I don't follow your reasoning on this. The engine is not supposed to be kept
'very cool', it's designed to operate in a certain temperature range and
running cool can ultimately result in damage just as well as running hot,
albeit over a longer period of time.
The original materials used for these pipes are indifferent conductors at
best. I don't believe the system was designed to be dependant in any way on
heat transfer from the pipes themselves for cooling. I don't have the means
to measure it at the moment (some on the list do), but given the various
factors involved (initial temperature from the engine/thermostat, flow rate
and ambient temperature just to name a few) I'd bet the heat loss in that
section on the stock system is generally negligible- and I'd further bet
that heat retention with rubber hoses is essentially negligible as well. I
think your cooling system would have to be otherwise seriously compromised
for the difference to ...well, make a difference. The Vanagon is in fact the
only vehicle I've personally seen that used anything but rubber hoses.
In fact I wonder that having metal pipes wouldn't contribute to operating
issues during the winter in some climates due to the very radiant properties
you describe.

Cya,
Robert

----- Original Message -----
From: "Ron Mueller" <wasserbox@MSN.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Tuesday, June 27, 2006 9:51 PM
Subject: Re: Coolant pipes replacement

> The problem withn using the marine grade rubber reinforced hose is that
> the
> rubber is an excellent insulator of engine coolant heat.
> The stainless pipes radiate the coolant heat just as large 20 ft; radiator
> would and aids immensely in keeping the engine very cool.
>
> Strike the rubber hose from the record.
> It is not an appropriate conductor of heat.
>
> Ron
>
>
> ----- Original Message -----
> From: "mark drillock" <drillock@EARTHLINK.NET>
> To: <vanagon@GERRY.VANAGON.COM>
> Sent: Monday, June 26, 2006 9:00 AM
> Subject: Re: Coolant pipes replacement
>
>> I have replaced them entirely with Marine Exhaust Hose. Get the wire
>> reinforced, smooth outside type, 1 1/4" inside diameter. Will not kink
>> with the gradual bends needed to follow the path of the original pipes.
>> You will need to enlarge the hole in the crossmember where the pipes
>> pass through, just like the Bentley says to do when replacing the metal
>> pipes with the later plastic ones. This 1 1/4" hose easily connects to
>> the existing radiator and engine hoses for models 1982 - 85 that came
>> with metal cooling pipes.
>>
>> Here is a link to the hose I am using.
>>
>> http://cgi.ebay.com/ebaymotors/Marine-Hardwall-Exhaust-Water-Hose-1-1-4-ID_W0QQitemZ4550097209
>>
>> Mark
>>
>> JP wrote:
>>
>> > Hi all,
>> >
>> > I need to replace  my coolant pipes on my 84 westy's (not the flexible
>> > one)
>> > Those are the rigid ones that goes from the front to the rear of the
>> > camper.
>> > Any other replacement alternative beside the stainless steel pipes
>> > sold by
>> > mr prospect? Cant they be replaced by flexible pipes? If so, what is
>> > the
>> > inside pipe diameter and where to get those.
>> >
>> > TIA
>> >
>> > --
>> > JP
>> > 84 westy
>> >
>> >
>>