[Healeys] Fw: BJ8 Cooling System

Earl Kagna kags at shaw.ca
Mon May 23 14:25:24 MDT 2011


Steve - of course, you are correct.  Thank goodness another Healey 'guru'
stepped up.  In any case, I believe that the conclusion is pretty much the
same:  it's okay to use an el-cheapo thermostat, but make sure that the
radiator is working well - I long ago modified mine (the BJ8) with a 4 row
core.  If anything, the car overcools slightly - in cool weather, it tends
to run below the 190 (sleeved) 'stat setting.  Maybe things will be
different when I finally fire up the rebuilt engine - soon, soon!

As for Simon's BBQ, I recommend synthetic propane - try RedLine.  Real good
shifting feel, but it's expensive.  (I love starting another 'thing' on this
list).  Don't worry Simon, the heat diffuser will get really black really
quickly.  If I see smoke here in British Columbia, I'll let you know.

Earl Kagna
Victoria, B.C.
BJ8, BT7 tri-carb

-----Original Message----- 
From: Simon Lachlan
Sent: Monday, May 23, 2011 12:18 PM
To: 'BJ8 Healeys' ; healeys at autox.team.net
Subject: Re: [Healeys] BJ8 Cooling System

Hi Steve, Earl, everyone,
Yes, this is very much how I see it, ie I think Steve is right. I think John
put an article of mine on this very topic on his site? Did you John? You're
very welcome & nobody has to read it!
Simon

-----Original Message-----
From: healeys-bounces at autox.team.net [mailto:healeys-bounces at autox.team.net]
On Behalf Of BJ8 Healeys
Sent: 23 May 2011 18:06
To: healeys at autox.team.net
Subject: Re: [Healeys] BJ8 Cooling System

Earl, my understanding is slightly different from yours.  When the coolant
is cold, the sleeve is down and the bypass passage to the head is open.  The
thermostat itself is also closed and the coolant does not enter the
radiator, but circulates back to the head through the bypass.  As the
coolant heats up and the thermostat opens, the sleeve rises and blocks the
bypass to the head.  When the thermostat is fully open and the sleeve is
fully up, the bypass is blocked and all of the coolant now has to go through
the radiator.  In other words, the purpose of the sleeve is not to speed up
the warm-up (which is the function of the thermostat itself), but to block
the bypass when the coolant is up to running temperature.

As alert listers will remember, last summer I reported problems with keeping
my engine cool in spite of all kinds of approaches to cool it down.  I
bought a 190-deg. sleeved thermostat (AC NOS, made in UK) from lister Kees
Oudesluys.  This did have the effect of lowering engine running
temperatures, but not as much as I had hoped.  It was only when I had my
stock radiator re-cored with a modern core with larger capacity that my
problem was solved for good.  My BJ8 now stabilizes at 190-deg. in hot
weather, even when stuck in traffic, which is what I think it should do.


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