What is YOUR carburetor setup? Tuning issues here...

[Kern Dog]

I am looking to increase the efficiency of the 493 in my Charger. Please, before you chime in that..."If you want mpgs, buy a Honda...", I feel that a well tuned engine should be able to run strong, relatively clean and get decent fuel economy.
The stats: 10.8 to 1 compression, 440 block with 4.15 stroke, .030 overbore. Edelbrock RPM heads and intake. MP '509 cam installed straight up. 2"TTI headers with 2 1/2" exhaust. Barry Grant 850 VS carb jetted 85/92 with a 3.5 PV. MP Chrome ECU. Timing set to 17 degrees initial, 31 total plus vacuum advance. 727 with 2500 stall, .78 GV Overdrive 3.91 diff, 3.05 final drive in OD.
I'm curious as to the details of FBBO members engine tune. The Charger runs strong. I got 12.9 mpg on a tank of freeway driving @ 60 mph. Yeah, the cam is a dinosaur and I'm leaning toward something more modern. I'm interested in what jets, power valves and settings FBBO members use.
Thanks, Greg

 

[tpodwdog]

...lol....youre joking....RIGHT ? id be happy with the 12.9

greg....buddy....my man....i have a 440..10.5 compression...hemi grind cam holley 750 3:55 gears..3500 stall converter.... and on a good day it gets 4 1/2 miles to the gallon...and thats if im nice to it, and i never in my life had a car run this good...EVERRRR. it cant possibly run any better than it does right now.

gas mileage and economy just aint gonna happen coz it sounds like you have a hellovalot more going in your motor than i have.

forget economy and just enjoy the car for what it is.oh...and if you want economy...BUY A HONDA!...or a volt...or a spark....or a bicycle.....or just walk for that matter !:headbang: ROKK ON BRUTHA!

 

[moparmarks]

How do your plugs look? Those are some big *** jets but your at sea level and I'm at 4700'. 12mpg with that setup is pretty good.

 

[Kern Dog]

I met up with 2 Moparts members when in LA last weekend. One has a 474 Hemi in a 70 Road Runner. He has his tuned in and gets 14-15 with a dual 4 barrel setup. Another had a 542 Wedge in a 68 GTX that has seen 15. These cars can be tuned to do better. If an engine is running efficiently, it will make more power, produce fewer emissions and get better mileage. I'm still hopeful that some here may chime in...

 

[moparmarks]

Thats why I ask how do the plugs read? They may hold your answers.

 

[lewtot184]

65 coronet, 440-sixpak, 9.3:1 compression, ported stage 5 heads, engle k65 solid, auto with street hemi converter, 3.23 rear, MP ignition with a good tune, 13-14mpg at 65-70mph.

 

[m79ded]

Your car is doing very well as a matter of fact fantastic is more like it. Don't laugh at this but I put a very nicely prepared Thermoquad and not only did the car pick up 2 tenths and 1 mph it practically almost got double the mileage. Go with a better cam as well like a voodoo 60304 or custom from places like Bullet cams or Cam Motion, you will thank yourself for doing that

 

[Kern Dog]

VooDoo? I have heard some good things there. I prefer to stay hydraulic flat tappet.

- - - Updated - - -

I just ordered an AEM Electronics Wideband Air/Fuel guage from Amazon for $168 plus CA tax. This should allow me to establish a baseline. From there I'll have clear evidence of each change i make.Thanks guys. I'll keep you posted, Greg

 

[Garys1969RR]

I am running a 509 cam in my 69 RR, 3.91 gears, Street Dominator intake, 12.2 to 1 C/R, Holley 3310 vac secondary 780 CFM. 906 heads, Auto, stock exhaust all the way from the HP ex manifolds to the oval tips. And if I dont feed this 451 the 100 Sunoco fuel it demands, it then coughs, sputters, and makes funny noises around the cylinder heads area. I'm guessing around 10 MPG on a good day. If I ever hit the lottery I plan to fill it up. Then I can get an accurate reading on MPG. Lol.

 

[Meep-Meep]

I'm not sure what type of metering circuit the BG carb has but you might do better by going to a street tuned carb (assuming the BG is race). The difference is the PVCR's on the race carbs are pretty small because they don't want to rely heavily on the power circuit to provide fuel at max power for fear it can close and go lean. Street carbs are jetted leaner, probably have a different emulsion tubes and use large PVCR's to dump extra fuel when needed. Also the .509" cam is an upper RPM power producer and probably doesn't like the OD. Somehow I think chugging along with a 3.05:1 ratio is not very optimum.

With a stroker motor you should be able to put a cam that has less overlap and better matched for off idle through 5000 RPM. Still 12.9 MPG is not bad assuming this is an accurate calculation.

