I've started to get things prepped for using the oil primer tool which arrived today. In pulling the valve covers, I can clearly see residual oil in the heads in all of the various "low" areas. I can also see it on the low sides ('low' based on gravity) of the top washers of the valve springs, in little recesses of the rocker arms, etc. The pushrods all look normal. There does not appear to be any 'slop' in the valve train. And I see no outward signs of wear such as the presence of metal filings or wear spots or anything like that. In short, things look very normal to the naked eye under the valve covers. Later today or tomorrow, I'll install the new AC Delco oil filter and put in fresh oil and then spin things up with the oil primer tool to see what that shows. I've also hooked up an oil pressure gauge right there in the engine compartment. If I see anything abnormal when doing the oil primer tool testing -- like still having no pressure showing on the gauge and/or not seeing oil coming up into the valvetrain in the heads -- then I'll have to drop the oil pan and really get serious.

As for the torque and clearance specs, here's what I found in my 1973 shop manual for a 350 SB for the main crankshaft caps and for the connecting rods. Let me know if any of you think these are not really valid in the "real world".

Crankshaft main bearings and caps: Torque to 75 foot pounds (65 foot pounds for the outer 2 bolts if there's a 4-bolt cap). Bearing clearance should be between .0013" and .0025" for bearings #1 through #4; between .0023" and .0033" for bearing #5. (QUESTION: Which bearing is #5? The one nearest the water pump or the one nearest the transmission?)

Connecting rod bearings and caps: Torque to 45 foot pounds. Bearing clearance should be between .0013" and .0035".

 

I'd try to independently confirm that the pressure gauge is working. Some NPT fittings, a pressure sprayer (or air compressor), and some hose clamps might do it. You don't need much pressure, just enough to confirm things are working. If the loaner gauge won't register until you are at 30 psi, you may never see it when running the oil pump tool, for example.

 

#5 is the rear of the engine, closest to the transmission.

 

I did not see anyone mention this. Have you pulled the fitting for the oil line out of the block? It is a small hole thru it and could crud over enough to stop flow to the gage. Also confirm the port in the block is open. Easy check.

 

#5 is at the rear of the engine, near the transmission. The bearing caps and the block should be stamped with the number so you can put them back in the right spot. Not sure if this was done at the factory, but it is true for every SBC I've ever had apart.

 

I'm late to the party but I think this is getting way too complicated way too early. And it seems OP is too worried and maybe making extra work for himself.

It has been suggested to disconnect the oil line and put it into a can, and see if it has pressure. If so, your gauge has an issue. Did you do this yet? Maybe I missed it.

Next (assuming nothing into the can) disconnect the line at the block and fire it up. If you have pressure, the line is plugged or kinked.

Another suggestion was to fire it up with a valve cover off. Unless you are brand new to this, you know oil will be (or should be) coming out of the pushrods and splattering around.

Why don't you do that much and report back, before worrying about pulling bearings and replacing the oil pump. Yes, it may very well go that far. But wouldn't you feel silly and PO'd if you do all that and find a bum gauge? Start with the cheap, easy and simple stuff before performing major surgery. Use logic and reason.

 

When you use the priming tool i like to use a really big drill that plugs into an outlet, not just an 18 volt battery one. And i spin it as fast as it goes...i can easily get over 40 psi

 

I think the concern about firing up an engine that potentially has zero oil pressure should be obvious. Hence my suggestion to use the priming tool. If using the tool produces evidence of oil distribution (pressure at the gauge, oil flowing out the pushrods), the need to drop the pan is negated. If not, the next step is clearly to drop the pan.

 

And in my experience it takes longer than you think it should to see oil pressure.

Please keep us updated.

 

I was under the impression that the Zinc additive was primary for flat tappet cam engines.

 

I understand your point. The priming tool is a very good alternative.

OP says he was driving the car with zero on the gauge, and then started it again for a test. I will modify my thought and say I'd start with seeing if there is pressure where the line leaves the block. That should take very little time. If the motor bites the big one in that short a time, it was done for already.

 

Fair enough. Fortunately it's up to him to decide if the risk is worth it. Personally I'm just dying to hear what he finds out.

 

Me too!

I think he'll find a clogged oil pressure gauge tube, a broken loaner oil pressure gauge, and everything else will be fine. Hopefully.

If it were my engine, I'd just fire it up with the valve covers off. But it depends how much risk you want to accept.

 

As I mentioned, I do have the valve covers off now and I *do* plan to use the priming tool and drill approach this morning. I also mentioned that all visual indications of the heads are that oil has been flowing all along... just not to the gauge.

The fitting in the top of the block that leads to the oil pressure gauge has been pulled and the fitting itself is not clogged. I stuck a 12 gauge copper wire into the threaded hole in the block and it went in about an inch or so before hitting something which FELT like it was a turn (change in direction) in the block casting which the wire would not follow due to the wire's stiffness. The fitting is back in the block and the line that attaches to it is back in place, too (and that line has no obstructions as I passed a much thinner gauge wire completely through that line with no issues). Right now, that line is hooked to an over-the-counter gauge but I may pull the gauge off and just put a catch pan under the end of the line as an initial test.

I'm going to use the priming tool and, as others have said, see if oil comes up through the pushrods, etc. If that works but it's still not coming from the oil gauge passage in the block, then I'm not sure what I'd do. I thought about trying to shoot compressed air into that oil pressure gauge fitting in the block ... but then I also thought of the potential giant mess that MIGHT happen if that air were to push oil out a bunch of places at a higher rate than the pump would normally do.

I am ALL ABOUT not having to pull the pan if I don't have to. And just to be clear, the engine has NOT been run since I started this exercise

 

I'll bet a nickel on bum gauge(s) but at least you're closing in on it. Hoping for a cheap, easy answer for you.

 

I hope you don't have to pull the pan.

If you have enough hands, and can run the oil pump while filming the rockers, a video might really help. You might need 6 hands if you want to turn the crank at the same time.

 

FWIW - as far as the priming tool - I'm not familiar with the oiling system on a SBC and only a little familiar with the BBC oil system but for a BBC I have heard it said that if you do not have a collar on the priming tool to simulate the bottom of the dist. above the oil pump you will not get oil to the lifters only the crank & cam I have heard of some engine builders using the bottom half of a dist housing as part of their priming tool. not sure if this is true with a SBC. My point being that the OP could spin the snot out the the oil pump and not see any oil come up thru the push rods and think the pump is shot when in reality it's working fine but the oil is not being forced to the lifter galley.

Pat

 

Both Big block and small block Chevys need that special priming tool that resembles the bottom half of the distributor

 

pspicci,

What you described in post 57 is basically, the difference between a $9.95 primer tool and a $25 unit.
One has no collar, so it may wobble, and may not build up pressure.
The better one has a somewhat adjustable collar that stabilizes it in the Intake and works much better.

Some people go to a junkyard and buy an old POS dizzy, strip it down. It's much easier and maybe cheaper just to buy the tool.

 

its not the collar, its the bushing at the bottom of the shaft that makes sure the oil gets to the passages