The Ford Barn

Heard · 05-21-2024, 11:09 AM

You guys that are using AF meters, where are you placing the O2 bungs? Are they going in the headers or after the headers.

I'm asking 'cause if they go in the headers, now is a good time for me to do that.

Thanks,
Heard

glennpm · 05-21-2024, 11:23 AM

IMPORTANT INSTALLATION NOTE - UEGO Sensor Mounting Orientation
A weld-in M18 X 1.5 boss is supplied for sensor installation. Mount the O2 sensor in the
exhaust system at least 18 inches downstream from the exhaust port. If you anticipate high EGT's (over 800C), run a turbocharger, run at high RPM for extended periods of time or plan on running leaded race fuel then you must mount the sensor at least 36 inches or more downstream of the exhaust port as all of these can cause the sensor to overheat.

To prevent collection of liquids between the sensor housing and sensor element during the cold start phase, the installation angle should be inclined at least 10° from horizontal with the electrical connection upwards,
see below. (Figure 8)

Figure 8. Minimum mounting angle for the UEGO Sensor

You may want to put in bungs on both left and right side banks.

Seth Swoboda · 05-21-2024, 12:13 PM

Michael at Third Gen has tuned using an AF Meter. It goes in before the muffler on the Y pipe or header pipe.

Bored&Stroked · 05-21-2024, 02:27 PM

Sponsored Links (Register now to hide all advertisements)

It can go anyplace downstream of the engine - usually a couple feet back from the block or head. On a flathead, your "ports" are already like headers, so I put mine back from where the rear port tube enters the main tube - about 6 - 8" back. I like to have the bungs before any header gasket or potential leak areas.

One thing that is very important is that you have NO exhaust leaks ahead of the O2 sensor (or the readings will be wrong).

If you're welding up headers for an OHV setup, I'd put mine in the collector area (at a 10 or 2 o-clock angle). Also, if you're making headers, consider putting some EGT bungs up by the block - as close as possible. In tuning, it is nice to be able to see the EGT temps and the O2 readings. If you can only find space for a single EGT bung, put it on the rear cylinder (which tends to run the hottest). If on a flathead, I put an EGT bung in the center port tube and the rear port tube.

I'd always put the bungs in both sides of the engine - in case you need to test/tune or compare one side to the other.

05-21-2024, 11:09 AM	#1
Heard Senior Member Join Date: Sep 2013 Location: Florida Posts: 592	O2 bung question You guys that are using AF meters, where are you placing the O2 bungs? Are they going in the headers or after the headers. I'm asking 'cause if they go in the headers, now is a good time for me to do that. Thanks, Heard __________________ Do I look like I have a plan B?

05-21-2024, 11:23 AM	#2
glennpm Senior Member Join Date: Sep 2014 Location: Wiscasset, Maine Posts: 2,089	Re: O2 bung question IMPORTANT INSTALLATION NOTE - UEGO Sensor Mounting Orientation A weld-in M18 X 1.5 boss is supplied for sensor installation. Mount the O2 sensor in the exhaust system at least 18 inches downstream from the exhaust port. If you anticipate high EGT's (over 800C), run a turbocharger, run at high RPM for extended periods of time or plan on running leaded race fuel then you must mount the sensor at least 36 inches or more downstream of the exhaust port as all of these can cause the sensor to overheat. To prevent collection of liquids between the sensor housing and sensor element during the cold start phase, the installation angle should be inclined at least 10° from horizontal with the electrical connection upwards, see below. (Figure 8) Figure 8. Minimum mounting angle for the UEGO Sensor You may want to put in bungs on both left and right side banks. __________________ Archives of historical but relevant older articles: ------------- Hover mouse over the links below and click! ~~~~~~~~~~~~~~~~~--------------- Rumble Seat's Notes Techno-Source for the 1932 thru 1953 Flathead Ford Last edited by glennpm; 05-21-2024 at 12:45 PM.

05-21-2024, 12:13 PM	#3
Seth Swoboda Senior Member Join Date: May 2010 Location: Southern Illinois Posts: 3,833	Re: O2 bung question Michael at Third Gen has tuned using an AF Meter. It goes in before the muffler on the Y pipe or header pipe.

05-21-2024, 02:27 PM	#4
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,250	Re: O2 bung question Sponsored Links (Register now to hide all advertisements) It can go anyplace downstream of the engine - usually a couple feet back from the block or head. On a flathead, your "ports" are already like headers, so I put mine back from where the rear port tube enters the main tube - about 6 - 8" back. I like to have the bungs before any header gasket or potential leak areas. One thing that is very important is that you have NO exhaust leaks ahead of the O2 sensor (or the readings will be wrong). If you're welding up headers for an OHV setup, I'd put mine in the collector area (at a 10 or 2 o-clock angle). Also, if you're making headers, consider putting some EGT bungs up by the block - as close as possible. In tuning, it is nice to be able to see the EGT temps and the O2 readings. If you can only find space for a single EGT bung, put it on the rear cylinder (which tends to run the hottest). If on a flathead, I put an EGT bung in the center port tube and the rear port tube. I'd always put the bungs in both sides of the engine - in case you need to test/tune or compare one side to the other.