Greg: the HE does not have an interface valve trajectory indeed, unless you throw an object inside it I guess... so the worry is whether the object has interfaced something, or do I see it wrong?

 

Agreed, if there is something large enough inside the combustion chamber, it could bend a valve. All I meant to mention was that if an HE valve was being jammed open and (as I should have made clear) the jamming thing was not poking very far through the opening, the fact the valve stayed open would not cause the valve stem to bend as the piston would not be in contact with the held-open valve.

As I have now just seen the photo the OP posted subsequently, that thing was definitely inside the cylinder and had been rattling about in it while the engine ran! And FWIW, it looks like it was introduced by someone. I still reckon, as long as both of the valves rise and fall with the cam when the engine is turned by hand, all will be well.
It remains a very useful cautionary tale for us all though, whenever we have the inlet manifolds off!

 

Alex

Perhaps it’s my poor English that I do not follow exactly: but where did you take that object precisely from?

I understand it was in the cylinder? Or was it in the valve gear cavity on the head? The term « rod », do you mean the valve stem?

it might be only gut feeling but I would be concerned about the many walls and profiles that thing can scratch irrespective of where it was found.

You may need a very very thin endoscope to inspect.

best

 

Yes I mean the valve stem although I think push Rod is another term for them. It was holding the valve stem open but I assume at some point it was actually sitting in top of the piston to be a squashed and mangled as it is in the photo.

Yes it could have done so e damage to the walls if it's been in there a while. Im going to see if I can borrow my mates proper endoscope as the one he lent me is a cheaper one and it's quite difficult to focus on it.

 

Alex
FYI, the V12 is an overhead cam engine, as you know, and usually such engines have the cam lobes acting directly on the valve stems, as yours does.
Many engines, particularly older designs, have cams situated in the block (indeed to this day most american V8s have cams situated in the block in the V). In order to actuate the overhead valves, a cam in block engine has a pushrod that is actuated by the cam lobes and runs upwards to the valve train where, using a rocker (ie a short arm with a central fulcrum) it actuates the valves. This pushrod is the rod people refer to, but they are not there in overhead cam engines.
In these snaps of my Ferguson tractor Standard diesel engine being rebuilt, you can see the valve rockers and the pushrods coming up through the head to actuate the rockers.

 

Greg, that looks like the head of a V8 six-and-three-quarters Bentley 😂😂😂

 

Greg,

Its like looking at a shrunk version of my TR6 engine (which it is!)

Paul

 

Paul
And it is identical to the 4 cylinder engines in the earlier TRs! This Standard 23c engine block was so robust as a petrol 4 cylinder block, that when they dieselised it, no beefing up was required! In fact, your TR6 engine is an expanded version of this one!

 

Andrew
How did you extract the foreign body, though the inlet tract in the head or through the plughole?

 

Well I done a compression test and about 5psi on that cylinder. The rest are up to about 200 so it's done for then!! I put it back together to see how will run and it's awful. I thought I might be able to run on 11 for the time being but runs bad and then cuts out. Which I thought was the original fault after cleaning injectors. But my mechanic reckons having no pressure at all on that cylinder is what's causing all the problems.

So looks like new engine or see how much it costs to get heads off if I remove the engine myself

​​​Expensive lesson!! 🙄

 

Also I see Greg has posted in the past about removing engine instructions. But can't find answer to question. Is it easier to remove engine with front sub frame out of the way?I have dropped it before so I know its fidly but not difficult. I don't want to take transmission out as well. Would taking subframe out help with angle as reading that exhaust manifolds etc have difficulty clearing it and you have to jack car up etc.

 

The engine will only come out upwards; providing you have an engine crane, the subframe has to be removed with the car on axle stands. The engine/transmission comes out as a unit. You may find the exhaust downpipe flange fouls the V mounts on the chassis rails, if so, remove the downpipes from the manifold, or unbolt the v mounts. These are what you need to do it, plus a pic of it happening! The tilt is important!
https://ige.ie/2-ton-folding-shop-crane-engine-hoist/
https://www.ebay.co.uk/p/1234649988

Getting a head off can be a sod of a job, and the timing chain has to be untensioned, and lots of other things can go wrong, so if it gets stuck on, or turns into a problem, a second hand engine is still an option, once you have the old one out.
Also once out you can do loads of important renewals in no time at all. Once out, though, you will be astonished that it ever got in there!
Good luck

 

Wow blimey just looking at those photos you wonder how it got in there. Thanks for the info wil have a look through the link.
Yea a couple of guys on here reccomended Surrey Jag. I spoke to them the other day and he sends the engines of to a guy who apparently worked for jag when they were first built. So will see how much they think it would be to strip. There is an engine near me for £550 but it's sat for 20 years after he took the car off the road. It dies turn and never siezed. Itan 85 mines 87 but less miles 76k.

 

Alex
I have been having brain fade, for which age is the cause. In fact the subframe does have to be out, and I have amended my original post. My car was on axle stands when i removed the engine. I took the weight on the crane, then removed the S/F, then removed the engine/gearbox.
A 20 year old engine that turns will be fine as long as the compression checks out. My parts car had been in a garage for 20 years, untouched, started right up! Don't get me wrong, a rebuilt engine is great, but the cost will be at least 15 times that of a second hand one, and no better in all liklihoood.

 

​​​​​​
Ha ha no worries, I did notice on the photo the sub frame was off. I need to speak to the guy as he has it on a hoist at the moment. So if I do get it hoping I could borrow it off him. He decided to strip the car down during lockdown so hasnt long taken the engine out so might be able to get some tips from him as well.

 

Greg,

It's not an engine-out just to get the heads off is it?

Alex,

As your car has very low miles for the year, wouldn't it perhaps be cost-effective just to get that head off, sort the valve, skim the head if absolutely necessary (probably not as it didn't overheat) and get it put back on. I know of another couple of of Jaguar Indies that would do the job if you want to talk to them?

Cheers

Paul

 

Paul,

YES. Some claim to get them off in situ, and I dont doubt it, with a SHIIIT load of juggling and engine jacking etc, WHY?, 6 hours its out on the deck.
Engine and trans as a unit, subframe stays in the car, and it simply lifts and angles and comes out. Markets with downpipe cats, NO, they will need to be removed, The rest of us, a small wiggle and a few odd words, and it slides out.

ALSO

You need to get at the 2 Tappet Block Banjo Bolts, and that is not possible in the car.

 

Paul
I am with Grant on this. Now, you do have to have the kit, obviously; but it took me 4 hours to get the engine out, start to finish. Once out you will see all sorts of things that need doing, from frayed starter leads, to poor alternator looms, to oil dripping out everywhere, to engine loom leads, that once the engine is out and they are accessible and inspectable in the chassis, will give you nightmares.
Not to mention a touch of welding required on the inner wings, decayed heat shields, etc etc etc. A few weekends' hard work and all sorts of things are back to spec.
And, as Grant says, if it is the A bank head, let alone if it is jammed and needs a puller...
If the independent guys you know can do it at a decent price, obviously an option. But my experience with these cars is "no manure like the farmer's footsteps!"

 

That engine you found, GO FOR IT.

Yours WILL have piston damage, FACT.
Head damage also fact.

Coz I am down here, I suggest buying a boat on the way home, as you will soon have the "perfect anchor".

OR


Wife will be ecstatic me thinks.

 

Ha ha ha now that's a coffee table!! 😁👌