What thread are Pyro Meters??

[Surfin Alec]

I have just bought a 3" exhaust for my 80 off e-bay and want to install it in the next week or two. I want to put a pyro in it soon after I get some more spending money.
So in the mean time I will drill a hole and get a nut welded on so I can put a pyro on soon but the question is, what thread are they mostly??

Where did you get your pyro and how much also if possible thanks?

Alec

[bogged]

http://www.thermoguard.com.au/

[me3@neuralfibre.com]

http://neuralfibre.com/paul/?p=489

[dogbreath_48]

I've got a VDO from Ringwood speedo shop (or similar - VIC). $318 with loom/probe etc.

It comes with a weld in lug/nut thingy (can't think of what it's meant to be called ) to suit the probe. Unsure of thread sorry.

[nastytroll]

its called a socket, others may have a different name for it though

[jeep97tj]

mine was 1/8 npt

I brought mine from mickyd213 over on www.patrol4x4.com
Its digital and has alarm outputs on it, got the gauge, thermal couple and postage for $200. He is importing them from the US.

Very happy

[philhod]

I got mine from this place http://www.atlanticspeed.com/default.asp

Was delivered to my door in 6 days and all up cost me $221.00. This was for a Autometer Pyrometer with probe and a Autometer Boost only gauge in the Ultra-Lite series.

The EGT gauge is in Fahrenheit though. But all you have to remember is don't let it go above 1000 Degrees.

I bought the pod a fair while ago it is the AUTRON one from the 4x4Store.com I think.

The thread for the Pyrometer was a NPT, and pretty sure it was 1/8". The weld on socket comes in the kit.

Here are some pics.

[nastytroll]

steel 1/8 npt or bspt sockets can be bought from any hydrolic companies.

[Surfin Alec]

Thanks for the tips.

[KiwiBacon]

Throw away the NPT compression fitting, it's a very uncommon thread in this part of the world.
Get a stainless steel BSPT (aka G thread) compression fitting. 1/8" will fit a 3mm probe, 1/4" will fit a 6mm probe. The 3mm probes react much quicker and are my preferred solution.

I went with 1/4" BSPP (aka Rc) tapped holes which I thread BSPT (aka G) thread fittings.
The BSPP threads are parrallel and easier to cut, but the tapered BSPT fittings still seal up properly.

Do not use brass fittings, they soften and loosen at exhaust temps.

[80's_delirious]

my VDO pyro used 1/4 BSPT thread

If you can find a weld in socket, go that way. BSPT tap will be hard to find and cost about $40 bucks. An expensive way to thread one hole and they are a bugger to use too.

[KiwiBacon]

my VDO pyro used 1/4 BSPT thread

If you can find a weld in socket, go that way. BSPT tap will be hard to find and cost about $40 bucks. An expensive way to thread one hole and they are a bugger to use too.

BSPT fittings thread fine into BSPP holes.
Weld on sockets are fine for steel, but difficult for cast-iron.

[Tim HJ61]

I've bought a VDO pyro for my 12H-T Landcruiser hj61. It has a weld on socket in the kit.

Can I silver solder/Bronze this onto the manifold, which I assume is cast iron?

I want to instal it pre turbo to get more accurate EGT measurements.
What tips for drilling the manifold, keeping filings out of turbo etc etc.?


Ta
Tim

[v6hilux]

What tips for drilling the manifold, keeping filings out of turbo etc etc.?

Grease lumped on the drill bit at low speed catches the filings. Also get a second person with a vacuum cleaner to suck!

Is it too hard to remove the turbo? That would be the easiest option.

[sierrajim]

So where do the diesel guru's recommend the mounting of a pryometer? before or after the turbo?

[KiwiBacon]

So where do the diesel guru's recommend the mounting of a pryometer? before or after the turbo?

Before.
After the turbo is a waste of time.

[me3@neuralfibre.com]

I have no idea why you guys stress over filings going through the exhaust turbine. Do you really think they'll bother it?

It's not like feeding ball bearings into it at full boost, it's idling some particles through that are smaller than carbon chunks off the manifold. Cast makes very fine particles.

Paul

[thehanko]

the dyno place put a 1/8 bsp in mine.

[sierrajim]

I have no idea why you guys stress over filings going through the exhaust turbine. Do you really think they'll bother it?

It's not like feeding ball bearings into it at full boost, it's idling some particles through that are smaller than carbon chunks off the manifold. Cast makes very fine particles.

Paul

For the sake of the very little time it takes to do properly, i'll be removing my manifold. Most likely clogged with crud by now anyway.

[Zeyphly]

sorry to go a little off topic but why is it bad to put your pyro after the turbo. I know of a well used system that goes in after the turbo.

[thehanko]

A pyro pre turbo tells you very accurately what temperatures are being endured by your important bits.

Post turbo you are making a guesstimate of what the temps might be pre turbo.

I dissagree that post turbo is a waste of time as it still tells you if your approaching dangerous temperatures, but its not a accurate.

As a rule the guess is about 200 deg drop pre to post. but it could be 150 or 250. hence less accurate but still useful.

You can probably push your vehicle closer to its limits without damage if the pyro is pre turbo.

but then again when i got mine dyno tuined they put in a sensor post turbo for the testing.

[KiwiBacon]

As a rule the guess is about 200 deg drop pre to post. but it could be 150 or 250. hence less accurate but still useful.

Just to show you how much of a guess that 200 deg is, here're some calcs to predict the temp change across the turbine in a few different operating conditions. The range in temp drop is roughly 290 deg C to 100 deg C.
If you put on a big fudge factor then you lose a lot of performance, if you put on a small fudge factor then you risk cooking your engine.

For example, my engine under full load uphill.
20psi boost, 20psi backpressure.
Pre turbo EGT's of 750 deg C.
Calculated post turbo temp is 565 deg C.
That's a temp drop of 185 deg C. For this situation 200C isn't far wrong, but if your turbo is less efficient than mine, then it's even hotter upstream.

My engine under hard acceleration.
20psi boost, 40psi backpressure.
Preturbo EGT's of 700 deg C.
Calculated post turbo EGT's of 411 deg C.
That's a temp drop of 289 deg C. If I guessed 200C and ran at a downstream temp of 550 deg C, then I'd still have a cooked engine and turbo.

My engine at 100km/h cruise.
9psi boost, 13psi backpressure
Preturbo EGT's of 450 deg C.
Calculated post turbo EGT's of 353 deg C.

Putting it pre-turbo avoids all the guess work.