Technical Oiling issues on Small Journal 327, no oil pressure at idle

My 2 cents , physics = increase volume = increase in pressure also . But this has nothing to do with the issue at hand . The o rings or clearance at the dist base is a bad oil pressure robbing bandit ! You have already tapped oil galley holes so you pretty much solved questions about that . I have tinkered with a Chevy sense being released from the " nut ward" at Leavenworth Summer Camp , but seems I remember something different on the rear journal of early cams verses late cams and oil pressure issues .

 

.022" total between both rods.

 

Early chevys the 265 had a notch in the rear cam journal it got oil to the lifters only when the notch uncovered 2 holes in the cam bearing later they put a grove in the rear cam journal and later yet they put a grove behind the bearing.

 

.008- .014 is stock on must small blocks.

 

So, this is the #1 main bearing. The shiny marks are just barely detectable with a fingernail. They are symmetrical and in line with the chamfered oil holes in the crank. The discoloration you see was a coating that came on the bearings.

 

True. The Scat rods are always a little undersize. From what I have been told it shouldn't hurt anything.

 

The down side is more oil on the cylinder walls you can get in trouble with low tension oil rings on oil control. Like I said in a early post with the pan off put air pressure on the sender port and listen of any big air leaks it can't hurt.

 

Internal friction in the oil itself, as the oil is sheared in use, results in heat. The relief valve puts a lot of shear forces on the oil, but it's not the only place this happens. The point is that operation over relief should only be sporadic, not constant. If you're running too much flow, and/or too high viscosity, you will put a lot more stress on the oil and increase the rate of degradation. Oxygen attacks the base oil resulting in oxidation. This is a chemical reaction, and like all chemical reactions the rate increases with temperature. Arrhenius rule states that for every 10*C increase in temp the rate of reaction doubles. Oxidation of the oil results in longer chain heavier weight compounds resulting in sludge build up and lacquer and varnish deposits. Some of the compounds are acidic or corrosive and attack soft metals (lead/tin/copper).

 

What do you guys think about the bearing pic?

 

I know we are off topic but if the relief valve is hardly ever open then changing or shimming the spring will little or no effect. good video www.dailymotion.com/video/xyg5ix_engine_oil_relief_valve_auto

 

Something wasn't clean. Cut the filter open and spread out the paper.

 

.015"-.020" on race engines.

 

Honestly, I don't know what I could do about the rods other than start over.

 

that shiny spot on the left upper, you will probably find a piece of dirt on the back side on the bearing , the other marks are also dirt, are those a decent brand???? dirt behind bearing, not clean enough on re assembly, other dirt, probably same reason unless something up stream has failed.

 

http://www.jalopyjournal.com/forum/threads/new-small-block-oil-pressure.1016109/page-4#post-11484964

 

This thing was ran through the jet washer twice. Scrubbed by hand with rifle brushes etc. Dunno where it came from.

The bearings were almost $100 set. HD Federal Mogul.

So, I am ready to either put the oil pan back on and use the primer on it or hold off and inspect other things. I don't want to put it back together if there are other suspect areas. Any other things I need to inspect?

 

Do all the bearings look like that? Do the chamfer oil holes in the crank look polished after grinding? High spots or trash maybe?. Those marks don't look good.

 

I polished the crank with 2000 grit using oil as a lube after the last inspection, just to make sure the edges were smooth. They look a lot worse than they feel.

 

What's the part number for those bearings? I can't see the chamfer on the bearing that well in the pic but this could also be an issue. Another thing to check is the lifter bores. H series bearing have a larger chamfer for large filet cranks.

 

Could the roller lifters be an issue? Is there even a correlation between the rear oil pressure sender cavity and the lifter galley? I'm too far invested int this thing to abandon ship....

 

Make sure your distributor is snug in the block. That groove in the bottom of the housing is for oil to get to the RH lifter gallery oil supply hole and a leak is created if your distributor does not have a tight fit which will drop your oil pressure. Ask me how I know !

 

Hey Root

You got some bad ' JuJu ' in there some where so take that baby apart or you could get a blue crank pretty quick, and you sure don't need that

The oil galleys are all tied together, the oil takes different routes on where it has to go to lube all the different parts

You sure got some dirt in there hiding on you, as you should never see bearings looking like that

Wish you good luck finding where it is

DND

 

those shells should live in a bin somewhere, Id be getting the crank ground OR ask a machine shop for their thoughts on its condition, looking like that I don't see them living for long, it nearly looks like they are starting to fail (bit near your thumb) cant say much without the crank and shells in my hand. Did you run something like a rifle cleaner brush through the oil galleries? (followed by rifle cloth or similar till clean)

 

My same thoughts, almost like the chamfering on the journals was done after polishing them, even the finest metal displacement could scar a soft bearing.
Edit
But I think something else is at the heart of your oil pressure issues.
Don't recall whether you dissected the oil filter. Was that done after the initial fireup?

 

I threw it back together with the new Milodon pump and it gets basically 25-30 lbs when I have a fresh battery for my cordless drill. I would think that should equate to about idle speed.

I am going to have to borrow an electric drill to see if I can get oil up to the rockers. It was starting to dribble out on the forward right rocker arm, just about the time the battery died on my drill.

Oh and only that bearing has that marking.

 

.022" on side movement of the rods is ok but it will show lower pressure at idle for sure. It means more flow and throws a lot more oil at the Pistons, walls, and cam. You may consider a pan to block side scraper. We use one with flat tappet cam because of our rod side clearance. The bearing looks like something on the oil hole did make the marks. If you have a bearing scraper you could save it but many would make sure there was nothing on the crank and just change the bearing. I would remove the crank and reclean all of the passages in it paying close attention to the holes and chamfering. Good luck.

 

Man if I have to pull the crank, I'm sending it out for repolishing etc. This thing is making me ill.

 

It all has to be right and clean for them to live

 

Man if you knew how much time we spent on cleaning and polishing the casting flash out of this thing. I probably have 80 hours in prep. I am wishing now I would have just bought a crate motor and went on.

 

Try to limit downward pressure on the primer, especially if you use a heavy 1/2 in drill motor, as this can cause the oil pump gear to score the pump cover.
Were all root'n for ya hawg.