Dustin,

I looked up the SS O2 sensor bungs. They are not very tall. If this thickness of bung is used to bridge the distance between the inner and out walls of the riser it would seem that the bung would end up essentially flush with the inner and outer walls of the riser when welded so as to seal the water jacket. Is that the case or is there a taller/longer SS bung that must be used?

Like what Dustin said or you could drill the hole in the top layer (don't go all the way thru) a little bigger than the one on the inside layer then set your bung in and weld the inside layer first then fill in the the outside layer. I have some ss o2 bungs that are about 1/2 inch tall If you need some.

muffman,

Yes I need two ssO2 bungs (and two ss plugs for the bungs as well). Let me know how to proceed.

Thanks,

[email protected]

Buy the LM-1 from Innovate. I've been using it for several years. I won't tune an engine without it anymore.

www.innovatemotorsports.com

You could forget about the o2 sensor and dial in with your exhaust temp
You will still need to weld bungs in so you can insert your thermocouple.
you can use a hand held fluke that has to be a hellavu better than comparable guages that are out there.
Jr.

J-Bonz,

Have you done this?

What is the step by step procedure to dial in using exhaust manifold temperature?

Thanks!

Exhaust temp and CO coincide. As your temp goes up, your afr goes down.
It would have been best to gather your before data from you original setup, but its to late for that. What you need to figure out is your exhaust temps when u run to lean and to rich. These i dont know right off hand but, I beleive any repitable full time engine/dyno man could tell ya right of the top of there head. You should take some caution though since your dealing with efi, I am not up to date on how the 496 operates, especially choke mode. Ask AKA hillbilly for this knowledge, the dude knows his Sh*t.
I hope this helps,
Jr

If you can get an accurate wide range a/f meter, you would be wasting your time measuring exhaust temp. First, you would be looking at the average of 4 cylinders unless you go to one cylinder or all, next if your not data logging and have accurate sensors, then the numbers are not accurate enough to do much with unless you have a prior baseline. Next, temp will vary with spark advance as well, so depending on the load based table of the 496, it may very, then you have cylinder to cylinder timing which will retard/advance in certain cylinders during knock and occassional AE, again changing your numbers.

As for EGT's going up while afr goes down, that would only happen if your getting raw fuel burnt in the pipe or you have a very inefficient cylinder such as low compression with low air flow. Otherwise, your going to get you hottest readings at 14.7:1, after that, it will actually cool down as you get leaner. If your richer, it will cool down as well.

Stock NA motors, cast iron heads, with 91 octane fuel should run around 12.5:1 for peak HP and reliability. With aluminum heads, I like 12.8:1. If a motor gets close to detonation, then you have to richen the motor and or modify timing. There's usually a balance where you can get more power with timing and slightly richer air fuels than leaner air fuels and lower timing. The leaner you are, the more dependent you are on temperature variation, whether it's engine temp, outside air temp, etc.

Dustin

I has also used this set up, nice piece
http://www.innovatemotorsports.com/x...cat=252&page=1

A/F sensor (wide band) is the only way to go. they are good from λ=.7 to λ=2.2 a Duel stage O2 is only accurate from λ=.9 to λ=1.05