Hi,
I am about to remove the head to have it reconditioned as it is tappety and the inlet valve clearances are shrinking to near 0 (and because itnwant it gas flowed and larger inlet valves fitted)
First, any tips on removing it. I have experience with British Leyland a series heads, but not jaguar xk. The engine is in situ, do I need to use my engine hoist to lift?
Second, whilst it is out, is there anything else you would recommend I do or change? Is it worth getting late xj6 cams?. The rest of the engine is standard.
Hoist helps, if it is stuck a bottle jack on the side helps a lot, get it up very straight so it doesn’t hang up. Alternate front to rear.
If it’s not moving double nut the studs and remove them.
Set the crank at 0° with both the cam lobes on the frontmost cylinder pointing away from the tappet.
Don’t move the cam shafts individually and remember that two valves protrude, so don’t set the head down on a table. You will need a helper if you’re not very strong.
I think larger inlet valves and cams are pointless, why not buy a S3 XJ head for less money and work that as much as you like without worry? This way if you want the original head back on you can do that.
I took mine off a couple of years ago. It hadn’t been off for about 30 years prior to that.
I removed all the domed nuts and squirted some penetrating oil around the studs a few days before. Don’t forget the smaller nuts under the front of the head.
It’s best to remove both manifolds rather than leave them on.
It’s possible to break the joint by leavering the head on the carburettor side.
Make up a load of wooden wedges of various sizes and gradually work the head up the studs, using blocks of wood to stop it dropping back down.
When it gets clear of the studs it can be lifted off.
I’m no Charles Atlas by any means, but I managed to lift it off myself.
Thanks for the replies. Started the job this afternoon and fed up with it already (just a little bit really), I have removed the carbs and water pipe on the inlet manifold, managed to get all 18 of the awkward inlet manifold nuts off but cannot budge the manifold itself. So I have left it soaking in penetrating fluid.
Any tips on removing it? Are there any hidden bolts?
The manual says remove the heater and radiator, is this really necessary?
i didnt have to remove heater or rad when doing my s type recently, just clears the heater. inlet manifold was the hardest bit to remove. had to get wedges in between when head was off. bit dodgy being alloy but i had a spare just in case.
From my experience it is not really necessary to remove the inlet manifold prior to head removal, Carbs yes, and exhaust manifolds loose and pulled back away from the studs.
If the inlet manifold doesn’t simply pull off, leave it. It adds a bit of weight, but not that much.
You can leave the radiator in, as it’s a nasty job getting it out. It just makes the front nuts under the head a bit more difficult to get at.
I had to cut the bottom hose off with a pruning saw when I did mine.
Ideally you leave the engine on TDC as I described and then it’s up to you. Removing the cams in situ is safer unless you turn the head over and all the tappets and shims fall out.
The intake manifold isn’t so heavy. Wedges was the word I was looking for, and then just get it up evenly.
Just to remind you, number 1 cylinder is at the BULKHEAD end, unsurprisingly, number 6 cylinder is at the radiator end. I’ve seen this mistake a million times!
Going by your avatar name, I have to ask, are you in the south west of UK?
If you are going to buy later XJ cams they might not be drilled for a tach generator on the intake cam. It could be an aluminum plug. If you want to tap that you really need a good way to hold the cam to get the tap to go in straight.
Think about whether you want to do tappet hold down kits. I do them on intake and exhaust, but others don’t believe in them or just do the exhaust side. To me, it’s cheap insurance.
Of course, with the head off, you will have a good look at the water passages and will have to decide if it’s bad enough to need welding. I recently tore down a Mk10 engine that had so much internal corrosion that I scrapped both the head and the block. It was a Florida car, and must never have seen antifreeze. Hopefully, you can get by with yours.
Be sure to inspect the seating surfaces for the oil-feed pipes and the pipes themselves. The banjo fittings often have indentations or irregularities, and it can cause a chronic leak that hard to fix. Be sure you use new crush washers - some are using a new coated style from SNG, but I haven’t tried them yet.
If you want to save your back, you can knock the center out of a couple of old spark plugs and weld on a ring for lifting. A cherry picker saves the old back as well as obviates the dropped part hitting the fender. The important word here is lifting, not forcefully trying to pull the head. It has to be loose. I also will install a head this way if I’m by myself. It allows you to be very controlled.
Work is progressing slowly, without any issues apart from the inlet manifold. Just the cams, head nuts and bolts, cam oil feed pipes, bonnet and rev generator to deal with and it should lift off without a hitch.
I will let you know how it goes.
One last question, is it best to remove the head with the cams in situ or remove them first? The head is going off to be reconditioned and the cams have to come off at some point.
Dave, I prefer to leave them in place, for the simple fact that they will be under tension from the valve springs in a couple places, and those nuts and washers love to pop off the cover portion of the stud when the cam releases. I’d rather it happens on the bench. You do have to be careful about that if you are doing valve clearances in-situ. It’s surprising how much flex there is in these camshafts. Also, as was already pointed out, there will be valves protruding below the head surface, so don’t put it down on a flat table without shims, or you might bend a valve. You must not rotate a cam with the other one in place, as valves will hit. It’s not too complicated - you will get it.
Stuff rags everywhere
Unbolt the first two camshaft bolts
Turn the engine to tdc with the notches in the camshafts at ~90° to the head, loosen chain, unbolt the other two bolts
Leave the timing cover studs at the front in the head
Pull the head with the cams installed and put it on the bench upside down (onto two bits of wood so it is not resting on the valve cover studs)
Bolt a piece of wood to the rear of the head and turn the head over. This way the valves are now securely protected and the camshafts can be removed; I‘ve never had anything flying around, just loosen things evenly and number the tappets so you know what goes where. Egg cartons are good for organizing.
And just don’t turn anything until it’s all back together. This way nothing can go wrong.
So, work is progressing slowly. I have removed the cams. Just about to remove the oil feed pipes and then the head comes off. Sounds simple. I will let you know how it goes.
I am a little confused and hope someone can enlighten me.
I set the engine to tdc, but the cam timing plate did not engage in the notch in the cam. I had to retard the engine a few degrees to get it to engage - see pics.
I am sure I would have noticed if I had fitted them. The car has had some work in the garage since I fitted the plugs. I wonder if the mechanic messed it up.
