[PAUL K]

Originally Posted by gtofreek

I just have a few things to say about this.

Everything being offered against me is strictly speculation on all Joe's friends part. Don't get me wrong, I have respect for those guys, I met them and they seem very knowledgeable, and I like them. BUT none of them were here at our shop or took part in any of this build. They came along after the fact so everything they say is simply their opinions. They question whether I even took the engine apart. That's ridiculous. I took this engine completely down. Even took all the pistons off the rods to make sure there were no issues with the pins or pin bushings. I even posted pictures on here of the rods and crank. I didn't want any more problems with this engine. The mistake I made was I measured all the pistons at their gauge point, which just so happens to be about the most structurally strongest point of the skirt. They all measured good. What I FAILED to do was measure the skirt tips. They looked fine and there was nothing that drew attention or concern, but still I should have caught that. My mistake. At least my mistakes are few and far between, but I am not perfect.
The idea that someone put out there that I was trying to hide the skirt damage by Scotchbriting them is about the most ridiculous thing I have ever heard. Scotchbrite will not fix a bad skirt. If I was trying to scam Joe or hide something I would have just bought a new piston and no one would have ever known any different. I'm not a scammer, and I stand behind my work.
Fact of the matter is anytime I am putting used pistons back into any engine, I am not going to put them back in dirty and carboned up. So I clean them in the solvent tank with a Scotchbrite pad to get the carbon off. So now this is criminal? I then use a fine bristled SS brush to clean the friction reduction grooves on pistons like these. Once they are de-carboned, I give them 3-4 strokes each direction in an "X" pattern on the skirts with the Scotchbrite pad to help hold oil on them. Been doing it for over 20 years. To think I was trying to hide something is just stupid non-sense.

Also, some speculate that the skirt got damaged when the rod bearing went bad and the piston hit the head. Two things wrong with that.

1. The rod bearing would have had to have spun the lower shell up into the upper part of the rod. That did not happen. It never spun a bearing. It burned the bearing up, and it started to stick to the crank and it blackened the rod as the bearing got damaged. The crank wasn't even chewed up and it's a stock cast crank. It just had black streaks on it, so I replaced the crank with another one, along with a new rod. The piston never hit the head. Also, that would have left a mark on the head if it did, but it did not. Plus the bearing shell would have had to have worn down to less than .020" thick and if that happened, it would have spun. As soon as we heard it start knocking, we shut it down.

2. When you hurt a rod bearing, you do not send pieces into the intake manifold. What hurt this piston was something non-metallic going down the intake and into #5 cylinder. From there it got pinched between the piston and the corner of the combustion chamber hard enough to put a dent about .020" deep in the forged piston. It then banged the piston and head two more times only much lighter as the first hit probably broke it up some. That initial hit is what cocked the piston in the bore and pushed that skirt in. I think any knowledgeable engine person would agree with that. Then, considering the piston goes up and down the cylinder dozens of times per second at even very low speeds, it doesn't take but a second or two for it to pound the skirt even further inward. I say non-metallic because there is no other damage done to the bore, or no dings in the chamber or valves. If it was metallic, all those things would be dinged up. Anyone who does this stuff for a living can attest to that.

Some say it's awful coincidental that it was #5 piston that was damaged and that's the same bearing that went out. Not really, that's only a 1 in 8 chance. That's really pretty good odds. You want coincidental, I'll give you coincidental.
My dad grew up in Iowa, but in his older age, moved to Utah. Meets a women in Utah and they get married. About 6 months later they are talking about stuff and turns out they both grew up in Des Moines, Iowa. Turns out her parents bought my dads parents house from them and when she was a young girl moved into and grew up in that same house my dad grew up in and just moved out of. This was 50 some odd years before! To top it off, her birthday is the same day as my moms, only a different year! This is a 100% true story. Now that's what you call coincidental. If that could happen, something falling into #5 cylinder is easy peezy.

So now the question becomes when did this piece of whatever go down the intake.
Joe says it must have happened here at our shop because as soon as it started, it knocked. That's understandable for him to think that way, he is new to this all and doesn't know about engines. Can't blame him for that.

BUT, lets look at this from another perspective.

That piece could have fell into the intake here, but keep in mind, between Jeff and myself, we have over 60 years experience doing this. We know exactly what happens to an engine when something goes down the intake besides fuel and air. We take precautions to make sure this does not happen. Could we still have accidentally dropped something in there without knowing? Sure. Sh*t happens.
But it is just as easy and entirely possible that something fell in when Joe and friends or the shop that got it running were putting this all together. Something could have been stuck to the bottom of the carburetor and fell in, or any other way, something could have accidentally fell in. Then the first time they crank it over to start it, it goes into #5 cylinder and hurts the piston, and as soon as the engine starts, it knocks. But you see, no one wants to think it could have been them that did this, so the blame goes to the engine builder, in this case, me. Fact of the matter is we will never know when it happened, so in this case, Joe can be the victim, and I will be the bad guy and take the blame and pay for it even though I could just as easily be the victim here.

