So, Can you have a Old-Style carbed V8 and get 25+ MPG?

My Flathead ('51 Merc, cam, dual '94s) T5 powered T-bucket AVERAGES 30-32 mpg. That's with 4:11 gears and drivin like a hot rod. Weight saves gas. Overdrive saves gas. Efficient running motors save gas.

 

how much does your bucket weigh?

I hear motorbikes get decent mileage too....same thing....

 

'Round about 1400 lbs. But, I'm a big dude of about 140lbs. So when I'm in it, the weight really adds up.

 

I've got my fingers crossed for good mileage with my truck, however I'm wishing a big 4 with a five speed would have made its way into the planning stages. My 40 PU will be powered by a 2001 explorer 5.0 sans EFI with an Edelbrock performer intake and Holley 570 street avenger carb. I left the stock hi torque roller cam in place and those motors came with the very efficient GT40P cylinder heads. 1 5/8" FMS headers will lead into a free flowing but fairly civil 2 1/4" exhaust system. I bought a 12" truck/RV tight-ass torque converter to go with a firm shifting C4. A 2.75 ratio pig for the 9" rounds it out. Once its on the road I'm not above putting it on the dyno and tuning the carb for max efficiency and drivability. I'm hoping this will get me decent mileage if not I could go with the ford 2.3 and a T5, however that would be as a last resort.

 

I am going to be building an old 49' Fleetline and hopefully will be able to get 25+ mpg out it. Here is the current parts list planned for the drivetrain. I am using what I have available to me for cheap or free...

84' L69 305
Ported 601 casting 305 HO heads with stock 1.84, 150 valves, polished chambers
9.5:1 compression
204/214 at 50 camshaft, 442/460 lift, 112 lobe sep
Going to start with a stock iron Qjet manifold and Q-jet, but want to eventually get the Crossfire setup working with a Megasquirt
TH2004R with a shift kit and 2000 stall - with the lockup converter working.
3.50ish rear gears

I would love to get upper 20's on gas milage and be able to run in the 14's with this car since I am planning on it being my daily driver next year.

Anyone think its possible? I am considering finding a set of headers that will fit also, or trying to find a 305 roller motor to start with.

 

ive got a 35 5 window so its quite a big heavy car, fully fendered and a full interior. i run a 350 in it with a crower cam 286/289 lift @50, 108 lobe sep, 3 94's on top running a progressive linkage - none of the carbs are blocked off. its got a 2spd ali glide behind it with a 2400 stall converter and out back is a 9inch ford with 3.23 gears, tyres are maybe a little tall at just over 30 inches. However with all these little bits i always get about 26mpg. not sure what it is about town but its not that sore. believe me if im out in it on the motorway i dont hang about in it...

never managed to get the car to the drags yet, next year..


i did toy with the idea a while back to change to a 700r4 box but modifications of the chassis put me off, so that box was sold on and i stuck with the 2spd.

 

A friend of mine, John Weeks, just got back from Scotland. He went over to get married and he honeymooned there for several weeks. He said gas was about 8 bucks a gallon, but, the rental car they had got about 70 MPG. This country is soooooo far behind the fucking curve its scary.

 

yep im paying about $1.90 for a litre..its not so bad once you get used it you will start walking normally again ;-), every penny in petrol for the '35 is worth it..he must have had a tiny little car to get all that from it.

 

well, we're sure catching up on the cost of petrol thing....

 

Interesting post. I have a 32 steel cabriolet hiboy. I run a 406 SB Chevy, TrickFlow alum heads, CompCam, Rhoads lifters, dual fours(500 cfm), Muncie 4 spd, 3.33 rear gears, and about 30" tall rear tires. The car weighs 2300 lbs. On the road I can get 22-23 mpg. On the way to Evansville last week me and my buddy in his 40 Tudor (350,stock cam, 2 bbl, 2004R) filled up at the same place. At our first stop,( he likes to brag about his gas mileage), he used 8.3 gallons. Mine takes gas kind of slow so I didn't get to tell him, mine took 7.3 gallons. I took it easy driving and most of the time I skipped 2nd gear. The motor has enough low end torque it doesn't need 4 gears anyway. I wonder how it would do with a 5 spd. Would the overdrive slow the motor down too much where it would be hard on the cam with the Rhoads lifters? I would hate to give up a V8 so to all of you motor guys if you were to build a motor to get the best mileage you could (V8), what would you build?

