I decided I don't want to pay a shop/dealer $400+ to install this tappet stakedown kit, when the instructions look so darn simple and if I'm careful, it's something I can accomplish myself.

I have the kit from Coventry West, which comes with 3/4" long #10 self-tapping machine screws.

The instructions say I need 5/32 holes, so I assume I need a 5/32 drill bit. Does anyone know what sort of drill bit is best for this sort of thing? I know the hardest part of this job is getting the holes in the right spot without the drill walking out on me.

 

Perhaps someone else can provide recommendations on fractional drill bit sizes as I have never used them, but you should probably begin with something smaller, whatever that size is, so you can have more metal for the 'self-tapping' screws to go through.

Using a centre punch will put a dimple into the metal so you can get the bit started without having it move across the casting.

NBCat

 

Hmmm... center punch sounds like a good idea.

Although now I'm conflicted... the Jaguar dealership out here has a 15% off coupon for any service, so they quoted me $430 before and that would be more like $365. What to do!

 

Essentially the $430 (or $365 with discount), is a labour charge. Do you know the hourly rate ? Are the cam cover gaskets included in the price, (not that they are all that expensive) ?

I would not think doing it yourself is a particularly hard job, but take the tip on using a centre punch to mark the drilling points. 5/32 drill is fairly standard size, I think I have one in my drill box. What surprises me is the use of self tapping screws; when I last read about the job, it was tapped holes taking 1/4 UNF screws, I think. What I am always puzzled about is how the swarf gets removed that drops out of the bottom of the holes when drilled. Or is it just left to get washed down into the sump ?

 

The hourly rate is something like $140/hr at the dealership. They said I would have to provide my own parts for this job, so I am assuming I'd need to provide my own valve cover gasket as well if I wanted it replaced?

Luckily I have a center punch already from the flexplate rivet job I just did. As far as the 5/32 drill bit, is there a special kind of drill bit I should use? I presume all drill bits are not created equal!

 

There's a lot of good info here https://www.jaguarforums.com/forum/x...uipment-58977/

I'm with Fraser on the self tappers, I'd think tapped holes with screws loctited in would be better.

 

Another interesting way of securing the tappet guides is this method using a small set-screw. The advantage to this approach is it not only stops the tappet guide from rising up from the head, but also prevents it from rotating within the casting.



This photo is from Coventry West, Inc. in Georgia.

NBCat

 

Out of curiosity, is there such a thing as being "too late" to put the stakedown kit in? Assuming the tappet guides have come loose from the head but are still intact, is it still possible to install the kit?

Also, why does it matter if the tappet guides rotate around after the kit is installed?

 

What you want is to prevent the tappet guide from rising up and being struck by the cam lobe so that a large piece breaks off and finds its way into the timing case causing catastrophic engine failure. The tappet guide rotating within the cylinder head casting is not so much a problem as the rising up, but the guide should remain stationary so there is no possibility of additional wear to the head casting.

There appears to be a wealth of knowledge on the subject as some of the previous postings indicate, so if you have a 'stake-down' kit, it's probably best to install it to prevent further damage. The choice of selt-tapping vs. machine screw threads is up to you.

NBCat

 

Don't pay the dealer and give them a chance to find other problems with your car. Chances are they've not done this job before. Unless you know the mech has done this before and you are absolutely too shy to do it, you can pay to have it done. I just installed this kit on my exhaust side and it was much easier than I thought, and I'm a novice mech at best. Use the 5/32 bit size and look for a quality metal bit. Drill 90deg to the block. I mark the bit with a sharpie pen to set the right depth. The screws are not suppose to penetrate the block so no need to worry about the shaving falling through the bottom. The tapping screws are very good so you don't really need to tap the holes, and will hold the plates in place nicely. Of course, cover the holes so the shavings don't fall into the engine. You can do this!!!

http://www.jagbits.com/28stakedown.html

 

Thanks tsingtao35, I think I will take your advice!

As an aside, I do trust this dealer as I've had work done by them before. They said they haven't done a job like this for years, but that they have people there that have done many of them, once upon a time. They charge a pretty penny, though! And the indie shop ain't much better!

 

So after reading that blurb on Jagbits, I'm a little confused. After drilling the holes and installing the plates with the screws, I then need to remove the screws and put some loctite on them and then screw them back in? Won't this strip the threads, possibly?

 

dont use the loctite, that's just someones' opinion, the screws are fine and will hold the plates down well without any adhesives...

 

You could put the loctite in the hole before you screw them in.

 

Ah, but I thought most of the directions say to wet the threads with WD40 or similar lubricant when putting the screws in. I'm guessing loctite would defeat the purposes of putting WD40 on it.

 

If you decide to do the work yourself, have a means of picking up the swarf left by the drill so it doesn't go into the oil passages in the head. When drilling the holes, it is good to use a lubricant such as WD40 so the drill bit does not stick in the newly-drilled hole.

If you're using the self-tapping screws, clean any engine oil or WD40 remaining in the area with something such as brake clean prior to using any product such as 'Locktite'. While the self-tapping screws will most likely hold the plates in place, it's always a good idea to use some form of locking compound on the threads so one of them doesn't back out and cause the same problem as bits of broken tappet guide should it find its way into the timing case.

NBCat

 

IMHO the Loctite will provide enough lubrication while it is still liquid.
If it was me, I'd have a clean hole, Loctite then drive the screw in.
You could get a piece of aluminium to practise with first.

 

ahh loctite schmocktite, these screws will hold real tight on the aluminum head..go for it.
do you have an actual tapping of the guides right now and/or have taken off the valve cover and seen the condition of the guides?

 

I've never taken the valve cover off to look at it, but I do have some tapping sounds from the engine that are probably consistent with tappet guide clatter.

1983 Jaguar XJ6 engine revving under hood - YouTube

 

I'm not so sure that's your guides tapping...Keep in mind you will also need a new valve cover gasket and that will take some time to get it right and tight seal. i've attached some pics of my kit job..