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914World.com _ 914World Garage _ SOT: radiant heat from header

Posted by: 3liter914-6 Mar 15 2006, 06:44 PM

It's not for my 914, but for my Volvo, but some of the V8 guys proably run into the same issue.

On my V8 install, I'm using a remote thermostat housing, in which coolant flows into the housing and then flows via a pair of 3/4" hoses to the top of the intake and circulates through the engine. I got the housing mounted in what I think is the best position today, and have started plumbing the lines to the intake. The problem is, as I'm planning on mounting them right now, one of the lines is going to hang about 3" above the left header. I'm wondering if this is going to be a problem for the hose, and if I'm going to be picking up too much radiant heat and run into cooling issues.

Is there a rule of thumb for how far away from headers things like fuel lines and coolant lines things should be? I'm planning on at least using some reflective wrap for the lines, and probably send the headers out to Swain for similar for a thermal barrier coating.

Thanks!

Posted by: Tobra Mar 15 2006, 07:38 PM

Do you not want to install a heat shield for some reason?

Posted by: 3liter914-6 Mar 15 2006, 10:37 PM

QUOTE (Tobra @ Mar 15 2006, 08:38 PM)
Do you not want to install a heat shield for some reason?

No, I'm fine with all the shielding it needs. I just wasn't sure if at 3-4" the shielding would be effective enough. That's what I mean by the reflective wrap--some kind of heat shielding for the coolant lines.

Posted by: davep Mar 16 2006, 06:30 AM

Radiant energy falls off as the square of the distance, so 1/4 the energy at 2" as opposed to 1". However, in enclosed spaces that is not true anymore. Reflective wrap is good at reducing heat absorption rates.

Posted by: 3liter914-6 Mar 16 2006, 06:41 AM

QUOTE (davep @ Mar 16 2006, 07:30 AM)
Radiant energy falls off as the square of the distance, so 1/4 the energy at 2" as opposed to 1". However, in enclosed spaces that is not true anymore. Reflective wrap is good at reducing heat absorption rates.

Interesting, that's a bigger drop than I would have expected. I'll guess that things'll be ok then, with a 3" air gap, thermal barrier on the headers (claimed 50% radiant heat reduction, and some wrap. At least as long as I keep some air moving through the compartment. It would probably take a good amount of direct heat to have very much affect 3/4" hose pumping gallons of coolant.

Thanks for the info.