Air_Adam

I got a really weird problem, and no one I've talked to can figure it out.

I recently did a carb/dissy/intake swap on my 350. I changed from a CC carb and distributor and factory manifold to a Holley 4bbl, vac advance HEI, and an Edelbrock intake. I did an oil change at the same time, with some Lucas Oil Stabilizer added.

This is my problem... for some reason, I now have no oil pressure. The factory guage read zero, so I hooked up a mechanical one... still read zero. I know for certain that the oil pump driveshaft is connecting to the distributor, the collar is not broken, and I have no visible oil leaks or drips. I've fed wire down the hole in the block for the guage to see if it was plugged. Its not. I thought maybe the Lucas stuff made the oil too thick for the pump to move around easily, so I dumped it out for regular 10w30. Nothing gained.

Anyone have any ideas? I'm so lost and frustrated right now...

430T/A

Pull out the distributor. make sure the oil pump rod is still in place, then grab a primer and spin the oil pump with a hand drill.. see what the guage reads then. If I'm not mistaken there is a big O-ring that goes around the distributor that seals the oil galley. somehow the oil pump shaft got messed up, its the ony way.

Vader

430 is right, but there are no sealing rings on the lower end of the distributor housing. The groove thaty provides an oil passage is simply sealed by a close-fit shoulder machined on the distributor shaft housing above and below the oil passage.

When you pull the distributor again to check that, take a close look at the lower end of the distributor shaft. The distributor driven gear should have a pin near the tapered opening that engages the slot in the oil pump drive shaft. You might also want to compare the lengths of the distributor gears (and subsequent overall length of the shaft from the clamp flange) to make sure you didn't inadvertently get a shorter one, like a driven gear from a tall deck BBC, a distributor designed for a high cam bore Dart block, or something strange like that.

In either case, I wouldn't run the engine any more, since you might be running dry.

Air_Adam

I'm way ahead of ya Vader and 430, I've already checked into just about everything you've suggested. The distributors are both identical... the exact same length, the pin is present and in the same place, everything... they are identical. It (the new one) was taken out of a running 350, so I know its for the same kind of motor too (ie. not a tall deck BBC or something)

The machining on the dissy housing you are talking about is also in perfect shape. Actually, its in better shape than the machining on the one that was replaced.

I can see though, when the dissy housing below the gasket (on the manifold) came out the 2nd time, that it was covered in the new oil I had just put in (it was cleaned before it went back in) so that should be a good sign right?

Hmm... maybe there is a kink in the plastic tube for the new guage. Would that make any difference?

Air_Adam

Just another little thing here... I know that it is connecting to the oil pump shaft because it took me about 45 minutes to make the distributor go all the way down last time it came out because it wouldn't wanna hook up to the shaft.

Air_Adam

I was just thinking... there is one thing that no one brought up yet.

I know there is a spring in the oil pump (can't remember the name right now) that releases pressure when it gets too high.

Now, what I was thinking, is this: My oil pressure was pretty good before adding the Lucas stuff. It was around 25psi at idle (warm) and about 50 or so at speed.

What I was thinking is that maybe the Lucas stuff made the oil way too heavy (it is quite thick) and possibly made the oil pressure get high enough that it could have damaged the spring in the oil pump, and now the spring will not hold any pressure at all.

Is this possible? At the moment, its about the only thing that makes sense to me, because everything I've been able to check is mechanically fine and appears to be in good working order. I changed out the oil last night for just 10w30 dino sauce (no Lucas) and there was no water or metal shavings in the oil I drained out, and all the mechanical parts check out as well.

Your $0.02 welcome here... PLEASE!!!

Air_Adam

Anyone?????

Vader

If you manually turn the oil pump shaft counterclockwise, can you see oil pumping from the cam gallery through to the hole vacated by the distributor? You might now build any pressure, but should at least be able to produce oil flow by that method.

Air_Adam

Never thought of that... but I did something similar... the mechanical pressure guage I hooked up goes into the back of the block, where the factory pressure sender goes. I left the tube open to see if any oil would come out, and I got nothing.

MR. KIDD

Hope your oil pickup tube in the pan didnot decide this was a fine time to come out.

Air_Adam

I had a shop take a look at it today, and the guy thinks it might be a spun bearing.

Does this happen from only changing the oil? I could see this happening if it was too low, or maybe if there was water in it, but there wasn't, its brand new, clean oil!

a73camaro

But the pump is submerged in oil.

Air_Adam

Well, I got my oil pump off today. BOTH of the 'ears' on that the oil pump driveshaft fits into on the pump sheared off. The mechanic who took a look at the pump said it looked like it basically hydro-locked and snapped them both off. Weird.

I kept the pump as a momento so I'll have pics later.

BTW - turns out there was otherwise no damage to the motor. Got a new pump in it, 5L of real oil, and she runs like a top with great oil pressure.

Air_Adam

#1

Air_Adam

#2

Here you can see the parts that broke off.

Air_Adam

#3

a73camaro

Have you opened the pump up? That is take the cover off and see if there is any crap in the teeth of the pump? And can the old pump drive be rotated without binding?

Air_Adam

Yup, spins nice and freely. No grinding, hanging up, binding, roughness, etc...

I still think it was because of that Lucas stuff. That stuff is so thick, it seems to me like it basically hydro-locked the pump, and the two driveshaft teeth gave out before the gear teeth.

Vader

Long, long ago, in a galaxy far, far away (actually, it was a Mustang, not a Galaxy), when I was first getting into engine work and didn't know any better (obviously, since I was playing with SB Fords), I was advised to pack the gearotor oil pump on a 289HP in my '68 with STP so that "the new pump would not start dry and would pump oil immediately on startup." Being the aforementioned "greenie" that I was, I readily complied. Two hexagonal oil pump shafts later, I decides to spin the pump backward to dispel the STP and allow the pump to turn easily enough so that the drive shaft would not twist off on startup. I had a helliva time even turning it slowly by hand, but managed to get it done without dropping the timing cover and pan again. I'm sure that the Lucas crap is just as bad, but with 30+ more years of technology and research behind it to make it even worse. Obviously, you just learned the same thing.

Still plan on using that crap, or are you ready to step into the 1960's and start using synthetics?

Vader

And that's not at all meant as a criticism. I'm just sorry you had to learn the same lesson in much the same manner. I hope you didn't suffer any more damage from the incident. As I recall, the distributor gear on the 'Stang eventually failed and took out the cam drive gear as a result, and I mercifully junked that POS before wasting any more time and cash on it. Since your pump was replaced, you probably got a decent look in the pan to ascertain that there were no fragments left over. Fortunately, the timing drive on the SBC is a bit more robust than that of older SB Fords, so you may not have caused any similar damage.

We'll keep our fingers crossed.

Air_Adam

No damage as far as I can tell, no offence taken Vader

The oil pressure is pretty good, around 45 at idle (cold) but I havent had a chance to run it long enough to get warm yet.

So I'll just stick to 5L of real oil from now on, heh. I think all the little bits are out of the engine, but I'll be changing the oil again very soon just to be sure its all flushed out.