Engine Pad - 1968 427-390HP Opinions

[Peter S.]

Re: Engine Pad - 1968 427-390HP Opinions

Only because your guest asked for opinions...I'm afraid there is nothing typical about the pad surface, the assy stamp or the VIN stamp that would merit points for these features. Factory workers made mistakes, but the "typical" way to correct was to grind them out, not hammer them in.

Hi Tracy,

So do you feel that the VIN derivative is not typical? Does the underlying "1" count against the VIN derivative or the pad surface? I can understand a deduct for the assembly stamping (since it is partially missing), but what is atypical of the VIN derivative?

I appreciate all the responses and am passing this along. Thank you.

[Michael J.]

Re: Engine Pad - 1968 427-390HP Opinions

Here is an example of an 88 point deduct engine pad:

[Dick W.]

Re: Engine Pad - 1968 427-390HP Opinions

I think the owner should be prepared to take an 88 point hit, judges might be a little lenient and not take that much, but from what I have seen, if I were still judging he would probably take the 88 points.

[Michael W.]

Re: Engine Pad - 1968 427-390HP Opinions

Mike - exactly. Since this gentleman will be having his car judged, question #1 is the immediate inquiry, but the other two questions are important to him.

The casting number/case configuration and the casting date both looked good. The question would be is how would you score:

- Assembly Stamping
- VIN derivative
- Stamp pad surface finish

I'll give it a shot from the judging perspective. Given that we're dealing with photographs that can alter things drastically from reality:

I think I see signs of broach marks on some sections of the pad. The rules do not require 100% broach marks on the full pad so no deduct there.

The VIN derivative appears to be typical although it seems that it's been applied over a grind out, possibly from a car with a different VIN. Such grind outs being done at the assembly plant are not unheard of. No deduct.

Engine assembly stamp- again it appears not unlike some factory grind outs. The problem is that the last two characters, at least in the photos, are not legible. For that reason alone, I think unfortunately a deduct is warranted.


From the 'is it the real deal'angle, I've never seen a double grind out before and can only imagine that such things would be extremely rare but not impossible. How often does something need to be observed for it to become typical? A person like Al Grenning might easily answer the question. Possibly there was a batch of engines in a close time frame that were reworked and restamped after grind out. I believe such a thing occurred with '66 390HP engines.

[Michael H.]

Re: Engine Pad - 1968 427-390HP Opinions

I'll give it a shot from the judging perspective. Given that we're dealing with photographs that can alter things drastically from reality:

I think I see signs of broach marks on some sections of the pad. The rules do not require 100% broach marks on the full pad so no deduct there.

The VIN derivative appears to be typical although it seems that it's been applied over a grind out, possibly from a car with a different VIN. Such grind outs being done at the assembly plant are not unheard of. No deduct.

Engine assembly stamp- again it appears not unlike some factory grind outs. The problem is that the last two characters, at least in the photos, are not legible. For that reason alone, I think unfortunately a deduct is warranted.


From the 'is it the real deal'angle, I've never seen a double grind out before and can only imagine that such things would be extremely rare but not impossible. How often does something need to be observed for it to become typical? A person like Al Grenning might easily answer the question. Possibly there was a batch of engines in a close time frame that were reworked and restamped after grind out. I believe such a thing occurred with '66 390HP engines.

I agree with you Mike, that's the way I would have judged it.........

Mike

[Rich G.]

Re: Engine Pad - 1968 427-390HP Opinions

Having been through this with a 68 L71 very close to this VIN, here's my two cents. Mine has a grind out on the VIN derrivitve. The Assy stamp looks good. BUT, who can say it was done at the factory or that someone found a correct motor for the car and re-stamped the VIN. I can't say. Guys on this forum have seen pictures and agree it looks like what would have been done at the factory. The judges at the chapter meet I went to years ago couldn't say as far as I can tell. It comes down to an educated guess (read: opinion) at whatever meet you're at.

I guess in this case you pay your entry fee and take your chances.

If I ever sell this car I would get an opinion from Al Greenings service before listing it and live or die by that.

Let us know what happens.

Rich

[Tracy C.]

Re: Engine Pad - 1968 427-390HP Opinions

Hi Tracy,

So do you feel that the VIN derivative is not typical? Does the underlying "1" count against the VIN derivative or the pad surface? I can understand a deduct for the assembly stamping (since it is partially missing), but what is atypical of the VIN derivative?

I appreciate all the responses and am passing this along. Thank you.

Yes Peter, The left over "1" kills the VIN derivative for me. It doesn't belong there. This is just my opinion, Others have suggested contacting Al Grenning. He is pricey, but considered to be among the most respected opinions in the hobby.

[Chris H.]

