Original Engine Block Decked

[Tracy C.]

Re: Original Engine Block Decked

Thank you Rick. I'm aware this process can be used on steel, but just to be clear, you have seen this process work on a cast iron block?

[Rick B.]

Re: Original Engine Block Decked

Myself and my partner performed this technique on approx. 6 or 7 engine blocks in the mid 90's. Some were cast iron, some were aluminum. The work was performed while the engines remained in place within the vehicles which proved challenging. My recollection was that it worked better and faster on the cast iron blocks then on the aluminum ones. In fact I believe we had to use heat to raise some numbers on the aluminum ones, which was even more destructive. I also recall having to use a different chemical mix on the aluminum blocks.
Gun metal yields good results too. I don't recall the steel of the barrel being much quicker, just easier to work with/on.
Given the time that has lapsed I called my old partner to ask what his recollection of this was, he concurs.

Rick

[Robert K.]

Re: Original Engine Block Decked

Back 15-20 years I believe Vette Vues had an article about a 427/435 that had been decked after the shop was given instructions to No decking! They called law enforcement I believe even the FBI. They raised the numbers heating the pad cherry red. The article even showed photos of the before and after. Look strange, but the numbers were definitely there and didn't disappear. Sounds like the making of an article.

[John M.]

Re: Original Engine Block Decked

I had a 71 LS-6 that some of the vin was removed when it was decked, I took a propane torch to the deck noticed nothing until the next day, it was faint but readable....John

[Rick B.]

Re: Original Engine Block Decked

Robert that is correct. Heating to ultra-high temps causes the variance in the crystalline structure underneath to "show" where the numbers were stamped provided they were initially done so with considerable force and not just a faint/light tap.
Due to the method of heating and damage caused to peripheral areas this is not often used and is done so only as a last resort given that in these cases the insurance companies would not be too happy with the end result sometimes (warpage, etc).

[Joe L.]

Re: Original Engine Block Decked

All------


Actually, this is all really an "academic" issue. As far as I know, a block that had been decked would receive the same credit regardless of whether it's proven that it was originally stamped with the car's VIN derivative, or not. In other words, it would not receive credit for correct stampings or correct broach marks either way. As has been discussed, "raising" the numbers is entirely problematic and, even if successful, yields entirely TEMPORARY results. So, while it might be "nice to know" if a block is original to the car, that's the most that one would get out of the effort.

I think that such procedures are best left to what they were designed for in the first place-----forensic examination for criminal or related investigations.

[Rick B.]

Re: Original Engine Block Decked

Yes, I believe you have put this into proper perspective Joe!
If you absolutely need to know it can be done but with acid the "raised" numbers typically are transient and both methods are destructive to a certain degree.
My 1972 had been stolen off of the dealership lot when it was new. Police recovered the vehicle several days later in a private garage where the engine had already been pulled and the culprits had begun grinding down the serial numbers off of the engine pad.
Initially I was unaware of the reason for the damaged pad when I bought the car 18 years (1990) but suspected something sinister had happened. Later I was fortunate enough to track down all of the previous owners and ask them why the pad had been partially obliterated. This lead me to the aforementioned story of which I was able to verify by pulling the microfiched police records from archives. Sure enough the tale turned out to be factual and as the numbers remain very very faint indeed, they are still legible to the discerning eye without the need to raise them further.

[Tracy C.]

Re: Original Engine Block Decked

Myself and my partner performed this technique on approx. 6 or 7 engine blocks in the mid 90's. Some were cast iron, some were aluminum. The work was performed while the engines remained in place within the vehicles which proved challenging. My recollection was that it worked better and faster on the cast iron blocks then on the aluminum ones...........Given the time that has lapsed I called my old partner to ask what his recollection of this was, he concurs.

Rick

Thank you Rick. I'll salute your testimony and swallow my opinion. Thank you for your service on the police force.

tc