TheAMCForum.com Homepage
Forum Home Forum Home > The Garage > AMC V8 Engine Repair and Modifications
  New Posts New Posts RSS Feed - New to the AMC 360...Oil pressure ?
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Click for TheAMCForum Rules / Click for PDF version of Forum Rules
Your donations help keep this valuable resource free and growing. Thank you.

New to the AMC 360...Oil pressure ?

 Post Reply Post Reply Page  123 4>
Author
Message
83CJ7360 View Drop Down
AMC Fan
AMC Fan
Avatar

Joined: Feb/21/2017
Location: 08060
Status: Offline
Points: 13
Post Options Post Options   Thanks (0) Thanks(0)   Quote 83CJ7360 Quote  Post ReplyReply Direct Link To This Post Topic: New to the AMC 360...Oil pressure ?
    Posted: Feb/21/2017 at 8:44am
I just installed an Auto Meter electric oil pressure gauge on my CJ with an AMC 360. I just recently got this Jeep and have never owned an AMC motor. The motor is supposedly all fresh and I can tell that the oil pump and timing cover is new. At cold start, the oil pressure is strong but at warm idle it drops very close to 0 on the gauge. Is this normal? Pressure shoots right up when I hit the gas or are cruising down the road. Also, I noticed that the oil filter they were using (Mobile 1...M1-206) doesn't appear to be correct for the AMC motor. What oil and filter should I be using since I have read that certain filters make a difference with oil pressure on these motors.
Back to Top
dltowers View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar

Joined: Dec/12/2012
Location: Friendswood, TX
Status: Offline
Points: 5822
Post Options Post Options   Thanks (0) Thanks(0)   Quote dltowers Quote  Post ReplyReply Direct Link To This Post Posted: Feb/21/2017 at 9:27am
Hello Louis, and Welcome as a new member....

First, may I strongly suggest that you invest in a Technical Service Manual, best $ you will ever spend on your AMC....
 
I am sure others will reply to your question with suggestions, below is a short memo that might help.
Also, when you ask about correct oil/filter, expect to get a "FULL GAMUT" of opinions.
As for me, I prefer to use Valvoline VR-1 Racing Oil 10w30 (Not Synthetic) and a Napa Gold 1258.
*Make sure any oil filter that you use has a good Anti-Drain Back Valve**




Edited by dltowers - Feb/21/2017 at 9:33am
Original Owner, 1974 Javelin:
360ci,2v,727TC. Motorola Multiplex with 8-Track.
G4 Plum exterior with 421Q Black Uganda Interior. Purchased on July 16, 1974 from Hooker AMC, Sherman, TX for $4500.20
Back to Top
83CJ7360 View Drop Down
AMC Fan
AMC Fan
Avatar

Joined: Feb/21/2017
Location: 08060
Status: Offline
Points: 13
Post Options Post Options   Thanks (0) Thanks(0)   Quote 83CJ7360 Quote  Post ReplyReply Direct Link To This Post Posted: Feb/21/2017 at 10:01am
Thanks for your reply...I'll surely get a shop manual. On the Napa website when I put in the donor vehicle (89 Grand Wagoneer) it only shows me a napa gold 1626 filter? Do you know what the difference is?
Back to Top
83CJ7360 View Drop Down
AMC Fan
AMC Fan
Avatar

Joined: Feb/21/2017
Location: 08060
Status: Offline
Points: 13
Post Options Post Options   Thanks (0) Thanks(0)   Quote 83CJ7360 Quote  Post ReplyReply Direct Link To This Post Posted: Feb/21/2017 at 11:21am
looks like the difference between the 2 filters is that the 1626 has a by-pass valve setting and the 1258 doesn't. the Wix site shows application for the 1258 as AMC (60-81) and the 1626 shows Jeep (87-93)

Do I need a filter with By-pass valve setting psi?
Back to Top
one bad rambler View Drop Down
AMC Addicted
AMC Addicted


Joined: Jan/09/2008
Location: On The Island
Status: Offline
Points: 2007
Post Options Post Options   Thanks (0) Thanks(0)   Quote one bad rambler Quote  Post ReplyReply Direct Link To This Post Posted: Feb/21/2017 at 6:39pm
Check the pressure regulator...make sure it`s not stuck
68 AMX 390 4 Speed,68 American,64 American 2 Door Wagon Altered Wheelbase,78 Concord Build 360,727,8.8
Back to Top
83CJ7360 View Drop Down
AMC Fan
AMC Fan
Avatar

