Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: frostbite on 01 September 2016, 20:29:41

Title: XEV rebuild
Post by: frostbite on 01 September 2016, 20:29:41
I have bitten the bullet and bought a second user head.

As my one has already been drilled and tapped I dont want to know the state of the two front studs.

If I were to rebuild it before getting it fitted, how what would need doing?
Title: Re: XEV rebuild
Post by: biggriffin on 01 September 2016, 21:33:26
For a proper job, get head skimmed, replace all the valve stem oil seals, lap all the valves in, and clean and polish all the inlets and exhaust ports, and you could even run all the threads' o forget clean all followers.
Title: Re: XEV rebuild
Post by: frostbite on 02 September 2016, 12:56:40
Ok if I were to replace the valves, should I just polish the seats?

Do you have any tools in mind to do the port polish?
Title: Re: XEV rebuild
Post by: Nick W on 02 September 2016, 14:45:05
Ok if I were to replace the valves, should I just polish the seats?

Do you have any tools in mind to do the port polish?


Replacing the valves won't be economically viable, as you'll also need to have the valve seats recut.
Replacing the valve stem seals is always a good idea, and they are included in the head gasket set that you'll need to fit the head to the engine.
Cleaning the valves is easy; lightly chuck the end in your drill, and polish them with fine emery paper of some sort. I've a box of 240 grit DA discs that I use for this sort of thing, because I've had them so long they're no longer self-adhesive.
Clean the ports with a good flush of your favourite agressive solvent(cheap cellulose thinners for me) and some manual work with the emery paper.
It's a modern engine, so neither the valves or ports will need much cleaning.
Then you re-lap the valve seats using grinding paste and a sucker on a stick to hold and turn the valve. That won't take much work either.
Run the appropriate tap through all of the manifold bolt holes and bearing caps.
Before reassembly, thoroughly clean out all the crap and most importantly the grinding paste from the head. More solvent and a thorough jetwash is an efficient method.


I would only skim a head if it needs it; some careful checking with a decent straight edge is a good way of deciding to go any further.


You'll need a valve spring compressor with a deep throat. I have one like this  (http://www.rallydesign.co.uk/product_info.php?cPath=&products_id=23032) which is excellent considering the price.
Title: Re: XEV rebuild
Post by: GrahamT on 02 September 2016, 17:27:00
Valve guides on the X20XEV do wear. I had that issue with my calibra. So check them when you are taking the valves out.
Title: Re: XEV rebuild
Post by: biggriffin on 02 September 2016, 18:07:42
Ok if I were to replace the valves, should I just polish the seats?

Do you have any tools in mind to do the port polish?


Replacing the valves won't be economically viable, as you'll also need to have the valve seats recut.
Replacing the valve stem seals is always a good idea, and they are included in the head gasket set that you'll need to fit the head to the engine.
Cleaning the valves is easy; lightly chuck the end in your drill, and polish them with fine emery paper of some sort. I've a box of 240 grit DA discs that I use for this sort of thing, because I've had them so long they're no longer self-adhesive.
Clean the ports with a good flush of your favourite agressive solvent(cheap cellulose thinners for me) and some manual work with the emery paper.
It's a modern engine, so neither the valves or ports will need much cleaning.
Then you re-lap the valve seats using grinding paste and a sucker on a stick to hold and turn the valve. That won't take much work either.
Run the appropriate tap through all of the manifold bolt holes and bearing caps.
Before reassembly, thoroughly clean out all the crap and most importantly the grinding paste from the head. More solvent and a thorough jetwash is an efficient method.


I would only skim a head if it needs it; some careful checking with a decent straight edge is a good way of deciding to go any further.


You'll need a valve spring compressor with a deep throat. I have one like this  (http://www.rallydesign.co.uk/product_info.php?cPath=&products_id=23032) which is excellent considering the price.

A more descriptive version, of what I wrote,  :y