SD12802J

[Gilmore1]

Good evening fellow SDonians .I recently purchased this SD Crank , Cylinder etc from a fellow member . I only needed the Block for a project but have some questions about the Block , Crank Case etc . The block is stamped SD12802J which in my reckoning makes it a late SD model . The block is a Long case , not a short case and the Crank Case is not drilled and tapped but is as like later 102 models with through holes for bolts tapped into the block , see attached pix . Now my question is , is this original , the casting on the Crankcase looks original and not modified , is this a late SD / early 102 transition . The base plate is rimless but no fly wheel with date stamp and I guess too new for a JM number on it .

Eddie.

[Collector Inspector]

THAT is very odd aye.

Is there a "Factory Repair" number anywhere, and I mean anywhere, small font, something like this?

Other thort to mind is that the crankcase could have been destined, lets us say, an early AD (1947 0n)...wrong parts trolley.

The engine number makes no sense......well, for me anyway.

Others will chip in I am sure.

Will be nice to have the whole parts story pictures on the bench items .

Cheers

B

[Gilmore1]

Collector Inspector, there are no stamped numbers on it other than the Serial# . There are casting numbers ,"e1280A /81A on the castings , same number as is on SD 2360.LS(last pic) .To me the casting doesn't look as if it has been bored out but made as it is ,the SOS site says 1946/47 so yeh my thoughts were maybe a very late model just on the change . There is only one casting mark on the Block .
Eddie .

[Charles uk]

Hugo are you able to pass comment on these pictures?
Hugo is the Australian Gentleman who is compiling the SD register

To the best of my knowledge no SD's were manufactured with a long water jacket cylinder & the serial number font on your crankcase looks different to fonts used by Seagull between 42 & 52.
Does anyone remember what year Seagull started using long water jacket cylinders without brass core plugs?

That crankcase cannot have been part of the Ministry of Supply order as all SD's were, without the use of a time machine, as it first appeared mid 1946!

If anyone knows different please shoot me down

Charles

[Gilmore1]

Charles Uk .
According to SOS , see attached mine was 46/47 . Who knows , could be someone bought the casing and stamped it up if they were repairing an SD .Or maybe at the tail end of the contract they used newer style parts . Unless some one else has a casing like this to compare .

Eddie.

[Charles uk]

Eddie go & search on the forum for "seagull register" this will show you all the details of all of the SD's on the register & many of their technical details, you will note that no one states long or short water jacket as they all had short water jackets & a crankcase with 4 studs for cylinder retention.

Can anyone help Eddies quest do you have this cylinder i.e. without brass core plugs & the date of the crankcase serial number?

[Gilmore1]

Thanks for the reply Charles .

I have been through the database and have put a couple on there myself and I've had a few through the workshop and have never seen a long case one , or a crankcase that didn't have the studs fitted in either . Every so often you get a curveball thrown at you .
As a side question do we roughly know how many SD , SDP's etc were produced in total .

Eddie .

[Hugz]

General consensus was there were about 10'000 manufactured though the #'s go up to the 12k's. There are a few blocks missing ie in the 6 and 7000's. In time l believe these will balance out and appear.
I agree with Eddie that it was probably an SD with a later replacement crankcase and barrel. The font also as Charles mentions doesn't relay to the correct time period. There's usually a dot after the number and after L1 etc. One also must consider the number itself.. 12802.. which is at the end of the range and would expect it to be an SDP or a HSD. Arthur Daley?