Pipe Tap bit for EGT Gauge

[2bclutch]

I've got a 1.25mm - 10mm High Carbon Steel Plug Tap bit to make the threads on my exhaust manifold for my TRE EGT Probe. Will that size work? They say 1/8" - 27 NPT not sure if that translates to the same, although the package the Tap is in says Use with 11/32" drill bit which is the drill bit that TRE calls for. Any info?

 

[lasertim]

10x1.25 threads are not the same as 1/8-27NPT threads at all. Pipe threads are tapered and the 10x1.25 tap you have is not and the thread pitch would be different.. You need the proper tap to make this work.

 

[oldman]

Yes, you definitely need the 1/8npt tap, 11/32" drill bit will do, .3390" to be exact.

http://www.korit.com/tapndrill.htm

 

[2bclutch]

Okay well I have the 11/32" Drill bit so I would basically need this then?

http://www.atoolcrib.com/catalog/product_info.php?products_id=2576&language=1


Good thing I asked.

 

[oldman]

You got it.

 

[GTM]

10x1.25 threads are not the same as 1/8-27NPT threads at all. Pipe threads are tapered and the 10x1.25 tap you have is not and the thread pitch would be different.. You need the proper tap to make this work.

Please note that metric pipe tap is not the same as SAE pipe tap.

Also note that Japenese metric is not always the same as European metric. The thread profile looks like this <-> for European; and a rounded/flaired [-] for Japenese. The Japenese argument is the pointed profile is more likelly to tear and gall threads hence the more rounded profile.

Cheers,
GTM

 

[2bclutch]

Thanks for the much needed clarification. Should I just start drilling or should I make some sort of a starter punch to keep the bit from walking?

 

[GTM]

Thanks for the much needed clarification. Should I just start drilling or should I make some sort of a starter punch to keep the bit from walking?

It's always best to have a center punch and then start small and work your way up. Wouldn't hurt to have a pipe plug in case you don't like what you have done you can relocate. Use good quality drill bits ... that doesn't mean the titanium nonsense.

Cheers,
GTM

 

[PeteGSX95]

Deppends if your usuing a drill press which i would suggest to do (alot easier) then you dont need to punch it first but if your going to drill it by hand it will be easier with a punch

 

[GTM]

Deppends if your usuing a drill press which i would suggest to do (alot easier) then you dont need to punch it first but if your going to drill it by hand it will be easier with a punch

Mobetta he punch it... little difficult starting on a radius don't ya think?

GTM

 

[oldman]

Get youself one small cobolt starter bit to get things started without using a center punch which isn't the best for exhaust manifold that can crack. If you must use a center punch, take it easy.

 

[PeteGSX95]

When i drilled mine i never used a punch i just clamped it down in the drill press and took slow.

 

[2bclutch]

When i drilled mine i never used a punch i just clamped it down in the drill press and took slow.

My deal is I'm not taking it off the engine. Car running at Idle, Grease on the bit to have the shavings stick to and do it that way, apparently many people have done it that way. I will do the smaller bit to start idea that seems like the best way to go. I was actually thinking that would be better.

 

[oldman]

I will do the smaller bit to start idea that seems like the best way to go. I was actually thinking that would be better.

Not just a smaller bit, it's call "starter bit", it has different tips than regular drill bits.

 

[2bclutch]

Not just a smaller bit, it's call "starter bit", it has different tips than regular drill bits.

Yeah, Cobalt Starter Bits. Helpful as always.

 

[GTM]

...
without using a center punch which isn't the best for exhaust manifold that can crack. If you must use a center punch, take it easy.

I guess you don't have an adjustable spring loaded automatic center punch which isn't the same as playing blacksmith. The other alternative or aid is to grind or file a small flat spot when dealing with radiused parts rather than risking the bit walking. These are machine shop practices that will get your boss raising an eyebrow for taking short cuts.

Cheers,
GTM

 

[oldman]

I guess you don't have an adjustable spring loaded automatic center punch which isn't the same as playing blacksmith.

Yeah, sorry about that, us home grown mechanic wannabes thinks center punch as "hitting the nail on the head", thanks for the clarification.

The other alternative or aid is to grind or file a small flat spot when dealing with radiused parts rather than risking the bit walking.

The spot for the EGT, 6 ins into runner #1, is actually flat so getting started shouldn't be too much of an issue.

 

[2bclutch]

The spot for the EGT, 6 ins into runner #1, is actually flat so getting started shouldn't be too much of an issue.

This looks to be the correct spot..

You must be logged in to view this image or video.

 

[oldman]

Looks good to me.

 

[GTM]

...
The spot for the EGT, 6 ins into runner #1, is actually flat so getting started shouldn't be too much of an issue.

I've seen this suggested before on this site and I've yet to see any valid argument to exclude the other 3 cylrs as if they don't exist. It's foolish to think a particular cylr is always going to fail first when all it takes is few micron size particle to give a bad spray pattern, wrong gap on a spark plug to set off a melt down on 1 of the other 3 but you can sleep well knowing #1 cylr is being monitored. You won't find this in marine or aircraft applications where you can't call AAA to tow you home.

No wonder my hair is falling out.

Cheers,
GTM

 

[oldman]

I've seen this suggested before on this site and I've yet to see any valid argument to exclude the other 3 cylrs as if they don't exist.