Joined: Feb/21/2017
Location: 08060
Status: Offline
Points: 13
Post Options Post Options   Thanks (0) Thanks(0)   Quote 83CJ7360 Quote  Post ReplyReply Direct Link To This Post Posted: Feb/21/2017 at 7:47pm
How exactly do I do that and does the pump need to be reprimed after doing that?
Back to Top
Rebel Machine View Drop Down
AMC Addicted
AMC Addicted


Joined: Jul/03/2007
Location: Western Il
Status: Offline
Points: 5118
Post Options Post Options   Thanks (0) Thanks(0)   Quote Rebel Machine Quote  Post ReplyReply Direct Link To This Post Posted: Feb/21/2017 at 8:51pm
Originally posted by 83CJ7360 83CJ7360 wrote:

I just installed an Auto Meter electric oil pressure gauge on my CJ with an AMC 360. I just recently got this Jeep and have never owned an AMC motor. The motor is supposedly all fresh and I can tell that the oil pump and timing cover is new. At cold start, the oil pressure is strong but at warm idle it drops very close to 0 on the gauge. Is this normal? Pressure shoots right up when I hit the gas or are cruising down the road. Also, I noticed that the oil filter they were using (Mobile 1...M1-206) doesn't appear to be correct for the AMC motor. What oil and filter should I be using since I have read that certain filters make a difference with oil pressure on these motors.



Definitely not normal. Spec is 13 lbs. minimum at idle and 45 lbs. and above at speeds greater than 40 MPH. That's straight from the AMC tech service manual.

Did you get any information on the build, specifically the main and rod bearing clearances?

The reason I ask is because there's some bad information on bearing clearances for AMC engines. I had this problem and it took 3 years to figure out. The symptom was similar to yours, good cold pressure but after running at operating temperature for a while the pressure would steadily drop well below spec. After about 500 miles I took it apart and saw the cam bearings were loosing their babbit because there was too much flow past the main bearings. There wasn't enough left behind to properly oil the cam bearings.

Mains 1, 2, 3 & 4 should have 0.0010"-0.0020" clearance and Main #5 should have 0.0020"-0.0030" clearance. Rod bearings should have 0.0010"-0.0020" clearance. I know these seem very tight but again, this info is straight from the AMC tech service manual. The AMC V-8 doesn't oil the mains first, it oils them last. Kinda stupid but that's the way they work.

This engine is not a Chevy, the old rule 0.001" of clearance for every inch of journal does not work with AMC V-8s.

I use Purolator 30005 oil filters.

-Steve-





Back to Top
gremlinsteve View Drop Down
AMC Addicted
AMC Addicted


Joined: Dec/16/2008
Location: houston
Status: Offline
Points: 884
Post Options Post Options   Thanks (0) Thanks(0)   Quote gremlinsteve Quote  Post ReplyReply Direct Link To This Post Posted: Feb/21/2017 at 10:41pm
I bet a chevy guy built the motor and ruined the main and rod clearance setting it up as a chevy
Back to Top
farna View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar
Moderator Lost Dealership Project

Joined: Jul/08/2007
Location: South Carolina
Status: Offline
Points: 19611
Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Feb/22/2017 at 6:51am
Another thing to consider -- electric oil pressure gauge sending unit. I'd put a mechanical gauge on it, even if only temporary, and check pressure. The electric gauge may be slow to respond or even off a bit. How old is the sending unit, and where is it located? You can put a T under the electric sending unit for a mechanical gauge and put a plug in it (or remove) if you don't want to leave it connected. But check with a mechanical gauge before doing much else. 
Frank Swygert
Back to Top
83CJ7360 View Drop Down
AMC Fan
AMC Fan
Avatar

Joined: Feb/21/2017
Location: 08060
Status: Offline
Points: 13
Post Options Post Options   Thanks (0) Thanks(0)   Quote 83CJ7360 Quote  Post ReplyReply Direct Link To This Post Posted: Feb/22/2017 at 9:20am
The sending unit is brand new...came with the gauge. It's installed in the "T" coming off filter housing and under oil pressure switch
Back to Top
 Post Reply Post Reply Page  123 4>
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.03
Copyright ©2001-2019 Web Wiz Ltd.

This page was generated in 0.094 seconds.
All content of this site Copyright © 2018 TheAMCForum unless otherwise noted, all rights reserved.
PROBLEMS LOGGING IN or REGISTERING:
If you have problems logging in or registering, then please contact a Moderator or