Re: Engine Pad - 1968 427-390HP Opinions

Anything hat screwed up had to be done by Tonowanda. I concur that contacting Al Grenning would probably be a good idea.

[Dick W.]

Re: Engine Pad - 1968 427-390HP Opinions

Yes Peter, The left over "1" kills the VIN derivative for me. It doesn't belong there. This is just my opinion, Others have suggested contacting Al Grenning. He is pricey, but considered to be among the most respected opinions in the hobby.

AND Tonawanda nor St Louis used a hammer on the pad

[Marco H.]

Re: Engine Pad - 1968 427-390HP Opinions

I'll give it a shot from the judging perspective. Given that we're dealing with photographs that can alter things drastically from reality:

I think I see signs of broach marks on some sections of the pad. The rules do not require 100% broach marks on the full pad so no deduct there.

The VIN derivative appears to be typical although it seems that it's been applied over a grind out, possibly from a car with a different VIN. Such grind outs being done at the assembly plant are not unheard of. No deduct.

Engine assembly stamp- again it appears not unlike some factory grind outs. The problem is that the last two characters, at least in the photos, are not legible. For that reason alone, I think unfortunately a deduct is warranted.


From the 'is it the real deal'angle, I've never seen a double grind out before and can only imagine that such things would be extremely rare but not impossible. How often does something need to be observed for it to become typical? A person like Al Grenning might easily answer the question. Possibly there was a batch of engines in a close time frame that were reworked and restamped after grind out. I believe such a thing occurred with '66 390HP engines.

Michael,
I think you are making a fair assessment here.
I do not believe it is a "double" grind out. You can still see traces of the first VIN strike that went over the last few digits of the suffix.

[Patrick B.]

Re: Engine Pad - 1968 427-390HP Opinions

Having been through this with a 68 L71 very close to this VIN, here's my two cents. Mine has a grind out on the VIN derrivitve. The Assy stamp looks good. BUT, who can say it was done at the factory or that someone found a correct motor for the car and re-stamped the VIN. I can't say. Guys on this forum have seen pictures and agree it looks like what would have been done at the factory. The judges at the chapter meet I went to years ago couldn't say as far as I can tell. It comes down to an educated guess (read: opinion) at whatever meet you're at.

I guess in this case you pay your entry fee and take your chances.

If I ever sell this car I would get an opinion from Al Greenings service before listing it and live or die by that.

Let us know what happens.

Rich

As long as the VIN stamped over the grind out was done with correct characters, Al Grenning cannot tell you whether or not it was done at St. Louis. He compares pad stampings to his huge collection of pad photos and checks to see if all the characters are identical to a sample he may have of the same engine option stamped the same day at the engine plant. Since grind outs would be a result of random errors there is no trend to observe.


If Al Grenning has an example of another identical engine stamped the same day to compare with an engine being evaluated for originality that is a pretty powerful piece of evidence. There are usually more than one variation in use simultaneously of many of the Flint and Tonawanda characters and some characters may even have some telltale flaw. Even if the grain of the pad looks good, it would be shear luck for someone to duplicate all of the variations of the characters in the correct order the factory used on a given day. However, it requires the assumption that the factory did not change any characters in the stamp holder except when setting up each tool for the day.

Several months ago, someone asked my opinion of a pad photo. I do not have a huge collection of examples like Al Grenning, but by a rare coincidence I had two examples of identical engines built the same day in Tonowanda as his. Both of my examples were identical and used two different types of the "0" character. His stamping also had both types of "0" in the same order as the examples but the 7 in his pad was different. However, the grain and the vin and the general appearance of the pad were perfect. I told I felt his pad was original, but if he sent it to Al Grenning and Al's examples were the same as mine, it would likely be labeled a fake. Also, I asked him to send me a photo of the pad and the rest of the deck if he ever happened to take the head off. Well, a few days ago he took the head off and sent me a picture. The rest of the grain was also perfect, and it sure looked to me that this pad was entirely original. I think the most likely explanation if that the factory changed the 7 during the work day. I don't know how common such intraday changes would be, but I think it demonstrates that even the best methods of evaluating the originality of pads have limitations.

[Kenneth B.]

