Pyro/boost install on Yanmar 6ly

[Eric]

I am going to add a pyro/boost monitoring system on my 2006 Yanmar 6ly-stp (370hp) engines. Based on Tony’s advice, I know where to tap into the boost pressure and the pyro probe before the Turbo, however, I’d like the probe to go after the turbo. Is the cap seen on the mixer a possible pyro sensor install point or should I just put in before the turbo and not worry about sensor breaking off and blowing the turbo (if i put it before turbo, how does the blanket fit?).
Also, running boost and pyro leads up to the flybridge will require 30-40 ft of tube/wire. I have built an arduino based engine monitoring system that sends tach, oil pressure, water temp onto the n2k backbone for display on a Raymarine MFD. I could also bring in the EGT and boost if I used an electronic boost sender and new the calibration curves for the boost and pyro sensor. I am considering setting up Turbocator gauges in the engine room, or maybe the lower helm and then tapping into the pyro leads and Teeing off an electronic VDO boost sensor and converting to n2k data.

Topic

[Corey Schmidt]

Read every article that we’ve created re: exhaust design and then construct a solid plan based on your available options (which includes available physical space)… that’s all you can do. You’ll have to think outside the box…

https://www.sbmar.com/category/articles/exhaust-systems/

Re: your arduino… have you figured out how to read the milli-volt signal from the thermocouple? If not, I have a signal amplifier for a type-k EGT probe that is 0-5V output with a 12V input…

[Eric]

Corey, I can read the sensor resistance and put the calculated boost or temp in the network using the arduino. I am however now more concerned with Tony’s (and your) opinion of the exhaust design overall. What do I need to do to fix it, or at least make it better?

[Corey Schmidt]

Eric wrote:

2) Its a home brew job. Monitors 4 batteries (V, A and aH), Fridge, Freezer, compressor, Freon, engine temps, 4 bilges. Displays all info and sends to the cloud so I can do analysis. I’m a complete nerd, that’s why I am trying to figure out the easiest way to get boost and pyro monitoring on N2k. Looking at https://www.summitracing.com/parts/vdo-360043/overview/ and a pyro sensor (does it matter how ‘deep’ it protrudes into the exhaust manifold bracket #16?)

In order to get boost and pyro to N2K you’ll need a specific module or device that can re-transmit the correct data to the CAN bus… you’ll probably need some Maretron sensors to make it all happen… the probe tip should be about half way in the wedge adapter to read exhaust correctly.

https://www.maretron.com/products/tmp100.php

[Eric]

Tony,
there appear to be 2 concerns here,

1) At shutdown, any water in the fiberglass tube from mixer to muffler could flow back STRAIGHT into the engine. Rocking the boat could be enough to do this…
2) Failure of the mixing elbow due to corrosion would send water straight into the engine.

Given that I have every little room to work with, a 2-3 inch spacer between the elbow and the mixer would raise the mixer 2-3 in higher and the angle of the fiberglass tube would increase, thus helping drain it after shutdown. Keeping engines running when rocking will also help. We dive a lot and I like to kill engines when waiting for divers or when they are boarding, but in 2-3 ft seas, I’m rolling. Reducing size of muffler could also effectively increase the angle, but this is not practical…

Switching to a stainless mixer and/or installing a fresh water flush would reduce chance of (2)

What are your recommendations? I simply don’t have room for https://www.sbmar.com/articles/custom-yanmar-marine-exhaust-design/

Thanks
Eric

[Tony Athens]

Eric,

Put on your thinking cap……………….Look/study the attached picture for a few minutes.

Now, think of your cast iron mixer sitting higher than your $20,000 + Yanmar engine.. Now, think more of what is going on 7000+ hours per year sitting at the dock……………Need I say more?

Tony

[Eric]

Thanks for the link. I have about 3 inches clearance on STB engine and about 4-5 on Port. I notice a couple of other items that will require some maintenance..

[Rob Schepis]

Exhaust Issues..

Eric, yes as to your concern in #1 above AND add to that the fact that seawater is sitting in the wet elbow (cast iron) for thousands of hours at the dock corroding it away… (you can see it “externally” on one already) eventually the internal jacketing rusts through and seawater runs back into the turbo outlet and beyond.

Have any shots showing overhead clearance to the underside of the deck above? How many inches of unused height do you have to work with? Need to get the angle of all as steep as possible going down to the mufflers so the water leaves the engine area as easily/quickly as possible and have the showerhead (mixer) design so that it self drains on shutdown.

Check this page out, the finished product pics towards the end are worth 1K words..

https://www.sbmar.com/articles/custom-yanmar-marine-exhaust-design/

[Eric]

Corey,
thanks for the fast replies, particulary on a Sunday!
1) – Talk to me about what changes I need to make to make it safer. Its been like this since the previous owner isntalled the engines in 2006. You are concerned with water remaining in the fiberglass tube after engines are shutdown and it could flow back into the engine with a little boat rocking? Is there an extension piece that would extend the mixer higher so the anlge is more acute?

2) Its a home brew job. Monitors 4 batteries (V, A and aH), Fridge, Freezer, compressor, Freon, engine temps, 4 bilges. Displays all info and sends to the cloud so I can do analysis. I’m a complete nerd, that’s why I am trying to figure out the easiest way to get boost and pyro monitoring on N2k. Looking at https://www.summitracing.com/parts/vdo-360043/overview/ and a pyro sensor (does it matter how ‘deep’ it protrudes into the exhaust manifold bracket #16?)

3) I’ll install Pyro before the turbo if that makes most sense. I’ll see how easy it is to remove the plug and then tap a 1/8 in it.

Thanks again,
Eric

[Corey Schmidt]

Eric,

A few items:

1. That exhaust design is giving me “goose bumps”… scary! That’s would be my MAIN concern before anything else. Looks like water can sit there and have it’s way with that elbow… wont take long IMO… that’s when BAD things happen.

2. I’m curious as to who makes the Arduino based system to monitor all of the engine parameters? Is that something you created by yourself or was it an open source platform that was already available? And it outputs to NMEA or is there an external gateway device that handles that?

3. Why do you want to monitor EGT after the turbo specifically? Seems like a lot of hassle as there should already be a provision between the manifold and the turbo in the adapter wedge…

[Eric]

Tony,
here are better photos of both engines. I thought that since the mufflers are so much lower, the setup would be ok?

[Tony Athens]

That “wet mixer” sure looks scary as to NOT sloping down….

Tony

[Rob Schepis]

No, that hex cap should be a water jacket port for flushing, draining, etc. You would have to drill and tap that dry exhaust bend if it’s not already fitting with a threaded port.

[Author]

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