RE: [T3] re head temp

["Martinez, Leon" <martinezl@ftscpac.navy.mil>]

Herman,

good luck on your home made exhaust system. You want
the temps I am experincing from my readings. These temps
only reflect the hottest head bolt (degrees f) and
not the actual exhaust temps so your readings may 
vary when you design your exhaust system. If you 
need to check higher temps you can buy a pyrometer.
this can check temps to 2000 degrees. Found it on 
the internet, I think also VDO.

I gave all my head temps in details in message thread
"CAR FIXED and BIG QUESTION" MSG# 26879 DEC 27 2000
but I can give you these again, (MODIFIED CUT AND PASTE):


I have dirven this car a total of one week at temps around 
70 to 75 degrees outside temps (nice weather here). 
My head temp gage sensor is
made of bimetal which has a thermal-electric characteristic 
(current flow caused by heat  to move the meter movement).
My sensor is installed on front top bolt nearest exhaust outlet
on the number three cylinder . Generator or battery voltage
has no effect on this meter.
Using my temperature meter I was enlightened of our engine's 
heat dissipating character. I found that the amount of temperature
is proportional to the position of the gas pedal. The head temperature 
changes drastically in tens of seconds rather than minutes; expansion
changes are continueous.

Temperature findings :

- Idle , cold weather (55 degrees f) temp gage read steady after 3 minutes
  at 325 degees.

- Idle , moderate weather (75 degrees f) temp gage read steady after
  2 minutes at 325 degree.

- With engine thermostat, engine warms to 325 in 3 minutes and stays
  there. Outside temp 50 degrees. Very quick warmup!

At 75 degress outside temp minimum two minutes readings taken from drive 
from Tijuana to city of El Cajon:


- Flat road, 50 mi/hr 350 degrees

- Flat road, 65 mi/hr 360 degrees

- Flat road, 75 mi/hr 370 degrees

- Flat road, 85 mi/hr 390 degrees

- Moderate Hilly road, 50 mi/hr 350 degrees

- Moderate hilly road, 65 mi/hr 375 degrees

- Moderatehilly road, 75 mi/hr 410 degrees

- Continuous climb, moderate  grade 55 mi/hr 370 degrees

- Continuous climb, moderate grade 65 mi/hr 410 degrees

- Continuous climb, moderate grade 70-75 mi/hr 450 degrees

- Continuous climb, moderate grade 80 mi/hr 475 degrees.


Found that heavy stop and go traffic, temps stays between 
325 and 350 degrees.  Downhill is 325 degrees. Continuous
heavy city driving, take offs, passing, blowing doors the temp
stays around 325 and 360.

To summarize:

The faster I go the hotter it gets, the steeper the hill  also the 
hotter it gets. I guess the term "slow down" also applies to us
and not only to upright engines.


Also found, that leaving the heater on in moderate to warm 
weather, increases engine head temperature, ( I am guilty of
prefering sauna temperatures inside car) because air leaks 
into car cabin.

 

>-----Original Message-----
>From: Herman Haustein [mailto:haustein@netvision.net.il]
>Sent: Monday, January 01, 2001 11:09 AM
>To: Martinez, Leon; type3@vwtype3.org
>Subject: Re: [T3] re head temp


>Leon ,
>With all this talk about head temps, you never mentioned how much do you
see
>(degrees F) ?
>The reason I ask is I'm on the verge of a "do it myself" exhaust manifold
>job. And temp's are important.
>Let us know how high you go.
>Herman

 LEON MARTINEZ
 martinezl@ftscpac.navy.mil

 1969 SQUAREBACK EFI/AUTO
 SAN DIEGO AND TIJUANA

-------------------------------------------------------------------
List info at http://www.vwtype3.org/list or mailto:help@vwtype3.org