Hi all

I've posted this in the XJ section of the forum, but having more V12 owners here I thought I'd duplicate it.

I'm looking at taking the heads off, apparently the exhaust manifolds can get in the way, should they be removed before or after the heads?

I've also heard the timing chain tensioner can be fragile, someone managed to remove the heads without touching the tensioner. Has anyone ever done it this way? I'll attach the URL.

Building the Legend | V12 Head Removal

Thanks for any responses.

 

The cam sprockets would be almost impossible to get back on with tension on the chain. Releasing tension on the tensioner seems a much better idea. The exhaust manifolds can be taken off in the car, but it is a real job as well. I've not done it, but from what I've heard, raising the engine one side at a time is what gets the heads off with manifolds attached.
As far as the head puller, that is a very impressive tool. I didn't go near that far though. I tried the small plates as shown in Kirby Palms book, but it started bending the tappet block studs. So I then made two more that would grab tappet blocks studs on each end of the engine, and the small one in the middle. Worked like a charm.

 

Many thanks superchargedtr6

I've got a low compression on B1, head to come off.

Thanks for the advice on the head puller, almost certain I'll need it.

 

Out of interest, I'm wondering if anyone knows how the valve seats are held in? Are they replaceable?

Thanks in advance.

 

They are simply pressed in. I have suffered a valve seat problem in two v12s now. Does your engine have the dreaded "ticking" noise on the top end?

 

I wouldn't know, I've got a blown manifold which makes it hard to tell, I've driven her for 1000 km's now, no new sounds.

You mentioned making your own head remover, what material did you use? How thick should I go? I assume you cut and drilled it yourself?

Curious cause my dad says this isn't possible... But I don't see why.

Thanks for the replies.

 

I used 1/2" plate steel. The three pieces are fairly small. The heads are different, so the forward plate has 8? holes in it. I've not had much luck posting pictures, so if you will send me a private message with your email, I can send you pics that way. The toughest part was cutting the steel. After you have the pieces, a drill press and a tap will do the trick. They pulled the heads off of the 6.0 I'm rebuilding with ease. And didn't bend any studs. Another trick I've learned is to purchase the highest grade of anti-corrosion cleaner you can find, and run it in your system for maybe 30 minutes to a hour if the car isn't running hot. The main problem pulling heads off of the Jaguar V12 is the corrosion on the studs that pass through the water pockets in the heads. The corrosion prohibits the head from coming off. I had a 71 V12 E Type that I pulled the heads off with no puller at all by running a industrial grade corrosion remover through the engine. Once I got the manifolds, cams, etc off, I literally inserted a wooden handles into a couple of the exhaust ports and worked the heads up and off.
Send me that email address, and I'll do my best to send you pics asap.

 

Btw, have you done a compression check? Are you absolutely sure the heads need to come off?

 

Super:


It isn't that hard to post pictures on this forum. I've done it a couple
of times. Much easier than on an other Jag forum I post on.


Use the "go Advanced: box to post. Check the icons. One will indicate pics. Click on it and get a "browse' offer. Browse your folders, open and in it goes!!!


Most of us delight in pictures...

Ugh, it didn't work???
Carl

 

Another way?


Carl

 

Jagcad
if you put your pic on Photobucket, you can just copy in a link from that site. Once you have selected you photo there are 4 "share this photo" options, click on the IMG line, the last of the four, and the link is automatically on your clipboard. The just paste where you want it in the text and it comes out like this:


And it's there. You will just see a huge double or triple line of URL type address when you paste the link in, but it will appear as a photo! Magic to me.


Greg

 

PM sent, thank you.

 

Ok guys. I have sent Nathan 6 pictures of these plates I made. I was wrong about the 1/2" steel. They are 3/8" steel. I won't say they are the end all to head removal, but they are compact, strong, and work great.
I looked around for
Use the "go Advanced: box to post. Check the icons. One will indicate pics. Click on it and get a "browse' offer. Browse your folders, open and in it goes!!!
and still don't get it. I feel confident that these could be duplicated by a shop for maybe less than 100.00?

 

Hey guys, this engine has 60+ lbs compression on the low cylinder. My experience is no compression with a dropped seat. I have advised Nathan to do a leak down test before tackling this job. Any thoughts?

 

Sounds like we're in the same boat

 

60 psi is way too low. If its an HE, the compression of each cylinder should be north of 180psi, even on a very high mileage engine, and, in the neighborhood of 220psi on a fresh motor.

 

I'm gonna throw some symptoms out there, here goes;

She has had this problem since the day I got her, hasn't changed or gotten worse.

Left-hand intake manifold is oily on the inside, right-hand intake is dry. Normal?

If I take the oil filler cap off the oil sprays out in a fine mist, but it comes out in pulses... Normal?

Getting about 62 psi on a compression tester.

She doesn't smoke at all.

Has anyone else ever noticed/experienced there symptoms?

 

Oil inside the left intake is normal, because, of the odd PCV system on the V12. I'm surprised that your right intake doesn't have some oil in it as well, since it freely flows from left to right through the balance tube connecting the intakes on my cars.

Are all your cylinders around 62psi, or, just one or two?
Your low compression numbers may be the result of the type compression gauge you're using. The screw-in style is preferred over the push-in style, for both accuracy and convenience. Even with the screw-in style,there can be air leaks around the threads. This can be avoided with bead of grease around the threads at the point where they join the spark plug threads in the head. Pour a tablespoon of motor oil down each cylinder before testing it as well, and you will see your numbers come up, yet, a leak in one or more cylinders would still be obvious, due to the numerical difference from the results of the normal cylinders.

I can't speak with 100% certainty about your oil spray from the oil filler hole, but, it sounds normal, since that is the area where the plumbing for the PCV system in concentrated.

Hopefully, others, who are more knowledgeable than me, will chime in.

 

Screw-in type gauge is what I used, it's brand new, and I made sure is didn't leak, only the one cylinder is sitting at 62 psi, the rest will eclipse 150 psi easily.

The strange thing about the pulsing I get from the oil filler is that it sits at the same frequency as the cylinder that is missing, don't know if they're in sync, I just know they're on the same "wavelength" so I'm thinking blow-by? Stuck compression ring? Maybe I don't have to mess with the dreaded chain tensioner after all...

 

sounds like you do have a stuck ring, maybe scored liner bore also!

time to pull the engine, and overhaul it!