E Type valve ajustment

[spit6 guy]

can anyone tell me how to ajust the valves on my 1971 xke II
4.2 in a easy way

 

[jessebogan]

There is no easy way. Whay you have to do is to measure and record the existing clearances. Rotate the engine, and check each one twice. Put the engine on Top Dead Center cylinder #1 (rear nost cylinder). Line the crank timing mark up, and check the cams with the TDC tool.Then you follow the instructions in the shop manual and carefully remove both cams. Use a magnet and remove the valve tappetsone at a time, being sure that each one is returned to the guide it came from. Under each tappet is a shim.( they often stick to the tappet on removal) Use a micrometer and measure the shim. Them you do the math to figure out what sized shim you will need to establish the correct clearance. Order shims and replace. Re install cams, connect timing chains, and measure everything again. If this is your first attempt at something like this, you may find a couple that need correcting.Correct them now as you really don't want to do this again. I usually aim for the looser end of the specs, as you get a little bit better "fudge factor" that way. You may also find a few of the existing shims can be moved around, saving a few bucks. This would also be a good time to look for signs that the tappet guides are coming loose in the head. They can actually come out enough to hit the cam. If this has happened, you need professional help, as the guides may need to be replaced at that point. Every big venor of Jag parts sells a "hold down kit". These are easy to install, and now would be a good time to do it.Most cars need the exhaust side done, but it is just as easy to do both. Good luck.

 

[DrEntropy]

I find using a "Sharpie" pen to write clearances and a "+" or "-" with needed change on the "lip" of the head adjacent to the valves helps me keep things in order, too. It saves a bit of time and is a quick refeerence.

 

[LarryK]

30 years ago dealer quoted me minimum 8 hrs. + parts( with head off ). That was when they were $60 an hr. I figured $480 + they're $100+ for parts and went a bought a bunch of shims from A-Z and did it on the bench in 2 hrs. Ran that 4.2 for another 100K. Not an easy job in the car as quoted above. Write down every measurement before you start, and remember to measure existing shim and + or - measure for the new one. Take your time. Time is harder than the job itself.

 

[vagt6]

Good advice above.

Although a rather poor comparison to an DOHC 6, I have a motorcycle with a single cylinder, 4 valve dual overhead cam engine with valve shims that are not dissimilar to the ones on E-Type Jags. Lots of bikes have such shimmed valves (BMW, Kawasaki, etc.). Sadly, mine must be checked/adjusted every 6,000 miles! After doing them a couple of times, it's now a snap.

I've adjusted valves aplenty on non-OHC engines of all sizes, so I was somewhat daunted by the OHC motorcycle engine (650cc) with it's bucketed shims. However, it's not as hard as it may seem and in some ways easier than a non-OHC engine.

A few observations:

> In some OHC engines you may not have to take the cams all the way out: simple loosen and lift the cam to the point where the shim just slips out;

> As mentioned above, be sure to draw up a chart or graph to write down all the clearances before and after measuring clearances. Very important, it's easy to forget or confuse readings;

> I purchased a pair of very long, curved medical forceps for removing the valve shims. Works like a charm. You don't want to drop the shim into the engine crevasse, and they're very slippery;

> I use clear packing tape to tape up the crevices in the engine near the cams to prevent small parts from falling into the crankcase (don't go there) during the procedure;

Give it a try. If you have halfway decent wrenching skills, it shouldn't be a terrible experience.

Let us know . . .

 

[LarryK]

Unfortunately the XK cams will have to come out to replace shims. Followers have to be removed to get to the shims which are a pretty hefty item. Pull cam covers and kill fuel and ignition, then turn over engine until first valve is at TDC then measure and then crank for each cylinder repeating the first for all 12 valves. Make sure you write each measurement down and number them accordingly. Add or subtract from the .11 or .10 or .12 valve lash adjustment per model then get the shim of the new total. Write these down as to where they go.
Now put engine at TDC and pull cam covers. Cam gears can be removed from the front of the cams and then remove cams. Remove follower cups and replace shims with the ones you have written down to replace. Re-assemble and torque appropiately and then re-check clearances. Put on cam covers and enjoy. Use of cam alignment tool helps considerably.