Date: Tue, 12 Sep 2000 10:23:39 -0400
Reply-To: Bulley <gmbulley@BULLEY-HEWLETT.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Bulley <gmbulley@BULLEY-HEWLETT.COM>
Subject: Re: Head temperature
Francoix,
Believe it or not, I've never had a head temperature gauge (and had 10+
air-cooled VW's).
Gauges are great, because information, in the right hands, is power.
Information in the wrong hands produces needless worry. I've never known
what to do with the head temp info, so I don't seek it. Head temperature
varies greatly under normal conditions. A long climb with a full load in
the wrong gear could send temps high enough to cause damage, while a long
"coast" down the same hill could cause head temps to drop to nearly ambient
temperature in a few minutes time.
The trick to using an air-cooled VW motor is to keep the fan (and oil pump)
spinning quickly. In a 2.0 liter 1976 bus, I have climbed 7,000-11,000'
peaks in NM & CO with 6 people and heaps of camping gear when the outside
temp was in the 90's. For many folks, that would mean a sucked valve, or
worse. The trick?
When the van slows in fourth gear (around 51 mph) I put it in 3rd, and give
it about 11/12th throttle. If you open the throttle fully, you close the
EGR valve (there is a "Wide-Open Throttle" cut-out feature to the valve).
The exhaust gas is vital to keeping the combustion temperatures low, so you
don't want the EGR closed during a hard climb, or you'll increase your risk
of sucking a valve.
If, because of the incline/your load your van slows in 3rd, pull it down to
2nd, give it 11/12th throttle, and relax. Even if you are only going 34
mph, if you have the motor spinning freely at 3900-4400 rpm, the tremendous
volume of air passing through the heads and the oil cooler will completely
eliminate the risk of overheating. Take your time. I've never climbed a
hill in a VW when I wasn't able to maintain 28+ mph in second. Be patient.
Your motor is happy spinning freely, and sad when you 'lug' it.
If you have any doubts about your EGR system, I wrote an EGR overhaul guide
for another chap a while back. It applies to the 1976-1983 2.0 type 2
motor, and possibly some other VW's
It is a bit boring...no pictures, few jokes. Here:
http://www.bulley-hewlett.com/EGRFIX.html.
Stay cool. Let me know if I can be of service.
Check out my wife's new business. http://www.Bulley-Hewlett.com/pen&ink/
G. Matthew Bulley, Principal Consultant
Bulley-Hewlett Corporate Communications
Mount Olive, NC USA
877.658.1278 Tollfree
http://www.bulley-hewlett.com
-----Original Message-----
From: francoix gagnon [SMTP:fxgagnon@hotmail.com]
Sent: Tuesday, September 12, 2000 9:03 AM
To: gmbulley@BULLEY-HEWLETT.COM
Subject: Head temperature
Hello Bulley,
I have always read with attention your good advices on vanagon.com. I sent
a
request on it concerning the head temperature but I have not satisfied with
the answer. I am concern about the head temperature of my air cooled. I
have
installed a VDO guage on the third piston but I don't know how hot it can
go
before domage occur. I usely drive it in sunny day 70F at 55-60 MPH and the
temp stay aroud 400-425 but on hill it goes up to 450. Is it normal and/or
could it get hier without problem?
I read on Type2.com some folks let the temp reach 500F. I am scared
thinking
of this heat!
What is your opinion on this topic?
Thanks
Francoix
West 81
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