Wot are these numbers on my engine

[Crusty]

wot do these numbers mean on me engine

[types26/36]

This is what I believe the numbers indicate but Gary will probably be able to correct me or add some more information.

[Chancer]

The one at the top left of the 2nd picture is a pattern reference/date, the circular figures are fixed but the arrow can be moved around, I think you can actually see the impression of the cheese head screw that locates it.

Interesting to learn that 68 denotes the model year, I am talking X/flow here not Lotus blocks of which I know nothing but I thought that the earlier ones were 681F and the later ones 711M, that said my 68IF block did come out of a 68 car, perhaps all X/flow blocks from 68 to 71 were 681F and thereafter 711M.

[garyeanderson]

http://mustangtek.com/FordDateDecoding.html

some good info at this link on Ford casting numbers,

Gary

[types26/36]

perhaps all X/flow blocks from 68 to 71 were 681F and thereafter 711M.

The 681 was avaible as both a 1500cc block (used in Lotus) and a 681 1600cc used in the Xflow.
There is also a 691 block used in Xflows (Capri) then Xflows got the 711.
Lotus carried on with the 701 which was only a 1500cc block.
There is also a 771 Kent block used in the Fiesta and the 831C Xflow which was used in Fords South African Sappires and Sierra range.

[Crusty]

Thanks for the reply chaps interesting stuff..

[Elan45]

In the pictures shown on this page, I don't think the 681 or 711M have anything to do with date, but rather a design variation on the basic engine that started life as a 105E, 109E and progressed to 120E that were used in the first Elans.

I'm pretty sure that the T4 designation is to identify an actual mold set or sub-casting line that produced the blocks and other heavy castings. You have to realize that Ford had multiple lines producing the same item, side by side, to be able to produce the volume required. You will see the same identifier on injection molded plastic items to designate which cavity of a multiple cavity mold the item came from. If, during production, you start getting some bad parts and they all have the same code, the technician will know which cavity needs attention.

For something like an engine block, that may get close inspection days after being cast, or machined a month later, this again is a way of tracing problems back upstream. Some people may have observed thicker bore walls in one T number over another but I would chalk this up to simple manufacturing tolerances or wear in the molds. I don't think there was ever any intent for these T numbers to mean thicker walls.

Roger

[types26/36]

As far as I know the designation? 68 1? began in 1967 for the model year 1968, like wise ?69 1? began in 1968 for the next model year 1969. This carries on with ?70 1?(1970) for the Lotus engines of that time.....Sprint etc.
The same applies for the ?71 1? (1971) the ?77 1? (1977) and the? 83 1? (1983) all of this cannot be a coincidence plus I was told this my someone involved at the time.
I am not saying the casting model year is for the car as you will find later cars with the earlier engines, Ford of South Africa carried on using the 71 1 until the 83 1 was introduced, the 83 1 later became known as the ?AX? block although all 83 1 blocks do not carry the AX letters.
As I understand it, the year denoted the model year when that type of casting was introduced into production.
I agree that the ?T? has no bearing on the thickness of the cylinder walls

[garyeanderson]

Hi Brian

The prefix of the part number is the variant, usually a model number then they changed it first time that it shows up for a production change. If a part was not changed the prefix carried over Look at the part number of the bellhousing, 105E-7505 is the prefix and thats where it show up first and has nothing to do with the year produced. At some time my guess would be 1967 as you state they changed things a bit in the naming scheme. I don't claim to know a lot but there is a lot of info if you look.
http://www.google.com/search?q=ford+cas ... CAcQ_AUoAA
This is Ford Detroit logic where the model year begins in September and the tooling changes happen in late July and Early August. My Grandfather was a tool maker at Ford for most of his life and as part of his job would have to go into work to make those changes during the 2 week summer shutdown.

I agree with Roger about the T numbers being casting core identifiers for tracking of parts. The date is on all of the blocks and all of the other cast parts this allow us now to say with some certainty when it was cast and its usually about 6 weeks before the invoice date from Lotus with many Elans.

Gary