Originally posted by Orange65
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Carb Tuning- whats first?
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Wow what a difference locking out the timing made. The idle is rock steady. I was able to readjust the carb for a steady idle with less curb idle (still 3/4 turn off of ideal). It now reads 13-13.5 on AFR and has no bog. I think I am going to start driving it now and work on the part throttle as well.Why think when you can be doing something fruitful?
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Nice!Life is short. Be a do'er and not a shoulda done'er.
1969 Galaxie 500 https://bangshift.com/forum/forum/ba...ild-it-s-alive
1998 Mustang GT https://bangshift.com/forum/forum/ba...60-and-a-turbo
1983 Mustang GT 545/552/302/Turbo302/552 http://www.bangshift.com/forum/forum...485-bbr-s-83gt
1973 F-250 BBF Turbo Truck http://www.bangshift.com/forum/forum...uck-conversion
1986 Ford Ranger EFI 545/C6 https://bangshift.com/forum/forum/ba...tooth-and-nail
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Originally posted by dieselgeek View PostAFR will read lean at idle when its tuned, not rich, because of excess oxygen passing into the exhaust.
a fire'n cyl should burn all the fuel and use all the aval oxygen if your idle circuit is working correctly.
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Nope
Glad it helped.
A nice thread a lot of you guys should read going on, some very bright minds sort out the ones that are not
Last edited by JeffMcKC; July 2, 2013, 12:30 PM.2007 SBN/A Drag Week Winner & First only SBN/A Car in the 9's Till 2012
First to run in the .90s .80s and .70's in SBN/A
2012 SSBN/A Drag Week Winner First in the 9.60's/ 9.67 @ 139 1.42 60'
2013 SSBN/A Drag Week, Lets quit sand bagging, and let it rip!
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Originally posted by NewEnglandRaceFan View PostWhy would there be "excess oxygen " at idle ?
a fire'n cyl should burn all the fuel and use all the aval oxygen if your idle circuit is working correctly.
Nothing has unburt fuel, that burns fuel.....................Last edited by JeffMcKC; July 2, 2013, 12:36 PM.2007 SBN/A Drag Week Winner & First only SBN/A Car in the 9's Till 2012
First to run in the .90s .80s and .70's in SBN/A
2012 SSBN/A Drag Week Winner First in the 9.60's/ 9.67 @ 139 1.42 60'
2013 SSBN/A Drag Week, Lets quit sand bagging, and let it rip!
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Originally posted by Orange65 View PostTo address the idea of an intake leak- I have gone over the intake with carb cleaner while it was running and found no leaks. Could there be one under? It is not burning any oil, so I don't think so.
BTW- I was pulling around 9 inches of vacuum at 1100 RPM but the cam has lots of duration (250/261 @ .050").
I realized that the timing I ended up with (26 degrees initial) will cause a problem with my total timing goal of 36 degrees. I have a Mallory Promaster distributor and the smallest mechanical advance I can get is 18 degrees. So I am going to have to back the initial timing down. I will do this tonight and reset the idle.
I understand where most thoughts are headed with the different replies. Some appear to have the same attitude most others that I talk to do- don't worry about the idle AFR so much, be concerned about what it does making power. I may end up this way, but since the carb circuits build on top of each other, if I get it right on power and then adjust the idle, the carb setting is screwed again.
Keep coming with the comments and thoughts- I am learning!2007 SBN/A Drag Week Winner & First only SBN/A Car in the 9's Till 2012
First to run in the .90s .80s and .70's in SBN/A
2012 SSBN/A Drag Week Winner First in the 9.60's/ 9.67 @ 139 1.42 60'
2013 SSBN/A Drag Week, Lets quit sand bagging, and let it rip!
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Originally posted by Orange65 View PostWow what a difference locking out the timing made. The idle is rock steady. I was able to readjust the carb for a steady idle with less curb idle (still 3/4 turn off of ideal). It now reads 13-13.5 on AFR and has no bog. I think I am going to start driving it now and work on the part throttle as well.
point... and each engine is different... if it idles nice and doesnt load up
and doesnt die then it close to ideal
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I've helped a buddy of mine tune on a lot of cars. If it has a big cam and plenty of converter, there really isn't any need for timing curve - as long as your starter will crank it over. I've had mine locked out for about 15 years.
I also have ditched my vacuum advance. I did it for bracket racing, where ANYTHING vacuum operated can cause inconsistency. Lately I'm considering putting the vacuum advance back on, for gas mileage. It's not a race car anymore, so if it helps fuel economy, why not?
36* locked mechanical timing, and up to 52* with vac. advance. I've read (repeatedly) that 52* is the magic number. The challenge may be getting the advance pot tuned properly, so it doesn't detonate when I roll onto the gas.
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Originally posted by MR P-BODY View PostWhy do you think its 3/4 of a turn off of ideal... its just a base starting
point... and each engine is different... if it idles nice and doesnt load up
and doesnt die then it close to ideal
Jeff- good thread on the Bullet- is Yeti a carb builder by chance?Why think when you can be doing something fruitful?
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Yes, he can get testy at times lol like all of us over there but he and Mark are very good at helping guys get them right. Lobes is another very smart guy he always has a different angle but just as on point gives you best of both worlds to pick from. If you know the players its a better site than most think just stay out of the trashed section and don't listen to the "sellers"2007 SBN/A Drag Week Winner & First only SBN/A Car in the 9's Till 2012
First to run in the .90s .80s and .70's in SBN/A
2012 SSBN/A Drag Week Winner First in the 9.60's/ 9.67 @ 139 1.42 60'
2013 SSBN/A Drag Week, Lets quit sand bagging, and let it rip!
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