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Post by spud on Jun 7, 2022 20:57:57 GMT -8
I didnt save any money. I spent about 450 bux to get second spark below 3000 rpm. Which probably will not do much if anything. I’m just trying it to see if it smooths out random misfirings i have at idle and see if it improve milage or does anything good . Its all experimentation. I may not help anything over my cheap old allison optical trigger ignition. As far as the gear goes i had a msd distributer gear fail against a new msd cam gear so i cant say if any gear will live. You can spend your life trying to find the holy grail perfect source of distributer gears or you can try them and see if they live. Drive it a few miles and look at it. If its junk oh no i killed a 304? Well no i have a blocked off filter bypass. Theres plenty of fools running chicom distributers that havent eaten gears and plenty of people that spend good money on supposed good domestic parts that have eaten gears so thats anybodies guess. If i was guessing i expect this gear to fail. Lets find out. It shouldnt take long.
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Post by spud on Jul 15, 2022 5:11:51 GMT -8
Ok so the extra spark seems to be a huge advantage. Low speed response, drivability, idle stability and economy are greatly improved. I think the configuration of my low compression 304 with a large combustion chamber atop a small bore is a disadvantage the msd has helped. The combustion chamber is bigger than the bore and overlaps the deck of the block. It may be multiple sparks has advantage lighting the complicated combustion area off. The summit billet generic distributer gear has survived, i have a curve i can live with. The a/f ratio gauge was instrumental in the ongoing recalibration of the avs-2 carburetor, which has improvesd as well. Still doing small tweeks to the power circuit. And it has all paid off, my last tank of fuel netted me 20.67 mpg commuting to work, even with the occasional alter ego power tests. Even leaned out it runs cool with no pinging. I still am looking forward to a good long roadtrip to see what kind of milage she gets on the hiway. All in all the eternal javelin’s 304 has surprised me with its happiness😁. I’m pretty happy with the summit distributer despite its unusable vacuum advance, and the performance of the msd street fire box, its a great ignition system for my tuneup
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Post by spud on Jul 17, 2022 18:29:12 GMT -8
I drove the javelin 470 miles round trip to east texas this weekend and averaged 19.1 mpg hiway. Whats interesting is i got a mile per gallon better commuting to work. I figure the interstate just eats more fuel at 65-70 mph. The car seems happy driving that speed and driving slower takes more concentration. My speedometer and odometer are accurate, as compared to gps data. So all the tweeking i did on that old speedometer was worth it. I had to go to a 21 tooth gear in the torqueflite fot the 2.87 rearend and 255/60r15 combo, and its actually closer that the 22 tooth gear and 3.15 gear with 255/69r15 combo. But anyways something that kind of sucks about the carter carb is you can’t tune the idle feed. Why that is a problem is i have tuned the idle mixture and cruise circuits to approximately 13.5-14.5 to 1, but when your just off idle with light accell or just below cruise in decell you go rich at about 12-1. This happens when your running on the transition slots. I dont know what to do to try and lean out the idle circuit in this range of operation. Now if i had a qft holley the new breed of billet metering blocks have tuneable idle restriction jets and the main body has changeable idle air bleeds to accomplish this. I think i can drill the idle air bleeds on my carter, but since you cant undo a change like that, i dont want to try it. I’m looking at maybe trying a quick fuel holley style carb again. The brawler is pretty cheap and has way more idle circuit tuneup options than my avs-2 . If your gonna tune your carb, a carb you can actually get in and tune might be the better option. I might be getting down to splitting atoms looking for a tune up that precise. Its just kind of interesting looking for better power and mileage. I must say the tuneup is much better than before. The car really drives a lot better and has better cruise power leaned out. I think it could be maybe a little better. Its not any faster but it definitly has better driveability and ecomony with a leaner cruise and idle.
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Post by landbarge on Jul 18, 2022 10:17:00 GMT -8
I got motivated to get off my ass and take a whirl with my antique AFB carbed 360. Dropped the exhaust pipe, welded in a bung and hung the gauge. I got to set the idle mix just in time for the O2 sensor to take a shit,
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Post by spud on Aug 4, 2022 17:37:02 GMT -8
Moving forward in intake system development. ( sounds impressive huh?). Yeah so this is what i did. I shifted gears a bit and bought a QFT “ slayer series” 450 cfm vacuum secondary carb. How that happened was i came to the conclusion my edelbrock 650 avs-2 had its limits. First off it was really too big for my porposes, secondly being as large as it is the idle calibrations are too rich for my needs. Now i can tune the idle, but the big issue is i cant tune the “ off idle” or “transistion” area, which is where i cruise at for the most part, and this is causing excess FUEL CONSUMPTION… which really bugs me. The carter design is not tuneable in this respect, in terms of idle air bleeds and fuel restrictions, they can be drilled out but not “ undrilled” out so tuning is pretty unforgiving. So my next idea was try a smaller 500 cfm avs-2. Which seemed a good idea, and would likely provide a leaner idle circuit, but its still not tuneable. So i started looking at a holley carb. And after a bunch of that i settled on the 450 slayer. (Which was the same money as a 500 avs-2 ) and i figured the size was very good for my 304, but the real sell was the slayer was the most tunable holley carb option. It has a fully tuneable metering block with replaceable idle restrictions, power valve restricions, 3 stage emulsion restrictions, idle and main air bleeds, the works. So i bought the damn thing. Now i can start tuning a smaller carb all over again. The 390 holley i had tried previously has some tuneup issues i could not resolve due to the unchangeable air bleeds, idle restrictions and noteably the woefully small power valve restrictions. It was a mess on the 304 really. I suppose holley calibrated it for something odd like a four or six cylinder. But that is definitly NOT a limitation with this qft slayer 450. So its on the car and ready for evaluation with the AF ratio gauge. Looking for more power and more milage from LESS carburetor. Why not. I was only using half of the 650 avs-2.
