Oiling Question
#2899013
03/14/21 01:14 PM
03/14/21 01:14 PM
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Joined: Jan 2003
Posts: 1,286 IN
GTX4spd
OP
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OP
pro stock
Joined: Jan 2003
Posts: 1,286
IN
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It’s a fresh rebuild on my ‘70 440. When I got it back, on cold start the pressure goes up between 80-90 PSI, then slowly drops as the oil warms. And once fully warm the pressure never got higher than around 43 PSI no matter the RPM & at idle it would drop to around 13 PSI. These were mechanical gauge readings but the factory electrical gauge was similar. Slower to respond but similar readings. I replaced the mechanical gauge with a new Autometer gauge with same results. This was with 10w40 oil, the engine builder, a relative, suggested trying 20w50, which I was skeptical of but tried it anyway. With the engine pre-warmed & the 20w50 warmed to room temperature I got ZERO pressure! I let it run just long enough to know that the pressure wasn’t moving either needle. He then suggested undoing the coil wire & cranking the engine to look for pressure ( a practice that I have since read is taboo). Again, zero pressure.
Unless some of you have better advice my next plan is to manually spin the pump & see what the pressure does, although since it won’t be getting warm I have to question whether I can get an accurate idea from this method. Opinions on that?
My presumption is that it’s a weak pump but it’s a new one, so....... Again, opinions? My engine builder is eight hours away so it’s not convenient to take it back or have him come to me so I need to try & figure this out myself. But before I pull the distributor & intermediate shaft out I would like some wiser heads than mine to weigh in. Wondering whether to just replace the pump before any other action or proceed with manually checking for pressure?
Any thoughts would be greatly appreciated.
Thanks.
"Gentlemen, we must all hang together, or surely, we shall all hang seperately."--Benjamin Franklin
www.wwnboa.org if you're interested in '62-'74 B-Bodies
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Re: Oiling Question
[Re: Pacnorthcuda]
#2899094
03/14/21 04:38 PM
03/14/21 04:38 PM
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Joined: Mar 2011
Posts: 3,083 Michigan
A727Tflite
master
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master
Joined: Mar 2011
Posts: 3,083
Michigan
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I would be a bit suspicious of the pump pressure relief valve, it may be stuck open. I would also replace the oil filter before any more testing just cause of the low money and ease of doing it. Pre oil the filter of course. This. Before you get inside I would use a speed handle to try and prime the motor. If a plug popped out you may hear it. Only plug inside on a B/RB is behind the cam sprocket and inside near the pump pushrod. Listen up front.
Last edited by Transman; 03/14/21 04:42 PM.
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Re: Oiling Question
[Re: GTX4spd]
#2899117
03/14/21 06:35 PM
03/14/21 06:35 PM
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Joined: Aug 2003
Posts: 43,223 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,223
Bend,OR USA
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Last edited by Cab_Burge; 03/14/21 11:34 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Oiling Question
[Re: dOoC]
#2899139
03/14/21 07:22 PM
03/14/21 07:22 PM
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Joined: Nov 2007
Posts: 21,831 Kirkland, Washington
Pacnorthcuda
Too Many Posts
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Too Many Posts
Joined: Nov 2007
Posts: 21,831
Kirkland, Washington
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GOOD TO SEE that certain are FILTERING OUT excessive usage of smilies I guess that the charge of 1$ EACH for the over usage of 5 per post is being followed !! Holy crap you goofball with the sTUpID hABITs......pot meet kettle.
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Re: Oiling Question
[Re: B1MAXX]
#2899163
03/14/21 08:00 PM
03/14/21 08:00 PM
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Joined: Nov 2007
Posts: 21,831 Kirkland, Washington
Pacnorthcuda
Too Many Posts
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Too Many Posts
Joined: Nov 2007
Posts: 21,831
Kirkland, Washington
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Could it have snapped the pump drive hex off with the 20/50? That’s an interesting thought, and I thought about that too when oil pressure went to zero. Longshot, considering the engine oil pressure RESTRICTION seem to be low even when pressure was being made, so 20-50 likely wouldn’t have stressed the shaft that much more....
