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8L denotes Xj6 Series 3 4.2 Litre (Liter) 6 Cylinder (and maybe some early S3's had carry over 7L numbers??)
121050 is just the sequential production number
-8 denotes compression of engine.
Yours looks like a worn 8 which is the standard comp for these engines in these cars.
7 was for lower compression markets with dodgy fuel quality (Which means Australia should have been sent these )
9 and higher was for higher compression engines like the E Type (XKE) and racing applications.
Hi JigJag
...
-8 denotes compression of engine.
Yours looks like a worn 8 which is the standard comp for these engines in these cars.
...
Hope this helps.
Cheers,
Nigel
I appreciate the information, but I have to disagree with your conclusion. This is most definitely an "S" not a worn "8". The midpoint is horizontal on the 8 and the S's is diagonal. The 8 is larger on the bottom and smaller on top while this S is symmetrical. The ends of the S are clean and well defined and they alter the curve. Here's a close up comparison.
This does jibe with info ( 8LxxxxxS 4.2 Liter XJ6 ) that I just found from this page Engine Numbers
But that doesn't help me with the reason I'm looking into this. I believe that this is a European spec 4.2 High compression engine. This is a "FEDERAL" stamped car, however, I have no air pump or pipes or the other anti-smog gear. These components aren't missing, they were never present. Here's a shot that... doesn't show them.
All the Euro 4.2 info I have at the moment...
E. Differences between European Spec XJ6's and US XJ6's:
European specification XJ-6's were commonly brought into the US as "grey-market" imports in the 1980's. The European models had some minor differences from US models, which may be important if you live in an area of strict emission rules. The European XJ6 may or may not have: 1) A catalytic converter, oxygen sensor, air pump or other smog gear fitted to the US cars. 2) The standard 4.2L found in US cars. Some European motors were smaller displacement 2.4 or 3.4L engines, while others are higher performance high-compression 4.2L engines which require high octane fuel 3) Large 7 inch outboard headlights with wipers and smaller 5 inch inboard headlamps. US versions have the same sized headlights in both inboard and outboard positions with no wipers. A chrome flashing is used to compensate for the smaller outboard headlight.
I'm also inclined to believe this because of the car's deep appreciation of Premium fuel. What I though was tappet noise goes away when I switch to the Premium-filled tank. This makes me think that I mistook sophisticated and quiet Jaguar brand pinging for valve noise.
Does anyone know if the heads are marked? I assume that all the variances between the different compression ratios are heads-based, or did they fit different pistons or a combination of the two?
All Series 3 heads were the same, the compression ratio was varied by putting domes on the pistons.
The 'S' may refer to the slotted block, introduced around 1981/2 to stop cracking between the bores. You'll only really know if you lift the head.
I have to say you are a lot better off not having all that emissions "plumbing", assuming your car is legal where you live in the US. Early emissions equipment was something of a lash-up and it was never really any good until we got digital, mapped, combined ignition/fueling ECUs.
But that doesn't help me with the reason I'm looking into this. I believe that this is a European spec 4.2 High compression engine. This is a "FEDERAL" stamped car, however, I have no air pump or pipes or the other anti-smog gear. These components aren't missing, they were never present. Here's a shot that... doesn't show them.
Since the "Federal" stamp doesn't necessarily indicate a USA-spec car...if that's what you were thinking....so it is quite plausible that the car was never equipped with air injection, cat converters, or even a lambda system. The federal stamp, in essence, simply means that it isn't a home market car. It meets the 'federal' requirements of whatever market is was intended to be sold in.
The 'S' may refer to the slotted block, introduced around 1981/2 to stop cracking between the bores. You'll only really know if you lift the head.
Not so sure about the 'S' being for slotted block, the original engine number from my car was 7L706254-S. Being a 73' engine it was not slotted.
My new engine is 83" and slotted.