o2 sensors in marine manifolds.
 

sorry forgot to include picture Ford 351 windsor pictured other applications including buick v6 gm 5.7 LS1 6.0 LS2

The Bros here have a 50 hustler with trip 900hp's and they run those.

The number you mentioned is what they go by. They shut off if it hits 1400. usually around 1100 I think.

Hope this helps.

On the truck if I see 1400 I back off but I never shut it down, I want the exhaust to keep flowing as it can cool, a boat is a different story though. I let it idle until it hits 400 or so. I see 1100 most of the time, only higher if I am towing a big load at speed up a good grade.

What type of gas enging needs a EGT guage. I don't have any experience with high hp gas engines. I have a little experience with diesels. I installed a egt and boost guage on a diesel in a truck. The temp guage was installed pre turbo.
We ran the engine without any mods to establish baseline data, installed an aftermarket chip, and gathered more data. Installed a propane injection system, and then you really had to watch it.

EGT's without mods 900 deg F
EGT's with chip 12-1300 on top end
EGT's with chip and propane, had to back off at 100mph, egt's touched 1500 for a sec,

Am told not to exceed 1325 deg F pre turbo.

I run and have run pyro's for sometime...first with my IMCO manifolds & now with my CMI's. BTW, you can send your CMI headers back to CMI and they will install the sensor coupling. I always encourage my customers to order their CMI headers with the sensor coupling, even if they do not plan on using it right away.

BTW, I usually mount the probe on the #1 and/or #8 cylinders and keep the temps at 1250 or below.

I had gaffrig egts in my lightning headers in #7 & 8,they read 1500 to pegged all the time when under throttle,plugs were black and sooty. I quit paying attention to them because they obviously were way off. I tested them once with a comtrolled heat source and compared them to my pyro 2000 gauges on my snowmobile-they read 200-300 degrees too hot so don't waste your time on the gaffrigs. I currently have a 02 bung in my stainless marine 3's in #8,about 1 inch from exhaust flange on bottom,on crocketts innovate it seemed very accurate,Smitty

Ever done any hp testing compared to cmi's or stainless marine 3's? Smitty