Now down to the dirty...

[Sgt.Rock]

Alright, I need some expert advice from any 'real' engine builder, as opposed to me who just did this one as my first only.
So I have maybe 30 minutes on my 383 B block. New hyperuetic pistons, mutha thumpa comp cam, new bearings throughout, new oil pump...everything ran great until last night. so I was getting 45 pds of cold oil pressure, then down to 25 when warm. Last night my friend was trying to set timing, however unknown to me the parts guy sold me a hemi h/balancer, so the timing marks were completely out. So basically my friend overheated the car(no fan yet). The rad spouted steam and I shut her down. After 15 min, I started it again and oil pressure was down to 5 lbs!!!! at idle. Anyone chime in what the heck could have occurred. I wouldn't have thought too much damage could have occurred in the short time, 1 min max of high heat. My buddy doesn't seem concerned he says use thicker oil, but to me that is a bandaid

 

[commando1]

Well, your spun bearing just presented to you your new engine rebuilding project.

Posted via Topify on Android

 

[Sgt.Rock]

Well, your spun bearing just presented to you your new engine rebuilding project.

Posted via Topify on Android

Really!! What do I look for to determine this? Can replacing it be done through the removal of the pan? Is this type of thing diagnosed by cutting my oil filter in half and look for metal? Damn, should never let a Chevy guru look into my Dodge!

 

[commando1]

Well, the first thing you have to do is not accept a diagnosis based on a post and a reply from the internet. You need a second opinion from an expert who can see the engine in person. And then perhaps a third.

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[Ripinator]

. . .so I was getting 45 pds of cold oil pressure, then down to 25 when warm. Last night my friend was trying to set timing, however unknown to me the parts guy sold me a hemi h/balancer, so the timing marks were completely out. So basically my friend overheated the car(no fan yet). The rad spouted steam and I shut her down. After 15 min, I started it again and oil pressure was down to 5 lbs!!!! at idle. Anyone chime in what the heck could have occurred. I wouldn't have thought too much damage could have occurred in the short time, 1 min max of high heat. My buddy doesn't seem concerned he says use thicker oil, but to me that is a bandaid

What brand and weight of oil are you using ?

 

[Sgt.Rock]

What brand and weight of oil are you using ?

I am using Comp 10w30...running 2 remote AC Delco filters...

 

[Mr C]

As Commando said, low oil pressure is often (not always) a symptom of damaged bearings (i.e. too much clearance because material was removed from the bearing and mating surface due to contact). In an overheat condition the oil gets very thin and loses it's ability therefore to create the fluid barrier between moving parts...this doesn't only happen for the one minute that the engine is "too hot" but also during the time leading up to the overheat condition.

Does the engine knock? If so- you have your answer. If not, then you may be able to get away with pulling the pan and replacing the the crank and rod bearings (after inspecting the crank journals for damage etc.).

http://www.imperialclub.com/Yr/1973/Kerrys73saga/73part21.htm

He is also correct that we can only do so much remotely and you'll need some in person hands on expertise to find out what's really going on.

 

[Big_John]

Was the oil pressure readings taken at idle? 25 PSI at anything above idle is too low to begin with.

Is the pressure gauge good? Seriously... If no noises etc. check with another mechanical type pressure gauge. One known to read correctly if possible.

Did you prime the oil pump before starting?

 

[70bigblockdodge]

If it is not making noise probably okay. Pull oil filters cut open with tinsnips,most.likely see some metal powder stuff, Babbitt and aluminium run a magnet over it, if no steel good. Was the oil level checked after this run, not being a smart *** but after getting hot more air bubbles may have worked out of that dual remote filter setup and made oil level low.

 

[68plymouth383]

Could also be running a low quality oil filter and its giving bad pressure readings......... Yes it happens.

 

[bluefury361]

With oil pressure that low I wouldn't take a chance running the engine to see if it knocks.

You need to drop the pan and remove #1 main bearing cap and visually inspect the insert. I won't hurt to pull the #1 rod cap also.
If they check out the next suspect would be a spun cam bushing.

All this is assumeing the engine was assembled with all oiling holes properly alligned.