EGT gage

[Rat407]

I'm having to go back into my engine, so now is an opertune time to install an EGT gage. Any suggestions as to where to mount the probe and recommendations on gages and suggested places to purchase from?
Thanks

[fatmobile]

It's about time for me to start thinking pyrometer too.
 Here are a couple links and coversations from a search on the old board:
 
http://www.hostboard.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=4037&t=284
 It was mentioned in this thread that the EGT probe was installed in the hole in the bottom of the exhaust manifold. The link didn't work anymore but I remember him drilling and tapping the hole that the turbo "outpipe" support bracket bolts to. It's right in the center of the exhaust manifold and just before the turbine.

 Something fspGTD posted there

The thermocouple pictured above is the larger, slower reacting "SS White" thermocouple. I prefer the smaller and quicker reacting VDO thermocouple. I have used both with the VDO pyrometer gauge. I switched to the VDO thermocouple when I switched the location to pre-turbine - the SS White thermocouple was too long to fit inside the exhaust manifold or turbine housing.

Make sure you make a secure electrical connection from thermocouple to pyrometer wiring. I also recommend wrapping the connections with electrical tape or do something to keep oil from getting on it (which makes the gauge read "0".)

 Another thread:
 http://www.hostboard.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=4037&t=421
 Jake ads:
 

Just noticed that you mentioned you had an Autometer pyrometer setup. I don't have experience with that brand of thermocouple, but I can tell you that the "SS White" thermocouple is larger (in length and diameter of the probe tip) and corresondingly much slower reacting than a VDO thermocouple. I recommend the VDO because of this. The VDO is about 2" in length, the SS White about 3". Good luck and have fun!

[fatmobile]

There's a picture of Jake's pyrometer install on page 4 of his VNT setup.
http://www.vwdiesel.net/phpBB/viewtopic.php?t=1306&postdays=0&postorder=asc&start=45
 Jake, how does it install? Tap the manifold and screw it in or do you tap the manifold and screw in an insert that it slides into?
 What thread does it use?
 I'm about to buy one, any suggestions on where to buy? Part #s?
 Also a link to Jake's suggested star washer fix.
http://www.vwdiesel.net/phpBB/viewtopic.php?t=687&highlight=egt+pyrometer

Another topic that answered my wire length question (before I asked it).
http://www.vwdiesel.net/phpBB/viewtopic.php?t=566&highlight=egt+pyrometer

[fspGTD]

Tap the manifold and screw it in or do you tap the manifold and screw in an insert that it slides into?
 What thread does it use?
 I'm about to buy one, any suggestions on where to buy? Part #s?

You just tap the manifold and screw the thermocouple directly in.  They uses pipe threads, best I can remember, I think 3/8"NPT but possibly 1/4"NPT.  There are also weld bungs available that you can weld on if going to a steel tubular exhaust section and the pyrometer threads into it.

I am partial to VDO, as they are an OEM VW supplier, so they not only have good quality but also a stock "look and feel" to their gauges.  I have so far tried their non-powered (cockpit series) pyrometer as well as their powered and newer (vision series) pyrometer kits.  The vision series is easier to read at night due to newer/better optics (the needle glows for example), but both of them work fine.  The cockpit version is easier to install because there are fewer wires to connect.

The cockpit may be quicker reacting than the vision, but it's hard to say for sure because they are installed on differnent engine setups and one of the engines may actually have temps that climb slower than the other (due to lack of piston squirters.)

I bought my latest one through a local auto electric store that is also has great prices on VDO stuff: http://www.blanchardelectric.com/list.html  The complete kit cost for the VDO setup was around $120.

Hope this helps, good luck with the install!

[fspGTD]

Also, for a 1.6lTD installation, this pic might help give you another idea of where you can put a pre-turbine thermocouple.  This is the latest thermocouple setup of my GTD autocrosser:


Warning - the cast metal of the 1.6lTD Garrett turbine housing has some hard spots that can make the drill bit wander if you aren't careful.

[fatmobile]

I got a VDO, EGT setup and am putting it in one of the bracket mount bolt holes:

 I saw this done over on the old board, can't remember who posted it and the picture isn't there anymore.


...and 1 more:
 

Does it look like it sticks far enough into the exhaust stream?
 I could probably grind off some of the extra threads and get it to go in farther.

[fatmobile]

Got the EGT setup installed and took the Golf for a nice drive.
 Looks like it takes 3 to 5 seconds for the setup to reach actual temps.
 This manifold had a broken stud in the hole I used so I would have had to drill it out anyway.
 Tapping through that much cast iron was a pain.

[fspGTD]

Hey, you re-used the downpipe support bracket!  Nice work.  Did you manage to thread a nut onto the pipe tap threads or use some other threads on the thermocouple?  

Are you using a VDO cockpit series nonpowered gauge or their vision series powered gauge (with additional +12v and ground connections)?

[Rat407]

Will that probe be able to hold up to the little bit of stress that down pipe bracket will put on it?  Might just have to do that to mine.  Nice work!

[fatmobile]

I used a vision series VDO setup so had to run a power wire to the gauge.
 There was already a ground wire to the gauge light so I just jumped to that for the other ground and only had the one ground running from the gauge. ...so there was only the one extra wire to run.
 On the manifold, it's a pretty deep hole so all the pipe threads were used. I didn't put a nut on it, just threaded it all the way in and against the bracket. I had to ream the bracket hole to get a good tight fit.
 The thermocouple slides into the threaded stainless fitting so there is no stress on the probe. I think the stainless fitting can handle the stress. It's fairly thick near the top, where the bracket rides. It's a deep hole so plenty of threads to grab it and hold the bracket in place.
 Seems to be working ok. My first EGT but response seems to be fast compared to what I've read.
 I didn't drill the hole straight in, kind of angled it away from the edge, toward the center of the hole. The 1/4" NPT insert didn't sit square with the bracket but still held it solid.
 If I would have drilled straight through the bracket bolt hole, I might have come out real close to the edge of the hole or on it. No real problem with that I guess. It could have run into the turbo exhaust housing and I would have had to remove a little metal from that to give the clearance needed.
 I can't take credit for this idea, I saw it on the old board a long time ago but liked the way it was centered and remembered it. It doesn't seem to sit too high or too low and rides in the middle of the stream. Easy to get to with the turbo on the car too.
 I also heard cast iron can crack around a hole drilled in it and figured with all the cast around this fitting there probably wouldn't be a problem with the manifold cracking around the hole.

[Maarten]

Installing my EGT probe:




The probe I got cheapo has no screw-in thing, I measured the probe at 1.5mm so I dug into my drillbox for a 1.5mm drill. Drilled the hole ad the probe fits nicely, needs some light persuation to get thru.

Any ideas how to seal off the hole? (gungum?)

The probe itself is about 12cm long, should I leave it this way or push it furter towards the 1st or 2nd cylinder?

With a simple switch I can switch between multiple probes so I'm going to install an extra 2 probes into the compressor exit and just before the intakebend (after the IC).

[fspGTD]

Another pyrometer thread:
http://vwdiesel.net/phpBB/viewtopic.php?p=35816