I am working on an AJ6 engine, with what I assumed was a blown head gasket. I have the head off, but found some weird things. I think the head has been off before, but there is no history on the engine.

I assumed that with cilinder 1 on top dead center, both cams would have the notch exactly straight up. But when I set the intake cam with the notch straight upt, the exhaust cam is a bit off.... I hope it shows on the picture:
Also, with number 1 at top dead center, I would expect the rotor on the distrubutor to point at terminal 1 on the cap, but it's already past the notch on the distrubutor housing, which aligns with the terminal going to cilinder 1.

I am uncertain if something is wrong, but it doesn't feel right to me. What do you thinkg?

 

Can't tell you why the cams seem 'out-of-time' (chain stretch?) but the ignition occurs BEFORE TOP DEAD CENTER so the rotor will be 'late' at TDC.

Someone may have installed it incorrectly at some time in the past putting it slightly past the optimal setting.

 

Hi, thanks for your reply.

I agree that the timing should be late, as it fires before TDC. so rotor might be at right spot.

The chain is in good condition and tight. No signs of stretch. Also the tensioner was fine.

The exhaust cam is off (when I set the inlet cam correct with the locking tool), but it's not a full tooth off on the chain sprocket. I think the difference comes from the finer teeth inside the chain sprocket.

Question now is: how to I teel which cam is off? how do I set it all correct? Is there a notch on the crankshaft pulley to indicate tdc?

The engine ran fine, but maybe a bit more rough than an aj6 should. I have 2 vehicles with AJ6 engines, and the other one runs better. Always has.
and of course there was the constant coolant loss, which led me to the point to take the head off.

 

The crank pulley/damper has a pointer/triangle mark on it at TDC.

Dial indicator can be used on the #1 piston through the spark plug hole.

 

Thanks!

As I now assume the head has been off before, I ordered a new set of head bolts.

Once they are in, I will set everything correct and put it back together.

With the crank pulley at TDC, Both the inlet and exhaust cam should have the notch exactly straigt up richt?

 

I use a timing tool for the AJ6/AJ16 engines.

 

yeah, I have that same tool. but that indeed means the notches will go straight up.

thanks

 

Jaguar did issue changes to the AJ16 engine in later cars.

 

Thanks, that is interesting. However, I don't think the cams were swapped on my engine.

anyway, it runs again. I figured uit TDC, and it turned out that both the inlet and exhaust cam were off quite a bit. Also the distributor was off. Now the distrubutor does not influence timing of ignition, but it has to be set correct in order to transfer a strong spark. I used my other, well running AJ6 engine as reference and set the distributor as well.

so now everything is back at the correct settings. runs good, but no testdrive yet. maybe later this week.


the 'noise' is a cracked exhaust manifold. The noise goed away when engine heats up. has always been like this. should go shopping for a good set of exhaust manifolds, but they are rare. also, the bit of smoke is oil/grease from wrenching on the thing. cleared up after a while.