EGT Sensor Installation 6CTA

[stevenagodfrey]

Hello –

I am in the process of installing the SBMAR EGT and Turbo Pressure sensor and have encountered an obstacle on the port engine. As shown in the first picture, the access port is lined up with the main bolts on the exhaust flange. I am thinking about attempting to loosen the flange bolts and carefully rotate the flange and exhaust so that I have enough clearance to remove the plug and install the probe. I thought I would slow down and ask for some input prior to attempting this with bolts and exhaust that hasn’t moved in 20 years.

Open to all ideas and input on the best way to install the EGT without an unintended consequence.

Also what is the best tool to remove the plug on the exhaust flange?

Thanks in advance
Steve

Topic

[Rob Schepis]

Nicely done – certainly strong enough!

McMaster sells them: https://www.mcmaster.com/4-point-drive-sockets/

[Douglas Fairchild]

1/8 socket for NPT Plug

I could not find a 4 point socket any where so I made one. It worked great. This socket and some heat got mine out after 17 years

[Rob Schepis]

stevenagodfrey wrote:

Is RectorSeal #5 the appropriate product to use for sealing the threads?

No, use anti-seize. RS#5 is for things at coolant temp and lower…

[stevenagodfrey]

Drill and Tapping Success

Tony and Rob –

Thanks for the input on this project.

My Dad (I am away from the boat right now) successfully drilled and tapped (HS 23/64).

For the pilot hole he used Sandvik Drill ( https://www.mscdirect.com/product/details/54732342 ). Hat tip to Tony on the hole size – per my Dad – “It would not have tapped with a smaller drill size”.

Is RectorSeal #5 the appropriate product to use for sealing the threads?

Thanks
Steve

PS Removing the brass plug on Starboard engine was unsuccessful – even using a good 4 point socket the plug head sheered off during removal.

[Tony Athens]

Good Pic!

I just cannot figure out what they were thinking. This started in 1985-ish and they just don’t seem to care although I brought it to the attention of various engineers I’ve met over the past 3 decades. In one ear and out the other.

[Rob Schepis]

Tony Athens wrote:

BTW, it was a pure couch engineer that put that where it is. It should have been put in the “no-slot area” like out flange is.

Yup….

[Tony Athens]

Super easy to drill and tap a new hole while in place.

Buy a good quality HS 1/8″ NPT tap

Buy a good 1/8″ or 5/32 drill–Pilot size
Buy a good HS 23/64″ drill ( 2 sizes over standard tap drill–Trust me)

Use oil when you drill and when you tap. Tap to 3/4+ on tap thread length

DO NOT worry about and chips, etc– When you start it, they all go out the exhaust..

You’re now done. BTW, it was a pure couch engineer that put that where it is. It should have been put in the “no-slot area” like our flange is.

.

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stevenagodfrey

[stevenagodfrey]

Drill and Tap

Rob – thanks for the deep thoughts.

Any opinion on drilling and tapping a new hole ?

[Rob Schepis]

The number of degrees of movement that it will take to rotate the riser enough for the egt port and the flange bolt to no longer line up will result in considerable reposition of the the riser the further you move out from the axis of rotation. So you’ll need to check clearances, etc. And that support arm does not appear to have any length adjustment feature incorporated into it so it will need to be altered – shortened, sleeved, hole ovaled out, etc depending on which way you go, CW or CCW

As the the tool to remove the egt port plug – a “4-point” square drive socket, also known as a pipe plug socket.

As to removing the turbo flange bolts – a quality “6-point” box end wrench, kroil soak, hammer taps, etc. We’ve covered this a bunch of times so the search function will prove useful. But do keep in mind, sometimes you get lucky with these, sometimes not…

If the boat is laid up for the off season, now is the time, in case this turns into a mini-project.

1 user thanked author for this post.

stevenagodfrey

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