Hi All,
Would someone be able to decode this engine number for me?

I'm thinking of buying it and I'm told that it's a HE

7P62649SA

Thanks & regards, Jim...

 

Link
Engine Numbers
Details

SOHC V-12 Engines

7Sxxxxx 5.3 Liter E-type
7P1001 5.3 Liter XJ12/Daimler Double SIx Series 1 w/carburetters
7P4000 5.3 Liter XJ12 & D6 Series 2 w/carburetters
7P25001 5.3 Liter XJ12 & D6 Series 2 w/fuel injection
7P42300 5.3 Liter XJ12 Series 3 Pre-HE (suffix ? = 9:1, suffix HA = 10:1)
7P45001 5.3 Liter XJ12 Series 3 HE
8S1001 5.3 Liter XJS non-H.E.
8S18001 5.3 Liter XJS H.E.

Note that for V12s 1971 through 1979, LA and LB suffix was 7.8:1 CR and SA and SB suffix was 9:1 CR. For 1980, suffix HA was 10:1 CR. From 1981 ?? suffix was 11.5:1 CR and ?? suffix was 12.5:1 CR.

So if the above is all true, you have an HE engine from a series 3 saloon with a S suffix which I think (not 100% sure) means a 11.5:1 compression ratio (standard HE comp ratio for USA V12s). The A refers to the tolerance matching of the pistons and liners.
Greg

 

Thanks Greg,
Next question will it work in a pre HE XJS 1977 model.

Mine is missing bits of distributor and lots of piping etc so I'm thinking that it might be easier to grab another engine to rat these parts off.

 

Thanks Greg, answers many questions.

JIm, your XJ-S is a D Jetronic EFI system.

The HE is a P Digital system.

The PreHE has:

A trigger board inside the distributor to fire the EFI system.
The ignition system is Opus.
The injectors are unique.
There is throttle position "switch" on the centre capstan.

The HE has:

No trigger board, and the P Digital is unique to the HE.
The ignition system is a CEI GM system.
The injectors are HE specific.
There is a throttle position "sensor" under the capstan.

Thats the bare basics, HEAPS of other differences.

YES, it will bolt in, BUT, you will need an aftermarket engine management system to operate it. If the donor is a WHOLE CAR, then convert yours to HE, coz all trhe little silly things are on that donor car, still lots of work, but equally doable.

I did it a LONG time ago, and vowed then NEVER again.

Do a list of what you reckon is missing, and maybe us downunder guys can dig up what you are missing. I reckon I got some odd bits stashed somewhere. Distributor bits are still around new.

 

Thank you,
That is what I needed to know. I'm pretty sure that the trigger board is AWOL as well as several other things.

Will be a couple of months before I get time to do anything to the XJS yet as I'm building a home (garage) for it at the moment because it is parked where my daily driver should park and I don't like the car that I rely on to be out in all weather.