Air/Fuel ratio, is there a quick answer? |
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Air/Fuel ratio, is there a quick answer? |
malcolm2 |
Feb 5 2017, 05:50 PM
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#1
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Advanced Member Group: Members Posts: 2,745 Joined: 31-May 11 From: Nashville Member No.: 13,139 Region Association: South East States |
OK, I have been tinkering with the new-to-me AFM on my 1911cc engine all weekend. I have adjusted the spring about 20 teeth CCW to get to this point.
I have been using an A/F sensor and gauge. can someone tell me, or direct me to a chart/table of what A/F I should be shooting for on my daily driver. The last adjustment of the CO screw has left me here: I have always had a strange idle situation, so lets ignore that for now. any normal adjustments to reduce the idle at normal operating temp eventually stall the car. A problem for another post. (IMG:style_emoticons/default/blink.gif) the idle is high.... at 1200 the A/F is a smooth 12.2. I found a long hill and drove up it at about 3800 rpm and the A/F was 12.5. thoughts? |
malcolm2 |
Mar 27 2017, 03:16 PM
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#2
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Advanced Member Group: Members Posts: 2,745 Joined: 31-May 11 From: Nashville Member No.: 13,139 Region Association: South East States |
I made it home.... 800 + mile weekend trip. I don't think I will go that far again until I get some new padding for my seats. (IMG:style_emoticons/default/driving.gif) (IMG:style_emoticons/default/driving.gif)
As far as the A/F goes... I filled up with pure gas, 89 oct I believe it was. So the 1st 330 miles started with maybe 25% 87 oct e10 + 75% 89 oct pure. MPG (best numbers I have ever recorded) tank 1: all interstate: 337.5 / 11.25= 30 mpg tank 2: 100 miles of city: 314.2 /9.99 = 31.4 mpg tank 3: 151 miles of interstate: xxx/xx = still on 1/2 I-40 from Nashville to Asheville has quite a few hills, some 4 to 5 miles long. The car ran very well. I visually logged @ 12.7 a/f cruising on flat ground at about 3400 rpm. Up the hills still at 3400 rpm, CHT reached 380-ish and the a/f evened out at 12.5. Oil temps were steady at 210. My total a/f interstate range for the most part was 12.3 to 13. Once thru the mountains with only about 20 miles to go, I noticed there were times it was running richer. I saw some 12.0's even 11.8 for brief times. City driving on Friday, it would idle at 14.6 then stop-to-stop up to 4th gear and 3000+ rpm I say I saw 12.5 - 13. I did not see the rich numbers yesterday. the range was about like the City driving 12.3 -12.8 all day on 87 oct e10 fuel. 3400 to 3800 rpm 70 - 80 mph. Unless someone thinks I am out of whack, I think I may not tweek any further. I will also edit and add a spark plug photo for Tim.... (IMG:style_emoticons/default/shades.gif) |
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