I have stainless marine manifolds and Exhaust which of course are wet. I need an AFR or EGT gauge and sender as well as a bung to weld in. Does anyone make the bung or should I just cut one out of stainless rod stock? Thanks. Any of these gauge manufacturers better than others? Thanks.

I have a Gaffrig EGT guage. Give them a call, I'm sure they have everything you need. As for the AFR setup, they do not work with wet exhausts. Water will destroy the O2 sensor on contact.



Darrell.

Yup, that's why I need a bung that will extend through the water jacket into the exhaust stream. I can then weld it on both sides to isolate it from the water

I mounted o2 sensors in my stainless marine manifolds in # 7 & #8 by drilling and tapping the bottom side of the exhaust about 1" from the exhaust flange where the manifold is solid,not water cooled,Smitty

Now that's interesting Smitty! I was thinking that I wanted the sensors to be in the accumulated exhaust and not on individual cylinders. Does you think this would be an accurate reading of the whole engine?????

send it back to stainless marine. they will put a bung in cheap.

just spoke to stainless, they are sending me a bung.

Put the O2 bung in the riser just before it reaches it highest point. If you drill the hole a little larger than the bung, you can dimple in the outer pipe and weld the two pipes together. You then have the water jacket closed off. Then weld the bung on the top on the riser. That way you don't have to weld the inside and the outside. Don't bother with EGT's. If you get the AFR where it needs to be, then the EGT's are whatever they are. Hope this helps, Eddie.

When I did this under tyler crocketts advice that was my question to him but he placed his wide band o2 sensors in with his rinda tester and tuned it on the water this way. I also feel that you would want the mix of all 4 cylinders to be read by the sensor to get the most accurate reading you would want the sensor in the main stream AFTER the exhaust had mixed together but it worked the way he suggested.I'm running stanless marine 3's if that makes a difference and the riser has individual ports and it doesn't mix until it exits into the tail pipe which I think he was concerned about water reversion getting to the sensors. That was 2 years ago,I still need to have him re-tune my newest set-up on the water to get the best driveability out of it,Smitty

As far as egt gauges,I had a gaffrig egt gauge a few setups ago on a blown 502 with lightning headers,it was pegged past 1500 degrees anytime I was in boost,even if it was set-up rich so you couldn't trust the numbers as they were not accurate. I tested the egt's with a steady heat source vs. a set of digital pyrometers off my snowmobile,the gaffrig egt read 250-300 degrees hotter than the pyro 2000 gauge did so I never placed much faith in the numbers,Smitty