We put a piece of wire around and the secondary pipe seems to be 57mm outer diameter using π

on the right hand side, but only 48mm outer diameter on the left side.🤔

Exhaust exits underseat so you would think central, but it goes to the right then up Perhaps a shorter right pipe needs to be fatter?

My mate points out that it must really be

8-4-2-1 exhaust from the two exhaust valves per cylinder on the Honda. Surely both exhaust valves open at the same time? Just has larger cross section looks oval at the head.

Does a golf 2 gti 8v head fit on a 1.3l block?

23 hours ago, yarne_l said:

Does a golf 2 gti 8v head fit on a 1.3l block?

Looking at the head gasket for Golf MK2 1.8 GTI, no sorry. Very different oil and water jacket holes to the block compared to 1.3.

I think EA827 type for engine code KR or PL in Golf versus EA111 in Polo.