Your point is valid but like eveything else in life, nothing you choose will ever be everything to all things, it's always going be a game of give and take, this is even further complicated by the fact that the "gives" and the "takes" vary from situation to situation, in this case car to car (or car to aircraft ). You make a valid point but tapping after the turbo also has its cons, some are associated specifically to a modified DSM.

1. Since the signal is already diluted (sp?) after the collector, it will take nothing short of a drastic change in the individual cylinders to properly reflect and raise the red flag. A badly clogged injector will certainly raise a red flag but I'm so sure if a change in spray pattern will. I'm not down playing the importance of a changed spray pattern, I'm just not so sure that an EGT sensor is design to catch individual cyliner failures unless you mount one on each runner which isn't really practical.

2. A partial and pre cylinder failure such as a clogged fuel line, clogged fuel filter or a dying pump, will almost always affect the cylinder furthest from the fuel feed on the fuel rail, #1 cylinder, the most. In this situation, tapping after collector may result in running lean on #1 without ever knowing it until it's too late.

3. This is rarely talked about because it's associated with highly moded DSMs which doesn't concern majority of our members. In a perfectly functioning system after a certain level of modifications, the stock fuel lines gets overruned and becomes the weakest link as it's clearly demonstrated in this article. In this situation, the effects will again be most felt in the #1 cylinder, this BTW is the main reason as to why I own one.

With all that said, EGT gauge should only be used as a reference gauge and should never be rely upon alone for either prevention or tuning.

No wonder my hair is falling out.

I thought they were gone long ago.

 

[GTM]

...
In a perfectly functioning system after a certain level of modifications, the stock fuel lines gets overruned and becomes the weakest link as it's clearly demonstrated in this article. In this situation, the effects will again be most felt in the #1 cylinder, this BTW is the main reason as to why I own one.

With all that said, EGT gauge should only be used as a reference gauge and should never be rely upon alone for either prevention or tuning.

They do make setable telltail alarms and expanded scale if you want something a bit more reliable. It's no better than thinking you engine is running cool when in fact you have no water to surround the temp sender. What good is the EGT stuck in 1# when the other 3 are going through a melt down and you can't see it. The argument just doesn't fly.

As for the url I've some issues with fluid dynamics and the location of the pressure regulator being after all the injectors in the rail. If there is a problem with fuel delivery then people should stop saying throw xyz size in there and all witll be fine. I don't see anyone saying you need a larger fuel rail or drill out the passages, jack the pressure, and add a larger pump.

Planes and boats are not highly modified and yet they rely on pryrometers just as they rely on the engine temp gauge and the other instrumets. If you don't look at them, know what to expect under xyz conditions then they are of no value save for bragging rights. Building a higly modified engine does not guarantee common sense nor does it make someone a mechanic.

It's a little iffy at best to represent this as safe sex when much of the industry doesn't accept this practice.

Cheers,
GTM

 

[DSM90AWD]

It's a little iffy at best to represent this as safe sex when much of the industry doesn't accept this practice

The illusion of safe sex

In my own findings with pumpgas, the only time I'd see a high temp readings (>900C) on my EGT is when knocking enough to experience severe timing retard. In such cases the cyls flame front is shooting right out of the exhaust valve at the EGT probe

For tuning, monitoring Knock is WAY more reliable since it tells you immediately that there is a problem with one or all cylinders. Waiting for the knock to become severe enough to retard timing and raise EGTs (especially with a slow-responding EGT probe) is asking for trouble, especially if you're not looking at it 100% of the time.

Honestly, I was sold on an EGT back when I didn't know better (everyone had one and a blinky light ). The big-name tuners will now tell you unless you have one plumbed in each cyl, you've wasted your money.

And with WBO2s available for $199 these days, a much wiser investment IMO

 

[oldman]

They do make setable telltail alarms and expanded scale if you want something a bit more reliable. It's no better than thinking you engine is running cool when in fact you have no water to surround the temp sender. What good is the EGT stuck in 1# when the other 3 are going through a melt down and you can't see it. The argument just doesn't fly.

You seem to be missing my point so I will try and re-phrase it. If someone was to ask me if they should install an EGT gauge/sensor my answer would be "don't waste your money" because it's almost useless. However if you already have one and you wish to have some kind of refference/warning, #1 runner would be the most logical spot as mounting it after the collector pretty much makes it pointless. Like I posted above, to make an EGT as effective as you want it to be, individual EGTs will have to be mounted on each runner.

As for the url I've some issues with fluid dynamics and the location of the pressure regulator being after all the injectors in the rail. If there is a problem with fuel delivery then people should stop saying throw xyz size in there and all witll be fine. I don't see anyone saying you need a larger fuel rail or drill out the passages, jack the pressure, and add a larger pump.

I'm not understanding this part of your post, if the pressure regulator isn't suppose to be after all the injectors and the fuel rail, where would you install a regulator? I do however agree that there are probably other factors involved which was not covered by the linked article.

It's a little iffy at best to represent this as safe sex when much of the industry doesn't accept this practice.

Neither yours or my way will provide safe sex because it isn't what it is designed to do. It's both foolish and dangerous to rely on EGT alone for "safe sex".

 

[oldman]

Damn it, I need to type fasta.