[mgarblik]

Originally Posted by Va68goat

mgarblik,
I know this thread and the other one has gone one way too long but at the end of the day, the motor is still knocking. I want this thread to end just like everyone else! There is a place where I can run it on a dyno and I have already contacted them. They're at $600. Don't know if I agree with the noise coming from the chassis considering the witness mark on the oil pump shaft. We are going to try another distributor. That's next on the list.

Of course we are all arm chair quarterbacks here. Everyone wants this story to end with a great running engine in your car. Probably no one more than Paul Carter. Changing distributors eliminates a known problem and a variable. I have never heard of an oil pump making a knocking noise. I would think a scraping noise would be the likely noise from something in the oil pump shaft area contacting. Wish all involved good luck.

[Va68goat]

Dont think it's the oil pump. We switched it out and the shaft. Same noise. This motor was on the dyno a little more than a month ago and it was told to me that it didnt have a knock.

Sent from my SM-G955U using Tapatalk

[ponjohn]

I am so confused.

The engine was delivered it made a noise.
It went back to Paul for fix and was refreshed.
It went back in the car - it is still making a noise?

Where does this thread fall into the whole process, before or after the original delivery?

[n20ta2]

I think I can hear it knock just before it starts, did you guys try disconnecting the coil and turn it over? Can you hear it knock?

[grivera]

If the noise is coming from dizzy area, disable coil as indicated above and test with a mechanic's stethoscope Then, remove dizzy and and use the stethoscope in same area - insert in dizzy hole close to oil pump shaft. Maybe you could then determine if the dizzy or cam gear is a factor in the equation.

[Va68goat]

ponjohn,
You're correct. Engine was delivered with a knock, it went back for fix and refresh, went back in the car and it's still making the exact same knocking noise. The purpose of this thread was for me to concentrate on the distributor and the bushing. It was told to me that the distributor bushing was the source of the knocking noise and that the motor needed new bearings, piston rings, a light honing of the block and the crank needed polishing. The reason I'm trying to concentrate on just the distributor bushing is because I don't think it was the source of the knock. I think it's the result of something else that is wrong with the motor. When the motor failed on the dyno, a new crank was installed, new bearings and two rods. My original question was if the pickup tube fell into the oil pan at the dyno, would anything occur while it's failing on the dyno that could have damaged the distributor bushing.

[DOC]

I just listened to the videos for the 1st time and it sounds just like a bad torque convertor I had to change out one time. Not saying that is your problem, but is the noise there with it unbolted from the flexplate?

[Va68goat]

DOC,
We pulled the converter back several times over the past year and the knocking noise was still present. I think a lot of people are scratching their heads on this one.

[Dragncar]

Originally Posted by Cliff R

Correct Steve, basically you just loose the screen to filter out the big chunks.

Far as oil pick up tubes falling out, OEM never budge.

The ones they've been sending with these pumps for at least the last 30 years are "soft" and don't have the memory like OEM. Rest assured if you do NOT take measures to retain them in the pump they absolutely will end up in the bottom of the oil pan, and may even get sucked up into the spinning assembly.

Take the extra time to effectively secure the pick-up to the pump. I don't recommend welding them as I've seen a few break loose and take a big chunk of the pump with them, but at a minimum make a strap to go back to one of the pump cover bolts, or drill and tap them for a hardened screw.....Cliff

Any time you weld cast there is the risk of cracking. Thing is, every time the hobbyist weld a pump to pickup its a dissimilar metal weld and very few have the right rod/wire to weld it. Most stick a Mig gun with plain hard wire and pull the trigger with wire meant to weld steel only.
Making a strap to a bottom pump bolt is the go to move. They make a 1/4" thick plate with straight drilled holes vs the thick cast plates with countersunk holes making the strap difficult.
You can high temp silver solder a pickup. Its very strong and does not take the heat brazing with brass does.
My gas tank and transmission pan have 1/2" nuts silver soldered to them for drain plugs. Holding a pressed in tube would be a piece of cake.

[chiphead]

Originally Posted by Va68goat

If you look at the pictures of the oil pump shaft, what would cause the oil pump shaft to have witness marks on only part of the shaft. It's definitely not completely around the entire shaft.

Also, before I sent the motor back to Arizona, we pulled the motor and we switched out the oil pump and the oil pump shaft. The knocking noise was still exactly the same. I don't know if that means anything to someone with experience but I think that may be telling as well.

I've seen wear like that on every high mile pontiac I've taken apart. It's common (in my experience) for the shaft to rub the retaining loop in the block when the distributor clamp is loose or the distributor bushings are worn. Worst I ever saw was a Pontiac 350 with a worn out HEI. The lower bushing was wasted, it flopped like a fish. The pump shaft had a big gouge looked much worse then your pic. Still ran strong, I only pulled it for a 400.

