kerb12":30mcohja said:
Been a few weeks, but I converted over to a Lokar pedal, got everything buttoned up, and chased down some electrical issues. Took it out for a couple short drives and then a good half hour ride this morning. Good news is that the engine seems more steady - vacuum is higher and less jumpy, a/f ratio at idle is a pretty consistent 13.4-13.6, and it starts instantly.
On the downside though... I have to say I'm a little disappointed with the power. I didn't expect a v8, but it doesn't feel a whole lot better than the Weber 32/36 on the small log. Off the line feels pretty good but midrange and top end feels like it's running out of steam. It's almost like there's no difference between having the pedal halfway down and flooring it.
Think I need something bigger than the Autolite 1.08?
Yes, you probably do, although there should be enough meat to take it out 150 thou to up to 1.23...if you break through the casting, you can JB Weld/Devcon it, and emery paper the venturi profile back. Bigger than 1.08 carbs on 200 sixes are hard to calibrate, and even Jeep guys with 258's seldom go above 1.08's.
When tuned properly for air fuel ratio at wide open throttle, the 1.08" venturis always cost top end power when compared to 1.21, 1.23's or 1.33's.
David's(
CZLN6) brother Dennis (
Hot 6t Falcon) has used the 1.21 and is looking at the 1.23 in his 250 I6. Mostly, we give up on the four bigger 2100 Autolites and 2150 Motorcraft's because they are so bitchy to get to work at the idle and cruise air fuels right in a 200 cube level...common complaint is that your fuel consumption will skyrocket with bigger venturi carbs, which is often right as they run very different power valve restrictions, different well tube sizes, different idle air blead restrictions. The Autolite is set up more like a Bendix WW in the way its calibrated, so the K cluster is calibrated by Ford for each instillation. The idle jet in 27 to 32 thu sizes goes down the tubes, and well tube failure influences idle as well. An important point, and what makes the Autolite/Motorcraft carb a little bit tricky to trouble shoot.
The efforts we have are here are always in making the factory fuel curve work without too much extra effort on a small Ford I6.
This is why people at Ford Six tend to only get good results with the smaller sizes of the eight types of generic 2100 series carbs, excluding the two later 200 and approx 360 cfm 2150 Motorcraft. The 1.01 was the first carb, a 240 cfm item in 1957 Yblock base engines. Then FoMoCo started fidling with it for the smaller and larger engines.
2100 Autolite 0.98 = 190 cfm 20 thou under, 30 cfm less, 57 Ford Y-Block V-8, 135 hp 221 2-bbl, 1962 221 FORD FAIRLANE AUTOLITE 2100 0.98
2100 Autolite 1.01 = 240 0 thou over, 0 cfm xtra, 1st 57 Ford 272 190 HP Y-Block V-8, 164 hp 260 2-bbl, 1963 260 FORD FALCON FAIRLANE AUTOLITE 2100 1.01 C3OF-E
2100 Autolite 1.02 = 245 10 thou over, 5 cfrm xtra, 164 hp 260 2-bbl, 1960 198 hp 292 FORD FAIRLANE GALAXIE AUTOLITE 2100 1.02 C0AE-H
2100 Autolite 1.08 = 287, 70 thou over, 47 cfm xtra, 200 HP 302 V8s from 1968 to '73
2100 Autolite 1.14 = 300, 130 thou over, 60cfm xtra, 1964 - '67, on 289s and 302s 200 hp 289 2-bbl, but also the Annular Discharge California 1966 289 carb
2100 Autolite 1.21 = 351, 200 thou over, 111cfm extra, 351 250 hp 2-bbl, 1973 351 MERCURY COUGAR COLONY PARK MOTORCRAFT 2100 1.21 D3MF-DA CARBURETOR
2100 Autolite 1.23 = 356, 220 thou over, 116 cfm xtra, 1967 - 70 from a 351 or a 390 engine, 351 C 265 HP 2-bbl, 255, 265,270,275, or 280 hp gross
2100 Autolite 1.33 = 424, 320 thou over, 184 cfm xtra, '75 F150 133" 360FE, 390 is 255, 265,270,275, or 280 hp gross
The problem is Ford profiled the air fuel mixture to suit V8 engine applications from 135 hp gross to 280 hp gross (approx 100 to 195 hp net) by the four and five hole brass emulsion tubes they called well tubes. The well tube or K cluster assembly selection calibrates the carb to suit applications.
Unlike the Holley Weber and Weber's, Ford's well tube cracks often along the 4 or 5 holes in the brass tube, and it causes other drivablity problems. Jeep guys use the Autolite/Motorcaft 2-bbl on there 232 and 258's and what they don't know, you aint got time to learn. Here is some really good tech info to show how to fix them if they are cracked.
viewtopic.php?f=1&t=70651&p=554757#p554757
Just making sure it isn't cracked is a vital first step. If it is, you can get a supply for a small cost if you know who to ask, or you can solder up the stock tube, or even remake the tube, all pretty easily.
