Supaloy head cooling

[christenlin]

Can anyone help? I'm building an engine and my query is regarding cooling and in particular the coolant passage from block to head that exists between the two central exhaust ports.

I came across an article in the PWA7 club technical pages by J Hopwood, which emphasises the need to keep this waterway clear due to it's location at a very hot spot between the two ports. I was, therefore, surprised when I examined the Supaloy head which I intend to use, to find that no coolant passage exists at that location, so the passage in the block would become a cul-de-sac! I might have been tempted to drill one, but I examined another alloy head, this time a speedex, to find that it did not have one either. See pic attached.

Does anyone know why these 'sports' heads are like this?


   

[Alan]

You have to remember the heat conduction of aluminium is considerably higher than cast iron. Anyways I used a Supaloy head for many years with no problems. I don’t recall drilling out that water passage so it’s probably ok as it is.

[christenlin]

Thanks Alan, I've had a closer look and there is no gallery there so drilling wouldn't be an option anyway.

[dickie65]

If the center exhaust stud is too far into the block it will close off the water passage in the block.