You were right Marek.
I look down with the endoscope.The chain was correct down to the crank, and tensioner to. I didn’t want to touch the tensioner so loosen the bolts of the A camshaft carefully then release the valves and every valve was ok. Doing the same thing on the B camshaft I took the photo and you can see the exhaust valve of the third cylinder is not backward. So seized or valve seat fallen and broken in parts.Why seized, because removing things for cleaning I removed the AAV and see a lot of deposit looking like dry coolant clogging the air valve. Same as what was in the manifold especially towards the 3rd cylinder as mentionned at the beginning of this topic.
I will try to have a look from the exhaust side of this valve to determine : seized or valve seat.I know now I have to remove this head.I am afraid of releasing the tensioner, but have no other option for removing B head. I’ll try to build a precise tool ( seen in kirby’s book) to minimize the force applied for removing the chain from B sprocket.
As it was not possible to turn the camshafts to access the bolts i decide to remove them with the sprocket on. Thanks to my rustic but efficient special tooling I release smoothly the tensioner until it was possible to remove the chain from Bank B camshaft sprocket.After that easy to remove bank A camshaft with sprocket on to.
First I will look carefully at the tensioner insuring ther is no crack.
Next step removing the B head !!!
Thanks to Kirby for his very good book and to all for your advices that help me.
Be carefull with this horrible AAV which is not able to give consistent idle over a long period and is able to drive coolant in the cylinder!!!Grrrr!!
I bought some nylon bushings at my local hardware store, got the closest I could find ID (but a little smaller) and OD (but a little larger, then used the correct sized drill and drilled the inside to the right size, followed by sliding bushing drill bit and gently letting fine grinding wheel take the OD to the correct size (my ‘make do’ lathe). The OD was just enough oversize to be a force fit into the support hole, so it is not going anywhere (has been there for years now), and the throttle linkage fits perfectly in the ID hole and rotates without resistance.
if Yves needs the throttle bushings, I’ve got a pair of Jaguar parts, and also some of the Amazon listed brass bushing
with the average millage I’ve done since I fitted them, I’ll probably never need to replace them
thanks i will find a solution.
Today tapett bloc B removed, and surprisingly no seal betwween tapet block and head!!
Edit - In Yves comment I assume “seal” = “gasket…”
Correct. A particular sealant is used there, maybe Hylomar if memory serves? Much detail in Kirby’s book.
As french my english is probably not so good so I apologize for some mistakes I can do.
But in that case I confirm there was nothing between head and tapet block either gasket or seal.
it was dry aluminium.
And there were no leaks?
My picture is not good but leaking of course and a lot of dust sticking on that oil.
Yves your English far surpasses my French. After I read you post again I figured that you meant that the tappet block was put on “dry.” Very interesting - and as you noted, guaranteed to leak!
Bob
After some hours fighting with the exhaust manifold the head is ready to be pulled out. A lot of coolant residus in the 3rd cylinder exhaust as in the intake.Probably a new big fight for removing the head.
Do you have access to a head puller? It’s really difficult to do it without one.
No I don’t have the magic tool. After a carefull examination half of the stud under the big bolts in the lower row look blocked with coolant. The rest looks free from above but I don’t know how it is inside.
Is there anybody in France renting the magic tool??
Based on this, looks like it would be easy enough to make one if one was not available. The hole sizes, spacing, etc, would be determined by measuring the head.
Should be.
not sure someone here would rent such tool, may be though a local club ?
(I didn’t need it, but have heard a few French owners made their own tool to lift the V12 heads
so I will probably build it my self
Kirby’s book has all the info and dimensions on how to build the tool.
Also pretty sure there is lot’s of info on the archives.
Bonne chance!
2 simple tools built today with 8mm threaded, doesn’t work. i will modify with 10mm
This may be of use.