<VV> RE: White pushrod tubes

[mhicks130 at cox.net]

I would think there is a significant amount of radiant heat from the very hot cylinder heads that are pretty close to the tubes.  I would agree that the main source of heat to the tubes (especially near the outer o-ring) is conductive heat transfer from the heads.  Unless the tubes only contact the heads THRU the o-rings (no metal-to-metal contact) - if that were true then I think the main source of heat transfer to the tubes might be the radiant heat from the head. (The o-rings would act like insulators).

Finch recommended painting the outer half of the tubes (near the heads) white and not the inner part (near the block)(at least in my old version of his book).  The block (metal) would be relatively cool compared to the cylinder head (metal). The oil temp probably averages out since it's always on the move.

mike


> From: "N. Joseph Potts" <pottsf@msn.com>
> To: "Dave Morris" <BigD@davemorris.com>,
>    "Corvair List"
>   <virtualvairs@skiblack.com>
> Subject: RE: <VV> White pushrod tubes
> Date: Fri, 4 Feb 2005 17:15:31 -0500
> 
> Dave -
>      White reflects RADIANT heat. Pushrod tubes are subject to CONDUCTIVE
> heat (from the heads) and CONVECTIVE heat (from the cooling airstream).
> White will shed all the RADIANT heat they are exposed to, which is zero. And
> yes, black will ABSORB all that radiant heat (still zero). No effect on
> conductive or convective heat.
> 
> Joe Potts
> Miami, Florida USA (plenty of all kinds of heat here)
> 1966 Corsa coupe 140hp 4-speed with A/C