So I've been trying to do a rebuild on my 2002 XK8 engine for a while now, and was trying to find the correct main and rod bearing sizes to use. Was grateful to find a really important resource on this forum: http://jagrepair.com/images/AutoRepa...Code%20168.pdf which details where to find engine information stamped on the engine:


Where to find engine numbers

And also how to interpret them:


But when I checked my engine, the numbers stamped on the block did not match. I could only find the bore diameter and main bearing bore inside diameter codes, but both crankshaft diameter codes where missing!


My engine dimensions stamp, missing info!


As you can see, no sign of the main bearing crankshaft journal diameter or the connecting rod journal diameter!! Where did they go??



p.s. I looked at a 99 model engine and everything was there, something seems to have changed.
p.p.s. mine was a change-model year, I think the final iteration of the 4.0 model manufactured in May 2002. The next change would be the introduction of the first 4.2 model.

 

somebody here just did green everything and it worked out fine

 

Very interesting, that's my potentially very expensive fallback plan. Still though, where are the markings??

 

The year actually shows its a 2003 block, iirc that was already a 4.2 engine, are you sure this was the original one that came with the car?

 

My research shows that you have an AJ33 , if it came from a XJ, or an AJ34, if it came from a XK. I don't know too much about these engines or the differencesfrom an AJ27. You might check the rear of the crankshaft under the flex plate to see if the crank codes are there.

 

The stamp on the front engine cover is dated at 5/2002, how do you figure the XJ thing? Any way, the engine shape and and internal dimensions are aligned with late 4.0 models. There are no markings on the crankshaft.

Back to the issue, and even if the engine was changed, why was it not stamped with crank dimensions? In order to proceed with the rebuild I'm taking the crank in for some high-precision measurements just to be able to buy the right size bearings. Whoever came up with this system at Jaguar is a real genius

Any ideas?

 

car might have a frankenengine. aj33 block with aj27 heads is easily doable when you have the morse chain gear on both engines

or it could just be an aj33 with drilled out intake holes

 

The engine stamp doesn't leave room for interpretation iimho, that you re-use a 4.0 cover is not uncommon as well to make an easy fit for the 4.0 pulley and other parts.

If you speak about dimensions, key would be the main bearing diameter as that is one area where the 4.2 and 4.0 differ, what have you measured?

 

In a rebuild you typically turn those surfaces so u need to measure both pieces and then choose the new correct size based on the new machined surfaces. And if I dont machine, I still measure and choose the correct bearing based on the sizes I measured. I never just blindly replace bearings without measuring

 

The manual said no resurfacing whatsoever, and the surfaces appear not to be damaged.

 

If I remember correctly the measurements took at the workshop with a caliper were aligned with the 4.0 model. I'll get more accurate ones tomorrow and report back, but it seems to be a 4.0 block.

 

might well be true, but seems like a lot of effort for very little gain. is the AJ33 engine not stamped with dimensions?

 

I have an engine with build date 020823. The engine is toast so I thought I would break it down to the crankshaft. The code for the main journals is on the first front " fin" of the crankshaft. As you can see the main journal code for this crankshaft is NLLNR.

I couldn't find the code for the rod journals, but I didn't take the crankshaft out of the block.

 

checked again and the crank, which I have taken out of the car, is certainly without markings. I'm starting to suspect foul play...

 

pull the intake manifold off and try to identify the head that’s on it