Re: [T3] CAR FIXED and BIG QUESTION

["Jim Adney" <jadney@vwtype3.org>]

On 28 Dec 2000, at 7:11, Martinez, Leon wrote:


> I did read something about head temperature gauges from Berg 

I think the real data may be in his write-up on heads.

>           Berg really knocks the accuracy of these meters, he says
> that these meters are off by as much as 400 degrees. He does not give
> any data on how did he arrive to this conclusion or against what type
> of temperature measuring equipment and what part of head was checked.

There are real thermocouple temp gauges which are certain to be 
within a couple of degrees; they just aren't made for this market.

> Some TYPE 2 sites have some data but they seem too cool for head
> temps... always below 300 degrees and occasional 350 degrees

Yeah, the numbers I see are lower than yours, but as you suggest, 
it ALL depends on where you measure and under what conditions.

> work and money (actually lazy), so I placed the sensor at the hottest
> bolt on the head and applied thermal compound to ensure positive heat
> conduction.

I would expect the bottom side of the head to be hotter, since the 
top gets the coldest cooling air. I don't have any data to back this 
up, though.

> - The sparkplug is probably the best and most temperature balanced
> place
>   to put the sensor. The sensor replaces the plug washer, so every
>   time one would pull the plug, the sensor would have to be dealt
>   with, one may break the sensor wire in the process. Removing tins
>   when repairing broken sensor wire would not be practical. The sensor
>   replacing the plug washer is not
> very
>   practical either because the sealing surface may not be adequate.
>   Since the plug compression washer is no longer there, the plug may
>   drive itself loose during shrinking and expansion of metals.

Yeah, I don't care for the plug washer idea either!



-
Jim Adney
Madison, WI USA

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