I figure that 20 pounds is a good saftey pressure. You can't get hurt with
lots of block pressure. The thing to measure is the presure when the engine
is under load and revving in the higher ranges . The high water pump revs
is what causes the caviatation and loss of pressure. Do this while driving
or on the dyno ( I did all this on the engine dyno) as the revs go up around
the 5 grand mark the pressure just starts to slide and goes down quickly
nearing zero at about 65 to 7 g's.. I've seen the normal block pressure go
to zero from cavitation at around 5000 revs in several engines. Most cases
the pumps were made to cool at normal STREET rpm which is under 3500 in most
cases ( my view) but at racing revs they are WAY too high fast. Probably
about 3 water pump to 5 crank will get the thing right. I don't remember the
exact ratios and a lot is dependant on the pulleys you can find. I remember
using a 3" on the water pump and the smallest I could find on the crank
which was in the 1" plus range. (These were Gilmer belt pulleys) These were
of course in the "olden days" so probably a lot more is available now.
AND if you the drive with a Gilmer belt you also pick up a nice piece of
power @ high revs.
From: <Gt6steve@aol.com>
To: <FOT@autox.team.net>
Sent: Monday, July 22, 2002 9:06 AM
Subject: Triumph water pumps
> Greetings Amici,
> I spent the weekend playing around with the water pump on the GT6, trying
> different combinations of things in an effort to improve cooling. I put a
> pressure gauge on the block and ran it into the dash with 1/8" copper line
> thinking to monitor pressures. I was surprised to find Zero pressure at
idle
> (with the rad cap off) and only saw 5-7 PSI when revved. Putting on the
cap
> the pressures came up to about 15 but that was with the temp coming up and
> not a result of the pump. A very trustworthy source on this list told me
I
> should see 20-25 PSI at the drain plug for best results. (Right Kas?)
> So the question, has anyone played around with their pumps, have any idea
of
> the flow rates? Does anybody measure pressures? I swear I measured 20
PSI
> at that fitting years back because I had to adjust the restrictor in the
> T-stat housing to get it up there.
> I'm a bit stumped...
> Steve Smith
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