Cracks between valve seats

[Mandia]

Hi I’ve stripped my engine for a winter rebuild and I’ve noticed during the cleaning of the head that there are cracks between the inlet and outlet valve seats on both cylinders. How serious is this. I am already planning on have new valve seats fitted in the head so that it can run on these new fuels. Any advice on the cracks ?

[Piotross]

Hello,

Cracks between valves are normal in Fiat 126 heads. If they are small, you can plug them and then check the valve tightness if you have the whole head with springs and valves assembled. If the cracks are large enough to allow air to pass through and there is no tightness between the valves, weld the cracks and process them, and then check the tightness of the valves again. It is known to do some work, and sometimes it is better to find the cylinder head in better condition, without cracks