[Scott MH]

I pulled my engine due to having 0psi if oil pressure when warm at idle. Anything above idle it would pop back up. The bearings have some wear showing and the motor only has about 1000 miles on it. It's a 383 with scat rotating assembly all professionally machined and clearances then I assembled everything


Bearing 5


Bearing 4


Bearing 3


Bearing 2


Bearing 1

[1968RallySport]

Did you check the oil pressure with a known good mechanical oil pressure gauge prior to removing engine? If so, pull the timing cover & inspect the oil galley plugs.

[Scott MH]

Originally Posted by 1968RallySport

Did you check the oil pressure with a known good mechanical oil pressure gauge prior to removing engine? If so, pull the timing cover & inspect the oil galley plugs.

Yep tried three different oil pressure gauges one being a snap on brand gauge all the same. The three oil galley plugs are all there

It has a solid flat tappet cam
Top end looked good as new

[1968RallySport]

You said the engine has 1000 miles on it. The oil pressure was OK until recently? Take a look at the pressure relief valve & spring in the oil pump.

[Eleanor's Nemesis]

I'd ask the machinist if the block was align bored and what the clearances were. Also, what weight oil did you use?

Hopefully you still have the oil filter and it's full of oil. Get it tested to see if it has fuel in it. Give it the smell test first and see if you can smell gasoline.

[Eleanor's Nemesis]

Also, what rod bolts did you use and did you check them for stretch? Were they the same rod bolts the machinist used to check the clearances?

[Scott MH]

The block was supposed to get the full treatment no expense spared. Here is the bad thing in my part. The engine is 5 years old I put the 1000 miles on in 2 years developed the problem and I parked it for almost 3 years. At some point I pulled the pan, filter, and oil pump the filter is long gone a buddy wanted the pan so I sold it to him and the pump was lost then I built my house another truck and the camaro just got lost. I am now trying to figure this out all over again. The rod bolts are arp bolts and the machinist was supposed to replace the ones he used during the mock up stage. The main bolts are stock if I remember correctly I was told the bolts and mains are in good shape otherwise I would have replaced them. I have almost $8000 in this motor. Here is the Kick to the nuts the machine shop that did the work ordered the parts did the mock up is no more as of last year FAIL


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[Eleanor's Nemesis]

Might explain why they aren't around anymore. How far are you from Houma?

[68rs406]

Those bearings look fine from here.
I think I would get with a good machinist and start over, re checking everything. Something seems odd, like maybe an issue outside of bearings or clearances within the motor.

Do you recall what the clearances where? No idea?

Too bad, but it could be worse, nothing looks not fixable at this point. It should be 100% re checked in my opinion, start over. At least you have parts that appear to be in good shape.

[Eleanor's Nemesis]

Sean has a good point-the bearings look good, probably something outside of that-

Did you have a high volume pump, and which one? Which oil pan?

[69cama]

Mock up the short block with the exact bearings on the journals they came off of and plastigage all of them them. If the clearances look good, then forget about the short block parts as the problem.

[Fred Ficarra]

Yep, first check the main bearing clearance. The wrong set will destroy your pressure. Ask me how I know. And no, I didn't do it. My racer buddy installed them in 1968 and I didn't get it until he got caught cheating that same year.
DO NOT RULE OUT THE SHORT BLOCK.
This is a really long story so here's the short version;
Over the counter 1970 LT1 from my Chevy dealer, year;1973. Short block taken to reputable shop for disassembly and balancing. Assembly returned after all work. Then installed by me. No pressure at idle. Took it to my friend who was the Chevy dealer parts man who sold my 427 to me that had no idle pressure. (Hmm, a pattern here?) Anyway, we had eliminated all possibilities (trust me) prior to taking it to his house for a "specialty tool" test. We were going to start with his oil primer distributor and power it up with the intake manifold off so we could see the problem. I had the manifold ready to pop off when I got to his house. We did so. End of testing before it began. The block had TWO overlapping distributor holes. It looked kinda like a Master-card logo.
It was a parts bin-block from GM. The jerk responsible for jigging that machining operation didn't have the block centered on the cradle and made the wrong bore. So, he had ruined the block but didn't want to get caught when it failed to hold pressure if it went to the production line so he re-centered the block, drilled the hole in the right spot and shouted "parts" and the block went to a dealer to 'correct' any insignificant production problem. I got the block. Plus a lot of trouble and expense not covered by warranty.
Check your block.

Is that a flat tappet cam!? Why?!

[DOUG G]

Look at the cam bearings also after all the other checks.
I bought a LQ4 motor with knowing it had 0 oil pressure until rev'd up....#3 cam bearing was shot but every other bearing in that motor looked factory fresh (100K+ mile motor)

[X-77 keith]

I think Doug is on to something. Oil gally s could be pluged, or hole for the camb bearing may be not ligned up. Could have late model three hole cam bearings making it almost impossiable to get pressure at idle. When rod bolts are installed sometimes the rod needs to be resized, did they check that? will never know. Have seen lots of people skimp on camb bearings or not lube cam , or prime the engine before first start.good luck hope this helps.

[Scott MH]

Ok guys I appreciate all the responses. So far my plan of action is to plastigauge the mains as suggested, record findings, remove rod caps and inspect bearings, plastigauge rod caps, record findings, remove rotating assembly, remove cam bearings and report back to here.

I will also be sure to note the orientation of the cam bearings