Stock exhaust manifold, EGT prob.

[Guest ON3GO]

Im getting all my ducks in arow and im trying to figure out my EGT gauge install.

I havent bought the EGT probe yet, was gonna ask what i should get if anybody had any ideas. I have the 2 5/8 Autometer Phantom Pyrometer .

Also i want to put it before the turbo, but where on a stock manifold!?!?!

would i have to drill the manifold and put the NPT fitting that comes with most of the probe kits in the hole i drill?

 

if anybody has done this, do you have pictures?

 

thanks!

 

mike

[Cody 82 ZXT]

Sorry I don't have any pictures but, what I did was to drill the hole in the back side of the manifold in the collector area. This area seems to have plenty od meat so work with and doesn't get inthe way of installing the manifold onto the engine.

 

Your right you just drill the hole and tap it to the correct size.

[Clifton]

Just before the turbo or in the turbo, just after the inlet flange is the best. I would just run a wideband though.

[Nigel]

I put mine in the manifold just before the turbo flange. I had a bung that came with the probe welded to the manifold. But if just taping the manifold works ok, then obviously that's easier.

 

As for which probe to get, the cheaper the probe, the slower the response time. I went with the mid priced autometer probe (the "Competition" version). Wideband is definitely the way to go, but it helps to have a backup reference.

 

Nigel

'73 240ZT

[Guest ON3GO]

ya i have the LM1, and im trying to get that to work, but ive had a EGT gauge forever now, never installed it.

so i wanted to have it working if i put it in.

 

ill drill the hole tomorrow.

 

thanks guys

 

mike

[hughdogz]

I finally got around to installing mine. I had to take the manifold off because of a leaky gasket so this was the perfect chance for the EGT probe install.

 

Like others mentioned, the bungs that came with the Autometer EGT probe are a joke. They loosely fit the 3/16" probe and used a set screw lol. This would leak worse than the gasket I was replacing!!

 

Thanks to this post, I found that they make a compression fitting. I found one, but the list price of the compression bung was $78...I found for $38. There has to be a cheaper piece other than welding in the bung.

 

It is reccomended to install 1-2 inches from the head, so the best place I could come up with is in the cylinder 6 runner. I never tapped an NPT thread before, to tap the hole you need a "Q" drill bit (I suppose that is a tapered bit?) or 21/64" drill and a reamer.

 

It really wasn't that difficult once you figure out how to do it. I hope this might help out others wondering how to do the install.

[BRAAP]

Hugh,

Are you planning to install an EGT for each cylinder and just use a rotary type switch to select which one to monitor and when?

[Tony D]

That looks to be a "Swagelock Thermocouple Connector"...which the lovely people at Swagelock charge a premium for, of course.

 

If you look at their dimensioned drawings, or even their catalogue you can see that the Thermocouple Probe Fitting is EXACTLY the same dimensionally as their Stainless Steel 3/16" (or whatever thermocouple probe size you use: 1/4", 3/8" etc...) TUBE fitting, except the hole goes straight through at tubing diameter, whereas the tubing fittings have a small 'step' and only the I.D. of the tubing is bored straight through. What I did was buy tubing fittings (Oranve Valve and Fitting, now Orange Fluid Systems I believe, in Anaheim---don't ask me why!) and then from the backside, with the nut and furreles removed, simply bored out the fittings from the backside with the appropriately sized drill! They don't always have the TC Fittings in stock, but Swagelock Dealers ALWAYS have tubing fittings you can modify. Just a thought if you want to save the difference in price between Tube Fittings and Thermocouple Fittings. If you really want to cheap out, you can buy Parker A-Lock, or Inperial Eastman Gyro-Lock which are patent infringements...excuse me, 'nearly the same thing' as the Swagelock fittings.

 

Me, I buy Swagelock---if it's good enough for the Space Shuttle, It's good enough fer Da Zed! LOL

 

Forgot to mention, I cut my hole and tapped it pre-turbine in the SPACER I made for the T3 hybrid so the compressor housing would clear the exhaust manifold. My manifold is still untouched, the spacer has two holes one for backpressure readings and one for the thermocouple.

[Warren]

I put mine right in front of the turbo, easy to install, plumb and works flawlessly.

 

 

As long as the turbo isn't on the manifold, you CAN install it with the manifold on the engine. Just stuff a clean rag into the manifold, behind where you want to drill. When you remove the rag, it takes any drilling shraff with it. This works only if you have a LONG drill bit, since the intake will be in the way. It's best to do it with the manifold off of the engine though.

 

 

Hope it helps,

 

Warren

[hughdogz]

Hugh,

Are you planning to install an EGT for each cylinder and just use a rotary type switch to select which one to monitor and when?

