Gasket ports vs. housing and head ports
 

https://cimg0.ibsrv.net/gimg/www.jag...0b127acab3.jpg
Left side of engine with cylinder head just taken off. And yes that is a bolt, that I had to saw off to remove the head. But look at the gasket....
https://cimg1.ibsrv.net/gimg/www.jag...c5c934d8df.jpg
Look at the gasket ports compare to the piston housing ports..... WTF. wrong gasket????? I checked online to see if this was a mistake. Nope all vendors have the same gasket for sale.... hummmmm
https://cimg3.ibsrv.net/gimg/www.jag...e66d39dfd6.jpg
those ports that were blocked by gasket from housing to head and vice versa, all had coolant in them...... I thought coolant was suppose to run through these ports to keep the engine cool??? so why sell a gasket that blocks these important ports???
https://cimg6.ibsrv.net/gimg/www.jag...79b4ab8bf8.jpg
this is the cylinder head from the left side of the engine. notice the clogged gunk. that gunk is radiator stop leak and/or gasket sealant, that people put in their cars to stop leakage. And trust me there was gunk in the radiator hoses also.......geeez! Also notice the valve seat rings hanging out, yup, poor car.

It looks like the holes that were in the gasket were also plugged up by the stopleak? Unless those spots are just residue from the holes in the head?

edit, looking online it does look like new ones also block those ports. No idea what's going on with that..

I dint know if that's stop-leak or the dreaded Dexcool ""sludge". My sons firebird was full of it and never had any stop leak put in it. Dexcool and air don't mix.

https://cimg6.ibsrv.net/gimg/www.jag...f22e7881e6.jpg
in the beginning of removing parts, I found this in the thermostat housing very bad goo.
https://cimg1.ibsrv.net/gimg/www.jag...ecc8867d84.jpg
i tried to clean some of it out but that stubborn gunk chunk did not want to leave.
https://cimg5.ibsrv.net/gimg/www.jag...bdbabbb94d.jpg
I used a flat head screw driver to see if I can easily remove that stuff.

was the gasket suppose to block those ports that are around the cylinder block?? Its crazy to see this beautiful car like this, especially one so pricey. I bought this car for 800. lol. now I know why it was so cheap. lol. listen learned in all directions, one is that I am learning more more about vehicles.

I put money on that the previous owner mixed green coolant with the orange that is used on these cars. This mixture made a sludge that caused the car to overheat and lead to the dropped valve seats. I bet the radiator is also clogged with the entire cooling system. The headgasket is made correctly. I believe those ports that are covered are from the casting.

The cylinder head gaskets were designed that way. The AJV8 employs precision cooling- and extensive CFD calculations were used to make sure that the flow velocities were exactly right in each area of the engine. Much more so than other contemporary engines. This is why the engine warms up so quickly. In addition, we tried an engine with water jackets designed the 'Ford way' and this thing had a much worse knock limit.


The head gaskets were designed the way they are to intentionally restrict the flow in those targeted areas. I cant speak specifically why, but it was all arrived at via simulation and extensive validation testing with thermo couples.


I would say, this is the case for BMW engines also- where a lot of detail engineering gets done. It probably isn't so much for US engines, like the much vaunted Chevy LS engines that yanks like to put into everything and probably explains why my Escalade has piston slap and excessive oil consumption.

Understanding the engineering behind the development of these engines
is 95% of the learning curve ;o)
Jaguar engineers spent a lot time in R&D with their biggest target was meeting
US emissions rulings and that required the fastest warm up time which switched out
the 'upstream' heated O2 sensors as early as possible.
For 1996-7, these were a very technically advanced engine and it's later 'cousins' still are ;o)

There is no evidence that Jaguar or BMW spent any more
development effort on their engines than GM.

Piston slap on the LS is not a seemingly endemic problem,
whereas the tensioners selected for the AJ26/AJ27 are a
well know problem and the cooling system on BMW's are
regarded as maintenance replacements.