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Re: Oiling Question
[Re: GTX4spd]
#2899169
03/14/21 08:25 PM
03/14/21 08:25 PM
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Joined: Jan 2003
Posts: 1,286 IN
GTX4spd
OP
pro stock
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OP
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Joined: Jan 2003
Posts: 1,286
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Thanks for the responses. I considered the pressure spring, but since the cold pressure prior to changing to 20w50 was always over 80 then I can’t imagine that being an issue. A problem with the filter after switching oils also could be a thought, but I always use Wix so I don’t really think that’s a problem, although anything’s possible. Before using the 20w50 I had changed to a different 10w40 and cut the filter from that change open & it was clean. And I forgot to tell you in the original post that the motor was already broke in, supposedly without any pressure issues although I don’t know that they were as observant as I am about that.
And maybe the somewhat heavier oil could have damaged the shaft, but with both the engine and oil being warm I tend to discount that. I once bought a ‘69 GTX that was parked outside in the cold winter weather that had 20w50 in it & it suffered no consequences.
I didn’t have time to tackle this today and won’t be able to mess with it until next weekend but I appreciate the feedback, it gives me something to mull over until I have more time.
"Gentlemen, we must all hang together, or surely, we shall all hang seperately."--Benjamin Franklin
www.wwnboa.org if you're interested in '62-'74 B-Bodies
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Re: Oiling Question
[Re: Pacnorthcuda]
#2899171
03/14/21 08:28 PM
03/14/21 08:28 PM
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Joined: Jan 2003
Posts: 15,411 Omaha Ne
TJP
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 15,411
Omaha Ne
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myself, I would pull the dist and intermediate shaft. If nothing is obvious one could try priming witha drill or speed handle as suggested. DO NOT FORGET it's CCW rotation. If still nothing one could try the filter. I would not discard the filter but bag it for inspection if needed. At that point, you can either A. Remove the pressure relief valve and try cleaning it and the bore. Reinstall and try priming again or B. Remove the pump for inspection. We had one years ago that hung the relief valve open. We removed the pump ( 340) took the cover off and the valve was stuck open. My buddy used a small screwdriver and just barely touched the valve and it snapped shut. Apparently a microscopic piece of something hung it open. Keep us posted
Last edited by TJP; 03/14/21 08:29 PM.
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Re: Oiling Question
[Re: GTX4spd]
#2899205
03/14/21 10:08 PM
03/14/21 10:08 PM
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Joined: Jun 2012
Posts: 1,899 MYRTLE BEACH SOUTH CAROLINA
ek3
top fuel
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top fuel
Joined: Jun 2012
Posts: 1,899
MYRTLE BEACH SOUTH CAROLINA
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It’s a fresh rebuild on my ‘70 440. When I got it back, on cold start the pressure goes up between 80-90 PSI, then slowly drops as the oil warms. And once fully warm the pressure never got higher than around 43 PSI no matter the RPM & at idle it would drop to around 13 PSI. These were mechanical gauge readings but the factory electrical gauge was similar. Slower to respond but similar readings. I replaced the mechanical gauge with a new Autometer gauge with same results. This was with 10w40 oil, the engine builder, a relative, suggested trying 20w50, which I was skeptical of but tried it anyway. With the engine pre-warmed & the 20w50 warmed to room temperature I got ZERO pressure! I let it run just long enough to know that the pressure wasn’t moving either needle. He then suggested undoing the coil wire & cranking the engine to look for pressure ( a practice that I have since read is taboo). Again, zero pressure.
Unless some of you have better advice my next plan is to manually spin the pump & see what the pressure does, although since it won’t be getting warm I have to question whether I can get an accurate idea from this method. Opinions on that?
My presumption is that it’s a weak pump but it’s a new one, so....... Again, opinions? My engine builder is eight hours away so it’s not convenient to take it back or have him come to me so I need to try & figure this out myself. But before I pull the distributor & intermediate shaft out I would like some wiser heads than mine to weigh in. Wondering whether to just replace the pump before any other action or proceed with manually checking for pressure?
