Resurface every time it's removed from the engine, unless it is still within the factory tolerance for the mating surface, forget the units but its so many x per mm.Has it been warpped ?
If it does not need a skim then it's not recomended due to the head losing it's heat properties and in turn making the head softer.Resurface every time it's removed from the engine, unless it is still within the factory tolerance for the mating surface, forget the units but its so many x per mm.
Most people take a ruler and say its level, but then most have failures straight after
Not got much of a clue of the desing tbh hob...I'm just saying what i have read when i looked into it... Can't find where i read about the heat properties but i should imagine it's on the same lines as the head becoming porus as mentioned belowWhat heat properties? Is it a special head or just cast ally?
Just bear this in mind when the common and uneducated comments come thick and fast that because your head gasket has gone you must have the head skimmed. NOT TRUE. Fact - if you have the head off the car for any reason then use a straight edge and measure for any face distortion and if present measure it and see if it is inside or outside tolerance and act appropriately.
The heads from the factory are given a "special coating" because they are so poorly made once they have been machined. He said, the sharper the milling tool to skim, the worse the surfcae was, this caused the head to push the material along (not visable to the eye) causing it to be porus. In other words, the heads are of poor casting quality.
from what i have been told, the bottom 0.2 mm of the head of the K is sort of pressure treated to make it stronger than the rest of the head, skim past that, and the head is pretty much jelly.
You have to remember the engine was originally designed as an 1100 cc unit for the Rover Metro. At the time it didn't make economic sense to fit a multi shim gasket since these were prohibitively expensive to fit to a 'shopping trolley'.
In many respects the K uses Formula 1 techniques to get its great power:weight ratio (best in its class); to do this a very lightweight alloy was used (the whole engine is only 85Kg, cf my all alloy 1000cc Climax engine at 65 Ks!) and to ensure the alloy is strong enough it is case hardened using a quenching technique. The upshot of this is that the case hardening is only 20 thousands of an inch thick on the head face - skim the head and you can rapidly go through this, overheat the head and you destroy the hardening.
I always though the Caterham and the Elise/Exige were pretty light cars?Wow didn't know or expect the K-series to have a case hardened head, does anyone know what the k-series was designed for? As they seemed to have a highly complicated engine for a budget car and on the weight side of things, the cars they put them in are not exactly light, especially the ZR.