 

My Dad, in his pickup was getting about 9 miles to the gallon then he rebuilt his carburetor. This carburetor hadn't been touched in 14 years and after that he was not only getting 20+ miles to the gallon, but better throttle response too. The motor is a 327 with about a 9:1 compression ratio, truck exhaust manifolds and the exhaust has rusted through about a foot before the mufflers. It has an RV cam in it, nothin special. The truck is a 72 gmc with a 69 chevy bed. Believe it or not, but he's got 3.70's in the rear too.
In about a year or so a friend of mine is going to buy my brothers FORD van and we plan on using it for road trips, so it's definitly going to have to be able to get damn good mileage, so we're gonna test out a bunch of things in the sake of mileage.
Smooth out and match port the exhaust ports on the heads, tuned headers, H-pipe, etc etc etc...Hopefully a van with 10 people in it shall get 25 miles to the gallon or else I'll have to take a hit from the bong and pretend...hahaha...fuckin hippies with their vans and all...

 

If you have a V8 combination in your HotRod or Custom that 's giving great gas mileage, please tell us about it !

 

My 33 pick up gets around 25-28 mpg..
It's got a pretty much stock 305 except for a decent size cam and three two's, 400 trans, 2.86 gear and 30" tires..
Ran 7.50's in the 10th mile short track (all in first gear mind you ) and is reliable as all get out.
Im pretty damn happy with that..
I started driving that daily again because it beats the hell out of my '02 GMC with 10 mpg...

 

That's damn impressive,........what's it weigh ?

 

I have no idea..
I don't think it can be all that heavy. At highway speeds it feels pretty light when you hit good size bumps..might be stiff springs though..

All i know is when i went to southern Pa this spring with it, coming from rochester ny...had to be just under 300 mile's..i only got gas once and i think it was around 30 bux..
My GMC cost's me on average 55 bux a week in gas, this cost's me 15-20..and i use the same grade in both

You have to remember that the tri power on the truck is a real one that the outboard carbs are 'dead' until you stand on it, so it run's on just the center carb....not all three.
I have the cam card here somewhere with the specs..can't get it right now..i'll try and get it tomorrow so you know what stick i have.

 

have you posted a picture of the truck here before?

 

Nearly bone stock 390 Thunderbird V8, 800 QuadraJet carb, new C6 Trans, 3.89 gearing with 205/70R16 tires. Car weighs in at 4200lbs minus the weight of my tools, self, copilot, cases of pomade, etc.

With the old Cruise-O-Matic trans (before it totally died) we went on a trip pushing the car damn hard (at elevations as high as 10,000' averaging 7000' throughout) and got 20+ mpg. I say 20+ because my speedo reads UNDER and it calculated out to 20. I'm hoping the new C6 with special converter will do even better.

The secret is the carb I think- I'm sold on the QuadraJet I put on. That carb is amazing, even at 800cfm rating it still gives decent economy. I will NEVER go back to any other four barrel for a daily driver again. It is an excellent carb with super small primaries. So long as you keep out of the seconadaries and tune the thing right, it will give good gas mileage for a long time. With finer tuning and slightly higher gearing, this car could EASILY get 25mpg, probably with just the fine tuning of the main jetting.

 

Yeah i've posted pics on here.. In fact i used to get my balls busted by my own friends about how many time's it's been posted..i guess i must have exceeded the limit....
A week or so ago i had listed it in the classifieds..for about a day til i realised i didn't wanna sell it afterall..there's a couple pics there, or if ya want me to post one here i will.

 

My stroker 351W (374") had a big cam, modified 700dbl-pumper, ported heads, & headers - got 20-22mpg on the road with a T5 & 3.50 posi in a 3200lb car.

