Engine conversion legalities

[Gq jack]

Hey guys, I am not sure if this topic has been addressed, though I did try a search for legalities on engine conversions and engine numbers but was unable to locate information needed.

We have had an engine conversion from an rd28 (gq)- to a TD42 and the engine blocks engine identification number is barely visible and I am unable to retrieve the complete number.
We have emailed the person responsible for the conversion and he said, and I quote "the engine number must have been machined off when the engine was reconditioned the second time"! We have still not received an engine number from this mechanic.

As far as I am aware the engine number must never be tampered with and any reputable mechanic/engine rebuilder would know this, can anyone confirm?

Also, if anyone is aware of the legalities of a mechanic supplying the appropriate documentation upon the use of a donor engine, that would be greatly appreciated. I fear that this mechanic may have used a stolen engine, or worse.
As far as I am aware, if the engine number is not visible on an engine/readable I could be arrested on the spot.
This is in NSW, as for engineering I know that an engine number is required from the engine that has been removed, as well as the donor engine as well. Can anyone confirm this?

If this topic has been addressed, please point me in the right direction. Furthermore, is there a way to retrieve the engine number? Barely visible, though can identify certain number just not all of them.

[AB]

What numbers are visible, the start or the end of the sequence?

http://www.nissanpatrol.com.au/forums/showthread.php?13772-GU-4.2-Engine-Numbers

The thread above explains how the numbers roll out, see if you can make sense of it if the start or possibly the end numbers are not visible maybe?

[Gq jack]

I'll take a good look when I get the chance today. Thank you for the info, I'll keep you posted.

Cheers AB

[Robo]

Once upon a time I saw an police officer paint a special chemical onto stamped area that had had the engine number servilely ground back.
this case number couldn't be retrieved.
but by sounds of yours, your in with a chance.

Ring the MTA they may shed some light on your question.
that is the mechanic's legal responsibilty.
and consumer affairs for your legal rights.

[Alitis007]

Your mechanic should have written down your new engine number on the receipt to show as proof of purchase when you go to change the vehicles details to the RTA as i do when i swap engines over.

Steel has a memory and i know for a fact that you can sweat the original numbers up by applying heat to the block, i'm not sure on the exact process but i know the EPA use this technic when they have to verify engine numbers that have been tampered with. A good friend of mine had a motor rebuilt and when he was trying to sell the car vic roads sent his car to the EPA because 1 letter was crooked and they used that technic.