Doesn't matter how much detail work went on if the engine
then blows up in service because the the engineers thought
they should save $1 and 20 grams per unit by going with
weak assed tensioners. And then try to fix it multiple
times with at best mixed results.

Some thought by Jaguar engineers on water pumps would
have been good too.

+1 plums

Plums, why are you continually whining about the water pump and 2ndary chain tensioners even on threads not about them?
You were whining about this 5 years ago on the differential thread also.


Piston slap isn't a problem on the earlier LS engines? I wonder why GM in Pontiac spend 100,000s series production changes then? If you were there as consultant you could have advised them otherwise and saved them a lot of money. What's the difference between GM and Jaguar apart from the volumes? Nearly everything GM makes is vaunted and praised and held up by fan boys.


The R and D investment costs of Jaguar, BMW and GM into their engines isn't widely publicised but it is well known within the industry.


Just like the thread about switching to a 15 HU differential- if you don't KNOW- then don't act like you do and post with such authority. Given, it IS a bit of a talent. Some of us talk from a point of knowledge and experience where as others are acidic armchair CRITICS, complaining about spelling, punctuation etc. That's ok, I guess you get your kicks that way and it some how validates you. We also get entertainment from it too. So everything's cool :icon_jammin:

yes, there was alot of gunk in the radiator. And some of the ports of the cylinder heads were clogged. A lot of work.......

Thanks for letting me know. I actually thought this was the wrong gasket, and was going crazy looking for the right one. I figure since it is never that cold here in S. Cally, it will need those ports open to continue from block to cylinder head... great info

I'm not whining ... I am bursting bubbles.

Your puffery about your imagined great achievements while
lambasting the Austrian consultants, and the choice of the
X308 differential stick in the craw. Not to mention anointing
yourself with the title of "Count".

The examples of the tensioners, secondary and primary, as
well as the many iterations of water pumps is simply an
illustration that the engine team did not do as well as
you would have us believe.

At least differential failures are relatively rare despite
your loud lambasting in public, by name, of the persons
you hold responsible for that choice.

In fact, there is nothing inherently wrong with the X308
differential despite the fact that you managed to shred
one.

I would be quite content with it, except that it has no
LSD and is a little tall.

Most X308 go to their graves with their original
differentials intact. I imagine that does not hold true
for the tensioners or for that matter, head gaskets
of a 2000 or older 4.0L.

LMAO


I missed this gem!


Burst my bubble? You hold yourself in high regard, but I already knew that.


I never said the secondary chains weren't a problem. The question to be asked is- does everyone know about this? And is there a fix.


Yes to both, therefore you're whining and nit picking.


I'm sorry that my title/handle and posts annoy you, but this is your own insecurities, and not my issue.


I go on aerospace and aircraft forums, and there are people that work for Boeing there and Cessna. I'm always interested to read their posts and ask questions and consider it a great privilege. I would have to be an arrogant/very insecure/petty person indeed to continually whine and poke and criticise them, questioning and acting like I know better. Incredible ego indeed.


Combine that with talking bollox..or should I say, "Plumbs"- based on conjecture and the picture is complete.:icon_headbang:


I do however think the clown of your avatar suits your persona very well. Good choice sir!:icon_clapclap:

BobRoy <> The coolant did come out green, and I believe they did put some 'stopleak' or whatever also. They told me it was just the fuel pump that needed to be changed. puh, that was obvious BS. other than that I am not going to give up on this 2000 XJ8 feline like some family and friend had tried to advised me to do. Nope, unless the transmission is total crap (knock-on-wood). Thank you for your imput on this.

Did you get that bolt drilled out and new MLS head gaskets on there?

Addicted2boost <> I lift that bolt there on purpose. That bolt I had to saw off to get the cylinder head out. I can take the bolt out and that piece still stuck there with a magnet, but I was too distracted with the ports of the engine block and cylinder head. I have not got nothing for the engine yet. I notice the whole engine is filthy. My objective is to rebuild the engine. The hardest thing soo far is getting the engine out without taking out the transmission out with it. I am still taking photos of every thing I do and every tool I use to remove anything off the car.