Any thoughts would be greatly appreciated.
Thanks. i would check the oil filter 1st.... i have had this happen to me 2 times ! the cold oil and hi pressure imploded the filter .. would only hit 15 lbs press. reved up.... 5 minutes and a filter will tell. i had to run lighter oil to stop it.. the cold start was when it happened....
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Re: Oiling Question
[Re: ek3]
#2899211
03/14/21 10:34 PM
03/14/21 10:34 PM
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Joined: Aug 2006
Posts: 2,522 God's Country Maryland
GODSCOUNTRY340
master
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master
Joined: Aug 2006
Posts: 2,522
God's Country Maryland
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If you bent a pushrod and threw a lifter out of it's bore you will lose all oil pressure. Pull both valve covers and make sure all the pushrods and lifters are in place.
I love the smell of Deer guts in the morning, it smells like... VICTORY!
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Re: Oiling Question
[Re: GODSCOUNTRY340]
#2899255
03/15/21 08:40 AM
03/15/21 08:40 AM
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Joined: May 2019
Posts: 6,282 nowhere
Sniper
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master
Joined: May 2019
Posts: 6,282
nowhere
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If you bent a pushrod and threw a lifter out of it's bore you will lose all oil pressure. Pull both valve covers and make sure all the pushrods and lifters are in place. I had that happen to me, I think I torqued down the rocker shaft too quickly on a filled lifter. Not like I was winging it up to high RPM or anything, heck I was leaving the doctor's office with my daughter when I lost oil pressure. I also had a very small chunk of casting flash break off in a 360 and get caught up in the oil pump, locked it up and snapped the end off the drive. Not even sure how it made it past the pickup screen.
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Re: Oiling Question
[Re: Sniper]
#2899308
03/15/21 11:57 AM
03/15/21 11:57 AM
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Joined: Aug 2003
Posts: 43,223 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,223
Bend,OR USA
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If you bent a pushrod and threw a lifter out of it's bore you will lose all oil pressure. Pull both valve covers and make sure all the pushrods and lifters are in place. I had that happen to me, I think I torqued down the rocker shaft too quickly on a filled lifter. Not like I was winging it up to high RPM or anything, heck I was leaving the doctor's office with my daughter when I lost oil pressure. I also had a very small chunk of casting flash break off in a 360 and get caught up in the oil pump, locked it up and snapped the end off the drive. Not even sure how it made it past the pickup screen. I had a small piece of aluminum from the rear main cap seal holder on one of my old 426M.W. stocker motor break out when I used non stock oil pan bolts in it, that small piece of aluminum got suck up into the oil pickup and through the hole in the center of the screen under the baffle and into the pump locking it up twisting off the shaft at the old Firebird, now Wild Horse raceway in Phoenix, AZ many years ago back in 1988 I thought it was caused at first by thick oil, it wasn't. I had to take the pump off and apart to find that piece stuck between the rotors after having it twist a new one off as soon as I started it up, stupid me for ASSUMING it was cold oil that caused it Every stock Mopar oil pickup I've remove the baffle from has that hole in the screen with a steel ring crimp onto the screen to hold the hole open
Last edited by Cab_Burge; 03/15/21 12:00 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Oiling Question
[Re: GTX4spd]
#2899403
03/15/21 04:05 PM
03/15/21 04:05 PM
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Joined: Apr 2003
Posts: 12,234 Looking for a way out of Middl...
IMGTX
I Live Here
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I Live Here
Joined: Apr 2003
Posts: 12,234
Looking for a way out of Middl...
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There are several things that come to mind. It could be the oil pump drive shaft sheared off. Known to happen. I have seen lots of stuff end up in the oil pans from gravel to shop rags. A very common one is when people put too much silicone on the gaskets, and it squeezes out into the engine like spaghetti eventually ending up in the pickup. I would suggest pulling the distributor and oil pump drive to see if there is a problem then try to preoil the motor from a drill. If the pressure won't show, you can check the relief spring on it because it's a big block but after that is time to pull the oil pan and see what you find. My Hope you find it to be a simple problem.
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