PackardV8 wrote: ↑Wed May 22, 2019 10:13 pm
While we appreciate the intellectual exercise in building for maximum fuel economy, the net savings in cost of fuel is usually ant-shit in the total cost of building a max-efficient engine/transmission/computer control system.
We have this discussion regularly with our local jackpine savages who want to drive their 2500 dually and get better mileage. When it's all costed out, the fuel savings would pay for the new build in about nineteen years.
I am not looking to go super crazy with modifying my setup for fuel economy. I am just open to a little bit of fresh thinking and maybe even learning something new. I know I could wrangle another 5 MPG out of this than what I am going to eventually get, but that is not why I am building this thing. This is going to be a fun "hot rod" that I don't want to be a pig when I am cruising. I am not going to be hitting the strip with this either as I have another car for that. I just want to have the "get up and go" when I get on it, and not be a pig when at part throttle.
Paul
"It's a fine line between clever and stupid." David St. Hubbins
My 77 Monte brick @ 4200 lbs. will knock down 19-19.5 ish running 65-70 mph highway. Nothing special. 421 sbc profiler heads 9.7 cr Vic jr. with an adapter to a Qjet. 4-2-1 headers. dynoed at 530 hp 540 tq. 200-4r with a lock up conv. 3.73 gears. I have the Qjet tuned so it runs about 15.5 afr cruise.
Have a hard time believing the 40 mpg in the truck on the first page.
77cruiser wrote: ↑Thu May 23, 2019 9:31 am
My 77 Monte brick @ 4200 lbs. will knock down 19-19.5 ish running 65-70 mph highway. Nothing special. 421 sbc profiler heads 9.7 cr Vic jr. with an adapter to a Qjet. 4-2-1 headers. dynoed at 530 hp 540 tq. 200-4r with a lock up conv. 3.73 gears. I have the Qjet tuned so it runs about 15.5 afr cruise.
Have a hard time believing the 40 mpg in the truck on the first page.
The most realistic measure of fuel economy is : ton-miles per gallon. That is vehicle weight times MPG. I've had some vehicles with large engine size, . . . , and got over 40 ton-miles per gallon on the freeway.
Ton-miles-per-gallon is an important measure if one is operating a freight train. In the rest of the world, it's a chimera which those driving oversize gas hogs use to alibi out, "She don't sweat much for a fat girl."
Jack Vines
Studebaker-Packard V8 Limited
Obsolete Engineering
77cruiser wrote: ↑Thu May 23, 2019 9:31 am
My 77 Monte brick @ 4200 lbs. will knock down 19-19.5 ish running 65-70 mph highway. Nothing special. 421 sbc profiler heads 9.7 cr Vic jr. with an adapter to a Qjet. 4-2-1 headers. dynoed at 530 hp 540 tq. 200-4r with a lock up conv. 3.73 gears. I have the Qjet tuned so it runs about 15.5 afr cruise.
Have a hard time believing the 40 mpg in the truck on the first page.
My stock 93 single cab short bed TBI 350 gets 19ish I usually run 70/75 on the hywy and easy on the peddle in town.
Please Note!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
Please Note!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
FC-Pilot wrote: ↑Wed May 22, 2019 9:13 pm
Thanks for more ideas guys. I don't have 400 HP hard set in my head. My car is an old 63 Chevy II wagon. Not a giant my any means. I used to get 20 MPG with the old 194 and the power glide. I just could not get it to run 70 MPH without its tongue hanging out. LOL I am not looking to set any records for mileage with this thing. In all honesty, if I get 20 MPG on the highway I will be happy. Any more than that and I would be as giddy as a school girl.
You know what might be dirt cheap and fun? Go find a 4.3L LT1-style V8 from a junkyard 94-96 Caprice. GM makes (used to make?) a dual plane carb intake for the reverse-flow-cooling SBCs. Do a basic freshen-up and a small cam upgrade, and I bet it would be a responsive street driver with great MPG.
FWIW, I have a '65 Nova with a 9.6:1 355. Vortec heads, 217/225 @ 0.050 hyd roller on a 108 LSA, performer intake, q-jet, tri-y headers, M20, and 3.36 gears. I've measured 18-20 mpg several times if I keep the highway speeds below 65 mph. Q-jet A/F ratio is around 15.3:1 at highway cruise.
FC-Pilot wrote: ↑Wed May 22, 2019 9:13 pm
Thanks for more ideas guys. I don't have 400 HP hard set in my head. My car is an old 63 Chevy II wagon. Not a giant my any means. I used to get 20 MPG with the old 194 and the power glide. I just could not get it to run 70 MPH without its tongue hanging out. LOL I am not looking to set any records for mileage with this thing. In all honesty, if I get 20 MPG on the highway I will be happy. Any more than that and I would be as giddy as a school girl.
You know what might be dirt cheap and fun? Go find a 4.3L LT1-style V8 from a junkyard 94-96 Caprice. GM makes (used to make?) a dual plane carb intake for the reverse-flow-cooling SBCs. Do a basic freshen-up and a small cam upgrade, and I bet it would be a responsive street driver with great MPG. A drop-in for a Chevy II with the right oil pan.
