 10 to 14 psi.
Highway speed (50 to 55) 30 to maybe 32 psi.
Using straight 30W oil (100 mi. old)

Changing the oil soon, what would you recommend ?

Thanks
Sounds low, the general rule of thumb is 30 psi @ idle and 10 more pounds per 1000 rpm. The first thing I would do before getting too carried away is check it with a different gauge to verify that your gauge isn't out of whack...
Black_Sheep is offline   Reply With Quote
Old 04-14-2018, 10:01 PM   #3
Fred n' Ethel
Registered User
 
Fred n' Ethel's Avatar
 
Join Date: Feb 2018
Location: Eastern WV
Posts: 161
Re: Oil pressure

I have a new gauge on the shelf, will try that tomorrow, thanks !

Found this while searching around .....
The full pressure 235 engines when new will have up to 50 PSI off idle and 20 ~ 35 PSI @ idle but that will usually drop by 10,000 miles .
Again , as long as the oil gauge needle comes up off the peg when you give it throttle , it's good to go , don't worry about it .
I was going down the freeway to-day at a good 65 MPH , engine singing it's song and oil pressure at maybe 30 PSI ~ it doesn't run hot and no discernable bearing knocks at any speeds or loads .



What is the modern equivalent of a "good" SUMMERTIME oil/weight to run nowadays ?
Thanks !
Fred n' Ethel is offline   Reply With Quote
Old 04-14-2018, 10:05 PM   #4
Speedbumpauto
Registered User
 
Speedbumpauto's Avatar
 
Join Date: Aug 2011
Location: Tucson, AZ
Posts: 917
Re: Oil pressure

Those things never had any real pressure to start with. You didn't say whether the cold pressure was higher than the hot pressure. If the cold pressure is somewhat higher than the hot, I'd change to a dino multi vis in the 20-50 or 20-40 range. That old 235 will live forever on 20-30 psi, IMO.
Speedbumpauto is offline   Reply With Quote
Old 04-14-2018, 10:50 PM   #5
Fred n' Ethel
Registered User
 
Fred n' Ethel's Avatar
 
Join Date: Feb 2018
Location: Eastern WV
Posts: 161
Re: Oil pressure

I'll take note of the cold pressures when I fire it up next time.
Will try the heavier multi-vis oil too.

I do understand the difference.
Just looks like this 54-235 is more resembling my 39-216
The 216 reallyworried me at first, till I learned it was better than average idling at 5 and rippin down the highway at 15.

Thank you.
Fred n' Ethel is offline   Reply With Quote
Old 04-14-2018, 10:52 PM   #6
Foot Stomper
Registered User
 
Foot Stomper's Avatar
 
Join Date: Oct 2015
Location: Calgary, Alberta
Posts: 1,252
Re: Oil pressure

Here's a short video (and picture) of my brand new rebuilt 235 running at idle. Running 40 PSI.
The motor hasn't run more than 20 minutes at the time of this video.

https://photos.app.goo.gl/GhbcuqTLEzsXeD0i1

The kind of oil is entirely up to you as there as many opinions on that topic as pebbles on the beach. Just use a good one, with a good filter and change it often.

I've read often times also that 5 psi at idle is quite normal and nothing to be concerned about.

Your water temp should be close to 195 to get proper power. They like to run hot.
Attached Images
 
__________________
So when is this "Old enough to know better" supposed to kick in?

My 1959 GMC build thread http://67-72chevytrucks.com/vboard/s...d.php?t=686989
Foot Stomper is offline   Reply With Quote
Old 04-15-2018, 04:04 PM   #7
dsraven
Registered User
 
Join Date: Nov 2010
Location: calgary alberta
Posts: 7,773
Re: Oil pressure

remember the guages are not even close to new, so they could be off some. best would be to run a "T" in the line and install a new guage right there. check the new against the old and see how it compares.
if it turns out that the engine heat is low, try a new OEM thermostat. I say OEM because I have installed many thermostats of the cheaper variety and they have been no good right out of the chute. replaced with OEM and the heat worked like it should.
dsraven is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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

Forum Jump


All times are GMT -4. The time now is 09:03 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com