Re: Engine Pad - 1968 427-390HP Opinions

As long as the VIN stamped over the grind out was done with correct characters, Al Grenning cannot tell you whether or not it was done at St. Louis. He compares pad stampings to his huge collection of pad photos and checks to see if all the characters are identical to a sample he may have of the same engine option stamped the same day at the engine plant. Since grind outs would be a result of random errors there is no trend to observe.If Al Grenning has an example of another identical engine stamped the same day to compare with an engine being evaluated for originality that is a pretty powerful piece of evidence. There are usually more than one variation in use simultaneously of many of the Flint and Tonawanda characters and some characters may even have some telltale flaw. Even if the grain of the pad looks good, it would be shear luck for someone to duplicate all of the variations of the characters in the correct order the factory used on a given day. However, it requires the assumption that the factory did not change any characters in the stamp holder except when setting up each tool for the day.Several months ago, someone asked my opinion of a pad photo. I do not have a huge collection of examples like Al Grenning, but by a rare coincidence I had two examples of identical engines built the same day in Tonowanda as his. Both of my examples were identical and used two different types of the "0" character. His stamping also had both types of "0" in the same order as the examples but the 7 in his pad was different. However, the grain and the vin and the general appearance of the pad were perfect. I told I felt his pad was original, but if he sent it to Al Grenning and Al's examples were the same as mine, it would likely be labeled a fake. Also, I asked him to send me a photo of the pad and the rest of the deck if he ever happened to take the head off. Well, a few days ago he took the head off and sent me a picture. The rest of the grain was also perfect, and it sure looked to me that this pad was entirely original. I think the most likely explanation if that the factory changed the 7 during the work day. I don't know how common such intraday changes would be, but I think it demonstrates that even the best methods of evaluating the originality of pads have limitations.

Exactly! This begs to ask the question where did Al get all the 1000's of "original" stamped pads to go by when we all know very few Corvettes had original engines in the day. as Dick said there were & are many sets of good stamps that are out there then & today. I saw many restamped engines lined up on cradles ready to ship to the owners.& this was back in the 80'S. In MHO only God knows for sure if a pad is factory stamped, if its a good typical stamp, & he doesn't care & we shouldn't ether. If is looks like a duck, walks like duck, quacks like a duck, its a DUCK. What nest it was hatched out of doesn't matter.

[Patrick B.]

Re: Engine Pad - 1968 427-390HP Opinions

Exactly! This begs to ask the question where did Al get all the 1000's of "original" stamped pads to go by when we all know very few Corvettes had original engines in the day. as Dick said there were & are many sets of good stamps that are out there then & today. I saw many restamped engines lined up on cradles ready to ship to the owners.& this was back in the 80'S. In MHO only God knows for sure if a pad is factory stamped, if its a good typical stamp, & he doesn't care & we shouldn't ether. If is looks like a duck, walks like duck, quacks like a duck, its a DUCK. What nest it was hatched out of doesn't matter.

Your point is well taken, and I think that Michael Johnson's example in comment #20 is a good illustration. Michael's pad is about as perfect a restamp as I have seen. I like to think I have a good eye for these things, but I find nothing to question about his pad. Had he not said it was a restamp, I would certainly not think so based on the good photo he provided. Maybe with the head off it would be easier to discern that work had been done. However, NCRS judging does not require head removal. I cannot understand why he was given a full deduct. In a previous posting, I believe he said the judges were not able to explain what they thought was wrong with it (my apology in advance Michael if I have mischaracterized your previous posting). The only rational explanation I can think of would be that maybe the judges knew a previous owner and were acting from that knowledge rather than from the appearance of the car. I don't know how far judges are supposed to take private information into account, but it seems unfair to deduct for anything you can't explain. Otherwise, how can an owner use the judging process to improve his car.

That said, I don't think there were many restamps as good as Michael's in the 80's when Al Grenning could be seen at lots of car shows taking detailed pictures. I think a restamp that good is still uncommon. I don't doubt that Al's collection is close to 100% authentic, but even a highly professional approach may not handle anomalies like intraday stamp changes correctly.

[Michael W.]

Re: Engine Pad - 1968 427-390HP Opinions

I believe he said the judges were not able to explain what they thought was wrong with it (my apology in advance Michael if I have mischaracterized your previous posting). The only rational explanation I can think of would be that maybe the judges knew a previous owner and were acting from that knowledge rather than from the appearance of the car. I don't know how far judges are supposed to take private information into account, but it seems unfair to deduct for anything you can't explain. Otherwise, how can an owner use the judging process to improve his car.

Either reason above for a deduct is not acceptable. Previous knowledge is specifically dealt with in the rules. The judge should either disregard what he thinks he knows or stand aside.

[Michael J.]

Re: Engine Pad - 1968 427-390HP Opinions

I hate to reopen this guys, it is water under the bridge, but instructive I feel. IMO engine pads are the most controversial item in judging. Now, mine was deducted at a regional attended by numerous national judges, and as I said, at the end to the day (after I spent over a year tracking down, with Billy's help, all the previous owners), they were correct about it not being the original engine to the car, but again, that is not the judging criteria as we know. The only explanation I really got, after pressing a little (but not much, I was too intimidated to fuss much at my first judging) is that it looked too perfect and not TFP. I did not get any info about fonts, stamp depth, broach marks, etc. So, it is what it is, and it is a really nice restoration engine. I did not, nor did I ever, try to represent it as original.