From: Bjorn Brandstedt (super_deuce@hotmail.com)
Date: Thu Sep 26 2002 - 04:58:49 PDT
Joe,
The pyrometer consists of two parts, the dial indicator and the sensor
(K-type thermocouple). The thermocouple generates a small voltage in direct
proportion to the temperature. This voltage is indicated on the dial,which
is graduated in degrees F. The range will be about 200 at idle up to a
maximum of 1200 degrees F or so. Never let the exhaust manifold temperature
exceed 1250 deg F! The only need for the 12 or 24 volts here is for
illumination.
The best way to install the thermocouple is to drill and tap the exhaust
manifold at a point near the turbo inlet. You really need to remove the
turbo first so that metal shavings will not fall into the turbine, which may
destroy it.
The thermocouple tip must be of highest quality. A bad thermocouple may get
its tip burned off and destroy your turbo.
There may be a way to install the thermocouple on the outside of the
manifold, but the reading will have to be corrected by several hundred
degrees and the response time fill not be good.
If you do not want the dial permanently installed, you may use a Digital
Voltmeter with an adapter for thermocouples and read the temperature on the
DVM.
You may spend $30-$40 for the thermocouple and $100 for the DVM plus some
for the adapter.
The Boost gauge is nothing but a pressure gauge with its "sensing tube"
plumbed into the intake manifold housing. There is a plugged tapped hole in
it, so that should be easy to fit with some copper tubing and a fitting.
You should be able to make initial readings here using any gauge with a
range of about 0 to 15 psi. Again the voltage would be for illumination
only.
The boost comes from burning more fuel. If you have too much fuel for the
air supply then there will be lots of black smoke (= unburned fuel).
When the turbo (LDT) version replaced the naturally aspirated (LD) version,
not much fuel was added. The additional air (boost) just made the combustion
more complete. The governor was adjusted to supply less fuel during sudden
changes in demand to reduce black smoke during acceleration, which also
reduced the torque some, probably. This was done with the "smoke limiting
cam", which was set at a different angle on the LDT version.
I'm getting carried away here...
Good luck,
Bjorn
>From: "GOTAM35" <gotam35@sc.rr.com>
>To: <mil-veh@mil-veh.org> (Military Vehicles Mailing List)
>Subject: [MV] 24 volt pyrometer?
>Date: Wed, 25 Sep 2002 23:54:14 -0400
>
>I want to thank all you guys for the advise about the diesel. One more
>question. I went to "Truck Supply" today and checked on a pyrometer and
>boost gauge. Everything they have is 12 volt. Do any of you have a 24
>volt
>gauge? If not how did you make the 12 volt gauge work? I can use my new
>transformer but I didn't plan to keep it powered up all the time.
>
>Also what kind of boost pressure will this thing run? The gauges come in
>two ranges, something like 0 to 25, or 5 to 50 somethings.
>
>The pyrometer will run me a little over $100. Can one be found cheaper?
>
>Thanks again for all the help,
>Joe Trapp.
>
>
>===Mil-Veh is a member-supported mailing list===
>To unsubscribe, send e-mail to: <mil-veh-off@mil-veh.org>
>To switch to the DIGEST mode, send e-mail to <mil-veh-digest@mil-veh.org>
>To reach a human, contact <ack@mil-veh.org>
_________________________________________________________________
Chat with friends online, try MSN Messenger: http://messenger.msn.com
This archive was generated by hypermail 2.1.4 : Wed Apr 23 2003 - 13:21:25 PDT