[TR] TR3/TR4 cooling

Bob Danielson 75TR6 at tr6.danielsonfamily.org
Sun Feb 22 09:25:18 MST 2009


Jerry,
A simple solution is to put in a 3-way switch for your fan: on, off and
auto-on. If it looks like I'm going to be stuck in traffic, I'll flip the
fan on and just let it run. I also like having the option of turning the fan
off so that it doesn't come on if I'm working under the hood. 

Bob


Bob Danielson
1975 TR6 CF38503U
Running w/ Throttle Body Injection
Toyota 5 Speed & Nissan LSD
http://tr6.danielsonfamily.org 

-----Original Message-----
From: triumphs-bounces at autox.team.net
[mailto:triumphs-bounces at autox.team.net] On Behalf Of Jerry Van Vlack
Sent: Sunday, February 22, 2009 8:42 AM
To: staffel at comcast.net; triumphs at autox.team.net
Cc: rtriplett25 at yahoo.com
Subject: Re: [TR] TR3/TR4 cooling

Folks,
Lots of interesting information as it relates to cooling and the elimination
of the engine driven fan. All good information too. I'd like to add to that
with some personal experirnces. I eliminated the mechanical fan on my 4A and
saw an improvement in overall vibration that was caused by the mechanical
fan at higher speeds. I liked that.

There is a down side and it hasn't been discussed. Without an engine driven
fan there is considerable under hood heat build up at slow speed in traffic
or of course while stopped at a light or stop and go traffic conjestion. At
slow speed the engine fan keeps air moving uder the hood where an electric
fan does not if it doesn't turn on immediately. That lack of air circulation
resulted in my case to vapor locking. Remember; our carbs sit right above
the exhaust manifold and heat rises. My system uses a temperature sensor
installed in the top tank of the radiator and is set to come on at approx
185. I run a 160 thermostat (original sleeved type which came with my car
when I bought the car in 1969). It turns off at something below 175 as I
recall. So if I find myself in heavy traffic I need to remember to manually
turn the fan on or I'll have bigger problems in a very short time. There is
a thin line between vapor lock or not and once it occurs the only thing that
resolves it is getting the car moving at something over 25mph. to get under
hood air circulation again and cool the fuel.

I added one of Joe Alexander's SS Heat Shields too and that made a
significant improvement towards keeping the carb float bowls cooler.

So if you experience vapor lock in traffic and have an electric fan
conversion you may try remembering to manually turn on your fan and install
a heat shield.

JVV
This list supported in part by the Vintage Triumph Register
http://www.vtr.org


Triumphs at autox.team.net
http://autox.team.net/mailman/listinfo/triumphs

You are subscribed as 75tr6 at tr6.danielsonfamily.org

http://www.team.net/archive


More information about the Triumphs mailing list