O2 Sensor Location
 

Guys, I having my CMI tails setup for O2 bungs. I tried doing some searches but didn’t get anywhere.

What side are you installing O2 sensors? I’ve seen a couple people reference doing the odd bank but with a single plane intake #8 is the farthest away. Does it matter? I have twins so maybe even on one, odd on the other?

Either way, looks like I’ll need to have them inline with then water inlet. Not a lot of room. Pic below is pre-carb builds.

Thoughts? I’m headed out shortly to drop off pipes.

https://cimg9.ibsrv.net/gimg/www.off...a4f3caa1e.jpeg

Id do all four pipes then cap the ones you are not using, 2 to 3 inches aft of the jumper hose should be fine, orient them so they kind of face each other on each engine is what Id do,

Here is where I mounted mine. Sensors not installed in this picture but you can see where they go. These were installed by CMI. Sorry for the mess I was finishing this years engine install.
Good Luck

https://cimg9.ibsrv.net/gimg/www.off...6b5f191aff.jpg

I have mine at approximately 1 o'clock with the bung 1/4" off of the band. Mine have a 1" ring before by the band. It worked great on the dyno.
https://cimg2.ibsrv.net/gimg/www.off...1e6a1850d.jpeg
https://cimg2.ibsrv.net/gimg/www.off...8d767b9883.jpg

Got it. Much appreciated guys!

They’re marked 2.5 inches down from the jumpers.

Wish I had the room outboard. It’s really tight against the sides. Wrenching anywhere around that area is a major pain.

Hey Gary, off topic but did you still need an HP500 filter head?

No it would not fit in the space I had. I modified my HP bracket to mount the Merc std head and added a temp sender to it. I used the Hardin 7 plate oil cooler that mounts onto the flywheel cover. All very tight but turns out very clean.
Again before clean up and detailing.

https://cimg1.ibsrv.net/gimg/www.off...8711464b4e.jpg

Nice!

Mine took a whole different turn with locations on a lot of stuff. I made new brackets for everything on the backend. I have my filters vertical because there was no room at all with the monster oil cooler. End to end it’s about even with the inside of the header tubes.


https://cimg3.ibsrv.net/gimg/www.off...21127605b.jpeg

I hope it all fits back in the boat! Lol

Anyway, sorry to have hijacked my own thread. I dropped everything off at the fabricator this afternoon. I should have the pipes back Friday. I went ahead and had all four done.

Here is the location of mine (before putting the extender on). About 10 o'clock, odd bank. I would also plan ahead for installing a bung extender/heat sink such as this linked below just in case you need it. This cured my issues of having water short out my o2 and I was lucky enough the o2 cable still cleared the hatch.

Heat sink/extender: Innovative HBX-1


https://cimg8.ibsrv.net/gimg/www.off...c7d8f96c43.jpg

Question regarding O2 sampling…

Number 7 is typically looked at as the leanest cylinder due to fighting for air with number 5. However in my case, I’m using Rookie’s cams that are 4/7 2/3 swapped (LSx - Gen VI firing order). Does that make a change in sides to sample? I’m guessing that fuel/air distribution is more evenly defined with this setup versus traditional BBC firing order.

Any thoughts?

I can’t help you with any possible benefits of the firing order swap. But I do know that you will need to read both sides to get everything tuned. The innovate dual lambda will let you read both banks on one gauge. Unfortunately you can only tune the average of each bank, so you have to stay in a really safe range if you want to be sure you’re not lean on any one cylinder. For this reason when I got all of my AFR‘s where I wanted them, I did a little old fashioned plug reading just to be sure nobody was an outlier. The good thing is you get a lot of time in the boat riding around. I had a buddy write down the AFR‘s from each bank at 200 RPM increments and vacuum gauge readings. When it was all done I had a different jet in all four corners and a power valve that opened up 200 RPMs before my secondaries came in. Good luck man and have fun with it. Wide band will change your life

Innovate is now Auto Meter btw.

Nice bilge:ernaehrung004:https://cimg6.ibsrv.net/gimg/www.off...3cfcaafabd.jpg

That looks familiar… Wish I had that room up front!

Little different now….

Well, it’s empty right now, but these are going in…


https://cimg1.ibsrv.net/gimg/www.off...36bb07de9.jpeg

I don't even want to hear you complaining about room up front Tom lol

https://cimg1.ibsrv.net/gimg/www.off...ec7dd644df.jpg

Yeah, you’ve got me best there… That thing is stuffed in there!

thanks for the info.