Thread: 300 Tdi cylinder head material.

In order to machine through the hard face you would have to machine way more than you should, something in the order of 15 to 20 thou, which would make the head a bin job anyway.

Don''t worry, I'd be more concerned that the head may have been softened by overheating etc .

JC

I have had hundreds of aluminium heads machined with no come backs.

I had my 300tdi head skimmed and then did 100000+ km in it without any further issues.

I do know that some aluminium cylinder blocks that are not lined(sleeved) have a hardened surface in the bores but have never heard of it on heads.

I also understand that some people will try and sell you a new head to eliminate other issues that your old one may have and stop you coming back to haunt them.

New alloy heads are far more readily available now than they have ever been. Use to be genuine replacements only and big bucks.

Dave

Land Rover say not to machine 300tdi and also td5 heads or use a scraper on them due to a coating on the head face. have seen heaps machined and had no trouble. If it needs machining, machine it. its cheaper than a new head.

the heads of all AFAIK land Rover diesels are hard anodised.

Hard Anodising is a term used to describe the production of anodic coatings with film hardness or abrasion as their primary characteristic. They are usually thick by normal anodising standards (greater than 25 microns) and they are produced using special anodising conditions (very low temperature, high current density, special electrolytes). They find application in the engineering industry for components which require a very wear resistant surface such as piston, cylinders and hydraulic gear. They are often left unsealed, but may be impregnated with materials such as waxes or silicone fluids to give particular surface properties.

If you want to know more look here
What is Anodising?
Regards Philip A

We send heads away to be skimmed by a specialist who is very skilled at what he does. We've never had a problem with any of the heads he's done, including TD5.

Originally Posted by Nomad9

Hi Forumites,
Yesterday I had a gent inform me that the Land Rover 300 Tdi aluminium cylinder head had a hard facing on it, he then advised me that skimming the head turned the cylinder head into a paper weight.
Me personally I've never heard of this I've had several 300 Tdi cylinder heads skimmed and valves reseated without a problem. To be honest I didn't know you could hard face aluminium, I don't think you can without overlaying with something else.
I have a feeling that the person who advised me was given the incorrect information by someone else to coax him into buying a new cylinder head. Companies make a business out of reconditioning aluminum cylinder heads I'm sure they would have long gone out of business if this was the case.
Aluminum will work harden, I'm aware of that, it is the hard facing bit that has got me.
Anybody got any constructive comments or know anything different?

Excerpt from factory Land Rover Engine Rebuild Manual for 300TDi (available from this site). Regards Frank.

Cylinder head - inspection

1.

Decarbonise cylinder head.

2.

Examine cylinder head for cracks, pay

particular attention to area between inlet and
exhaust valve seats. Cracks indicate engine
has overheated and cylinder head must be
replaced.

3.

Check core plugs for signs of corrosion and

leakage, replace as necessary.

4.

Check cylinder head for warping using a

straight edge and feeler gauges.
Maximum warping = 0.08 mm

CAUTION: Cylinder head must not be
refaced, if warping exceeds figure given,
head must be replaced.
5.

Check valve seat inserts for burning, pitting or

damage, replace inserts if pitting cannot be

removed by valve lapping-in or refacing.