Citroen XM Forum

I am assuming these are press fit inserts ?

Should I be worried about just how close it is (the opening) to the edge of the gasket ?

Bear in mind it's also the combustion chamber too as where the injector sprays the fuel. Yes press fit and me personally would sooner have it back central like the others incase it does turn right round and nessitage a head off again

I would think that does need putting right.
Now you've got the GPs and injs out, could you insert something into the opening, and rotate?
Probably not.
Google the issue - can't be the first time.
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Did find this...
https://www.ms-motorservice.com/en/tech ... r-inserts/

Reading that........I got to this

ATTENTION

Never regrind the cylinder head face with the swirl chamber inserts installed. Before regrinding the face, removal of the swirl chamber inserts is essential. Then, when reinstalling the inserts, you must check that the swirl chambers have the necessary projection, and take suitable measures (remachining the swirl chamber seat or grinding the swirl chamber insert) to adjust this if necessary.



Well mine are FLAT with the head.

Stickfinger wrote: Fri May 07, 2021 2:12 pm
Well mine are FLAT with the head.

That's normal.

If you are having the head skimmed have the engine workshop reset the swirl chamber.
Don't spin it round, unless it has been released from the head by contracting it. Normally they are pressed in already aligned.
Using either heat for the head and cooling for the swirl chamber (heat and water or compressed air), or freezing the swirl chamber, should release the interference fit.

An inverted can of air duster/ Co2, played onto the item, will see impressively low temperatures and metal contraction. Iirc, about -60c is achievable fairly quickly against regular ambient conditions.

The swirl chamber does need to face correctly, as that is where the ignited air fuel mixture fires out of.
In a worst case, as it is, the heat could melt the cylinder wall, like poorly squirting direct injection injectors can.

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All cleaned up now.

Valves No1 & 12 were both sticking in their guides but both seated & sealed perfectly.
Both 1 & 12 valves were bent.
Replacement valves from the spare engine run perfectly in the guides but both need grinding in.

Are you gonna use the same head then or swap heads from the. Other engine?

I I will let the machine shop decide which one is best.

I was going to a simple swap but there are two broken/stuck glow-pugs, a couple of very stuck injectors and a broken stud on the spare engines head so at the moment my bet is they will say use the original head.

To remove the stud and the stuck glow-plugs/injectors will cost a little extra on one head but the other needs the valve stems for maybe two valves.
(Both need skimming/swirl pots reset)

If the head pictured is the original one and you intend to use it, the swirl chamber on the right hand end is out of alignment and needs aligning.

Is this the head that had the swirl chamber on the other cylinder mis-aigned also, if so, I suspect they were knocked about when the pistons and valves were "networking".