Hi Paul, you ask some good questions. Right now the plan is to just keep the one without a switch. I like the way others installed them in the collector, but you might get temps that may be hundreds of degrees below actual. That is why I chose the runner. However, the collector would give a better average temp than just one cylinder. I wonder which would location gets a more accurate reading:

 

1) In a single runner, where it is closest to the combustion chamber, yet you only get 1/6th the exhaust pulses to read. You'd think that this would give more time for the probe to cool down between pulses.

 

2) In the collector, where you get cooler gasses since it is further from the combustion, but there is less sensor cooldown time between pulses.

 

I KNEW there was a reason why I posted here to get feedback before I drilled into the cermaic manifold I got from Ron. Be honest, do you think I made a poor choice in the location? Multiple EGT's and a rotary switch would be nice, but with the price of EGT's (and FITTINGS) I'd probably be better off with multiple WBO2 sensors.

 

Warren-I appreciate the pics. Thank you. That is a REALLY clean install. I might have to plug the hole in runner 6 and go your route.

 

Tony D, thanks for listing those other fitting choices. I had no idea they were available. If for some crazy reason I need to do multiple EGTs, I'll definately source those "knockoffs". If I only knew 1/1000 of the stuff you know, I might be twice as knowledgeable as I am now and I'd probably be four times as "dangerous"...lol

 

[Edit] Okay, now that I re-read this, you can still go with the swagelock...and the compression "sleeve" still fits too?

[Tony D]

Industrial Reciprocating Engines used for powerplants and usually fitted with a full array of diagnostic equipment (Kenicocks---you can trace cylinder pressures for BMEP Calculations during running!) have EGT probes in the following places (and in many cases these are dual thermocouples---two elements for one probe so if one fails you can switch to the secondary unit without shutdown).

 

Each Cylinder Exhaust Port, downstream of the exhaust valve, byone valve diameter.

 

Pre Turbine.

 

Post Turbine.

 

Each of these placements tells you different things, in the case of the individual cylinders, you can see delta T which is an indication of power balance between cylinders, and significantly exposes fuel mismanagement.

 

Pre Turbine -vs- Post Turbine reveals problems in the turbo itself, as well as possible problems in the exhaust manifold (such as a water jacket leak).

 

For anyone that is interested, I got JeffP hooked on the 6 cylinder EGT Analyzer for small aircraft sold through Aircraft Spruce. It is a full datalogging EGT box, with many different inputs, designed to monitor Small (er...471CID) aircraft engines in flight. It alarms on first up to temperature, highest temp, delta alarms, pre and post turbine temps... just a cool engine analyzer, and small enough for the dashboard.

 

If youwant to spend $1200 on such a gizmo! The kicker was for the small Cessnas, they offer it in 12VDC...

 

Onblard Datalogging for up to two hours, etc... Really cool piece, and a graphic display of all eight monitored temperatures...

 

I'm going off the deep end now, but that is where people stick EGTs, and kind of why. Each has a different usage.

 

IMO:

 

If you are only going to do ONE probe, I'd put it in the collector pre-turbine. In a cylinder port, without another to compare it to, the reading you get is totally useless on an enginewide analysis basis. Now if you add a second ... say in cylinders 2 & 4 for an SU poered car, you might be able to draw conclusions. But on a multi=port injected car, if you do one...you may as well do the other five or just stick to turbine inlet.

[proxlamus©]

i watched a video about those individual EGT monitors in my aircraft performance class! i wondered why cars didnt have those!

[Tony D]

 

Meh, the price went up since then, now it's like $1800! More specifics here:

 

http://www.aircraftspruce.com/catalog/inpages/ei-engineanalyzer3.php

 

I am truly the devil...

[510six]

My setup has 3 type K thermocouples on a stock 280zxt manifold, it uses one in the exhaust stream of #1 cyl and #6 cyl to determine if #1 cyl is running lean when the methanol injection is on.The AEM is able to dattalog both in real time and they are within 15* of one another at full boost.The wideband only has the ability to sample the mixture downstream from all the cyls.It`s a really nice tuning aid to have. The third themocouple goes to the Autometer gauge.I found some really nice 1/8 npt Themocouples that work well and take up a fraction of the space of an Autometer or a stock AEM unit.

 

http://redlinegauges.com/product_info.php?cPath=22&products_id=20&dfwtekid=6770aac693360d3ad4c671819929c982

 

http://www.dynojet.com/automotive_dyno/option_ThermocoupleAMP.html

 

http://webstore.o2simulator.com/index.asp?PageAction=VIEWPROD&ProdID=2

 

The 02 simulator unit works well and the price was right to integrate a 0-5v signal to my AEM Dattalogger.

[dapiper]

The N42 EGR return port works nice for average reading. I see 1250F at full blat.