[ponchjoe]

Originally Posted by Pronto Poncho

Not even a remote possibility. But Thanks

It’s a possibility but I’m assuming you checked by your response.

[Pronto Poncho]

Originally Posted by hurryinhoosier62

It's not the plumbing; it's the PCV valve itself. If you get a bad one they will sometimes flutter with engine vacuum. The fluttering causes a clicking sound. It's a long shot but worth a look.

Nope not It, Thanks.

[Pronto Poncho]

Originally Posted by grivera

He’s referring to the tabs on the oil pump shaft that keep it from pulling out when removing dizzy.

Dataway - ears are intact

Yes I know

[Pronto Poncho]

Originally Posted by ponchjoe

It’s a possibility but I’m assuming you checked by your response.

Ummm OK , Thanks.

[Pronto Poncho]

Originally Posted by dataway

I know the distributor has been pulled a few times .... are the ears off the oil pump drive shaft so it could be pulled and checked for witness marks?

Forgot to mention: The distributer was taken out, disassembled and checked as well. No signs of wear or bearing damage this time around.

While it was out another distributer was put in it's place and run which resulted in absolutely no change of tapping noise. So the mystery continues - - - - - ->

[STEELCITYFIREBIRD]

Originally Posted by Va68goat

dataway,
Here are the witness marks that were located on the oil pump shaft.

Serious question to all those thinking about this.
Why would the "witness marks" only be on one side of the oil pump shaft?

[HWYSTR455]

Originally Posted by STEELCITYFIREBIRD

Serious question to all those thinking about this.
Why would the "witness marks" only be on one side of the oil pump shaft?

Think it was a low spot on the shaft.

.

[MarkS57]

Originally Posted by STEELCITYFIREBIRD

Serious question to all those thinking about this.
Why would the "witness marks" only be on one side of the oil pump shaft?

That was my point in his other thread a week or so ago. And the idea that the cam gear might not be right. The recent vid of the cam gear rotating seems to show it is concentric but I guess the cam gear teeth might not be machined correctly....long shot...but I've never seen an oil pump shaft with such a clear off- center wear pattern either..others may have?

[Pronto Poncho]

Originally Posted by STEELCITYFIREBIRD

Serious question to all those thinking about this.
Why would the "witness marks" only be on one side of the oil pump shaft?

Great Question !

We talked about that in length and could not come up with a really good answer.

A little background on what we did. We did the following: Installed another oil pump, oil shaft and distributer. The results were the same, still tapping ! We also checked the oil drive shaft for damage or out or centric. Other than the witness marks all checked out ok. I am willing to believe the initial marks were made because of the bad bushing in the distributer. But why only on part of the shaft ?

[Pronto Poncho]

Originally Posted by MarkS57

That was my point in his other thread a week or so ago. And the idea that the cam gear might not be right. The recent vid of the cam gear rotating seems to show it is concentric but I guess the cam gear teeth might not be machined correctly....long shot...but I've never seen an oil pump shaft with such a clear off- center wear pattern either..others may have?

Here is some more info on that.

An altered 1/2 distributer base and shaft was installed. It was the base with just the shaft sticking up. The original timing gear was put on the test shaft. The motor was turned over without plugs. The shaft was just held in by gravity. This procedure was done with a small amount of lateral pressure put in the side of the exposed shaft and then agin with no pressure. There was absolutely no pulsing or any other type of irregular movement on the exposed shaft. It spun straight and true.

So still open to suggestions because we are out of ideas on this one.

["QUICK-SILVER"]

Originally Posted by Pronto Poncho

Great Question !

We talked about that in length and could not come up with a really good answer.

A little background on what we did. We did the following: Installed another oil pump, oil shaft and distributer. The results were the same, still tapping ! We also checked the oil drive shaft for damage or out or centric. Other than the witness marks all checked out ok. I am willing to believe the initial marks were made because of the bad bushing in the distributer. But why only on part of the shaft ?

Was the slot dead center of the shaft?

This one pic "looks like" it had some ear spread on the right side. If so, that would have pushed the opposite side, where the ware is, closer to the guide hole.



Clay

[Pronto Poncho]

Originally Posted by "QUICK-SILVER"

Was the slot dead center of the shaft?

This one pic "looks like" it had some ear spread on the right side. If so, that would have pushed the opposite side, where the ware is, closer to the guide hole.

Clay

Thanks Clay,

If you get an opportunity look at the video posted last weekend. You can see that there is no irregular movement then. I would speculate that the marks happened at a higher RPM during the first Pulls on the first Dyno runs before Joe received the motor. That was when the bushing in the distributer was bad.

Just a reminder to everyone: This may not be discussed on the thread enough but please Remember:

When Paul did the first Dyno on the motor it had a major failure from oil starvation which resulted in wiping out the bottom end of the motor. Can't say for sure but if I understand correctly he only replaced the crank rods and bearings. I sometimes wonder if this somehow is connected to our tapping problem ?

