Holley Carburetor for my 440

[Chatt69chgr]

I am planning on using a Holley 750 cfm carburetor on my 440 in my 69 4-speed charger.  The engine will use a dual plane intake, factory hp exhaust manifolds, be roughly 9.5:1 static compression ratio, and use a hydraulic cam slightly hotter than stock.  I want a choke and vacuum secondarys for street use.  I see that Holley has one offering---a 4160---in shiny finish only.  I don't want the shiny finish.  So my plan is as follows:  Buy a Holley 0-3310C which will give me a 750 cfm, vacuum secondarys, manual choke 4160 style carb with secondary metering plate (ie, fixed jet size).  I then plan on buying the secondary metering block to replace the plate, thus allowing me to change jet sizes on the secondary side, and add the electric choke in place of the manual one.  All these parts are available from Holley.  I believe this carb comes with 72 jets  a 6.5 power valve with blowout protection on the primary side.

Do you folks think this setup will work OK?

Would a number 76 jet be the best for a starting point on the secondary side?

Any and all comments will be appreciated.  Thanks.

[Ghoste]

Try it out of the box first.  I think you'll find the metering plate works but you'll need to run it first to know for certain.  If you plan to tune the carb for maximum performance or modify the negine a little more in the future, that changes things.

[Just 6T9 CHGR]

I was always under the impression that a double pumper would be best suited for a 4 speed car & a vac sec for an auto?

[Ghoste]

Yep.  Depending on how modified and the intended use, the vacuum one will work fine.  Remember, the Six Packs were vacuum secondary.

[firefighter3931]

If you're running a low stall and mild gears.....the vac secondary carb will be fine.  You'll have to try it out before making any jet changes to get a baseline. Using the sparkplugs as a guideline works well....ideally a tan>light brown color is what i like to see. 


Ron

[jg68]

Yeah, i would stay with the 3310, there a good all around carb, just get you a quickfuels quick change vacuum pod #793-63-1, then you can tailer in the seconderies were you want them, they also make metering jet plates for the rear, or get the metering block conversion kit

[Chatt69chgr]

I called Holley this morning and talked to their tech guy.  He confirned that the only way I can get the 750 cfm 4160 in dichromate finish is to order the 0-3310C and add the electric choke kit (45-223).  I will need to add the 20-36 throttle stud, the 20-7 throttle lower extension, and the p/n 26-27  5/16 inverted flare fuel inlet fittings as it comes with 3/8 inch fittings to make it Mopar specific.  The carb comes with a pri jet size of #72 and a -21 secondary metering plate which has an equivaltent jet size of #75.  The power valve is only located on the primary side and is a #6.5 and is blowout protected.  He said I can add the secondary metering block p/n 34-13 if I want to but he said he probably wouldn't for a stock to mild engine build.  Secondary metering block p/n 34-13 doesn't come with a jet so you have to order it extra.  Blue non-stick gaskets are available as p/n 108-90-2 for the secondary metering plate and 108-89-2 for both the primary metering block and the secondary metering block if you change to that.  He said that Holley has an adjustable vacuum secondary pod as p/n 20-99.  I don't know if it is the same piece as a QuickFuels Technology 63-1 or not (and I could never get QuickFuels Technology website to come up).  He said that their quick change vacuum secondary housing cover p/n 20-59 and the secondary vacuum spring kit p/n 20-13 would probably be all I would need however.

If you call them, use the unlisted 800 number 1-866-464-6553.  It took me 25 minutes on hold before I got to talk to a tech person.

