Head gasket bore diameter to cylinder bore diameter?

[Bigsi15]

Hi all

Firstly apologies this is a bit of a repeat of another post of mine, however slightly different.

Basically I have a 2.3 t5 850 now bored up to 83mm not 81mm due to bore wear. As such the stock 2.3 t5 head gasket is now slightly too small and slightly overhangs the edges of the bore. Is this a problem? My other post asks about using an s60r head gasket but they seem to have different coolant flow holes at one end (850 has about 4 the r just 1) but otherwise seem to match up ok.

So basically must the bores exactly match up to avoid hot spots etc or doesnt it matter? Also as a bump to the other post has anyone successfully used an s60r head gasket on stock 850 head?

Thanks guys!

[Dangerous Dave]

You should be able to use the head gasket from the B5254T which is the 2.5 LPT engine with the 83mm bore.

No idea about the overhang but I don't think it's a good idea as the metal sealing ring is usually narrower on one side of the head gasket meaning less sealing at some part.