| Slant Six Forum https://slantsix.org/forum/ |
|
| Holley 1920 air bleed/idle transfer slot mods https://slantsix.org/forum/viewtopic.php?t=27635 |
Page 7 of 10 |
| Author: | Aggressive Ted [ Tue Jun 24, 2008 9:46 am ] |
| Post subject: | |
Michaels, No, the shot I added with the adjuster screw is of a regular 1971-73 or so 1920. Some of my older ones have a solid brass plug shaved off. Totally non-adjustable. What you want to check for is if the idle air bleed hole in the throat is plugged. For example the carb in the picture with the big idle air bleed well, I tried pushing a fine piece of steel fishing leader, like a .010 guitar string in there to no avail.......both pictures are the same carb with the brass adjustment screw. Right now it is stuck shut. Eric got his to free up so he can adjust it. My carb had the well totally potted in lead as you can see from the first picture. When I drilled through the lead potting, it opened up the emulsion circuit. By stepping up from a 58 jet to a 61-2, the carb came to life. No bog, and a nice smooth transition at light throttle settings. A #60 works good too. The #64 jet I am running now is overkill, way more power than I really need. I find that I am driving way to fast at cruise, more at 70 and less at 60 mph. I will be swapping the #64 out and back to the 60 or 61-2. The #64 jet has dropped me back to 20 mpg. |
|
| Author: | MichaelS [ Tue Jun 24, 2008 12:03 pm ] |
| Post subject: | |
I just had it all apart (the 1920) and the air bleed hole is open as it should be. Another question, behind the main jet is some kind of metering device that is blocked from any tampering with by a plug. Is this a point that can be changed? |
|
| Author: | Aggressive Ted [ Tue Jun 24, 2008 1:37 pm ] |
| Post subject: | |
No, that area should be left alone unless it's blocked with debrie. Just blow it out real good. |
|
| Author: | Wizard [ Tue Jun 24, 2008 4:20 pm ] |
| Post subject: | Walker contacts problems. |
I have found the website for Walker carb parts. Tried to contact them by email and got email bounced back as undeliverable when inquiring about resellers where to get Walker stuff. Cheers, Wizard |
|
| Author: | Wizard [ Wed Jun 25, 2008 6:34 am ] |
| Post subject: | While on tuning the carb.. |
Now that I settled the carb and now "fine-tuning" stage... How much A/F do I should see when I start to move into mains while leaving idle jet (leaving from progression slot/holes)? We're not talking air jet involved yet. Cheers, Wizard |
|
| Author: | Aggressive Ted [ Wed Jun 25, 2008 6:25 pm ] |
| Post subject: | Report on jet changes in modified 1920 Holley |
Mileage in the modified idle air bleed 1920 dropped to 20 mpg with the #64 jet. It had lots of extra power for a little one barrel! Put the #61-2 jet back in and I am back to 23 mpg. That includes plenty of passing, stop and go, twisty back country roads and 65 to 70 mph on the freeway. Still had plenty of power and good response as well as descent mileage. 
|
|
| Author: | Wizard [ Wed Jun 25, 2008 6:56 pm ] |
| Post subject: | |
it is best to monitor with a/f to see more clearer picture of what you are doing on the tuning. I have WBO2 that I put together on a shoestring budget. JAW kit (build yourself one from a barebones kit and supply your own materials (case, heatsink etc). 50 appox. WBO2 sensor bosch 70ish wires with contacts crimped on and correct connector from VW dealer (appox 20 bucks total). Most expensive I had to spend was autometer 20 LED a/f made for narrowband. JAW works with these as these a/f meters works like 0-1V voltmeter. That is why I asked those questions with a resolutions like I can tell where I"m at just looking at it and know i"m in the mains or idle, or have both barrels open. BTW, power valve seems not to come in at all. (spring load is not very heavy judging by finger pressure on the spring). What are the jet you are talking about in 1920? This air jet or main jet? Not idle jet? Cheers, Wizard |
|
| Author: | Aggressive Ted [ Wed Jun 25, 2008 9:16 pm ] |
| Post subject: | Specifications on the R7585 1920 Holley Economaster 1968-72 |
Wizard, I have not gotten a air/fuel meter yet, that is why I didn't answer your question right away. I tune with the vaccuum gage and tach and then driving at least 250 miles (two round trips to work and back) and check the mileage. Usually only put in 10 gallons sometimes it will creep up to 11 gallons in the winter months with the ice and snow or some where in between the two. I drive aggressively and enjoy the Dart very much! Specifications on the R7585 1920 Holley Economaster On jet sizes, I am always referring to the main jet. In today's post a #61-2 which is a .060 diam. hole factory tuned half way between a #61 and #62. Idle air bleed: .035 which is the same as a #65 drill bit. The idle mixture hole: .080 in diameter. The accelerator pump hole: .035 in diameter. Idle mixture screw: 4 turns out set at 750 rpm out of gear at 18" vacuum. 600 rpm in gear @ 16" vacuum Sorry, I can't give you a A/F meter reading at this time. My extra cash is going into body work and some IAS Edelbrock shocks.
