[Gach]

WOW ! Those auction prices are unbelievable. Never realized they go for that much.

[TRADERMIKE 2012]

We finally removed the Crank and Pistons from the 428 ci YK Block and as Lou and I deduced (using the stethoscope from Harbor Freight) that the noise was emanating from the # 7 Piston/cylinder Crank Pin "not" From the Piston slap, so confidently diagnosed by many Forum members, that was etched in stone.

This is why I take my time and gradually use the process of elimination to solve the various issues that I am experiencing at any time. The Piston slap prognosis was optional and was going to happen eventually, if not next.

The # 7 cyl Crank pin Journal was worn the most and is rough running my finger nail across the etched lines in the Journal. In addition, the Crank Pins need to be turned, if I decide to keep it. I would need matching Rod Bearings. The Crank itself also needs to be turned and new matching Bearings to suit.

The Piston Skirts were measured at the lowest point on the Skirt as well, measurements appear on the document that I am supplying with photos of the actual parts. You can look at the information in the upcoming attachments in order to let me know your thoughts.

Most of the upper compression rings were broken into 30%-70% two sections, can someone explain the reason for that? Originally the # 2 Piston had the groove in the Piston top orientated toward the front of the motor and all the remaining ones pointed toward the rear. Once we removed the group of Pistons and lined them up on a flat table, we could see that the Spurt holes were not lined up facing the intended lower Skirts/Wrist Pin or Cam area.

Both halves of the Rod and Cap were marked accordingly from number 1-8/Piston, where they join using a through bolt. I elected to orientate the Pistons, with the spurt holes up and let the Piston pointing groove fall where they may, for the time being. I noticed that the # 1 & 2 Piston grooves pointed forward and the other six faced toward the rear of the motor. You will see this in the photos soon. The engine builder that modified this Engine in 1968 had the Piston Grooves pointing toward the rear for race reasons according to my vast documented research, only to leave the Spurt holes pointing in the wrong direction, I recently learned.

However, the aftermarket Bearings don't have the necessary channels to flow the oil anyway, or so I just read in my new book. Perhaps that is the reason he built the Motor, the way it is today. I re-orientated the Piston/Rod with the Spirt hole up and pointing the oil to the opposing Pistons Wrist Pin and under Skirt to see what that would look like and I found out that is the way it is supposed to be. This means I will have to remove six of the wrist Pins and install the pistons the opposite way, that is the way to have the Thrust load as Pontiac meant it to be. Do you agree with my Theory?

Note: On these Rods, there is no bevel or camphor, one larger or smaller than the other that would clear the weights on the Crank, as was explained to me over the forum. The only difference we found was on one side of the Rod, on the lower half @ the webbing, is a raised portion, that resembles 1/16" diameter dowel x 3/16" high, cast in mark, perhaps for strength or maybe it depicts direction. For now, I base the orientation of the Rods by the Spurt holes only and the Pistons by the groove etched in the Piston edge top. I can only feel that since these Rods don't fit the description that was given to me, that maybe these are Forged ones? One could only hope! Let me know, they have an "H"- shape to them.

What if I want the Spurt holes to work as Pontiac had before, where am I going to get modern bearings to work like the old ones, are they special? Can I get away without the Bearing/Spurt hole Bearings that supply the oil to under the Piston Skirts and Wrist Pins, without this oiling system will the motor fail before its time? I have to wonder if that is the reason my existing Top compression rings cracked /Broke in the first place?

Butler sells a kit with Forged 455 ci Crank stroker, Forged Rods and Pistons. New Bearings, etc... From what I am reading in this new book that the price to turn and polish the existing Crank, Rods have to be sized, Crank turned, Pistons checked, Rods shot peened, nitride this and that, I might just start new. JMO

Lots to weigh out, this is a good start, as far as I can tell the Block is reuseable and just needs TLC.

[TRADERMIKE 2012]

The next posts are going to be photos, so please be patient with the process of the way I relay the Information to the Thread.

The arrow is the direction that the groove is notched in the Pistons, I have orientated the Pistons on their Wrist Pins as installed previously by the engine builder that completed the work in 1968 and stamped the front PS Block to the left side under the Head. The next group of photos will show exactly how this was done.

[TRADERMIKE 2012]

Photos continue...

This is the Main Bearings in order showing the ware over the years.

[TRADERMIKE 2012]

More photos starting from # 10 in my archives, this helps me not duplicate them.

This is a 1967, four bolt Main, YK code, 428 ci HO Pontiac Engine. It has 376 Hp out of the box and this one is more like one HP per cube inch because it has functional air Induction, 041 Cam, new inner wearable parts were replaced, MSD Ignition, Headers and dual 2.5" exhaust, 067 D-port Heads and Tri-power under the Hood. 3.23 rear gears and a Gear Vendors over under drive. Hurb Adams suspension, full roll bar in the cab, trunk and around the motor.

[TRADERMIKE 2012]

The photos keep coming...

[TRADERMIKE 2012]

Start at number 20 in my archives...

[TRADERMIKE 2012]

Start at Journal number 6 in my archives...

[TRADERMIKE 2012]

Start at motor number 4 ...

[TRADERMIKE 2012]

The photos continue...

[TRADERMIKE 2012]

Here are photos of the Piston, so one can determine what type we have here?

[TRADERMIKE 2012]

Start from number 6 from archives...

[TRADERMIKE 2012]

start after Piston Skirt...