That shaft is going to normally wiggle a bit because it's transmitting a lot of force to drive the oil pump The only thing holding the distributor in the block is the clamp, and it's going to wiggle a bit. If the bushing failed, then it would allow the shaft to contact the retaining loop and show wear in short order. I seriously doubt you could hear it, even during a bushing failure.

As far as the navel gazing about the dizzy bushing... If you're worried about it, pull the dizzy and check the slack by wiggling the shaft. It's easily checked. I doubt it's an issue.

As for oil starvation on dyno. It sucks, but it happens. The bushing doesn't require nearly as much oil as the rod bearings. The rod bearings would fail long before the bushing would be impacted. Usually the only issue seen with the dizzy/oil pump drive is acclerated gear teeth wear when using 80 PSI oil pumps after several thousand street miles. The bushing is a red herring IMHO. It would fail silently and only show up as a distributor failure when the engine stops running. You're not going to hear a tiny reluctor vane hitting the dizzy's magnetic pickup over the rumble of a big engine.

During oil pressure loss near WOT when loaded on a dyno (or road), I would expect the rod bearings to be damaged after 15 seconds at WOT with no oil pressure. Main bearings would go next, likely thrust main shoulders. Engine would sound sick, labored. HP readings on dyno would fall like a rock. Engine temps would increase. Loud knocking would set in after 20-40 seconds. I estimate it was shut down after 15-20 seconds had elapsed, based on report of one rod bearing spun and heat damage to other rod on same journal. Theoretically It could run for a minute or two like that before having an actual uncontained failure (thrown rod) that would ruin the block.

What you had was rod bearing failure due to low oil pressure. A real "blow up on dyno" throws parts across the room. Not negating your pain, just some may see title and think engine was total loss.

Reference below video for a real explosion.

https://www.youtube.com/watch?v=RUquK_6WIjk


Can you provide a link to most recent videos?

[Cliff R]

"Any time you weld cast there is the risk of cracking. Thing is, every time the hobbyist weld a pump to pickup its a dissimilar metal weld and very few have the right rod/wire to weld it. Most stick a Mig gun with plain hard wire and pull the trigger with wire meant to weld steel only.
Making a strap to a bottom pump bolt is the go to move. They make a 1/4" thick plate with straight drilled holes vs the thick cast plates with countersunk holes making the strap difficult...."

At a MINIMUM get the oil pump pick-up driven all the way into the pump, adjust the height, then drill a small hole thru the pump body and pick-up tube, then tap for a hardened machine screw. I have 8-32 hardened screws here just for that purpose. After the drilling/tapping operation you need to take the pump apart and clean out the metal chips, but the pump should come apart anyhow for cleaning and inspection before being put in service.

In the past 40 something years of doing this I took a short cut ONE TIME and welded the tube to the pump. That engine was in a street/strip Pontiac application. Got it back after about 10 years to be "freshened up" and the pick-up was down in the bottom of the pan and hurt nothing. No telling how long it was in there, but the engine bearings/bottom end was fine. In addition to drilling/tapping the pump/pick-up to keep it from falling out again we just rolled new rod bearings in it, timing chain, valve springs, new set of roller rocker arms and right back in business......Cliff

[tailored68.........]

fu*n stupid mistake..

[hgerhardt]

In the one and only time I had someone else build an engine for me, he forgot to torque the oil pump pressure relief valve cap and it unscrewed itself in about 5 hours of run time. When that happens, you have no pressure at all.

The motor is a 428 with solid roller, and I didn't hear any bad noises while running. I happened to look at the oil pressure gauge and saw it reading zero while driving, but I was 1 block from home, and again no noise. Assumed it was a bad sensor. Diagnosis showed it indeed had no pressure, so I disassembled the engine and found the pressure relief parts in the pan.

Figured the 1st thing to get damaged would be the rod bearings, but they all looked good. Same for mains. Thinking crisis averted, I reassembled the motor. Engine ran fine, but valve lash kept opening up on the center cylinders more than the end cylinders. This went on for a while until I changed oil and found lots of debris in the filter. Crap. Disassembled again and found the center 3 cam bearings had spun.

SO... lesson learned is, with solid roller, the cam bearings are under more stress than the rod bearings. To save the block, I had it bored to accept needle bearings. This happened 23 years ago and that motor is still in my '66 GTO.

[dataway]

First time I fired up my engine on the test stand a few months ago I noticed some strange oil pressure readings. Not zero ... but some weird transitions between pressures at various rpms .... pulled the pan, yep, I didn't torque on that same cap ... it was out about two threads, which of course loosened the regulator spring a bunch.

[abefromen]

Is ther a factory torque spec for that cap?

[hgerhardt]

Originally Posted by abefromen

Is there a factory torque spec for that cap?

13 lb-ft

And that's for the V8 and OHC-6 according to the 1970 shop manual.

[dataway]

In my case "didn't torque" would be a white lie ... I didn't tighten it passed finger tight when I put the pump back together.