You people in the lynch mob need to consider this before you go throwing a rope around my neck and stringing me up from the nearest Oak tree. Remember, many innocent men were strung up by lynch mobs in the 1870's without any evidence of those persons guilt, only suspicions.

Seems plausible.... Except for the part about Iowa

[Holeshot71]

Originally Posted by PAUL K

Seems plausible.... Except for the part about Iowa

LOL.. that's funny!
Glad to hear the hear this was FINALLY figured out. Hopefully this will get resolved where everybody is satisfied because life is too short... I would be willing to donate $20.00 towards some beer... and a smokey burnout!!

[mgarblik]

Paul, In my attempted explanation of what caused a piston skirt to collapse, I didn't know anything about something getting into the #5 cylinder. That could have been in the nearly 1400 posts somewhere, but I missed it. I also thought the bearing failure somewhere along the line was more serious and since I know you like a tight quench, I could see the piston contacting the head in a failure situation and collapsing a skirt. Your explanation makes just as much sense and you were there! When I began building engines decades ago, pistons came in a box with the nominal size on the box only, not actual measured sizes. It was up to the builder 100% to measure each piston in several places, do all kinds of math and averages and either hone each cylinder to the piston or hone to an average. Cast pistons were usually +- .0015 through a set and forged .003. As you know even today, forged custom pistons are still kind of all over the map. It's very unfortunate you guys and the engine owner got bit by this series of events. There are always a few rock throwers, experts chiming in from the sidelines as other's struggle. It's just more public with the internet and message boards. I doubt very seriously you would be in business for decades and have a reputation where people are willing to send their engines from all over the country to have your shop work on them. So to implicate that without a public forum you would have washed your hands of this engine is unfair IMO. Again, WE ALL MAKE MISTAKES. The shop I have worked out of for 30 years 5 years ago had 8 of the 10 top qualifiers in NHRA Stock and Super Stock at the US Nationals and is a builder of Australian Pro Stock engines they ship back and forth all year. 2 man shop. Mistakes are still made, few and far between. When they happen, just like this Pontiac, the problem is eventually found and corrected.
One of the worst I had happen that relates to this Pontiac, happened on the dyno. We had the jam nut that holds the air temperature sensor in the Superflow air hat vibrate loose and fall through the carburetor of a new engine on it's 3rd. or 4th pull. It bounced all through the engine, breaking 2 sleeves, bending valves and cracked a head. Lots of time and money lost because of a small jam nut. It was about the size of a car radio stem nut.
Personally, this whole drama should do more positive good for your business in the long run. If I didn't do all my own work, your shop would be on my short list. Take care.

[Formulajones]

So glad you set that straight Paul, and for doing all that you did. It shows what kind of guy you really are and the stand up work you guys do at the shop. I am however disappointed just as you are Paul at the forum here and several people in particular that threw you under the bus without knowing really any of the back story and what you've done to this point, let alone know who you are as a person and what you guys stand for. That is uncalled for and unfortunate, but not surprising.
This whole deal unfolding on the forum here should do nothing but encourage people to deal with Paul, and my self and others I know that have first hand experience with Paul will continue to support Paul with business as usual.

Excellent work Paul, you went above and beyond what most any other shop would do that I've had experience with.

Now get out there and enjoy that engine Joe.

[pastry_chef]

Originally Posted by Formulajones

several people in particular that threw you under the bus without knowing really any of the back story and what you've done to this point, let alone know who you are as a person and what you guys stand for

I missed the throwing under the bus part.
I think anyone in their right mind could agree the root cause should have been remedied when the owner paid the long distance shipping bill back and then the second dyno. The pistons were removed from their bores? If not, why not?

[Formulajones]

Originally Posted by pastry_chef

I missed the throwing under the bus part.
I think anyone in their right mind could agree the root cause should have been remedied when the owner paid the long distance shipping bill back and then the second dyno. The pistons were removed from their bores? If not, why not?

Read post 1400. Paul explained everything you need to know right there.

[Va68goat]

So, I'm going to have to go through this whole thread to see who guessed the piston slap first so we can determine the winner. I will send the winner a Pontiac sign like I said I would. Hell, I'll even throw in some local Virginia beer. Hopefully we can all agree on the winner! Hahahaha!

