Hey guys whats up..it been awile since ive messed with da slant so im stopping in to see whats new.

I have a '72 Dart /w a 225 (what else), 904, 276's...

Its bone stock other then an orange box in place of the points...

It gets "ok" mileage but with gas prices going nuts I was thinking of putting some work in to making it better.

I have the oversized head off my almost 10:1 CR slant...upping the CR help or hurt milage?

BBD get better milage then the 1bbl 1920 thats on there? Whats the best carb for pure milage?

I recommend the BBD and freeing up the exhaust for mileage purposes.

D/W

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If it ain't broke, fix it!

Welcome back ! Carter BBS for mileage.

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Isnt there a year BBS that will bolt right up to everything for the linkage and kickdown?

I have a supersix intake and a 4bbl one but no Ssix exst manifold so ill hold off on that upgrade for now...

Maybe tomorrow ill remove the stock style muffler...wonder how crappy its gona sound with just a strait pipe hehe

Did the Orange box replace the "pointless webserver"?

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Yeah....Im the one who destroyed this rare, vintage automobile.....

no...

http://cralt.com/ replaced the pointless server...it to is also pointless.

For a '72? Yes, any '68-up BBS will bolt right up; a '70-'71 Dart/Valiant 198-engine BBS is the best match for all the hose hookups (and for best mileage).

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

i would not remove your muffler. I heard you get 16% better gas mileage with it on. Besides i noticed better gas mileage after putting mine back on, i think....

You could always try Fred Flintstone style. Yaba Daba Doo !!

Oh, Sorry, I couldn't resist.

My "gut" tells me the BBD will get better mileage than the BBS (given the same driving "style" parameters, i.e. not running WOT), due to the smaller venturies (two "small" versus one "big"), the booster venturies, and overall better fuel atomization.

I know for a fact that my Duster got significantly better mileage with the BBD than it did with the original 1920 holley, but I can't definitively say the same thing about the BBS because I have not compared the two on the same car...

D/W

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If it ain't broke, fix it!

[quote="CrAlt"]

I have the oversized head off my almost 10:1 CR slant...upping the CR help or hurt milage?

quote]

Raising the compression ratio will help fuel milage, as long as you do not have to retard the timing to keep from pinging. At 10-1, premium gas is almost a must.

I don't know first hand, but have heard the progressive Webber 2bbl gets good fuel milage. (the model Pro Line Fuel used)

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

This may not really be applicable if your driving is mostly city. Have a friend from MI who drove his bone stock 74 slant 904 Duster from Ann Arbor to the Nationals and got 26 MPG. Of course that was at 55. Drove back home at 70 and mpg dropped to 19. We had a lengthy discussion about slants and good mileage and we came to the conclusion a 4 speed OD (or better yet a 5 sp OD), lighten the car up and driving at a reasonable speed could probably net 35 mpg plus on the highway. That's better than a lot of imports plus you've got the advantage of a bigger car (yeah a Duster/Dart IS a big car nowadays). Just my (our) 2c worth.

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65 Dart station wagon slant 6 - now under construction
47 Dodge Custom 4 Door sedan
87 D100 Short Bed slant 6

Retired USAF 1966-1986
Retired US Postal Service 2004-2014

Good to see you back, CrAlt.

Higher comp = better gas mileage if tuning is done right. Bigger exhaust is good, but not too big (2.25" single is good on stocker).

I would also recommend a BBD for mileage. BIG improvements can be made with timing curve as well. Easiest is to get a later 70s Aspen dist, which should have less mech advance and a 9.5 or 11 deg vac canister. Lots of vac adv on the hwy is key (45 deg total minimum).

Gas mileage is slippery in terms of what really works. Man trannys give substantial improvements. Cruising speed is a huge factor.

My 64 Dart is still getting 23-25 on the hwy at 70-75MPH. This is a "built" motor with 10:1 comp, TBI, and 5spd. Car has a big cam (250@0.050")and runs mid 14s@ mid/high 90s in the 1/4. Somehow this is a very efficient engine and gets better gas mileage than any other Slant car I've had. I really need to try cruising at 60 sometime for comparison. I gained about 2-3 mpg with the 5spd over a 904, and about 1-2 mpg with EFI over a good Edel 4bbl.

Lou

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Home of Slant6-powered fun machines since 1988

Ok thanks guys

Im gona try simple stuff first like a good tune up..i just relized i havnt changed the oil in this dart in about 20K miles...oops...

This car always had really crappy brakes and a miss...well this morning i figgered out it was #6 that was missing, and it was missing because the powerbrake booster is bad. Clamped off the vac hose to it and its smooth as glass now. Now i just have a car with crappy brakes.

I drive alot of highway and dont care about HP in this car..my cruzing speed is about 70-80mph...sounds like i should lower this by about 10mph.. I get about 20mph now.

When i had the 10:1 slant, big isky, 4bbl, 3K stall houghs TC, 323's in the scamp it always got about 14MPG..

Well I changed the oil for the first time ever that ive owned it and found alot of milage killing stuff...


1st off the powerbrake booster is shot and basicly vacuum leaked #6 so bad that it wasnt firing at low RPM's... pluged that off, all good.

Next i noticed the carb nuts had come so loose and one of them of almost came all the way off... How it ran so good before I dont know.

Next I need to run the valves... I need to find my old feeler gauges that wont crush so i can set them on the fly.

Next I put some autolite 985's in. These things look hot as heck. I hope it doesnt start pinging. Any one have problems with this?