matching eng dates to tags

[haje]

How far apart would an original eng number be from the build date of the vehicle eg 2/76 hj ute, could it be a couple of months or the same date exactly?

[ozbox]

ive seen them up to 4 months prior to build date...most recent being an hq sandman ute i put a thread on here of..the ute had logbooks and was original.

[Beast Master]

I have 2 torana's that have the build date 11/77 and one has a date code of 5 weeks prior and the other is 9 weeks. Both are log book cars original engines. I don't think Holden practised FIFO.

[HK1837]

When you see the Service/Warranty records you can see the results. The LC/LJ records many have on CD show you well enough but not as good as you see on HQ-HZ. It is obvious they just grabbed the next engine they could get to to whack into the car as it came along the line, that matched the coding on the Production Broadcast Sheet. You can see when a new batch of engines has come in as there is a much higher number (especially on high volume engines like 202) then they'll drop down many thousands in numbers as the new ones get used and they get back into the older ones. Add to this the sometimes days, sometimes months between cast date and engine assembly (anything damaged during maching got put aside to be fixed and used later) and you get no pattern whatsoever. Here is a sample of engine numbers from consecutive Dandenong HZ's. These are consecutive PSN's, not chassis numbers. Remember that chassis numbers went on late in the production line and cars with consecutive PSN's will not be consecutive on the line, they may be pulled off waiting for something then get put back on, further muddling up the PSN vs engine numbers. The only reason GMH have records of engine numbers used at all is they were recorded when a car went back to a dealer for its 1000kM service, so you can also imagine the scope for error in: a) recording the number; b) writing it down to send back to the zone office; c) entering it into the GMH computer system used back then.

Note that gaps are where no engine number is recorded.
QL878804
QL881203
QL880888

QR894579
QR896806
QR880801
QR885345
QR892919
QR889702
QR892944
QR885355
QR895799

QT895460
QT895392
QT892517
QZ895433
QT891300

[adam perth]

it would be good to have a graph of numbers against time on a graph to roughly determine ballpark correctness.

[HK1837]

You'd be grasping at straws to get it close to right, as it is different across each plant, and the numbers used to track cars on each assembly line varies: Pagewood used the firewall number, Dandenong and Acaia Ridge used the PSN and Elizabeth used the build sequence number (BODY number on HQ-late HX, PSN on HZ). Add to this the fact that a lot of the cars we are interested in here (vans) were assembled at Pagewood an Dandenong using Elizabeth bodies with Elizabeth body plate, so imagine the confusion that threw up as there is no Pagewood firewall number and no Dandenong PSN for tracking. ANd then engines get thrown in at random. And chassis numbers get put on at different stages in each plant. Cras get pushed off to one side to get finished later if something is wrong. Therefore no real trend that any of us could come up with really helps. We can give possible the first 2 digits given a chassis number, but even then they can jump on consecutive cars from QL91xxxx to QT87xxxx to QR89xxxx then back to QL87xxxx. So all you can do is estimate and look close as you can. Engine number is what matters though, as long as the cast date is prior to your build then all is sweet.