[Spridgets] Ignorance is bliss

rrengineer @dslextreme.com rrengineer at dslextreme.com
Mon Apr 13 21:31:51 MDT 2009


David,
     I DID think it through several years ago.  It is NOT a radiator bypass
hose, it is a thermostat bypass hose as I stated in my last post.  Granted,
Bob and I live in Southern California.  We barely have need of a heater most
of the year, but my Bugeye comes up to temperature very quickly and once
hot, I certainly don't need another source of hot water being pumped back
into the engine.  I don't think that it is needed, even in cooler weather.
All you need do is cover the radiator with some cardboard.  Of course, you
can set up your car any way you wish if it works for you.
Mike

On Mon, Apr 13, 2009 at 8:16 PM, David Riker <davriker at nwi.net> wrote:

> Think it though.  It is really a "radiator bypass hose".  When the
> thermostat is closed, the water pump is still spinning, and still wants to
> pump.  Water comes out of the top of the head and usually goes to the
> radiator, cools down, then is pulled by the waterpump from the lower hose
> and pumped back into the engine.  So until the thermostat opens, the water
> pump just pulls the water down from the head, and circulates it back through
> the block in a smaller circle.  This allows the engine to warm up more
> quickly, and more uniformly without hot spots and cold spots.   Also, for
> those of us who still run a heater, that bypass hose means warm water begins
> flowing to the heater core almost immediately, instead of needing all the
> water in the radiator to be heated first, which in a cool or cold day could
> be...NEVER....  Yes, on a hot day, that is water that in theory is getting
> recirculated without ever seeing the radiator, but is is a very small amount
> compared to what passes through the much larger radiator hoses.  So, in a
> racing motor, block it off,  in Death Valley, block it off, for a street
> driven car in cooler weather, leave it be.
> David R.
>
>
> ----- Original Message ----- From: "rrengineer @dslextreme.com" <
> rrengineer at dslextreme.com>
> To: "Hal Faulkner" <frog.aye at gmail.com>
> Cc: "Spridgets" <Spridgets at autox.team.net>
> Sent: Monday, April 13, 2009 7:05 PM
> Subject: Re: [Spridgets] Ignorance is bliss
>
>
>
>  Vizard's book addresses the bypass hose on page 501 under "Thermostats".
>> The bypass hose is actually called the "thermostat bypass hose".  It
>> connects the water jacket adjacent to the thermostat to the water pump. It
>> was fitted to A series engines up to the early 80s.  Vizard calls the
>> bypass
>> hose a nuisance and the hole in the pump and the hole in the head should
>> be
>> plugged.  He says then drill two 1/4 inch holes in the thermostat to
>> prevent
>> overheating in the event the thermostat gets stuck closed.
>>
>> On Mon, Apr 13, 2009 at 6:43 PM, Hal Faulkner <frog.aye at gmail.com> wrote:
>>
>>  I believe the bypass is there in order to cause the thermostat to open a
>>> little sooner than it might otherwise.
>>> Hal


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