[400 Lemans]

Originally Posted by TRADERMIKE 2012

The photos continue...

Looks like a crack in number 7 ring land in the second pic of post 130.

[steve25]

Yes it does look like a crack below the top ring.

And here’s two other things.

The rings used are not even up to factory quality.

I see only a Moly top ring on those pistons where as the factory rings where a far better Moly face top and second ring.

The rods are old type that still have the unnecessary oil hole spurt hole in the parting line of the big end.

Moly face rings need to be installed very carefully so as to not scratch there face and the cylinder wall finish must be what’s needed for such a ring face.

[TRADERMIKE 2012]

Look up at the number one Rod where the Crank Pin meets the Rod, the # 69 exists, this raised area points to the number 69 and on this particular Piston to Rod group the notch is on the same side on the Piston, that is the only difference on these Rods from one side to the other and they are cast, because I can see the cast line on the edge view from the side looking at the bolts that hold the Cap to the Rod itself. These are "not" Forged Rods. It has been established that the number 1&2 Groups of Piston and Rod are orientated correctly, now that I have viewed all eight lined up with the Spurt hole up, that gives us the correct way that the hole system is viewed upside down on a flat table looking down with the viewers eyes. The other six Pistons are facing the rear # 3-8, which means that they would have to be taken apart at the Wrist Pin and spun 180 degrees on the Rod and the pins reinstalled, this is what I think, correct me if I am mistaken.

I tested each Rod to Piston Wrist Pin and tried moving them every way possible and they just rotate as expected. A careful look at the way the Piston gets oil through the oil ring groove for one thing, then there are Wrist pin filler ports on the sides of the Wrist Pin and drainage dumps at the bottom of the Wrist Pin ends under the Skirt area. Very thoughtful I would say.

[TRADERMIKE 2012]

Originally Posted by steve25

Yes it does look like a crack below the top ring.

And here’s two other things.

The rings used are not even up to factory quality.

I see only a Moly top ring on those pistons whereas the factory rings were a far better Moly face top and second ring.

The rods are old type, that still have the unnecessary oil spurt hole in the parting line of the big end.

Molly face rings need to be installed very carefully so not to scratch their face or the cylinder wall finish. A smooth finish must be what’s needed for such a ring face.

Mikes reply:

"Why did the Top Compression ring Break into uneven parts anyway, on about 5 combos of Piston and Ring sets?

[400 Lemans]

Originally Posted by TRADERMIKE 2012

Look up at the number one Rod where the Crank Pin meets the Rod, the # 69 exists, this raised area points to the number 69 and on this particular Piston to Rod group the notch is on the same side on the Piston, that is the only difference on these Rods from one side to the other and they are cast, because I can see the cast line on the edge view from the side looking at the bolts that hold the Cap to the Rod itself. These are "not" Forged Rods. It has been established that the number 1&2 Groups of Piston and Rod are orientated correctly, now that I have viewed all eight lined up with the Spurt hole up, that gives us the correct way that the hole system is viewed upside down on a flat table looking down with the viewers eyes. The other six Pistons are facing the rear # 3-8, which means that they would have to be taken apart at the Wrist Pin and spun 180 degrees on the Rod and the pins reinstalled, this is what I think, correct me if I am mistaken.

I tested each Rod to Piston Wrist Pin and tried moving them every way possible and they just rotate as expected. A careful look at the way the Piston gets oil through the oil ring groove for one thing, then there are Wrist pin filler ports on the sides of the Wrist Pin and drainage dumps at the bottom of the Wrist Pin ends under the Skirt area. Very thoughtful I would say.

The 3-5-7 pistons and rods just need to be installed in the 4-6-8 bores with the notches to the front and vise versa. That will put the pistons and rods back in the right orientation. But you will probably get new pistons anyway.

[Dragncar]

Broken rings, detonation.
Just get some 4340 rods and bore or ridged hone it to the next size and but some real pistons and be done with it.
Basic oil system mods, 60lb pump and go have fun.
Not sure what heads you are running but keep the static CR around 9.5-1 and you will be fine.

[Kenth]

Originally Posted by TRADERMIKE 2012

1. The Piston Skirts were measured at the lowest point on the Skirt as well, measurements appear on the document that I am supplying with photos of the actual parts. You can look at the information in the upcoming attachments in order to let me know your thoughts.

2. Note: On these Rods, there is no bevel or camphor, one larger or smaller than the other that would clear the weights on the Crank, as was explained to me over the forum. The only difference we found was on one side of the Rod, on the lower half @ the webbing, is a raised portion, that resembles 1/16" diameter dowel x 3/16" high, cast in mark, perhaps for strength or maybe it depicts direction.
For now, I base the orientation of the Rods by the Spurt holes only and the Pistons by the groove etched in the Piston edge top. I can only feel that since these Rods don't fit the description that was given to me, that maybe these are Forged ones? One could only hope! Let me know, they have an "H"- shape to them.

1. You are measuring at the wrong spot.

2. All rods has a chamfer to leave room for the bearing to the radius on crank. Look closer. Also the rods are offset and needs to be positioned with the notches towards radius on crank. You can NOT just look at the spurt holes.
If there are no notches on rods (aftermarket) you need to check how the bearing sits in the rod, side with more room goes towards radius on crank.
Your 1967 and earlier rods are cast I-beams. 1968 and later rods are reinforced at the big end as shown on my picture.