Raising partial VIN after block is decked

[lbnaz]

I have a 302 short block that has been decked. There is still what looks like a partial vin visible on the pad. There is no vin by the oil filter area. Has anyone had any luck using dye penetrants or something to try and raise the numbers. I'm trying to put it with a car here locally. Its dated correctly for the build of the car and history says its the motor. Any help is appreciated. Thanks, Larry 520-349-2337

[elonblock]

Larry,

From what I understand law enforcement people use some sort of acid process to make the stampings readable after it has been machined.

I am not clear if this is the process which they still use, or of there is a better way.

Maybe someone else can chime in?

Elon

[Tracker1]

http://www.chevy-camaro.com/faq/chevy-camaro-engine-code-restoration.shtm

[ChevyThunder]

I have tried a solution of muriatic acid on the deck pictured below and I did not notice any significant results though I thought what I started with was a bit more defined. However I would not let my experience discourage you from trying .

A friend of mine found the local labs in the SF Bay Area where law enforcement sends a gun when the numbers have been filed off.... they actually x-ray the gun and get good results because the process can image the change in the metallurgy when the numbers were stamped. The lab will also do engine blocks for $400

http://img.photobucket.com/albums/v600/ChevyThunder/Daytona%20Yellow%20Z-%2028%20Van%20Nuys/th_DSC00237.jpg (http://img.photobucket.com/albums/v600/ChevyThunder/Daytona%20Yellow%20Z-%2028%20Van%20Nuys/DSC00237.jpg)
http://img.photobucket.com/albums/v600/ChevyThunder/Daytona%20Yellow%20Z-%2028%20Van%20Nuys/th_DSC00240.jpg (http://img.photobucket.com/albums/v600/ChevyThunder/Daytona%20Yellow%20Z-%2028%20Van%20Nuys/DSC00240.jpg)

[John Brown]

Wouldn't hurt much if you tried Magnafluxing it either.

[iluv69s]

I remember a few years ago a 67 vette that had labrotory documentation that the original VINs on the block and frame had not been restamped over. They apparently did some acid etching type test. I believe it was an L-88 or L-89 car. I did a search, but cannot find it.
I also had contacted a scientist here in Pa at one point about ten years ago that did such tests. I will have to look for his number. I believe his last name was Klauser..??
If I come up with anything, I will post.

[67 Nova Boy]

That would be great! My 67 327 was decked waaaaaay back in 74 and is the original motor to my 67 Nova SS. Would love to bring it up to see. I have a the pop to the car that would help.

Dave
67 Nova Boy

[Kurt S]

http://www.camaros.org/public/acidetch.txt also describes the acid process. All depends on how much it was decked....

[njsteve]

Interesting article but they left the most important point out: have a camera and lights ready to take photos as the process is ongoing.

The etched result is not permanent and will fade after the process is finished. It also cannot usually be repeated with any degree of success. Take many photos from all sorts of angle with incandescent as well as flash lighting. Your photographs will be the permanent evidence of your results more than what the pad will look like after the process finishes.

[parsone]

Hello, I was wandering if you could supply the name of the lab in San Francisco that can x ray engine blocks. i have an L78 motor that was decked, suppose to be the original engine. thanks, mark

[bergy]

I have heated up the pad on a decked '69 427/435 block and got the numbers to come up. It's a little risky, but if all else fails..... The factory stamping puts a stress in the metal -you get it hot to relieve the stress and the numbers come out. have a good insulating pad to place over the area after heating to allow it to cool slowly. There <span style="text-decoration: underline">IS</span> a risk of cracking. Actually, cosmetic repairs on blocks at Tonawanda MCP were done after heating to cherry red &amp; covering to slow cool. Repairs on the intake rails using this method were common. The success of this method also depends on how much the block was decked - as Kurt said. I'll say it again though - this method could result in cracks if cooling is too rapid. The good thing is that the stampings pop out permanently.

[Verne_Frantz]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bergy</div><div class="ubbcode-body">I have heated up the pad on a decked '69 427/435 block and got the numbers to come up. It's a little risky, but if all else fails..... The factory stamping puts a stress in the metal -you get it hot to relieve the stress and the numbers come out. have a good insulating pad to place over the area after heating to allow it to cool slowly. There <span style="text-decoration: underline">IS</span> a risk of cracking. Actually, cosmetic repairs on blocks at Tonawanda MCP were done after heating to cherry red &amp; covering to slow cool. Repairs on the intake rails using this method were common. The success of this method also depends on how much the block was decked - as Kurt said. I'll say it again though - this method could result in cracks if cooling is too rapid. The good thing is that the stampings pop out permanently. </div></div>

You can also reduce the sudden cooling and possible cracks by just reducing the flame a little at a time and fanning it around, Think of it as slowly turning down the gas burner on your stove until it as cooled slowly by itself. Glass blowers use this technique to prevent cracking between the area that was worked and the solid glass next to it.

Verne

[parsone]

Thanks for the suggestions. What do you use for a heat source? welding or cutting torch?