FWIW, I have a '65 Nova with a 9.6:1 355. Vortec heads, 217/225 @ 0.050 hyd roller on a 108 LSA, performer intake, q-jet, tri-y headers, M20, and 3.36 gears. I've measured 18-20 mpg several times if I keep the highway speeds below 65 mph. Q-jet A/F ratio is around 15.3:1 at highway cruise.
One of the best MPG/$ mods for highway speeds is a front air dam. Just a crude vertical sheet of Coroplast or the like, extending down as close to the ground as possible and braced as needed works about as well as anything, although esthetics may suffer. A further significant gain for a bit more time but little money is to improve the sealing of any ducting/paneling to the rad and then block off as much of the grill area as possible without causing overheating.
MadBill wrote: ↑Thu May 23, 2019 3:55 pm
One of the best MPG/$ mods for highway speeds is a front air dam. Just a crude vertical sheet of Coroplast or the like, extending down as close to the ground as possible and braced as needed works about as well as anything, although esthetics may suffer. A further significant gain for a bit more time but little money is to improve the sealing of any ducting/paneling to the rad and then block off as much of the grill area as possible without causing overheating.
I have also herd that lowering the vehicle and removing or reducing the size of mirrors are 2 "nearly" for sure benefits.
Please Note!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
There's a lot of aerodynamic things you can do to an old car, and a few of them end up helping cooling as well as fuel economy (air dam, undertray, front spoiler). But around town you tend to have to chase the harder to fix mechanical efficiency problems.
Have you considered forced induction? That way you can have your engine-of-medium-cubes tuned for low-mid range torque so it's both smooth and economical but still have a big power hit (of variable size because boost control!) when you want it. From what I hear even a stock 4.8 with a turbo struggles to make less than 400hp.
I know for a fact that if you put a GT3582 on anything over 4L you'll both be able to launch at full boost on any factory stall converter and have turbo flow for 450whp. There are more than a few cars in Australia running 11s so-equipped (4 litre engine, gt3582, bolt on mods, 1700kg cars)
Not thinking of going forced induction, I would never be able to afford the tickets my wife would get, that is if she didn’t loose her license. So it sounds like good use of compression, lean fuel mix, late model trans and converter, cleaning up some aero on the front end and bottom air dam (which I was thinking about any way as being in AZ in the summer will be a pain to keep cool anyway). Now help me if I am wrong, yes I would like a peppy street car but don’t really plan on it ever running over 6k RPM’s so would a single pattern cam be the best option “usually “? I was planning on ordering a custom cam anyway as I know the wrong cam can screw up everything, but in my weak mind it sounds like if I was just piecing stuff together staying with a single pattern would best suit a daily driven street car. Next would be exhaust. Would headers help or hut? I know they can be a big benefit to power, and the helped MPG on my old truck but that does not mean they would be best for this. I would love an exhaust manifold that flowed well and acted like a header but was not loud like a header. (Yes I know I am asking for the impossible). Just more ideas to kick around.
Thanks for everyone sharing their ideas. Even if they don’t fit my purpose who knows how they may impact a reader tomorrow.
Paul
"It's a fine line between clever and stupid." David St. Hubbins
MadBill wrote: ↑Thu May 23, 2019 3:55 pm
One of the best MPG/$ mods for highway speeds is a front air dam. Just a crude vertical sheet of Coroplast or the like, extending down as close to the ground as possible and braced as needed works about as well as anything, although esthetics may suffer. A further significant gain for a bit more time but little money is to improve the sealing of any ducting/paneling to the rad and then block off as much of the grill area as possible without causing overheating.
I have also herd that lowering the vehicle and removing or reducing the size of mirrors are 2 "nearly" for sure benefits.
My car only came with one small mirror on the driver side and it is getting an aftermarket front suspension as well so it will sit a little lower. Tire size is another contributor I have thought about. I am not going to go with monster wide tires, but I do want it to handle. If only that balancing point were easier to find. Lol
Paul
"It's a fine line between clever and stupid." David St. Hubbins
A factory manifold can be streamlined for decent flow, lots of them are, but the real benefits of headers are the pulse tuning aspects, which typically occur at much longer lengths than any cast part.
I'd suggest throwing a couple of hundred $ at an engine simulation program (I use engine analyzer plus). Learn to read and interpret the data, play around a while. It does give bsfc numbers, but only at full throttle. Also has a handy optimise function where it automatically varies selected parameters for the outcome you want. As a general rule if you're improving specific torque at the revs you normally use or lower you're going to improve economy.
Hell just mess around with the demo version and it's 302-HO. You can't change head specs, bore/stroke, or forced induction, but that doesn't stop you much as you can change everything else and learn an awful lot about how things work
My old truck pushes 38.5 square feet of air going down the road. 605 Hemi, with the small heads it made 765 ftlbs at 3500 rpm peaking at 818@4800ish. Solid roller 288/292@.050, Weiand Tunnelram with 2 850 Carter Thermoquads. The convertor stalls at torque peak, torqueflite tranny, 4.56 gears, 32.5" tall street tires.
IF I drove it nice at 60mph and didn't dip into the secondary I could make 10mpg. I figured that was very good for the package.
