Cylinder head refurb

[JohnMorin]

Hi All

I just had the cylinder head from my S4 converted to run on unleaded - at last!

The work was carried out by Steve at Vulcan Engineering at Brands Hatch and I am very pleased with the result, see pics here:

https://m.facebook.com/story.php?story_ ... 9012534496

Incidentally my cylinder head is now 116 mm/4.56693" thick which I believe is well below the stated minimum thickness, it still pressure tested OK though.

Regards

John

[geni]

Quelques questions pour ne pas mourir idiot !
- ait ce uniquement un spécialiste moteur ?
- qu'elle ait la hauteur en origine d'une culasse ?
- peu ont reconnaitre si elle possède des sièges de soupapes pour du sans plomb (nécessaire)?

[JohnMorin]

Hi Geni

I'll try to answer your questions based on my understanding.

1. Vulcan engineering is an engine specialist specialising in, but not limited to, Lotus, Ford and Jaguar, their website is here:

https://www.vulcan-engineering.co.uk/

2. The original thickness of the head would have been 4.638" / 4.643" or 117.80 mm / 117.93 mm

My head was 4.577" or 116.26 mm.

According to the manual the maximum permissible metal removal for this head would be 0.045" or 1.14 mm. Making the minimum thickness 4.595" or 116.71 mm. You can see from these figures that my head is now below the stated minimum height.

3. I'm not quite sure what you are asking here, it sounds like how can you tell that the valve seats are suitable for unleaded petrol. Visibly you can't but I have the invoice and receipt for the work stating that they are. There is also the guarantee from Vulcan backed by their experience and reputation.

Regards

John

[geni]

un grand merci de vos réponses mais éclairer moi encore un peu
quel modèle ,type en joint de culasse adopter vous alors ?
et sur ma dernière question je voulais savoir :comment peu ont reconnaitre si les sièges de soupapes sont pour utiliser du sans plomb ?

sur quel revendeur de pièces spécifique au moteur Twin Cam me conseillé car j'ai eu des soucis avec un fournisseur qui n'était pas au top (a mes yeux )mais je reste en attente d'un retour a sont professionnalisme
pour rectifier le déconvenu

[JohnMorin]

Hi Geni

I haven't bought a cylinder head gasket yet but I don't envisage using anything other than a standard one. My engine is not particularly highly tuned and I have never had one of these gaskets fail so I see no reason to change.

Regarding the material used for the valve seats Vulcan do not specify what it is but generally it should be some kind of steel allow such as Stellite or austenitic stainless steel alloys such as 21-2N and 21-4N, not cast iron.

The valves themselves are 21-4N.

Regards

John

[bitsobrits]

Not to rain on your parade, but the cylinder head was already suited to run on unleaded due to the factory fitted hardened seats.

You may of course needed other work done, but seat replacement is not needed.

[JohnMorin]

Hi

Regarding suitability for unleaded. When unleaded petrol first appeared in the UK I was working for an automotive technical publishing company. At that time we produced a book listing by manufacturer which engines were suitable for unleaded and whether any adjustment was required. We had to ask all the manufacturers for this information. At that time virtually everything British made at that time and before was not suitable for unleaded. Now it could be that the older engines had never been tested on unleaded so for safety's sake the manufacturers said no. I do know of someone who ran a Morris Marina with an A series engine for about 3 years on unleaded before rust sent it to the scrap yard.

As it happens there were other issues with my head that needed sorting. But now I know for sure that my engine is safe.

Maybe you can tell me what material the old valve seats were made from.

Regards

John