Although the open-plenum, shitty-but-cheap Holley dominator manifold had poor throttle response initially, I fine tuned the carb quite a bit, ran 2" 4-hole spacer & K&N stub-stack radically improving the crispness of the throttle on that big cam/big intake combo.

My mileage improved after that (17-18 to 20-22) & I'm convinced it's because it had a stronger signal to the venturies & more efficiently utilized the fuel.

Of course my '88 FXR gets anywhere between 48-53mpg on the road!



I think a well-built, small displacement V8 (280-ish to 330-ish) with a focus on the intake tract building good flow (not big flow), using a cleaned up dual-plane intake, well-tuned carb (or even a progressive 3x2), and free-flowing exhaust w/H-pipes to help scavenging, coupled to a 5-spd tranny & modest rear gears (3.00-3.50), in a relatively lightweight car (2500-3000) could easily top 25mpg.

 

I am surprised that noone has mentioned water injection yet.Even Edelbrock use to make a kit called Vari-jection.A friend of mine installed one on a Porsche 924,which was a 4cyl 5 spd.He claimed it helped the mileage by 3 mpg.My dad made his own for '65 Ford Econoline van with a 200 6cyl way back in the day.I just called him about the gas mileage deal,and he told me about the water injection.He told me he netted a 4 mpg increase,and drove by a vacuum gauge.Might this be an answer?

 

My virtually bone stock 1960 Plymouth Fury with a 318 Polysphere/pushbutton Torqflite gets a damned good 24 MPG and I know that's accurate because the mileage was from Mapquest. I'm thinking with some new exhaust, an electric fan to replace the mechanical one, an alternator to replace the generator, electronic ignition and a few other tweaks I'll get 26-27 out of it. We'll see next year.

 

I CAN BELIEVE THAT .....I HAD A 64 FURY WITH A 318 POLY .....AND A BUTTON TRANNY .....THAT THING WOULD GET 23 MPG ....EASY .....DAMN I MISS THAT CAR......BRANDON

 

You may be right !

 

This 40 gets a little under 20, no b/s
286 inch f/h
two 97’s
¾ cam
stock running gear.
Unknown rear gear, but wound pretty tight at 65-70.

How much better could it get with a T5?

 

Ya, a buddy of mine has a 53 Ford that he put an Olds big block into. After a few trips around the block it became quite clear the big block had serious internal issuses. I came to his rescue with a 307 Olds small block from an 86 Caddy my mom used to own. It is a recently rebuilt engine, and got really good milage in the caddy. It has not been in the Ford long enough to get acurate milage readings though. The Caddy also had an over drive trans in it, but this was not used in the Ford. Not a bad fit in there either.

 

Two thoughts.

If a 389 Pontiac with a 2-barrel would go 18 MPG in a 4000-lb car, how would it be in a 2800-lb rod? Especially if you go from a 3.08 to a 2.73 or run a 5-speed manual instead of the hydro it had on it.

If you dig through your Rod & Custom magazines circa 1970-1972 there is a car shown, I think maybe just some event coverage and not a feature. Anyways this was a chopped 33-34 tudor with a 350 that had a blower on it. Owner claimed 20-22 MPG....

 

Personally, I believe that having the engine in real-fine-tune, and keeping the RPM low are 2 of the keys to higher fuel mileage.

I've set a goal of 20-25mpg for a 401 Buick powered "A" project, and I hope I can achieve it.

 

Yep. Tuning equals efficiency, and keeping the RPMs low helps. I'd think that with the torque that 401 makes, the light wieght of the A, and reasonable gearing selection you should be able to make your goal easily. Now if I can squeeze 25 out of a 360/727 in my 50 Packard I'll be giddy with delight. I suppose I oughta build the car first....

 

yea, I put a 3.00 gear in it, and with my 30" tall cheater-slicks, the old motor should be loafing around 1900-2000 rpm. In time, it may drop to a 2.79 gear if need be........

 

Bttt