Robert N

Was looking at another early C3 the other day and noticed that the engine numbers were not visible as the block was decked. The owner said he believed the block was original and all other numbers seem to match. Any other way to tell? Any loss of value? Not looking to buy it - hands full already, just curious.

Bryan Lee

Wireless: I have heard that there is a chance that you can use some type of acid that will bring the stampings back if the decking was light. It is the same procedure that the police use to bring back ground-away numbers on pistols, etc. If you know a policeman, it might be worth a try.

RB

SBR

Look for the block casting number and casting date at the rear of the block. This will give you a better idea if the block is original. Remember the casting date should precede the build date of the car by about 2 weeks to 3 months although 6 months is acceptable by NCRS.

67HEAVEN

Over to you Mac. :D

3X2-427

There is a system for "raising" machined away numbers, I have seen it used on guns where the numbers have been removed although I have never seen it used on engines. MAC??

Mac

Yes, there is such a method. The serial number on items such as motor vehicles, firearms, bicycles, and motorcycles are commonly removed or altered in an attempt to prevent the identification of the original owner of the item. The serial number can sometimes be restored depending on the degree of obliteration or alteration.

When a number is stamped into a metal object, the metal underneath the number is compressed and hardened. If the number is ground off, as in this case by the decking, this hardened area may still be present. By using an acid solution the metal can be slowly eaten away. In this process the softer metal will be eaten away first and the numbers may reappear. This is commonly referred to as "raising the serial number". The numbers will appear raised rather than as indentations.

While this may restore the original serial numbers, it's not guaranteed and you are using acid to eat away from your stamp pad. Are you sure you want to do that??

topless68

Damn Mac, I knew we had you around for a reason. :cheers:

Robert N

My home neighbor is a Sheriff's deputy and my office neighbor is a police officer - both confirmed the that there is a method thy used to "raise" serial numbers and it works quite well.

As a note, according to NCRS - a decked block is only an 88 ponit deduct if all other cating numbers match. Good info for the future since driving 200+ miles gets you 90 points.

Mac

I thought it was for my youthful good looks and inimitable charm.

I was just thinking (and re-reading) the posts here. An 88 point deduct isn't fatal by a long shot so all those NOM cars (like mine, for instance) really should have their motors redone and redecked.


[Modified by Mac, 8:59 AM 5/24/2002]

Robert N

If you think about it, most rebuilt engines are not really original - generally they are bored or bored and sleeved. And since the judges can't see inside the engine (??), you could use any cam, crank, pistons, and valves. I would have to believe that as long as the compression numbers matched, the deducted points would be based on them amount of original parts - heads, manifold, carb, etc. The 88 point figure was based on a numbers matching engine, with the exception of the blank pad, but based on the points system, a proper looking NOM engine could still get a Flight rating.

JohnZ

Clarification - 200 miles driven would get you 2 raw points - calculation is 1% of miles driven. As long as the rest of the car is really good, you can lose the 88 points for the stamp pad and still make it - you can "spend" a total of 270 raw points and still make Top Flight.

John McGraw

The other thought is to have the pad "restored" with broach marks and proper numbers and take no point hit if done correctly. There is a general misconception that restamping the pad is against the rules and will get you disqualified. If you read page 5 of the NCRS judging reference manual, you will find that restamping a correct block that conforms to the original engine installed in the car is considered restoration. Changing to a higher horsepower engine and restamping it to appear as if it came in the car is counterfeiting and is not allowed. If the stamp is done corectly and appears as oiginal then you take no point deducts, even if you acknowledge the restamping.
:seeya

Mac

Holy smokes! So, having a NOM really means squat if you've done your homework.
Once again proving "numbers matching" means less than nothing, straight from the Bible of Corvette Restoration!
This only makes sense. If your car had a small block, representing it to be an original big block is fraud. If it's a small block and you've brought it back to what how it was made at the factory, then the block is irrelevant.
Man, it's just as well Chuck has chosen to absent himself from our presence, for the sake of his health. Maybe I'll have my car judged someday after all!! :cheers:

67HEAVEN

BmmGrmmHmmmYmmmm......(the sound of my common sense over-ruling my big mouth) :D

Robert N

Consider this - even a verifiable matching numbers block means nothing...it could be decked, bored (and sleeved), contain a hopped cam, and sport the matching number heads (ported and angled with larger valves) and still qualify as original. Restored yes, original, maybe not. Matching numbers to me means only that the car is what it was being sold as - 1970 and 1971 LT-1 are tough to verify otherwise.

