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gimmesomeshelter
Samba Member
Joined: May 08, 2004
Posts: 1466
Location: San Carlos, CA
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 Posted: Fri Dec 15, 2017 11:22 am Post subject: Single or Multiple Air Fuel Meter Sensors |
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My original plan was to weld a single bung into my muffler so I can run a wide-band air fuel meter. In an ideal world I would have one sensor for each cylinder, but I have no idea how much benefit this would provide. Has anyone tried this? Was it worth the money/effort?
Cheers,
Paul
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ps2375
Samba Member
Joined: April 24, 2014
Posts: 2471
Location: Meridian,ID
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| Posted: Fri Dec 15, 2017 4:08 pm Post subject: Re: Single or Multiple Air Fuel Meter Sensors |
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| Depends upon how much control you have on the mixture to each cylinder/bank. If you have a single center mounted carb, one sensor after the collector would suffice or one per bank. If you have a carb throat for each cylinder, you could conceivably want a bung for each and just move the sensor around. How fine are you wanting to tune it? |
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gimmesomeshelter
Samba Member
Joined: May 08, 2004
Posts: 1466
Location: San Carlos, CA
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| Posted: Fri Dec 15, 2017 7:13 pm Post subject: Re: Single or Multiple Air Fuel Meter Sensors |
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My plan is to use dual Zenith 32 NDIX carbs. Would I prefer more control over less? Sure. I would think quad O2 sensors would be worth while if they 1) would allow me to quickly identify clogged jets, and 2) are needed to have each cylinder perform to the same standard. I have no idea how minor changes to flow, combustion chamber shape, or head temp (think #3) will impact the output of a particular cylinder. If they're all within 5% of each other, I would think quad censors would be a waste. If there's a 10 or 20% difference, that would be a completely different matter.
What I'm really looking for is someone who's compared cylinder output and can tell me how much they us usually vary.
Cheers,
Paul
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mkbug
Samba Member
Joined: October 12, 2004
Posts: 145
Location: Northern California
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| Posted: Thu Aug 08, 2019 9:11 am Post subject: Re: Single or Multiple Air Fuel Meter Sensors |
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I've been watching Shin Watanabe's FaceBook posting on his conversion to Gene Berg grooved 26x30 venturi in his 40 IDFs. So this Air Fuel Sensor topic is of interest.
Paul or anyone else please chime in on how you've monitor your air/fuel mix.
Shin is using a handheld Digital Air/Fuel Ratio Wideband Meter at over $200. And there are gauges that I can mount under dash (hidden) in the $150 range and monitor the ratio all the time.
What's the benefits of either method?
Thanks,
Martin
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TinCanFab
Samba Member
Joined: April 04, 2006
Posts: 2743
Location: Waterford, California
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| Posted: Thu Aug 08, 2019 12:24 pm Post subject: Re: Single or Multiple Air Fuel Meter Sensors |
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| mkbug wrote: |
I've been watching Shin Watanabe's FaceBook posting on his conversion to Gene Berg grooved 26x30 venturi in his 40 IDFs. So this Air Fuel Sensor topic is of interest.
Paul or anyone else please chime in on how you've monitor your air/fuel mix.
Shin is using a handheld Digital Air/Fuel Ratio Wideband Meter at over $200. And there are gauges that I can mount under dash (hidden) in the $150 range and monitor the ratio all the time.
What's the benefits of either method?
Thanks,
Martin |
Using a handheld wideband isn't worth much in my opinion. Real world driving situations under load is where O2 readings are necessary. I have a PLX wideband with its own gauge, ive used it to tune carbs. Now it is connected to a Microsquirt EFI and I can read it or data log from a laptop.
Hard acceleration, driving under load and cruising is what is best to monitor. Since mine is in a truck, it tells me what the a/f ratio is while hauling concrete and gravel like I did the other day. If you are getting altitude changes or driving up a steep grade, etc, you will want to know if you are running lean.
You can read through the super long wideband tuning thread, too. My idle is always super rich ATM. 10-12 ratio constantly. I'm running batch fire injection and a cam with more overlap than stock, so I don't think I can ever tune the idle perfectly lean with the setup I have. Every engine is different, but the one thing that kills them all is lean mixtures under load.
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