>     When I start my engine from cold the heater boxes are still cold (well 
>     barely hot anyway) after 5 minutes. 

Don't forget they've got cold air blowing through them. The merged headers 
on my buggy get hot enough to burn after about 15 seconds of starting the 
engine. Ask me how I know (oww, ah, ouch!). And after a fast run the J tubes 
glow red!

Andy E.

A.C.Erskine@lut.ac.uk