[Gach]

Here’s what your looking at if its a spun bearing. Cost wise, having rods resized new rod bolts and possibly having the crank turn .010 under. Not really that expensive ordeal.

[Gach]

Of course I don’t know how many miles are on those pistons or what condition the cylinder walls are in. That’s something I would do is mic the Pistons and check the bore. To see if just putting new rings will work.

[Gach]

Another question Has this block ever been bored and had new pistons installed don’t remember reading anything as far as that goes

[TRADERMIKE 2012]

Originally Posted by Gach

Another question Has this block ever been bored and had new pistons installed don’t remember reading anything as far as that goes

Mikes reply:

From the earlier measurements that we took in other Threads, we could say that the Bore is stock 428 ci from the factory. The Pistons are stock as well , they are installed backwards for race reasons, we deduced, except number 2 cyl, why" In addition, the number 6 cyl Rod is in reverse, noted by a forum member, why?

Further examination to come for sure...

[TRADERMIKE 2012]

Originally Posted by Gach

Of course, I don’t know how many miles are on those pistons or what condition the cylinder walls are in. That’s something I would do is mic. the Pistons and check the bore. To see if just putting new rings will work.

Mikes reply:

In other Threads of mine this information is readily available, go to my name and press on it and the system will take you to all my input both in my own threads and others as well. If the thread is by Tradermike 2012 then I initiated the Thread in the first place. Other than that, I took over a few, not on purpose, I was learning PY forum 101.

The measurements we took were an inch from the top, middle and an inch short of the bottom, there was a slight difference and no scoring on the cyl. walls either, all in all, my first impression is one could just re-ring and change the Bearings, but we will prove that in a short time.

It is best to cruise my Threads for the information that I have provided, some will be in photos that I took of written notes that we wrote as we research and developed this ten-year project. I would not be surprised if I had 500 pages of these notes in my files at home. Forget about all the documents on my computer.

I was able to salvage, with the help of the forum, all the HO data lost when the servers were cleaned or purged of older data, to make room for the new. This is why I like to leave information in text on my threads, instead of leaving URL's, that get wiped out during one of these events and you don't when it's coming. Unfortunately, the forum does not agree with me on this issue.

We will provide more Info. as it is available, with actual photos to collaborate what I think vs actual factual measurements, that count.

[Gach]

One can't just install the parts as they came out, especially in my case where Pistons are backwards and at least one Rod is as well. However, thanks to the...

I read this before, thats why I’m confused so someone put a couple pistons in backwards. So it was just re-ringed with stock pistons, or bored with new pistons or just a couple of pistons were changed. I guess it doesn’t matter, just wondering if it stock bore.

[TRADERMIKE 2012]

Originally Posted by Gach

I read this before, that's why I’m confused, so someone put a couple pistons in backwards. So, it was just re-ringed with stock pistons or bored with new pistons or just a couple of pistons were changed. I guess it doesn’t matter, just wondering if its stock bore.

Mikes reply:

We measured and found them to be stock bore.

This motor was rebuilt in 1968 and the mechanic put a date on it 2/2/68 or (2268), the forum is aware of this and the consensus is that is when it was built for race purposes and was used in moon shining later in its life. This motor, when built in 1968 for racers, was completed with the Tri-power Cam #588 and the Tri-power Intake. Mostly racers knew that you could buy these parts, over the counter, in those days. As a matter of fact, race rules in the day require that by rule, you must use factory parts in stock class, only.

Seven Pistons were in backwards and the # 2 Piston was the only one to be installed correctly. # 6 Rod is in wrong because you can see the squirt hole in the photo and you are not supposed to according to the man that discovered the error. It is presumed that the builder swopped the Pistons from side to side in the same Journal, as they would do, back in the day for race purposes. The pistons would have maintained the wrist pin and rings this way. How things got messed up is a mystery. Perhaps we might discover the "why" of it all, soon.

Until then, we (myself and the forum) have found an error in the 1967 shop manual drawings of a piston orientation that could have contributed to the error, when seen by a mechanic, trusting too much in the factory manual.

If you have time, please go through my Threads, because all this stuff about Piston slap was discussed in full and it explains "why the racers reversed the Pistons," on purpose.

[Gach]

I gotcha, it was to make up for the pin off set, pretty interesting that was one of the things they ( racers) would do. Now I’m clear on exactly whats going on. I’ve read most of your post, but you just gave a better explanation. Thanks.

[Gach]

There’s a whole article in HO book, about pin off set..but don’t quote me its been a long time since I’ve read that book. Way back it was like the Pontiac book on engine building.

[Kenth]

Originally Posted by TRADERMIKE 2012

Until then, we (myself and the forum) have found an error in the 1967 shop manual drawings of a piston orientation that could have contributed to the error, when seen by a mechanic, trusting too much in the factory manual.

The 1967 Pontiac Service Manual is correct regarding piston/rod orientation as showned is Fig. 6-80 and Fig. 6-136.

FWIW

[TRADERMIKE 2012]

Originally Posted by Kenth

The 1967 Pontiac Service Manual is correct regarding piston/rod orientation as showed in Fig. 6-80 and Fig. 6-136.

FWIW

Mikes reply:

Someone indicated that in one of the Manuals, possibly 1968 then, that a drawing was shown from the front of the vehicle looking back toward the windshield and the draftsman did not call out what direction to look from, with an arrow. You will find both the drawings in my threads. I am not giving any mechanic an excuse for misreading a confusing drawing.

No matter, in my case, to have seven Pistons in reverse for race reasons, does "not" negate the # 2 Piston being the only one to be correct. The # 6 Rod also, why would anyone orientate that particular rod backward? Unless he modified it by clogging the squirt hole with a rod and then drilled the other side to compensate to squirt the oil into the opposite cylinders Piston pin area. This, I will find out, when I rip it apart soon.

If the mechanic was any good, he could have ground down any rod, "not" to interfere with the weight side of the Crank, when he performed this build. I have been trying to reason, "what would I have done? If all I had to work with was the parts in my motor. Then you must add to the aquation, it is "not" like the builder of my motor was out to sea repairing this motor, with only its parts. There I go over thinking again, my bad!