I recently removed the engine from my 2003 s type r I had it rebuilt at a speed shop I replaced rings rebuilt heads etc. I'm setting the timing chains. I followed the shop drawings and want to be 100% certain before I close the cover up. I bought the timing kit to lock the cams in the flat position and the key that goes into the bottom of the bell housing in the cam sensor opening . My question is that top dead center ? I installed the new chains and tensioners as described in the shop manual . Any advise and help would be appreciated . Pictures would be great as well.

 

I'll try to add my 5-cent worth here, but I do not know, if that helps:

Since you have an STR, you have a V8 engine, and most probably the same as in a XJ8 (X308).
The X308 V8 engine is an interference engine, i.e. pistons and valves occupy the same space, JUST NOT AT THE SAME TIME, because if they were, that would be "decremental to the valves", or in other words: Catastrophic. This is, why the timing needs to be pretty much spot on.
I think it is good advise that - after you assembled the timing chain in a manner, which you think was the right way - you turn the balancer bolt (the bolt, which hold the front "pulley" of the crankshaft) with a big ratchet very slowly and carefully by hand clockwise for 2 turns of the balancer (if possible). If you managed to do that, it means that no piston got stuck on any valve... (which is the idea)...

Maybe this helps:
https://www.jaguarforums.com/forum/x...e-swap-266724/

I changed the timing chains on my X308 and was confident that I did it right, as I marked all the relative positions (chains to sprockets) and transferred those makings from the old to the new chains/sprockets. But I am confident that if you search long enough you will find references to where every sprocket is supposed to be when you are in TDC (top dead centre).

I could tell you all that only of how it is on my van: TDC normally refers to Cylinder 1 being in the uppermost possible position, which is easy to spot, when you have the cylinder head removed, which is most certainly not the case in your situation, but there is a trick: Remove the spark plug of Cylinder 1 and place a long enough screwdriver in there (something, which would definitely not be able to fall thru the spark plug hole and be stick in there). When you turn the bolt of the balancer (always clockwise) with a ratchet, the screwdriver will be lifted up and then sink down again, So when it is in the uppermost position, this should be TDC.

And from here I have to be guessing my way: I think, when you have the description of where everything should be when you are in TDC, and you got that right, you should have managed to find a position, where the interference engine will not self-destruct, when you try to start it. But because the camshafts make 1 rotation for every 2 rotations, which the crankshaft does, I think that it might be possible to build everything together incorrectly still (even though the TDC was right) to the effect that the engine is 180 degree out of tune. It should not harm the engine, but the engine would not start... I might be wrong there, but that is how it would be on my van, where I also would have to check the position of the dizzy (distributor), to make sure that you are not 180 degree out of tune. But the Jag has no dizzy, but has an electronic ignition system instead.

 

IIRC the crankshaft is at 45deg ATDC with the locking device in place.

 

Norri is Correct (As usual!). When setting the timing on that engine follow the JTIS. When the locks are all in place the engine is NOT at TDC!!!
It's not what we use to do in the old days! These are much different engines.
.
.
.

 

I've rotated the engine clockwise and the crank turned unobstructed . What I should have asked is if the cams are locked on the flat and the key is inserted into the crank / flywheel is that the correct position to install timing chains tensioners ? I followed the shop manual just want to be clear .

 

Yes, if you have the lock in the flywheel and the cams locked with the flats level you should be good to go.

 

> What I should have asked is if the cams are locked on the flat and the key is inserted into the crank / flywheel is that the correct position to install timing chains tensioners ?
>> Yes, if you have the lock in the flywheel and the cams locked with the flats level you should be good to go.

That's what I thought, but I could not remember 100% if it was like that when I refitted my marked chains on the X308...
I had something in mind like asking myself: Why did I bother making all those markings? - but it's always better to have double confirmation.

 

All this info is in my copy of ENGINE COURSE 168 I upload over a dozen years ago. (converted from paper 3 ring binder to .pdf)

The 4.0 and 4.2 are mechanically the same.

 

I was surprised the sprockets are pressure locked and not key locked. That's why there are no marks on the components . Also whem the crank is locked the key on the crank sprocket is facing down exactly in center. I'll post some pictures when I get the rest of the gaskets I need thos week. Thanks again for all the replies . Mike