|
|
| Author: | argentina-slantsixer [ Fri Jun 27, 2008 6:44 pm ] |
| Post subject: | |
ted did you try leaving the #64 and A) lowering your bowl level with your gizmo back at 3-2 or B) crewing back to 2.5 ~3 turns the idle adj screw? |
|
| Author: | Aggressive Ted [ Fri Jun 27, 2008 8:13 pm ] |
| Post subject: | |
Juan, a) No I left it at 4 lbs. for the most part. Two pounds just mellows it out and makes me get into the power valve more. At 4 lbs. I was doing allot of passing and hard launches......I reset the float per spec, no extra down angle on the float. I installed a .090 thick aluminum heat deflector plate with half inch carb gaskets it keeps the carb from heat soaking and boiling over like it used to. No more stinky car after you shut it off. It will start right up after you been running hard and go into a store, then come back out to a big fat vapor lock, crank crank crank......That problem is all gone now. Hit the key and boom! b) Yes, I ran it in as far as 2.5 turns. It will idle fine out of gear but when you drop it in gear the vacuum gage went nuts and, dropped about 4 pounds and the idle was like a lopy cam. It would take off fine no bog, but idles like a race car. I sit in rush hour traffic allot and don't like the smell of the misfiring when the windows are down. It's in the 80 plus degree range now......3 turn is much better, 4 turns is just sweet. It can idle at 500 rpm or 600 rpm in gear all day and not stink. I chose to set the idle at 750 rpm per spec which results in a 600 rpm idle in gear. It helps keep the voltage up when the fan comes on sitting in traffic. By the way, no bog.......you can lightly accelerator or go sideways in a heart beat. My son and I were playing with his G-Tech and both agree that the engine has allot more potential. It starts out with allot of authority but fades fast because of the one barrel until you hit about 2500 (60 mph). Then your off like a shot up through 4000 rpm in a blink. For an automatic it's pulling pretty good 3660 pounds with both of us and a full tank of regular. Now that we got this set up working I am ready for a 4 barrel. I would like to see what this motor will do with more carb. Maybe get better mileage off the two front barrels? Most of my friends have found that going to a two or four barrel brings the vacuum at idle up to 20" instead of 18" that I see now. The extra velocity has got to help mixing of the fuel (atomization), power output and mileage. Let em know what you think 
|
|
| Author: | Aggressive Ted [ Fri Jun 27, 2008 8:45 pm ] |
| Post subject: | |
Quote: Aluminum intakes save weight and offer a moderately slight improvement in cold-engine driveability. They do not materially reduce heat soak, they do not significantly reduce the mileage reduction caused by winter driving conditions with a carbureted vehicle, and they do not make your coffee taste better in the morning. I know you like your aluminum intake a lot, Ted, but it is not the magical piece you seem to believe it to be.
Dan,Nice URL for the link. Your the man... I understand your thinking however, consider this..... Our engineers know aluminum is a very good conductor, which in my case with the carb heat deflector and no fan blowing on it during start up, warms very quickly. My aluminum deflector also acts a nice heat sink combined with the fan after run function when you shut off the car, cools very quickly for no vapor locking. Cast iron is much slower in warming up and holds heat much longer for major heat soak..........that is why it's good for wood stoves and cooking! I could use some coffee!
|
|
| Author: | steponmebbbboom [ Thu Jul 10, 2008 12:49 pm ] |
| Post subject: | |
Quote: Michaels,
epic thread.No, the shot I added with the adjuster screw is of a regular 1971-73 or so 1920. Some of my older ones have a solid brass plug shaved off. Totally non-adjustable. What you want to check for is if the idle air bleed hole in the throat is plugged. For example the carb in the picture with the big idle air bleed well, I tried pushing a fine piece of steel fishing leader, like a .010 guitar string in there to no avail.......both pictures are the same carb with the brass adjustment screw. Right now it is stuck shut. Eric got his to free up so he can adjust it. My carb had the well totally potted in lead as you can see from the first picture. When I drilled through the lead potting, it opened up the emulsion circuit. By stepping up from a 58 jet to a 61-2, the carb came to life. No bog, and a nice smooth transition at light throttle settings. A #60 works good too. The #64 jet I am running now is overkill, way more power than I really need. I find that I am driving way to fast at cruise, more at 70 and less at 60 mph. I will be swapping the #64 out and back to the 60 or 61-2. The #64 jet has dropped me back to 20 mpg. i finally figured out how to take closeups with my digicam, so i took a few shots of my economaster in these key places.  you can see the air bleed hole is open with what appears to be a slim insert, this hole goes down at least an inch before it bottoms out.  second shot is where the sealed air bleed adjuster screw would be, right in the center of the shot is the blank boss.  third shot shows the normal location for the calibration hole dan mentioned, which is missing on this carburetor. |
|
| Author: | Aggressive Ted [ Thu Jul 10, 2008 1:22 pm ] |
| Post subject: | |
Thanks for sharing the pictures! I have not seen an idle air bleed that large on a 1920 and bushed as well. That is a pretty good size hole! The hole does not go that deep, maybe 3/8" max before you hit the bottom of the cavity. What diameter drill shank or # drill do you suppose will fit in the hole? What #jet does your carb have in it? What is your MPG? They sure have done alot of changes over the years. What is your carb number? It is on the front of the fuel bowl vent housing. On the third shot, mine looks the same. |
|
| Author: | MichaelS [ Thu Jul 10, 2008 1:28 pm ] |
| Post subject: | |
My Carb (1920) has the same brass bushed hole, nice and clean and open, and the same undrilled bosses. Same body without the economaster style deflector in the venturi. |
|
| Author: | SlantSixDan [ Thu Jul 10, 2008 2:52 pm ] |
| Post subject: | |
Quote: second shot is where the sealed air bleed adjuster screw would be, right in the center of the shot is the blank boss. Quote: third shot shows the normal location for the calibration hole dan mentioned, which is missing on this carburetor.
It's not missing, as such...the calibration hole is present or absent depending on which exact variant of the 1920 you have. Same with the BBS, the BBD, the WA, the WW, and probably other carbs as well.*We spell it that way here, remember? 
|
|
| Page 7 of 10 | All times are UTC-08:00 |
| Powered by phpBB® Forum Software © phpBB Limited https://www.phpbb.com/ |
|