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Post by spud on Aug 7, 2022 8:01:38 GMT -8
And heres what happened. Its super lean. Not exactly what i wanted, but i asked for it i guess. I adjusted the idle speed and mixture and it idled fantastic, smoother than the avs and a much steadier a/f reading. But when i tipped the throttle it died. I richened the idle to about 13, and when i tipped the throttle it stumbled and showed 16-17 to one, super lean and surging. I pulled the metering plate out, it had 26 idle jets. I only had some 39s, so i tried em. I checked the mains and they were 55. Qft sez they come with 56’s factory. Uhh not this one. So i tried the 39 idle jets. It runs and drives ok, but the idle jets are a little richer than my ideal, and the mains are too lean, it suges over 2000 rpm. So i ordered parts. So it looks like this is gonna take some tuning. Good thing is i can do it to this carb. The a/f readings on this carb are a lot more steady than the avs. It is a nice carb and i am not discouraged. I think it will be nice when tuned in . The vacuum reading at idle a little higher and steadier than the avs. Well when i get some jets i think i will try some 36 idle jets and some 60 mains and see what it looks and runs like. One thing that does suck is holley bowl gaskets dont fit the qft metering block pins. Order more gaskets. I got so many carb parts i cant keep up with them.
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Post by landbarge on Aug 7, 2022 8:46:32 GMT -8
You're gonna have a helluva carb parts inventory by time you're done.
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Post by spud on Aug 7, 2022 8:49:46 GMT -8
They have been piling up for many years. I could fill a room with carbs and parts. Not sure why the carb fetish. I guess i think they are magic or something. I’ve sold so many good carbs and seem to have kept the ones i dont love. It bugs me my best stuff gets sold to carb butchers who dont know how to love a carb properly. I have carb guilt. I have carb envy. I am a carb hoarder. I need to be in the carb business i guess. I’d like to go carb picking at cappys carb treasure island. Its so hard to keep carb stuff organized. I always go rumaging and screw up my alleged system. So many small parts and different models. Argh !Time for a beer run.
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Post by landbarge on Aug 7, 2022 9:44:04 GMT -8
At one point I had a healthy bunch of AFB rods and jets. Besides their strip kit, I had a more than healthy assortment of rods and jets that I collected over time from bone yard shopping. The garage fire quickly turned that into a brass reinforced puddle of plastic. Now that I'm tuning this old 390 AFB takeoff, I'm back to getting jets by the pair and waiting 4 days at a time for the mail to arrive
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Post by spud on Aug 7, 2022 10:08:35 GMT -8
I sold a 400 afb years ago. Big mistake! It was an original amc carb from a 290. I havent seen another one in decades. I love carter carbs. I have a thermoquad that i always wanted to try , but neverhave. I am waiting for a quadrajet pattern amc manifold that i guess doesnt exist. I have this idea in my head there was a quadrajet pattern amc manifold, made by somebody, but i think now i am mistaken.
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Post by Captain Awesome on Aug 7, 2022 10:11:48 GMT -8
I've been pretty lucky and found 3 Edelcock kits at the Swap Meets for $5 each.... I have an Old unopened Carter Strip kit I got from a neighbor for $20. One Eddy kit I got raped on at the Junk Table for $25.. I should be set..... I've missed 3 Swap Meets this year, and prolly more cheap kits....
Uncle Randy has about 200 Carbs and one Carbed car. Everything else is EFI. I actually want to smack him when he picks up another carb....
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Post by Captain Awesome on Aug 7, 2022 10:12:50 GMT -8
This 400, is that the same small bolt pattern Carter they used on the 50s/60s Chebbys? Real small barrels in the intake too.
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Post by landbarge on Aug 7, 2022 10:35:03 GMT -8
One of that bargain basement shit exists round here
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Post by 69Rebel on Aug 7, 2022 11:33:44 GMT -8
A Q-jet won't fit the AMC spreadbore manifold?
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Post by spud on Aug 7, 2022 12:14:03 GMT -8
A Q-jet won't fit the AMC spreadbore manifold? Naw. The amc spreadbore intakes fit the queer motorcrapt spreadbore carb… I tossed about a half dozen of those into the scrap bin a few years back. I have never found an amc intake that fits the normal quadrajet/ thermoquad/ holley spreadbore pattern.
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