Date coding explained

[TwoTees]

the 4 253 i have here are : 12J3, 18J8, 16G2, 31A9. I think i still have one or maybe two in the back of my dads shed.

how does the coding and numbering system work. how do you match one to your cars manuf date??

eg. from above
12J3 = 12th(12), 9th month september(J), 1973 (3) or if its blue it may be 1983

i is not used in the month section I think.
This date needs to be near your build date.
There is a thread on it in the technical section.

EDIT: http://www.mysandman.com.au/forums/showthread.php?t=570
Chris

[HK1837]

the 4 253 i have here are : 12J3, 18J8, 16G2, 31A9. I think i still have one or maybe two in the back of my dads shed.

how does the coding and numbering system work. how do you match one to your cars manuf date??

I'd like to see a 16G2 on a red engine!

As before trying to match cast dates is really a folly. You are much better off trying to match engines numbers with cars around it or match your original engine number as close as possible.

[TwoTees]

As before trying to match cast dates is really a folly. You are much better off trying to match engines numbers with cars around it or match your original engine number as close as possible.

From your data can you tell how the engine numbers ran and were distributed between plants?

As you say the cast date may be close but if the engine came in a car from a different plant would the engine number be way off for that VIN?
(with VIN I mean the collection of other properties for that build)

[Absinth]

As Byron has said try to find an engine number close to your original engine or if you don't know the original engine number ask for the engine number range around your build date.

Casting dates vary considerably.... I had a July 76 Monaro with original engine in it and the cast date was March 76 so three months prior to the vehicle build date.

[HK1837]

I don't have the original service/warranty records, but I do know people who have access. I do have access to copies of them for LC and LJ Torana, and most of these were in the same engine number sequence as HQ-HZ Holden 6cyl and V8 engines. When you sit down and look at them you get a better picture of how the numbers work. These engines were built at Fishermans Bend and all stamped there. They were sent out in batches to the assembly plants, and then stored for varying periods until they were used. Common engines like QL, QR etc got used up pretty quickly. But rarer engines like QT and especially CK or JP didn't, and you find rarer engine prefixes appearing next to a PSN (last bit of the VIN which is how the records are recorded) where the next PSN has a more common engine, and the numbers vary by 10,000 in some cases. What is happening here is the last of say a batch of 308's was used in a car, and the next car in sequence got the first of a newer batch of say 202's. Plus, depending on how they were packed into storage, an engine might have sat around for a long time. Also, some plants didn't use a lot of a certain engine, or heaps of another one so they held heaps in stock. So when you look at engine numbers between plants you can also see a large difference sometimes. Just looking at LC and LJ records where most were Adelaide or Brisbane build, cars a month or more apart from different plants can have consecutive numbers. HQ-HZ are worse as there were 5 x assembly plants in Australia plus exported stuff.
In addition to the above, the time difference between an engine being cast, and it getting built and then stamped with an engine number varied greatly in some cases. One case as explained to me was if a tap broke off in a block, it would get put aside until a later date eg engine plant down day, or the apprentices were back from school or whatever. Then that block would get fixed and put back into the production sequence. This explains the sometimes large gaps in timeframe, however it is not obvious on Holden numbers unless you have access to a large amount of data. Chev engines however have the assembly data stamped onto the engine number pad, and it is readily apparant on all of these with timeframes varying from a few days to 3 months difference.
The way to get the best hope of finding the right number is to email me the car's ID and i'll see what I can dig up. The only problem children are Adelaide HQ Elizabeth post mid June 1974 and all HZ after mid 1978.

[razsandman]

I'd like to see a 16G2 on a red engine!

whats specal about 16g2, it is a red 253. however it also has a repco rebuild sticker on it? maybe its a mix and match?:Chin:
or my eyes by tourch light where on the blink last night.

[HK1837]

A 7/72 Holden V8 should (from memory) still have US date coding. So it should be G162. Unless it is a blue 253 then it could be 16G2.

[ozbox]

that date in 72 would have been g162 as holden were still using the american date code system...so you would assume its a blue motor as its dated 16g2..if its a repco rebuild it could have any engine number on it if its been decked....whats the engine number?..

[vanman]

got a reco QR numbered 253 date code H8 if anyone interested ?
I'm casing a Qt... numbered 308 with date code of K5 or L5

[Blocker]

I split and moved the Engine Date code thread to here. It is more appropriate to have the technical discussion here instead of the (Sale Yard).

...Continue. :Hair: