EGT Gauges

[Richard Dodson]

I’m planning on installing EGT gauges on my 2005 480s.  Most of my boating friends place the pyro in the flange, post turbo. All of my trucking friends put it pre turbo and have stated that post turbo temp isn’t that valuable.  One would think the most accurate EGT measurement would be as close to the exhaust valve as possible. There is a pipe plug on the top of the exhaust manifold. Other than having a broken pyro destroy the turbo, rare occurrence, what is your opinion for the best location. 

Topic

[Steve Lewis]

RD,

I use ours just as PWROBERT indicates.  I use it to see if something is changing from my base line.  We have the same engines.  Our baseline in our full cruise load, we read 750F on the port and 700F on the strbd.  We are in Elk Rapids MI for our summer trip and we ran 5 days in wildly varying conditions to get here but the baseline is what I compared against.  Our fuel burn at 2240 is 29GPH and EGT is 750/700.  IF I advance to 2320 our fuel burn goes to 31gph and EGT decreases about 25F on each engine.   The actual number is not super important to me but the trend is. 

We had a 3 hour leg on day 3 that was in 5-6footers on our port bow quartering.  I slowed as the conditions built until we had to drop off plane as we were approaching the 800+ mark on EGT.  With the waves and hull speed combining to generate a rather uncomfortable running state, we turned and ran in beam seas at our normal 2240 and the temps came back down and our 460 let the waves roll under us in a rather comfortable way until we got some shelter from the shoreline by Tawas.  Saginaw Bay is just gnarly on a windy day………

I posted last year on a related item.  We were running for about 10mins when I saw the port side jump up over 1000F.  We slowed to hull speed and the temps went back to our normal baseline for hull speed, 1140RPM, which is 500F on both sides.  We ran back up on plane and the port side went over 1000F again.  We continued at hull speed to our swimming hole and I found that a clamp broke on the turbo air tube.

So I argue there is value in measuring the baseline temp of the exhaust gas at Turbine out for your seetup in your different running states.  Just base line your setup and watch it to see if there are big changes which indicate that you need to look at something.

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Mike Veal

[pwrobert]

Boats and on the road vehicles are similar but their operational situations are vastly different. <br />cars and truck operate over a widely and quickly varying RPM and load set of factors. <br />boats work under relatively slowly varying speeds and at almost full load at all times. <br />race cars and trucks do get minute by minute temp info and that may be if value. Some cars put a probe in each exhaust manifold right after bolt onto the head. They can read each cylinder and micro diagnose each cylinder. <br />boats just need to get a general idea how the package is performing and if general performance is changing from day to day. <br />put them wherever you want but ease of placement for what you really want to know is satisfied by the boating standard location after the turbo. 

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