Dean/Walt,
I'm not sure that the thermostat is to blame here - if it was, then the
water in the engine block would get really hot, and your temperature
guage would go up - but the water in the radiator would stay fairly
cool, so you wouldn't get expansion into the bottle.
I suspect that you're right Dean - the radiator isn't cooling the water
as well as the old one. But radiator caps are cheap enough that it
might be worth getting a new one just to see.
As for the water in the expansion bottle - there's actually no need to
worry about it unless the temperature guages goes over about the 3/4
mark. The radiator cap actually has two valves - one lets water out
when the pressure in the radiator gets too high, and the other, smaller
one, lets water back in from the expansion tank as the temperature of
the coolant goes down and the pressure decreases after the engine's
turned off. (Of course, if the temperature guage is over 3/4, then your
engine is too hot and you have to do something about it.)
Good luck!
Dean Dashwood
--------------------------------
>----------
>From: Walt Fogle[SMTP:foglew@hotmail.com]
>Sent: 07 July 1999 17:48
>To: deanr@saville.co.uk
>Cc: spitfires@autox.team.net
>Subject: Re: Vanishing Water.
>
>
>
>
>
>Dean:
>
>The expansion you describe is normal. The expanded coolant should, however,
>return to the engine block when it cools down. Perhaps your thermostat is
>not functioning properly, or at all. I have installed in my '73 Spitfire a
>180 degree thermostat and the engine runs cool and consistent. I also put
>on a new cap, replacing the 26 year old unit when I had the radiator
>reconditioned. I also found about 2 inches of rusty sludge in the expansion
>bottle when I first bought the car. The expansion bottle tube may be
>clogged and not allow proper return. (There should always be a couple of
>inches of coolant in the bottle)
>
>
>I'd recommend a thorough system flush, new hoses and a cooler thermostat.
>(Most Spits have a 190 degree unit) Make sure that your head gastket is not
>leaking (check for brownish/milky residue on the underside of the oil filler
>cap. A bottle of Stop-Leak in the radiator will probably postpone your
>having to pull the head for a while) Throw away the old cap and put on a
>new one!
>
>Good luck,
>
>Walt Fogle
>'73 Spitfire "Rose"
>
>WA State/USA
>
>
>
>>From: Dean Rayner <deanr@saville.co.uk>
>>Reply-To: Dean Rayner <deanr@saville.co.uk>
>>To: spitfires@autox.team.net
>>Subject: Vanishing Water.
>>Date: Wed, 7 Jul 1999 17:16:24 +0100
>>
>>Hi
>>
>>I have a strange cooling problem.
>>
>>My original Stanpart radiator sprung a leak, so I replaced it with a
>>second hand 'Coventry Radiator Co.' radiator. (after-market patten
>>part)
>>
>>Since then, every time the engine gets hot, ie. worked hard, coolant
>>escapes past the radiator cap and into the expansion bottle. The
>>engine over heats and I have to top it back up with water before
>>continuing.
>>
>>I have checked the cap and it is a 13lb one as it should be.
>>
>>What do you think is happening? Is the cap which worked fine on the
>>Stanpart radiator not sealing properly now??
>>
>>The new (old) radiator does not seem to have as many cooling fins as
>>the Stanpart one. Is it not as efficient and therefore boiling up too
>>easily?
>>
>>Your combined wisdom would be very appreciated.
>>
>>Dean Rayner
>>MKIII Spit '68
>>
>>
>
>
>
|