John McGraw

Mac, That is exactly right. A lot of people never participate in judging because they think that it is for "original" cars only, There is a class for those cars and it is called Bowtie. In Bowtie if a part can be identified as having ever been removed for any reason then that part fails. NO restoration is accepted!

For the rest of us there is flight judging and your car can be judged Top Flight If you start with nothing but a basket case and enough patience. The whole purpose in flight judging is to determine if the part in question is consistent with the "as installed by the factory" condition, no better, no worse.
Anyone with enough attention to detail can restore a car to Top Flight condition regardless of the condition of the car when they start. This policy does nothing but encourage people to return cars to their original glory.
Some people take the hot rod route and that is fine, I have one as well, However some of those people look upon those of us who restore cars to their factory correct condition as elitist snobs with cars unobtainable to most people when that is simply not true. It is simply a mater of time and patience.
It just bugs the hell out of me when one guy knocks another's view of what a Corvette should be. We all like corvettes for different reasons, some like hotrods and some like restored, but we ALL love Corvettes.
:seeya

Juliet

You're right that any car can be restored. It's only a matter of cubic dollars and enough donor cars for the right collection of parts. ;) It can only be original ONCE! :) The elitist snob thing irks me to no end. And one of the thing that propagates that is those judges who 'refuse to share their secrets.' The little tricks on how to tell if something is original or not. They tout it around like some big hidden thing which gives them power. That's one great thing about the NCRS board - it helps get rid of that attitude because there is generally someone willing to explain it. In the long term the sharing of the knowledge just notches the level of the restorations up. That's why they say that top flights today are harder to get than those of 10 or 15 years ago. :)

Can o' worms with that one John. I believe that statement is not correct (anymore). There was a team leader who insisted that was the case, however it was clarified by Roy Sinor that removal of a part was not grounds for failure. There was a big stink over that at the Nationals in Galveston in one of the shark divisions. I think that there might have been a time when that was the case (whether or not it was endorsed by the National Judging Chair I don't know), however I don't believe it's true anymore.

John McGraw

Juliet, you are correct that simply removing a part may not cause it to fail, but removing and restoring it will. I think that Bowtie cars are a great asset in showing haw a car should have looked when built, but probably would not want to own a bowtie C1. It would be almost undriveable,and have never seen one with pant that I would want to be seen in public with!
I agree with your statement that a car is only original once, and that point happened long before any of us owned our cars. Originality is not an issue of black and white, is more shades of gray. The first time you have the oil changed on your car it starts to lose it's originality. Most Flight judged cars in my years are completely restored cars that have little in common with an "original" car.
I still fail to see the rationale for feeling that it is acceptable to replace almost any part of a car with NOS or repro parts, including paint, interior, plating, suspension and most drivetrain parts, but if the engine is not the one that came in the car, then the car is not "original". There are people over at the board who decry the proliferation of "kit cars" at flight judging, but those people are definately in the minority. In my humble opinion any part that cannot be told from original is as good as original. One has to wonder how may of those people who decry the loss of originality, have little secrets hiding under their hood!

:seeya


[Modified by John McGraw, 8:31 PM 5/25/2002]

Juliet

:yesnod: I'm sure a good many of them do - or did and then sold 'em! :lol: :jester

My goal is to eventually get my C3 so that it will top flight in NCRS but also win trophies at NCCC events. Your typical bowtie car at an NCCC event would be laughed off the field. :lol: But a restored one I think might be able to do OK at both. At least that's what I hope to eventually find out.

Mac

Thanks for clearing up that misconception for me, John.

I've posted before, wondering how a non-original motor built to factory correct specs could be less desirable (less correct) than a hot-rodded original motor simply because of stamped numbers. I've always maintained that "numbers matching" was a concept designed to extract more money from the pockets of the gullible. Apparently, I'm not so wrong after all.

I can't get over how many misconceptions I've had shattered since I started posting to the Forum. Knowledge, they say, must be shared to be useful. This bit of common wisdom rings true.