To your point James, the most common issue with the AFB pumps in my experience is the check valve in the space under the two jets . it can stick closed or almost closed ,it corrodes , as does its cast surroundings --- then does not slide freely , especially in stored cars. It was fitted too tight by design error !!!There are multiple styles , some brass , some rubber tip etc To find that , was a real bear , as gas still comes out of jet, -- just not enough . --- other things get blamed , like the pump .adjustments etc etc
Combine that with your explanation of nozzle jet size = bog , backfire , no start etc , with a perfect pump
The pump is not designed , imho, to seal perfectly to sides of well , scratches just do not matter, look at how the center is joined ( often an unsealed fit on original parts, ) can pass gas too .
It just does not matter , most goes out jets, the psi is set by the spring -- leak or not at well --minor scratches in well mean nothing .Expansion spring in a circle with leather pushed it out wards
The original leather is very good if oiled / soaked in oil at assembly
But drys up in stored car , can be oiled again , not a cool new kit with nice color rubber pump .
New rubber / plastic ones are marginal get scrapes / cuts on rubber lip , leather kind of self fixes
Just me ,no self proclaimed carb expert , but 56 years of hard knocks on AFB
I like WCFB more now -- with the cast iron bottom , --- with aluminum, the bottom shafts get worn loose , leak air , unstable idle/ idle mix . You can buy reamer and bushings for 40$ to fix that, save 500 rebuild .
Floats on AFB are often mangled by prior attacks by the golden screw driver expert bending the float arms. , not all at same exact height BEFORE setting shut off height , then one side of float leads the other= mayhem .
Best today imho is AVS , terrific carb very accurate out of box due to emissions driving machining tolerances on carbs , ever better uniformity / accuracy
Have personally seen dyno test where zero adjustments were needed, golden screwdriver just makes it worse. .... perfect real time measured A/F ratio across all conditions , --- with just one of them , 750cfm 600 HP on 500" 460 Ford / Lincoln . ( can you say 413, 440 ?)
Let chevy or Ford guys try to match that with weeks of fooling with Holley " strip kit" , once you do , you get 10 mpg .
Thermo quad good too, but less support , odd huge secondary holes .Like GM
Edelbrock sells AVS now ..
Back to EE
Allen, the accelerator pump exits through the jets. The diameter of the jets sets the rate of flow of the jet. A larger well would mean a longer squirt, not a larger squirt.
I think I have is write in my head, but these days who knows…
I will go look when I am back up in Winters as I have a spare carb up there.
An interesting dilemma.
James
I have been going in circles on a replacement accelerator pump configuration. My carb was rebuilt with a 3/4"
but shorter pump. Aluminum has worn into the leather after a short time, so i thought I had to replace with a 11/16".
The manual and the Carter product pages state that the 3614S takes an 11/16" pump. The well measures 47/64".
As does a 3615S for an Imperial and New Yorker.
I now find this little snippet online:
Why Your 3614S Measures 3/4" (Instead of 11/16")
Carter's official technical charts for the 3614S blueprints list an 11/16" pump cup, but you are holding a 3/4"
bore in your hands for one of two highly common reasons: [1,
2]
- Mid-Year Production or Heavy-Duty Casting Changes:
Carter frequently updated castings mid-run or shared cast bodies across different assembly lines. Heavy-duty applications (like the high-performance Chrysler 383/413/426 Wedge big blocks that the 3614S belonged to) were routinely upgraded to the larger 3/4"
accelerator well to dump more fuel and eliminate the off-the-line flat spot inherent to moving massive Mopar B/RB-body cars.
- A Past Machining Rebuild (Sleeving/Boring):
It was incredibly common for commercial rebuilders in the 1970s and 1980s to clean up pitted, corroded aluminum Carter wells by boring them out exactly 1/16" oversized to accept the larger 3/4" plunger cup.
Has anyone else run into this issue? Both bores and scored up a bit, so I don't think they were machined any
larger in the past.
Allan
--
For archives go to
http://www.forwardlook.net/300-archive/search.htm#querylang
---
You received this message because you are subscribed to the Google Groups "Chrysler 300 Club International" group.
To unsubscribe from this group and stop receiving emails from it, send an email to
chrysler-300-club-international+unsubscribe@xxxxxxxxxxxxxxxx.
To view this discussion visit
https://groups.google.com/d/msgid/chrysler-300-club-international/784063014.52402.1784493422336%40connect.xfinity.com.
--
For archives go to
http://www.forwardlook.net/300-archive/search.htm#querylang
---
You received this message because you are subscribed to the Google Groups "Chrysler 300 Club International" group.
To unsubscribe from this group and stop receiving emails from it, send an email to
chrysler-300-club-international+unsubscribe@xxxxxxxxxxxxxxxx.
To view this discussion visit
https://groups.google.com/d/msgid/chrysler-300-club-international/CH2PR19MB3463CEF051B890649E96D76C93C32%40CH2PR19MB3463.namprd19.prod.outlook.com.
Back to the Home of the Forward Look Network
Archive Sitemap