[Shiny]

Originally Posted by "QUICK-SILVER"

Was the slot dead center of the shaft?

This one pic "looks like" it had some ear spread on the right side. If so, that would have pushed the opposite side, where the ware is, closer to the guide hole.
Clay

This is a good hypothesis.

Another speculation - may also be just natural movement of rod relative to pin? If the worn spot is normal to the slot and there is a natural CG or inertial pull to one side, the rod may just slide sideways on the pin ???

[Va68goat]

"QUICK-SILVER",
When we pulled the motor out prior to the motor being sent back to Arizona, we installed another oil pump and oil pump shaft. We reninstalled the motor, started the motor up and the knocking noise was still present. We then installed the original parts and it was sent to Arizona.

[Pronto Poncho]

Originally Posted by Va68goat

"QUICK-SILVER",
When we pulled the motor out prior to the motor being sent back to Arizona, we installed another oil pump and oil pump shaft. We reninstalled the motor, started the motor up and the knocking noise was still present. We then installed the original parts and it was sent to Arizona.

I agree Joe, Shaft is not the source. Not sure why we are headed back in that direction ?

It had a major failure from oil starvation which resulted in wiping out the bottom end of the motor. It appears that only the crank rods and bearings were replaced.

Hoping to get thoughts on this instead: I sometimes wonder if this somehow is connected to our tapping problem ?
__________________

[MXTex]

If I understand correctly; when the motor let go on the dyno, the crankshaft and two connecting rods were damaged. If/when this motor gets disassembled (which I think is inevitable), I'd recommend looking very closely at the pistons that were on the connecting rods that were damaged on motor #1. A failed connecting rod could apply some very strong and abnormal forces on a piston. Assuming that the piston locations from motor #1 were duplicated in motor #2, I'd look very closely at these two holes. Do we know which cylinder numbers received the replacement connecting rods? If so, what are the compression numbers for these holes? If one of the cylinders that received the replacement connecting rods has vastly differing compression than the other 7 holes, I think we're looking at piston damage from the original scatter as the root cause.

[JLMounce]

I'm just getting back to this thread since I've been out of country.

MXTex it was stated that the crank and two rods were replaced, not because they failed, but because the owner should not be receiving a brand new engine with a crank turned 10/10 and two rods already resized. This wasn't a "blown" engine. Instead it had an oil starvation issue that ate the bearings.

One thing that was brought up earlier was the new M&H harness in the car. Was it verified that the ignition wire had been jumped? I have all M&H harnesses in my bird and they would not sell me an "HEI Ready" dash harness. Instead they provided information on how to jump the ignition line in parallel to achieve full voltage to the HEI. My dash harness is only about 2 years old. It's possible they will sell a harness that way if you really want them to, but that wasn't my experience. It's something that I would check all things considered. Put a voltage meter on the coil wire.

[grivera]

Originally Posted by JLMounce

I have all M&H harnesses in my bird and they would not sell me an "HEI Ready" dash harness. Instead they provided information on how to jump the ignition line in parallel to achieve full voltage to the HEI. My dash harness is only about 2 years old. It's possible they will sell a harness that way if you really want them to, but that wasn't my experience. It's something that I would check all things considered. Put a voltage meter on the coil wire.

Jason - Interesting - In 2011 I ordered an M&H engine harness for HEI and they also sent one without the wire installed. I questionet it after install and they sent me the wire so I could add it. At the time, they said it was an issue with the order.


Joe - I would check the coil wire for 12V when engine is running. Likely not your issue but will make for a funky running engine.

[JLMounce]

Originally Posted by grivera

Jason - Interesting - In 2011 I ordered an M&H engine harness for HEI and they also sent one without the wire installed. I questionet it after install and they sent me the wire so I could add it. At the time, they said it was an issue with the order.


Joe - I would check the coil wire for 12V when engine is running. Likely not your issue but will make for a funky running engine.

I should clarify here. I asked for an HEI ready harness and I wasn't told "no" I was just told that it adds significant cost to have it done. The rep without saying it couldn't or wouldn't be done, really pushed not to even go there. Since all you need to do is run a non-resistance wire in parallel, it's not hard to make the change yourself.

One other item to possibly look at while you're testing is the coil wire itself. I don't know how it is on the GTO, but in the birds, the resistance wire is in the dash harness and while the coil wire from the engine bulkhead is not a resistance wire, it is not large enough to really carry more than the 7-8 volts that it would be receiving with an unmodified dash harness.

What you would likely want to do is replace that wire with something more suitable for 12-14 volts.

Anyway, just something to check and mark off the list.

[Sirrotica]

They ran a jumper wire directly from the positive battery post directly to the distributor last weekend, it's in the posts from last weekends diagnostic efforts.