Merry x-mas & Happy Hanukkah everyone. Is their a way I can check to see if the cam and crank are in time with each other? Move #1 cyl to TDC on comp. stroke and check the cam timing perhaps? Any idea on where I find cam timing markings? I was going to bring it to JAG but before I do (or have to) I was wondering if their was a quick and dirty way to see if I've jumped time? I assume the distributer is run off of the crank shaft so a timing light would tell me if the distributor and the crank shaft are out of time but would tell me nothing about the cam and crank timing. Thanks

 

Remove the cam covers. At the front of each cam is a notch....you''ll see it.....about3/8" wide.

With #1 @ TDC compression the notchces of the cams should be pointing outwards like rabbits' ears and perpendicular to the plane of the cam cover mating surface. In other words, if you ran a straightedge across the surface the the cam cover rides on the noches should be perpendicular to the straightedge.

Hope that makes sense. I'll try to find a pic.

There's a tool for checking this but eye-ballng it should be good enough for what you're trying to do.

Here's a pic of the tool which may help you visualize things a bit

Camshaft Alignment Tool. Cam Tool . Jaguar E-Type (1961 - 1974) # C3993X

Cheers
DD

 

Doug is giving you good advice. On the XK engine, cylinder number one is closest to the bulkhead (firewall) and number six is closest to the front of the engine near the timing chain.

Unless there has been major work to the engine, the XK motor does not 'jump timing'.

What are you actually trying to accomplish by inspecting the camshaft timing?

 

My 84 xj6 just will not start. Fuel, air and a good spark and not even a sputter, I made my fire triangle so I should have ignition unless something slipped or the distributer went way out of wack. But it looks like when the #1 cyl is at TDC the rotor has just passed the #1 contact on the distributer.

I thought it might be worth a look, should I look somewhere else?

I was thinking maybe the computer or that (forgive my ignorance) electronic coil distributer timing pack thing on the front passenger side I heard about is sending an mis-timed signal and needs replacing.

 

If you got good spark, then the ign amp (front of the inlet chamber), and the rest of the ignition system is deemed OK.

I am leaning towards the ign timing being out of whack, and "maybe" the firing sequence in the cap is wrong. I have seen this at times as so many people do not know #1 is at the rear of the engine.

Get it on #1 TDC comp stroke, note the rotation of the rotor at the same time (anti-clockwise from memory), and start from scratch with placement of the HT leads in the cap.

 

So doug when those notches are as you say then the number one cylinder (nearest the firewall) is at tdc on compression stroke? Mick

 

The workshop manual s1 page a23 gives specs for checking valve timing and refers to no 6 piston being at tdcpage a24 fig 20 shows the camshaft aligning tool with the notch as you specify but this is in reference to no.6 piston at tdc I presume on compression stroke. The position of the cam lobes would support this the lobes on number 1 piston are both pointed downward almost about to start depressing the cam follower and open the valves while the no 1 piston lobes are up at almost 45 degree angle.

 

Hmmmm. Yeah, in one section my manual also references #6 but likeswise doesn't actually specify compression stroke.

Now I'll have to do some mulling!

I'm quite certain that when I've replaced cylinder heads I've referenced everything to #1 @ TDC on compression stroke but now I find myself second guessing

#6 and #1 are at TDC at the same time....that much I remember





Did you mean to say :
"The position of the cam lobes would support this the lobes on number 1 piston are both pointed downward almost about to start depressing the cam follower and open the valves while the no 6 piston lobes are up at almost 45 degree angle"


Cheers
DD

 

Doug Im pretty certain that they mean tdc compression , well that would be the same for every other car but Im new to jags.

Anway just went out to check her again, the little 3/8th inch notches are in position at the front of the cams, the timing mark on the pulley, and the number one piston (nearest firewall) is at tdc but it is definitely not compression stroke as the exhaust is just closing and the inlet is opening, this would be the exhaust stroke up and the inlet stroke down.

Now the number six cylinder (front of motor) is definitely tdc on the compression stroke.

If this is the case my question would be is my cam timing correct or 180 degrees out?

Bear in mind the previous owner knows nothing about cars , his dad restored it a number of years ago before he passed away, it has been sitting for quite a number of years, while but the son said it was going ...before it stopped for some reason. Thats just a bit of background but illustrates that the history of the car is a bit clouded...

Any advice/discussion appreciated. Thanks. Mick

 

Hmmmm looking at page A22 re fitting the cylinder head and setting the valve timing I see they specify first thing you do is set no. at tdc and set the distributor with the rotor arm opposite number 6 segment.

This confirms that the jag engine is set with number 6 piston at tdc on compression stroke and my cam timing is correct (lets hope). Answered my own question, helps to read the book must remember that next time. Mick

 

My remembering incorrectly in far more likely than the engine mysteriously jumping time by 180º !

Sorry for starting you down the garden path.

Cheers
DD

 

No worries Doug. On my first baby steps with the jag. I question everything on it as I cant speak to the bloke who did all the work. Its pretty rust free though and after I replace a bit of the chrome work and get things working should come up well. I deliberately wanted a SWB with carbs because of its simplicity, as much as a jag can be simple, I have a rover sd1 to give me EFI headaches.

When I replaced the plugs the old ones smelled of petrol so if I can get spark in there at the right time things are promising.

 

Thanks for sorting that out MickVic, It confirms my suspicions- collaborated with a photo in a Haynes manual & elsewhere on the net (certainly couldn't trust a Haynes photo on its own .) The fact that some twit engineer at Jaguar decided to number the cylinders his "special" way so many years ago has caused so much mis-understanding & confusion.