sweatybetty Posted August 13, 2017 Share #97 Posted August 13, 2017 On 4/25/2017 at 2:53 PM, 240260280 said: Because both throats are controlled by a single idle set screw, sometimes wear or manufacturing variations cause one throat to flow more than the other at idle. The bypass is used to balance air flow between the two throats. Normally the bypass valves are closed off but if one throat is flowing more air than the other at idle, you can balance the carb by opening the bypass on the throat flowing less air. This procedure is only needed at idle. FYI: The old way was to drill small holes in the throttle plate to balance (see photo below). (btw the holes solder-up nicely if over-drilled). where is the bypass valve? im not seeing it Link to comment Share on other sites More sharing options...
240260280 Posted August 13, 2017 Share #98 Posted August 13, 2017 the carb above is an early one w/o bypass valve so a small hole was drilled in the brass plate as a bypass to balance air flow at idle. Link to comment Share on other sites More sharing options...
blodi Posted August 14, 2017 Author Share #99 Posted August 14, 2017 Got the 165/225 combo back in as well as the .35 exhaust jet. Removed wideband sensor and re calibrated it. I'll report back later with results. Link to comment Share on other sites More sharing options...
blodi Posted August 16, 2017 Author Share #100 Posted August 16, 2017 (edited) 165/225 with 35 exhaust..... oddly it's half a point richer than this same combo before. 4 pulls all confirm. Back to 155/225? 81617-165225 by blodi, on Flickr Edited August 16, 2017 by blodi Link to comment Share on other sites More sharing options...
240260280 Posted August 17, 2017 Share #101 Posted August 17, 2017 I guess the calibration must have drifted in past runs... oh well, it looks flat which is good. Yes please try the 155 again btw how does the butt dyno sense the rich lean changes? Link to comment Share on other sites More sharing options...
blodi Posted August 17, 2017 Author Share #102 Posted August 17, 2017 I'll get the 155's back in tonight. Butt dyno....not sure I feel a huge difference between each of the setups. I felt more change when changing the choke sizes. Honestly, the car starts, runs, drives and pulls well with any of the setups. It's more about me obsessing over the numbers I guess. Link to comment Share on other sites More sharing options...
blodi Posted August 20, 2017 Author Share #103 Posted August 20, 2017 155/225 35 exhaust... 8-20-17-155225 by blodi, on Flickr Link to comment Share on other sites More sharing options...
240260280 Posted August 20, 2017 Share #104 Posted August 20, 2017 That looks great! 13+/- 0.5 for most of the run. I'll overlay it later today after church. Link to comment Share on other sites More sharing options...
240260280 Posted August 21, 2017 Share #105 Posted August 21, 2017 OK I think you are there. 13 AF +/- 0.5 If you want to go one step further, it will take another fuel jet and air corrector based on the data below. A 160 fuel and 230 air would be as good as it could get. Link to comment Share on other sites More sharing options...
blodi Posted August 21, 2017 Author Share #106 Posted August 21, 2017 You've got me tempted. Let me think about it. Might order one last setup. I'm going to have one large collection of mains/airs/chokes/accel pump jets to get rid of when I'm done. 1 Link to comment Share on other sites More sharing options...
Patcon Posted August 21, 2017 Share #107 Posted August 21, 2017 When I start tuning some triples I might be able to help lighten your load... Link to comment Share on other sites More sharing options...
240260280 Posted August 21, 2017 Share #108 Posted August 21, 2017 I looked at E tubes and F2 are going to be sent. Still deciding on a second set. We have to tame that lean spike at start too. Link to comment Share on other sites More sharing options...
Wilbur
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