Header tank size, and pressure cap rating help

[captainsmelly]

For a chevy v8, need to know how large the header tank wants to be, also what sort of pressure the cap needs to hold.
Engine is NA, bloody massive radiator too.

[stevieturbo]

captainsmelly said:

For a chevy v8, need to know how large the header tank wants to be, also what sort of pressure the cap needs to hold.
Engine is NA, bloody massive radiator too.

I assume you mean a remote header ? 1 litre should be adequate. Just run it at a level where there is some water in it when warm. It is there purely for expansion so does not need to be full.

Cap will largely depend on what temperature you want to run. Hotter will require a stronger cap to prevent the water boiling. Normal 1 bar is fine up to say 90degC, maybe 1.3 bar to 100degC, or 1.5 bar if you might see slightly hotter than this during normal usage.

There arent really any downsides to running a higher rated cap though

[Steve_D]

if you are talking Small block then I am running 13lb cap.
The tank size will depend on engine placement. If mid engine front rad then the suggested 1 litre may be a bit small as the system has more coolant volume to expand.

Steve

[captainsmelly]

Sorry, yes it is a remote tank. Front engine, front rad. Small block indeed.

[stevieturbo]

Steve_D said:

if you are talking Small block then I am running 13lb cap.
The tank size will depend on engine placement. If mid engine front rad then the suggested 1 litre may be a bit small as the system has more coolant volume to expand.

Steve

Possibly, but I'm talking about a 1 litre bottle that is ran empty. Most people will fill theirs with water leaving hardly any room.

But if space permits, there are few negatives about having a large reservoir.