I’m rebuilding my gto engine atm and I bought a engine gasket kit from autodoc, a brand called FAI.
Many of the gaskets didn’t fit, the oil pump, cams, valve stem seals. However the headgasket did and I just popped it on not much thought behind it tbh. Now I’ve ordered a new gasket set and the headgasket is metal! The one from the other set wasn’t. It was hard but rubbery too? It had orange bits on it too. I’ve just finished the timing belt install and thermostat and now I’m wondering if I need to go back and change the headgasket now
I’m very confused, I’ve looked into it and I think the one I put in is composite. My car is twin turbo so I’m a little worried about the headgasket holding up. Any insight would be fantastic!
Different people have different thoughts on this so my opinion is just my opinion from my experience.
The reason that the gasket set doesn’t fit is because lots of companies that lack knowledge of these cars are buying gasket sets from China where they only have the SOHC engine fitted. Only the head gaskets and a couple of odd bits fit the DOHC engines. The same problem exists with fuel pumps, ignition leads, ignition coils etc.
If your head gaskets are the same grey/silvery material as the original gaskets, they should be fine.
In my personal experience, the stainless steel gaskets are a bad choice. The steel reacts with the alloy heads around the waterways over time and it causes the heads to break down. The heads are rarely repairable after the damage has occurred because it is too far gone by the time you notice.
As I said. This is my personal experience with many damaged heads and metal gaskets but please get feedback from others and make up your own mind. Don’t forget that someone fitting the gaskets does not mean they are a good idea, you need to hear from others that have removed the heads after 10k miles and seen the results.
In a nutshell, imho, a composite gasket is better at sealing between imperfect/unmachined surfaces, especially when used with a coating of wellseal - but wont survive very long if overheated or the combustion temps and pressures of a very hard driven car or beyond mildly modified. An MLS gasket is superior in every regard but ONLY when both mating surfaces are machined perfectly flat without imperfections.
A composite gasket HG set will be fine for a car used sensibly.
The aluminium head with a cast iron block will encourage corrosion. I agree that a stainless steel gasket is a bad choice as this will set up a strong galvanic cell encouraging corrosion. A non metallic gasket will insulate the two different metals, if the inner ring of the gasket is aluminium I would say is a good choice.
A significant influence on corrosion is the type of coolant addition, this should be suitable for iron and aluminium, most are but worth reading the small print.
The level of concentration of the addition to the coolant fluid is also important if its lower than recommended then protection from corrosion will not be as good, always keep the coolant level topped up with the (antifreeze) addition and not just top it up with water, this will dilute the optimum concentration you started with .
