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#1
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Whats the best all around carb for a 440 ?
looking to get some opinions on what would be the best
carburetor for my application. Also hopefully Cuda66273 will reply as you seem to know quite a bit about carbs. I have learned a lot just reading your carb tuning posts. Anyway I do not get along well with carberators. I understand the principles about tuning them but I just don't seem to get it right or ?? So a carb that requires a lot of tuning is not a good choice. I can do a little tuning so thats okay. Application is 1969 HP440 w/edelbrock performer intake. 1 7/8 headers going into 2 1/2 dual exhaust to rear. Meineke (?) quitest heavy duty mufflers. I know a lot of back pressure but I want quite. A727 torqueflite w/B&M shift improver kit (RV/heavy duty). 3.92 gears, NP 205 transfer case, 31 inch tires. 1974 Dodge adventurer sport 4X4 (5100 lbs) For the most part the truck is used with rpm's from 1200 to 2500. The gearing causes me to be around 2800 to 2900 @60. I currently have a carter AFB 625 cfm but there is just nothing there when you step into it. I have one of the larger carter thermoquads (1 1/2 primarys) that is supposed to be around 830 cfm but I don't want to spend the time rebuilding it (has sat for a few years) just to put it on and have it work like @#$%. So bottom line is that I would like to find a reliable carb that would give me the good low end response like the carter but have a little more when I step into it. A long time ago I was using a Holley double pumper that was only a 650 but it sure had a lot more when you stepped into it. Any opinions greatly appreciated. |
#2
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Carb
Holley 750cfm with vacuum secondaries...
Jet it and tune the spring (secondaries) and your done...I`ve never had to tune the chock on these, they have been set right out of the box. Joe Indianapolis,In. |
#3
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UUMMM! yeah right?
yeah okay you say jet it? I am assuming you are changing the
main jets? Did you do this to richen a lean condition or ?? Remember I have little knowledge of carbs. Tune the spring I think I can handle but why jet it? Sorry for the lack of knowledge but of course that is why I ask. |
#4
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tuning
Hi,
The way I tune is to set the idle mixture first, on a holley there 2 small screws to do this...1 on each side of the front half of the carb...Hook up a vacuum guage to it while running and turn each screw until you get the highest reading. Turn the screws 1/8 turn at a time....It a slow prosess but worth it.... After that is set, cruse around abit (3 or 4 miles) don`t use full throtle. Shut down and pull a few plugs....Look at the color, if black your too rich, if white your too lean, if a tan just right.... The main jet control the cruse..They are behind the front float bowl, when removing the bowl gas WILL leak out, so be ready... The jets (2) are brass,have a hole drilled thru it, and a wide blade screw driver slot in them..They are also numbered on the side... If your plugs are black you need to install lower numbered jets..I got 2 steps at a time until I get a tan plug reading..After each jet change you need to do the cruse thing... The secondary spring set how quick the back barrels open, the lighter the spring, the quicker they open.... I start with the light spring in the kit. (sold seperaly) Drive down the street in low gear around 10mph and then floor it....If it bogs down, the spring is too light....Step up to the next lightest spring, do the same test until the bog is completely gone and your done....... You can leave the stock spring in there and be ok, the secondaries won`t open up as fast but you`ll be ok.... Hope this helps. Joe Indianapolis,In. |
#5
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I'd opt for two Holley 450 center floats myself!
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#6
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Get the Edlebrock 750 cfm vac secondary electric choke.
I had to screw around with the linkage. The only other adjustment I had to do was set the idle mixture. Good runner, no problems, and cheap(I bought the factory reman, It's a fair bit less than the new) I gained nearly 50 horse power(on my G-tech meter) when I bolted this on in place of the edelbrock 600 I was using. |
#7
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Hey Jeff..your just up the road from us...why don't you give me a call tomorrow morning on our toll free line
TOO-TOO-MUCH....866-866-7845 I'd like to talk a little about how your using the truck and what you expect out of before I make a recommendation. Later Don |
#8
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This fella knows T-Q's! He'll do you right.
http://www.geocities.com/thermoquads/ |
#9
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ThermoQuad by Demon Sizzler. They are the best, & Dave is super with them & very reasonable - your carb custom tuned to your application for under $175.00 !! Use the link from Rumblefish - above, and if that doesn't work, I'll give you his address, phone number & email address.
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#10
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great lots of choices
Cuda66273
tried your number you list and it doesn't work. Got a local #? I can call that. In any case the truck is simply an all around truck. I use it to haul motorcycles up into the mountains, haul a yard of bark back to the house, pull stumps out of the yard, See how deep of snow I can get through without getting stuck etc. I am looking for a carb that would give me good low rpm response and the little carter 625 AFB is great for that. With the carter it runs really well at low RPM's but when you put your foot to the floor you almost want to get out and just start dumping some fuel in. The Holley 650 D/P had so much more it is just remarkable the difference. The holley always had the big stumble coming off the idle circuit. To prevent a stall you had to tap the pedal a couple of times. I am looking for a carb that will work good at low rpm's but also be able to provide enough fuel when I step into it to get the motor to come to life. The little carter just doesn't do it. I want to be able to step down on the gas and if the tranny downshifts it should bark the tires. It used to with the holley. Everybody, The link you guys provided to the thermoquads looks good. Do the Thermoquads actually work really well. I have heard good and bad things about them so ?? |
#11
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The ThermoQuad is the most intelligent carb ever designed. The best part is that it's a regular production carb - not just a buzzword carb designed specifically to make one guy rich. The T/Q is easy to tune and easy to make go fast. It gets great mileage and low-end torque, due to the tiny primaries,and great top end, due to the huge secondaries. No power valves to blow, no gas spilled all over the engine when you want to change something - making you and your car a giant fuel-air bomb. The plastic body keeps your fuel cool and dense, for more mileage and power.
