No oil pressure

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V8-valiant

V8-valiant

FABO Gold Member
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Hey guys and gals just for the record I have used the search option on the forum and haven't got anywhere so I'm looking to the members for help. My dad and I have been working on his 70 swinger to get ready for a local show in September. We were going to fire off the fresh engin today but ran into an oil problem. We have tried everything we can think of prior to pulling the engine back out. The engine is full of oil there are no leaks, we hooked a oil pressure gauge right to the back of the block and are not getting any readings on the gauge. We have tried priming it with a 1/2 corded drill and are coming up with nothing. We checked the plug at the distributor bushing & it's there, we checked the plug in the block at the oil filter & it's there. We have enough pressure after priming it that it will squirt out when loosening the oil filter. We also tried turning over he engine while priming with no luck. We're not worried about cam break in because the cam is a used one that came out of my motor when I went through my 360 last year. Just trying to rule things out before we pull the motor. Any thoughts?
 
Try loosening up the filter or even remove it. Then prime the engine. Sometimes you get some air in the pump and that will usually solve it.
 
Who built the engine?

Could the main bearing shells been put in upside down. The top of the bearing has an oil hole to feed oil to the cam. If you switch the top and bottom bearings, then you will block the oil feed hole in the main...

Or could the cam bearing holes not be lined up properly?
 
I always put some oil in the pump before bolting it to the main cap...actually sort of prime the pump prior to installing it....

as said...fill the oil filter.....I have even poured oil down the hole where the oil pressure gauge bolts onto the block to get some oil in the pump....
 
70aarcuda said:
...fill the oil filter.........
Click to expand...

As above. If you are getting oil out of the filter mount, the pump is working. This doesn't mean there's a crack or leak, like the infamous ARP stud interferance issue. Some pans interfere, and can bust the casting

But make sure the filter is full and make sure you crank it long enough to fill it.

Did you check / do you have the little drive in plug down in the vertical gallery in the rear?
 
If the pump is really pressurizing the oil, then oil will spray out of the filter base pretty hard. If it just dribbles or runs out in a mild stream, then the pump is not creating good pressure.

As said in the related thread. when you spin the drill, it ought to spin pretty freely for a few seconds and then the load on the drill ought to suddenly get very heavy and will slow the drill down. And, if your drill is only spinning at 400-500 rpm, then it won't likely build max pressure; that's not fast enough to simulate even fast idle, much less cruise RPM's. So check your drill speed.

New oil pump? Could be that the relief valve is stuck partially open; new or old pump.
 
Thanks everyone for the suggestions. We have used the same priming tool and drill for the last 5-6 engines that we have put together. We pulled the gauge out to prime and see if we can get oil to the hole where the oil sender is. We cannot get oil to it. We have spun the priming tool for a good min to 1 1/2 mins. Getting a lot of pressure at the filter, my dad and I put the motor together which we have done many before (not saying we couldn't have made a mistake, just saying it's not the first one). The drill does spin free then draws down after a few seconds. We have checked the plug in the distributor opening and the plug at the oil adapter. We haven't gone as far as pulling the front of the engine apart. The engine was put together with all factory bolts no arp studs used.
 
OK. let's "review"

You have pressure at the filter, but not anwhere else? What filter (brand / part no) you using?

If not that, then it's bleeding pressure somewhere
 
To find the problem; Spin the pump with the priming shaft and tear into the engine gradually until you see oil gushing out ---> that is where you are loosing pressure...

Unless you have a blockage somewhere, like I mentioned earlier with a backward bearing or something...
 
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