I have a couple of old Holleys that I'm going to rebuild for my tunnel ram. The list # is 4224-S / 1383. I need some info on these - like factory specs, original metering plate #, pump size, etc. Thanks
Just a note here. The 4224 is not a great choice for a tunnel ram or dual carb setup. I know Holley advertises them as being good for this application, but they are a mechanical secondary carb WITHOUT a secondary accelerator pump! The lack of secondary pump combined with mechanical secondary linkage creates huge bogs and flat spots on throttle response. The 1850 vacuum secondary 600 cfm is a much better choice, and will be easier to tune, plus run better even in stock form. The 450 cfm version of your carb is equally a PITA to make work in a tunnel ram. I really haven't figured out why Holley offers these carbs, other than they're cheap and people buy into the "dual carb" advertising Holley is using.
Not technically correct, the 4224 is called a "center squirter" because the accelerator pump nozzle sprays into all 4 barrels at once. That's why it has the bigger 50cc accelerator pump. I and many others have had good results using them on tunnel ram applications. Good for gas mileage, not so much.
Had 2 center squirters on a 671 blown sbc. They can be a real Pain to get working good. Very temperamental carb in my OP.
Like anything else the usefulness of a part is dependent on it's intended application. The 4224 is a drag race carburetor designed for 2x4 tunnel ram applications. They have been successfully used in street applications by many who spend the time to tailor them to their application. If you have a suitable application, the time and desire to "dial" them in and stock in an oil company they make a great deal of power.
Yeah I know they are drag only, but I wanted to swap out my Carter Competition Series AFB's & give them a try on my TR1 tunnel ram. I think they would be tough for a daily driver.
Back in the day they were the hot setup. Not much else was available. They had rich idle and off idle problems. Many magazine articles were printed on how to get them better. Different secondary cam patterns etc. I never liked them because of the uneven fuel flow problems. The secondaries would puddle above the plates when doing low RPM maneuvering and were hell on plug life. I went to twin short bowl 750 double pumpers and the engine ran much cleaner and made more power. Big cube BBC They would be a terrible street carb..
That is a good question, I do not know that I have ever heard of anyone attempting that with a center squirter. Obviously you would have to add metering blocks to the secondary's. Something to ponder today...
Can't, secondary bores are not drilled for the idle ports. As far as the rich idle, restricting the idle passage in the meter block with piece of wire helps.
Changing them to a 4 corner requires a secondary metering plate. Yes, they're center squirters, and yes they have a larger 50cc pump. It still wont make them easy to get running well on the street. The center squirter makes very little difference vs. a primary squirter; it's still squirting gas into a common plenum, and it still doesn't have the secondary accelerator pump or vacuum secondary needed for a smooth transition when used for most street applications. I just took a couple 450's off my engine that I had converted to 50cc pumps, and larger nozzles, plus all the tricks I could do to idle circuits to make them cleaner at idle. I got them running pretty well, but still had a little stumble when easing into the throttle. Great at WOT, and under acceleration. I'm switching to a pair of 600cfm vacuum secondary 1850's, as they are much more street friendly. I bolted a pair on the tunnel rammed 464 BBC in my Falcon, and they run 100% better right out of the box than the Holleys with mechanical secondaries and no 2nd accelerator pump.
I'm going to order a couple of these kits, #34-6 http://www.summitracing.com/parts/hly-34-6 I also attached a parts breakdown pdf
When you're all done rebuilding, reworking, and getting those 4224 up and running, you'll wish you'd just sold them and purchased the new 600's from Holley. I just bought two Holley 1850's 600cfm vacuum secondary factory refurbished carbs for under $200 ea. and that included shipping and insurance. The Holley "refurbished" carbs are new carbs that came back for warranty, and nothing was found wrong with them. They get pulled down, checked, new gaskets, flow benched, and repackaged. A very good deal, as Summit and Jegs sell them for $379, so they're almost half priced.
#4224's are great . . . just make sure you bring a change of plugs for the short drive to the staging lanes from your pit spot!
I got the pair for a good price, so I'm ok with trying them out. It also looks like these survived without being modified in any way (date code '75) I'm gonna start with just cleaning them up with a Holley renew kit & put them back to factory specs. I may try the wire trick in the idle circuit while I have them apart (& I'll get a few pics). My plan is to run the Carter 500's on the street. They are dialed in pretty good right now for a driver, & I really don't want to mess with those. These Holley's will only be for the track. I also am using an MSD box with a Bubba high-winding coil. Here's the post I did on my AFB's for my 455 Olds http://www.jalopyjournal.com/forum/showthread.php?t=634943
Holley also made the List #-4223 which is a 850 center squirter.. I have one all apart in my garage...
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