I don't make any money when someone has his carb done by Dave at Demon Sizzler - he just does a great job - really inexpensively. You can spend a hell of a lot more money, but for your application, you can't buy a better carb. You could put on fuel injection if you want a tiny bit better cold start and incline performance, but for most real applications, it cannot be beaten. |
#12
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Doug thanks
Thanks for the reply and I do lean towards getting the TQ
rebuilt. I searched web pages about Thermoquads quite some time ago as I have 2 and wanted to find out what they were for. My understanding is that they basically made 2 versions 1 with the smaller 1 3/8 (approx) primarys and rated it at about 800 cfm. They also made a larger model that has the 1 1/2 primarys and is rated at about 830 cfm something like that. I have both versions 1 with the smaller and 1 with the larger primaries. On the chart I came across the larger primary one is a 6452s which is supposed to be from a 1974 HP360. Would this work well on a 440? The other one I have with the smaller primaries is a base model 1979 truck w/360. If I go with the Thermoquad I am thinking I would be better off with the 1974 HP. Right? Wrong? Again thanks for all the help Jerry (jlcoffell) |
#13
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Jerry - on my 440/452 tow motor for my '75 Ramcharger 4X4, 4 speed truck tranny with 33" tires and 3.56 gears, I used the little one, because I wanted the best low-end, and the best economy - if you can use the terms "440" and "economy" in the same sentence. The 800 cfm will feed your truck fine on the top end, unless you really want to pull a lot of RPM. I designed my engine for use under 5000 RPM. Desktop Dyno says I have 375 horsepower at 4400, and 500 pound feet of torque from under 2000 to over 5000. I believe that will pull a good sized stump. By the way, I'm using a factory T/Q manifold now, but I'm about to switch to an Offenhauser Dual-Port, with a 1 inch 4 hole wood spacer, to enhance the torque curve some more. The primary use of the truck is to pull a 2 horse trailer - lots of it in the mountains.
By the way, there was also a Competition ThermoQuad, which flowed over 1000 cfm. |
#14
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For your application, I would agree. Get that TQ rebuilt and bolt her on. I had a TQ on an old 383 with a Torker intake. This thing hald lots of low end grunt (unusual for a single plane). You could tell when the secondaries opened, as it was like dropping in a larger engine.
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#15
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HHHMM??? Which one?
So does this mean your vote would be for the smaller primaries
or larger? Doug is using the smaller carb but has a very simliar application. I was kinda leaning towards the larger one but Doug is making me think of the smaller one. |
#16
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Sorry, to say this but Wedge 440 has it wrong.
Cruising around then checking for spark plug color is not the correct method. The method to get ACCURATE reading of the spark plug color is to drive WOT then immediately shut off the engine and coast to a stop. Then get out and remove the spark plugs to inspect. I know that is not the most convenient way, but the other way will give false readings due to idling. Also gasoline additives and/or octane boosters will discolor the plug too. |
#17
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What the larger primaries do, is to let you rev the engine a little higher before the demand for the secondaries occurs. On the top end, there is very little difference between the 2 carbs. I tend to drive with as high a vacuum as possible, on the primaries. for the best possible (so-called) economy, and the quickest possible throttle response - because it's a high-geared rear-end with a stick tranny. If you are more lead footed than I am, you might achieve better economy with the larger primaries, because of the delay in secondary tip-in. With an automatic, throttle response would not be an issue, but economy would. Lots depends on your whole engine and chassis setup, as well as your preferred driving style.
If I was looking for a substantial performance increase, I'd use the 1000 cfm T/Q, stiffer rear end ratio, RPM Air-Gap manifold, and a hotter cam. This isn't what my truck is designed for. Horsepower for me, in my truck, is very secondary to moving the torque peak as close to idle as I can. I also designed the engine to be as detonation - spark knock - free as I could. 66Dodge is right about reading your plugs. Additionally, if you use multi-electrode spark plugs - like SplitFires, or Bosch Platinums - it is very difficult to read them. Also, if you're using a very high energy or multi-spark ignition, it's tough to impossible to accurately read them. Any questions? |
#18
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Doug and Ed are right about the T.Q. If a T.Q. is what you desire,
a well prepped/tuned T.Q. is hard to beat and will not only perform, it will deliver pretty d a r n good gas mileage too. Use the large primary(850 cfm) carb since it will perform better even in it's stock state-no initial tuning vs the 800 cfm small bore, DAVID. |
#19
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DEMON SIZZLER IS "The Man". He is the dude you want to have set up your carb. When he is finished, he even runs the carb on his big block!
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