I do have a question though. There seems to be some confusion if the bearing spun or not when it failed on the dyno. After reading the recent post, I do remember that it was discussed about the spun bearing. Has anyone heard of a piston skirt collapsing when a bearing is spun? Is that normal? What happens when a bearing is spun that could or would cause the piston to hit the head. Is that even possible? Considering that the knocking noise has been the same since when I first received the motor and stopped when that one piston was replaced, I would just like to get a better understanding of what happens when you have a spun bearing.

[chiphead]

Originally Posted by Va68goat

So, I'm going to have to go through this whole thread to see who guessed the piston slap first so we can determine the winner. I will send the winner a Pontiac sign like I said I would. Hell, I'll even throw in some local Virginia beer. Hopefully we can all agree on the winner! Hahahaha!

I do have a question though. There seems to be some confusion if the bearing spun or not when it failed on the dyno. After reading the recent post, I do remember that it was discussed about the spun bearing. Has anyone heard of a piston skirt collapsing when a bearing is spun? Is that normal? What happens when a bearing is spun that could or would cause the piston to hit the head. Is that even possible? Considering that the knocking noise has been the same since when I first received the motor and stopped when that one piston was replaced, I would just like to get a better understanding of what happens when you have a spun bearing.

If I don't win, I want a framed picture of the piston as a consolation prize. LOL

As far as collateral damage from a spun bearing, that's a theoretical debate that could keep this thread going forever. When a rod bearing spins inside the connecting rod, it rapidly self destructs due to friction and heat. During normal operation, the inside diameter of the rod's big end clamps the bearing halves in place (bearing crush). When bearing crush is lost for whatever reason, the inserts will spin inside the rod's big end. Loss of lubrication will also cause a spun bearing, when the friction wanting to turn the bearing insert overcomes the bearing crush keeping it stationary in the rod. Usually it makes a hell of a racket and the damage is limited to the rod and the crankshaft, unless the rod comes apart (thrown rod).

Since this engine didn't throw a rod, the rod bearing would have had to do one of two things to damage a piston:

1: Rod bearing is destroyed enough that the excess slack between rod's big end and crank journal allows piston to hit the head during TDC. That would have left witness marks on chamber and top of piston. Should result in damaged piston crown and pinched #1 ring land.

2: Rod bearing gets hot enough to friction weld itself between crank and big end of rod. Rod is then effectively welded to crankshaft. Rod tries to whip around with crank, restrained only by piston. The piston is damaged from the abnormal forces. However, this typically tears the rod cap off or breaks the rod, resulting in total carnage. Motor would have had to be shut down just before it chucks a rod across the room, to damage a piston like this but not chuck a rod.

[hurryinhoosier62]

Originally Posted by mgarblik

Paul, In my attempted explanation of what caused a piston skirt to collapse, I didn't know anything about something getting into the #5 cylinder. That could have been in the nearly 1400 posts somewhere, but I missed it. I also thought the bearing failure somewhere along the line was more serious and since I know you like a tight quench, I could see the piston contacting the head in a failure situation and collapsing a skirt. Your explanation makes just as much sense and you were there! When I began building engines decades ago, pistons came in a box with the nominal size on the box only, not actual measured sizes. It was up to the builder 100% to measure each piston in several places, do all kinds of math and averages and either hone each cylinder to the piston or hone to an average. Cast pistons were usually +- .0015 through a set and forged .003. As you know even today, forged custom pistons are still kind of all over the map. It's very unfortunate you guys and the engine owner got bit by this series of events. There are always a few rock throwers, experts chiming in from the sidelines as other's struggle. It's just more public with the internet and message boards. I doubt very seriously you would be in business for decades and have a reputation where people are willing to send their engines from all over the country to have your shop work on them. So to implicate that without a public forum you would have washed your hands of this engine is unfair IMO. Again, WE ALL MAKE MISTAKES. The shop I have worked out of for 30 years 5 years ago had 8 of the 10 top qualifiers in NHRA Stock and Super Stock at the US Nationals and is a builder of Australian Pro Stock engines they ship back and forth all year. 2 man shop. Mistakes are still made, few and far between. When they happen, just like this Pontiac, the problem is eventually found and corrected.
One of the worst I had happen that relates to this Pontiac, happened on the dyno. We had the jam nut that holds the air temperature sensor in the Superflow air hat vibrate loose and fall through the carburetor of a new engine on it's 3rd. or 4th pull. It bounced all through the engine, breaking 2 sleeves, bending valves and cracked a head. Lots of time and money lost because of a small jam nut. It was about the size of a car radio stem nut.
Personally, this whole drama should do more positive good for your business in the long run. If I didn't do all my own work, your shop would be on my short list. Take care.

Well said, Mike.

[ta man]

I've followed this thread..great thread with a great end. Finally!