While surfing on this subject I found an interesting website:

Carburetor Tuning the Scientific Way
or
How to Tune Your Holley Carburetor
and Other Fuelish Ramblings
By ASE Certified Master Auto Mechanic, Engineer, and Inventor, Gerard Forgnone 

I'am sorry that I don't have the website address (hopefully you can find it by surfing) but he talks about using a Starndard Brands SG-12 oxygen sensor to tune the primary jet size.  You weld a bung in the exhaust pipe  just past the manifold.  Said to use a Chevy spark plug antifoul adapter for the bung.  Then you simply measure the millivolt output of the oxygen sensor which will vary between 100 mv and 1100mv depending on the air/fuel ratio.  He said to shoot for 400 mv.  You simply connect a digital voltmeter to the oxygen sensor output to make the measurement.  He said the secondary is not as easy but usually doesn't have to have jet size changed.  He has a method to use if it does.  He also talks about the vacuum secondary metering pod and how to select the spring for it.  I will note that he doesn't like the electric choke but does like the hot air actuated choke but I don't have a easy way of doing that so will stick with the electric.  He made a point of saying to make sure the electric choke thermostat had a clean fresh air source, o/w, it will burn up and that the electric to it only is supplied while the engine is running or, again, it will burn up. 

Most of you old timers probably know all this stuff anyway but I thought I would post this info for the less knowledgeable.

[is_it_EVER_done?]

Chatt:  Just out of interest, why are you so determined to go with the carb build that you are talking about?

I don't intend to try to talk you out of it because I'm sure it will work great, but you CAN'T SEE the carb with the air cleaner on, so it's finish is irrelevant. Plus, a Carter style is more "accurate" (if you could even see it).

From 35+ years of experience, I find that a double pumper is more suitable for a 4 speed car (about 2 tenths quicker), but the gas millage is horrible. I prefer a Thermoquad for a street 4 speed car as it flows more (850 to 1000+ CFM), but has very small primaries that can get as much as 5 MPG better gas millage over a double pumper in cruise.

I run an 870 CFM Holly Street Avenger on my RR vert, but it has an automatic trans. It gets 15+ MPG on the highway (very mild 440 engine) but will get better once I get the 850 Thermoquad on it and set up properly.

What I don't like about the vacuum secondary Holly's for a 4 speed car is that the transition from the primaries to secondaries is just a touch slow. I believe that a properly set up "Carter" style carb can be quicker on a 4 speed, and it certainly gives better millage than a double pumper. A double pumper can probably get you a 10th or 2 more in the quarter, but for a street car it's irrelevant, and comes at the cost of substantial gas millage.

In any event, if you really want to adjust everything for max performance and millage, you should invest in an LM1 unit. Basically this is a commercial unit that does what you posted in your last post (O2 sensor in the exhaust), but goes much, much further. In my opinion it's the coolest tool you can own.

I only post this before you invest a ton of money into a carb that is at best an extreme compromise, and takes a lot of time to learn how to adjust.

Also, even though I know it's not your statement, the info about an electric choke being weak and prone to failure is a crock! I have accidentally left my key "on" for 4 days and still didn't have a problem, plus I have never had one fail.

[Chatt69chgr]

I guess I don't have any real good reasons for wanting to use the Holley.  I had one pretty much like I described on my 66 Ford Fairlane 390 GTA with C6 trans.  I got a little experience with it so have some familiarity with these.  The finish deal is just personal preference.  I mentioned the O2 sensor because I already have a Fluke digital volt meter and thought it would be real easy and inexpensive way for me to go.  I didn't like the idea of the double pumper because I really didn't want the secondarys to open unless I get heavy into the accelerator.  I really don't plan on ever racing the car at all.  But I do want it to get up on it's hind legs when I hit the accelerator.  The Holley seemed to me to be easier to tune than the AVS since it is mostly a matter of getting the primary jet nailed down and the vacuum secondary opening up the secondarys when I want it to.  I did notice that you are using an 850 CFM.  I kind of thought the 750 would be big enough.  I could give some thought to going a size larger than I had originally planned.  It's good to know that the choke won't be an issue from a reliability standpoint.  I appreciate the input.

I bet it's getting hot in your neck of the woods.  Stay cool if you can.  We are in a drought situation here in Chattanooga.  If we don't get some rain soon, we will be rationing water.