Holley did the same as Ford in calibrating the imortal 2300 2-bbl series, and ran a range of venturi sizes to create five kinds of carb.
200 (Tripower 289/406/427 inner carbs)
265 or 275 cfm (Tripower 289/406/427 outer carbs, or Early AMC 60-64 AMC 250/327 v8,PN 2040/2228/2442/2463, and 64-70 IHI V266,V304/V345, PN 2520/2977/4574/6380/6386 (Holley 2300c series) cfm depending on if it had the truck or car booster),
then 350 (PN 7448,9117, 7217 etc),
500 (PN 4412)
and 650 cfm carbs (PN 6245)
they were, respectively, factory 1.0625, 1.125, 1.1875, 1.375 and 1.4375" ventui carbs (lets call em 1.06,1.13,1.19,1.38, and 1.44".
The Holley 1.19" was the standard SP 221 2-bbl 166 hp carb for the Argentine performance Falcons, and ran a 53 to 56 jet, 6.5 power valve, and Holley RX 7217 part number carb from the factory for years. If an Autolite 2100 1.21 or 1.23 is found, it can be calibrated by K cluster assembley to copy the factory 166 hp I6 settings, with a Holley power valve, reprofiled stock jets to Holley jets sizes, and it will certainly work in the bigger sizes. That's what I run in my Fox Mustang, with a 53 jet.
The way to reprofile the stock Ford F code jets is to solder them up, and then have a jewler copy the Holley 53 to 58 call size jets, which should get you close. A good jewler can actually make a whole brass jet in the Ford F pattern screw size, but in the listed Holley jet profile. That kind of jet will flow very close to the stock flow rates listed in the link.
If the air fuel ratio is lean or rich, you can then add or remove one hole from the stock 5 hole K cluster. This is the method David Vizard used for Holley and Weber carb calibration, and it is the secret to creating a proper fuel curve for our 2-bbl carbs, no mater if its Autolite, Motorcraft, Holley, or Holley Weber.
Good thing is, Autolite 2100s, Motorcraft 2150s and Holley 2300 series carbs aren't really sensitive to emulsion/well tube calibration, but it certainly leans or richens up fuel delivery if its a problem at the low or high end, and its very easy to fix if you have access to an air fuel meter. Its easier than making a hash of the idle air bleads
Note that after 1964, Ford rehashed all the formerly Holley jets to the Autolite/ Motorcraft F jet calibrations due to intellectual proprety issues, as Fords purchase of Autolite was crossing over Bendix patents, and Ford eventually ran foul of Government anti trust legislation, and its was why Autolite became Motorcraft, and FoMoCo had to shell out to Bendix Stromberg over patents and purchase of Autolite. The Holley to Ford interchange is listed here below on oriface size.
The F jets interchange on oriface/drill size to flow rate, but they don't physically interchange due to the screw size being different.
After 1964, the Ford F stamped jets and Holley jets divereged. If the Holley 350 cfm 1.19 carb in the 166 hp 221 SP ran 53 to 56 jets, you'll get away with going down about 3 or 4 jet sizes in a 1.21 carb if your engine is simarly kitted out.
Due to the flow rate and profile of the Ford xxF stamped jets after 1964, all 2100 and 2150's and 4100's get away with lots smaller jets in Fords F stamped jets than the same size venturi Holley 2 and 4-bbl carbs.
A set of 43F are like 47 Holley jets by the way they flow in cc/minute, 20% more than a Holley 43 jet
A set of 47F are like 51 Holley jets by the way they flow in cc/minute, 15% more than a Holley 47 jet
A set of 50F are like 54 Holley jets by the way they flow in cc/minute, 15% more than a Holley 50 jet
A set of 58F are like 62 Holley jets by the way they flow in cc/minute, 21% more than a Holley 58 jet.
The Autolite/Motorcraft flow rate curve is dickey, though. Due to the way in which Holley's oriface sizes differ from the Holley call size, and how Holley flow rates change, its unlikely a Ford jet stamped 72F would out flow a 76 Holley jet by 25%.
See as well
viewtopic.php?f=1&t=68684&p=526505#p526505
I'm sure you do know what you're talking about Faron. The point is, ideal these heads are not in the first place when it comes to fuel distribution and it's impractical to mount a 2100 with the bowl torwards the rocker box. Lot's of people have run that configuration. And I suspect with a phenolic riser, 1" would be better, and the mounting plate the problem with butterfly orientation is being minimized.