My 440 is very mild and ran its best with a 750 Eddy AFB, factory iron intake, Hooker 2" headers and 3" noisemasters all the way out. Gears are 4.10 but I have had 3.55's which also worked well. The carb is jetted box stock on the primaries and 4% richer on the secondaries. My speedo is not working correctly plus I don't have the proper gear so I never bothered to calculate mileage.

 

[Garys1969RR]

Well it still seems that the original factory setup on a 440 is hard to beat, far as low end torque and efficiency goes. And that is the Carter AFB, (Eddy these days), stock iron intake, magnum type cam, and 915 closed chamber heads with a .020 head gasket, and piston to deck clearance of around .040, .015 even better. I've heard of this type build running high 12s in a 3800 lb car, (with minor refinements) and still getting decent gas mileage and great drive ability. Chrysler spent alot on research and development, and came up with a really good package in the 1967 440.

 

[Garys1969RR]

Another option for economy in a muscle car engine, is converting to E 85 fuel. There are special metering blocks you put in your Holley carb, to allow E 85 to be used. This is a 105 octane fuel, cheaper than premium. Works well with high (12 to 1 and up) compression ratios. I intend to put 915 closed chamber heads on my 451 this winter. This will bump C/R to 13.3 to 1. Then will try the E 85 test. Have heard of guys running it at the track with 14 to 1 C/R, running in the 11s. $2.89 a gallon sure beats $7.99 C Ya

 

[m79ded]

VooDoo? I have heard some good things there. I prefer to stay hydraulic flat tappet.

- - - Updated - - -

I just ordered an AEM Electronics Wideband Air/Fuel guage from Amazon for $168 plus CA tax. This should allow me to establish a baseline. From there I'll have clear evidence of each change i make.Thanks guys. I'll keep you posted, Greg

Lunati voodoo cam 60304 hydraulic cam

 

[Kern Dog]

That Lunati 60304 number comes up as a Buick 455 cam. Mayby Lunati's site is AFU ?

 

[451Mopar]

Your combination looks good. Your MPG is decent too. You may be able to add a few degrees of total timing?, and may want to see how quick the curve comes in so the timing is advanced when turning low RPMs in overdrive. I guess the vacuum sec does not have a power valve? Carb tuning with a wideband air/fuel meter and a vacuum gauge may help spot areas you may be too rich? You may be able to change the power valve restrictions to tune in the increase of fuel when the power valve opens? You could tune the main jetting for around 15:1 A/F with the power valve closed, and around 12.5:1 A/F when the power valve opens. A MSD type ignition may also help if you have inconsistent fuel distribution (fuel drop out, etc) at low RPMs.

 

[67 coronet]

i dont really even look at milage #'s, thats not why i drive a muscle car.that being said,my current ride is gonna get some really horrible millage.880 cfm fully custom flow benched holley dp.600 lift cam and around 11.8 comp ratio along with a victor intake should make for some serious fun on the street!screw the mpg's(anybody can fake those #'s with a spread bore tq)i am here to make power and nothing but power.see ya at the gas pump!

 

[RustyRatRod]

Buy a Honda. ;)

All kiddin aside, As has been said, the plugs tell the story of the tune. Get the plugs readin right and it's dead on. Optimize the timing and make sure you're getting all the advance you need. Does it have vacuum advance? Is it hooked up? If not, that will help mileage. Get the carburetor as lean as possible without a sacrifice in performance and that will help as well.....but honsetly, it sounds like you're doin purdy good.

 

[moparmarks]

Buy a Honda. ;)

All kiddin aside, As has been said, the plugs tell the story of the tune. Get the plugs readin right and it's dead on. Optimize the timing and make sure you're getting all the advance you need. Does it have vacuum advance? Is it hooked up? If not, that will help mileage. Get the carburetor as lean as possible without a sacrifice in performance and that will help as well.....but honsetly, it sounds like you're doin purdy good.

Thats what I was saying. Read the plugs. 85/92 seems like alot of jetting but may not for sea level.

 

[m79ded]

That Lunati 60304 number comes up as a Buick 455 cam. Mayby Lunati's site is AFU ?

Those guys @ lunati are messing with part #'s. it used to be that #

 

[Kern Dog]

I got the wideband guage today. I'm going to buy a vacuum guage as well. I'm going to mount them where the ashtray door currently is. I don't smoke, so this is as good of a place as I can find. I bought ABS pipe and some pebble grain 3/16" plastic sheet. Stay tuned. I'll post pics as soon as it is done.
M79ded: That Lunati cam seems milder than what I have now. I am not nearly as knowlegeable on cams as you may be, but I wonder how that might work with 53 more inches than a stock 440. I guess I'll have to call and talk to the techs at Lunati. Thanks for the suggestion.