Timing Chain alignment 4.0L

I have an XJ 1990 4.0L. Harmonic Balancer went bad and slipped, so I'm replacing it. Decided to check the timing chain and it has more that 1/2 inch play, so I'm replacing it too ... but ...

I'm perplexed about the timing marks on the gears. When I have it at TDC on the compression stroke and the rotor pointing at #1 spark plug wire, the timing marks don't face each other. While the mark on the crank gear is facing the cam gear (expected), the cam gears timing mark is 180 degrees off on the other side. I just doesn't seem to match the books I have. I also count 62 pins and not 48 pins like my book says for a 4.0L.

http://www.geocities.com/jacobsen_mike/1990XJ/xj90_timing_chain.jpg

http://www.geocities.com/jacobsen_mike/1990XJ/xj90_dist_pos1.jpg

I'm the 3rd owner and it may be possible this is a rebuild or replacement engine. The blocks casting number is 701MX03 with a 97 to the right and a R1D01 or RTD0T below (kind of fuzzy pic below).

http://www.geocities.com/jacobsen_mike/1990XJ/xj90_engine_701mx03.jpg

I don't think the Cam is 180 degrees off, but could it be? or am I looking at the wrong engine or parts?

Thanks,
Mike

No, it's all good. The cam rotates at half the speed of the crank so all you have to do is turn the crank one full turn and the cam sprocket will rotate half a turn, bringing the notches of both sprockets into alignment.

I rotated the crank one full turn and the timing marks on the crank and cam gears now face each other. I put my finger over #1 plug and didn't get any compression (exhaust stroke). The dist. rotor is now pointing at #6. Still sound okay?

Sounds OK. If you're in doubt, follow this procedure to index the distributor:

http://www.angelfire.com/my/fan/dist_index.html

I'm thinking that the timing chain and gears on this engine are from a newer engine. Are the timing chains interchangeable between and 1990 and 1997 engine? The timing set that is currently on sure looks alot like a Cloyes C3041 or Sealed Power KT3385SA.

I'll plan on talking to a dealer and see if i can get some info on the engine number to see if it was replaced. 701MX03 97.

According to your engine no., the engine was built on 3rd January 1997 so your '90 XJ has had a '97 engine swapped in at some stage.
The timing sets on '94+ 4.0 engines are different than on earlier models, but they ARE interchangeable as long as you swap the whole timing set (including both sprockets) and not just the chain alone.
Since the '94-'98 OEM sprockets and chain are beefier than the earlier versions, the '94-'98 OEM timing set is a good upgrade for '93 and earlier 4.0 engines if you don't want to opt for the Cloyes dual roller set.

That clears up my confusion!! I'll replace the entire timing set, but get the Cloyes dual roller or the beefier 94-98 version. I will post the results. Thanks!!

New timing chain (94-98) version installed and aligned exactly as previous timing chain. Starts up a runs. Thanks.

Thanks for posting your results. Thats a big help for those of us following various threads.