I'm with D.I here, i love Holley 4bbl's but i HATE Holley 2bbl's (well the 2280 anyway )

The Holley 4160 is the easiest 4bbl to work on and its fairly forgiving, i'm running a 600cfm vac secondary carb on a bonestock slantsix with fairly good results, the plugs were a black color last friday when i took them out but the insulators were a dark tan. I swapped from a 55 to a 50 size jet and the plugs are a dark/light tan all the way around now (i put new plugs in) gas milage report is around 20MPG 60/40 hwy/city driving. my only complaint is that at part throttle i have a bog spot, its great off idle, and great after the bog spot but right at around 60mph (where i drive most of the time) there is an aweful bog, the car jerks around etc.. i havent had much time to mess with it saying this was just a test to see if it'd work, i'll finish tuning it when i put my cylender head on, etc....

I can do a jet change in 5 min, with 2 tools and 3 parts, the socket for taking the bowls off, a flat screwdriver for the jets, new O-Rings for the transfer tube (the 100% reason why these things leak is b/c the orings "fold" or "break" and people are too lazy to replace a .10cent item ) and a new set of gaskets (well not for me, i have the "blue" re-usable gaskets )

Justin

P.S. I'm kind of curious as to Carters, i've had no real expirience with the AFB Carters or "thermoquads", what type of vehicles can i find these on? i wouldnt mind trying to "mess" around with one myself...

You're going to love rebuiding a Thermoquad (or as it was sometimes Known: Thermobog) they came in two versions smallblock 750cfm and a rare big block 900cfm version, introduced in 1974 they can be found on mid 70s chrysler smallblock Cordobas in my experience. This is a 2 piece aluminum and phelonic casting and therein lays the problem the phelonic casting is brittle and subject to breakage and cracking and replacements are damn near impossible to find also uses an odd adjustment set screw to set the secondaries and this requires a specific tool if you are not to loose your primary settings this was the number one performance complaint as no one seems to be able to set these correctly. Also the use of foam floats that become poris and require frequent replacement. Also need to be comfortable with a hammer and drift to remove the accelrator pump....Its pluses more then make up for its deficencies, excellent at keeping gas cool due to that phelonic body and capable of infinite adjustments and high flow. Same can't be said for most smog carbs. Still have one laying around but would be way too much cfm for a slant.

I have 3 big block TQ's (2 from 400's, and one from a Cali 440).
the primaries are about as lean as a little BBD, then you got the wopper secondaries. They are the 'worst' carb I've ever had the priviledge of keeping in my 'spares' pile. I wouldn't mind running one on the Hpak to see if it even responds. These are emissions carbs, and the plastic bodies and foam floats made my grandfather keep his AFB in the trunk in case the experimental TQ on the 383 died...

Woof.

-D.Idiot

Justin, wht are you running for your power valve, if it's a 6.5 you might eliminate the bog by coming down to something in the 8.5 range maybe.

D.I
you hit it, i have a 6.5 PV, like i said i pretty much changed the jets and thats all for now, i've been working 10hr days and really only have 3hrs before work each day to mess with it. I'll have to do some experiments later when my cam is installed with the cyl head.

thanks again for the tip, i'll have to take the vac reading while in gear, then subtract two and buy that size PV (i think thats the formula)

Justin

At fast idle I pull 20", at the stop light warmed up it pulls 15-17 depending, and at 70 mph in OD with the 3.55's I still am at 15"....

The little 390 I have will start at 10.5 and see if that works out.

-D.Idiot

That's VERY debatable!

"DW"

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If it ain't broke, fix it!

Rare? I guess that depends on who ya are and where ya are... I have a shelf full of the big ones, but had to search high and low to find a small one to go on a 318 I was warming up! The big "Thermos-quad" came on every 440 from '72-'78 and a bunch of 400's. The small one was introduced on the '71 340 and was later put on a few 318's.

"DW"

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If it ain't broke, fix it!

How so? i could get a 8yr old kid off the street to rebuild one... the hardest part of a Holley is getting it in tune, after that its simple, i've NEVER had a holley go out of tune on me unless i go and piss around with something else...

As for the carters, i have a BBD that i bought new 2yrs ago, 1yr in it quit running, after taking the new ones i got on warrenty back 3 times i got a decent one, guess what? 9mos. in its ****** again

Justin

I can understand not liking the 2280's; It's an OEM emissions carb.

I thought the 2300's were basically the primary side from a 4160?

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My truck is a Frankenstein creation
Built from the dead carcasses of others
And brought BACK TO LIFE!

That was in response to your statement that "The Holley 4160 is the easiest 4bbl to work on...", you then go on to say, in the same post, "...i've had no real expirience(sic) with the AFB Carters or "thermoquads"...", so how can you make that statement on any authority to start with? (which I'm NOT saying the TQ is a good example of simplicity) You go on, above, comparing apples to oranges "...I have a BBD..."... Whoa, wait a minute, I thought you were talking about four barrels! The BBD is quite a simple carb in any case, you don't get a whole lot simpler than they are. Maybe if you really reach back to the stone age...

"DW"

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If it ain't broke, fix it!

As far as easy-to-work-on holleys, the 4150 and the dominator top my list. The transfer tube in the 4160's was a dumb idea. Yes, you may be able to get it to seal, but why? What's the purpose? Simply putting another inlet on the rear float bowl is what they should have done. As far as tunability, if you can get a carb as big as the 1050 to run on something like the stock piston, low compression, fairly small cam 440 I used to run, the carb can't be too un-tunable.

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Everyone driving slower than me is a moron. Everyone driving faster than me is an idiot. With all these morons and idiots on the road, I can't get anywhere!