mtx28

does anyone have a big block and get decent mileage? i saw an old corvette in a CHP magazine in the readers rides section that had a 502 and the guy claimed 15mpg. by the time next semster ends(may or so) im going to be buying an engine, and im certain im getting an EFI system, such as the ones holley and elebrock offer. right now im looking at a 383 that beck racing engines offers, which puts out a stout 400hp and 450ft/lbs torque, but SDPC offers the 454 for about 800 dollars less, and it has 425hp and 500ft/lbs torque.. im just quite concerened about gas mileage does anyone have a bb, fuel injected or have a carb and dont have to cringe everytime you fill up? i could live with 10 in the city, but geez, i cant get away from the thought of a nice new BBC under my hood

AlkyIROC

My 91 454SS gets 10-12 mpg. But then my old 4x4 with a 350 got the same milage.

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Stephen's racing page

87 IROC-Z Pro ET Bracket Race Car
383 stroker (carbed) with double hump cast iron heads and pump gas
454 Big Block buildup now in progress for the 2001 racing season

Best results before the 383 blew up
Best ET on a time slip: 11.857 altitude corrected to 11.163
Best MPH on a time slip: 117.87 altitude corrected to 126.10
Best 60 foot: 1.662

Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car
91 454SS daily driver
95 Homebuilt Harley

mtx28

is that under normal driving? what happens when you start getting on it more often? is there any hope? i'd LOVE to have a big block, its too easy to have so much power if you get a big block rather than build up a small one with really nice parts.. gas just concerns me, after all, i am still in college, and money is too tight to be getting less than 10 around town

jrr

The last time I saw a big block (ANY brand) get good mileage was in the pre-smog days. A de-smogged 1970's big block could get respectable highway fuel economy. I had a de-smogged 1975 Lincoln Town Car beater (460 V8)that got consistent 21 mpg at 60 mph. Around town, it got 10-12 mpg. De-smogged or not, a 5000 lb car takes a lot of gas to get it going!

A big block like what you're looking at won't even BEGIN to break a sweat moving a small F-body. It may get better gas mileage than you think!

88 427 Camaro

I get 8-12mpg being easy on it, but usually it is 6-8mpg . And this is with a 3.27 gear. If you want double digit milage, look for something else.

Miles

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88 427 Camaro
12.18 @ 113mph 1.75 60ft
http://www.geocities.com/mek88427

Chris Luongo

I used to drive a '97 Ford F-350 4x4 tow truck with a fuel-injected 460, with automatic transmission. It was in perfect tune, had a very light tow body (made by Dynamic), and got around 6mpg in the city. Of course, it was very heavy, was towing cars half the time, and this was all in stop-and-go Boston traffic. On a highway trip (towing a Volkswagen Passat 50% of the trip), it got around 8mpg.

But man, that power sure was fun. A 6-7000 pound truck that could smoke its DUAL rear wheels.

snow427

The 427 in my Chevelle gets about 14-15mpg on the highway. Around town about 9-10mpg. thats with a m-21 and 3.73's. I had a 454 in it for awhile and got as high as 20 once but only that once.

RB83L69

My 74 Caprice convertible (5270 lbs) 454 gets 17-18 highway and 12-13 in town. Or, I should say, got when it used to have 2.73 gears. I just put 3.42s in it, and I haven't had the chance to measure it since then.

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"So many Mustangs, so little time..."

mtx28

so.. suppose, i stuck one in my camaro(weighs in at 3400), i have 3.23 gears, and my overdrive is a .68 ratio... suppose(some more) if i put an EFI unit on it such as the ones holley and elelbrock offer, would it be worth it? i mean, it'd be hella nice to have 500ft/lbs of torque.. but not if im getting around 10mpg. anyone know how much better these EFI units get in mileage, they claim 'much better fuel economy' but no where on the site does it tell you any estimates. thanks for the help

Grim Reaper

Face it, big blocks like gas and are thirsty. While you can lessen their appetite with taller gears and EFI, they will still burn more gas than an SBC. And when you are in "stop n go" traffic, your gas mileage is horrible. A 454 is 30% larger than a 350, so it burns 30% more gas even when it is just idling. And when you stomp on it, it can burn even more, depending on the HP it is producing.

If fuel economy is a major concern for you, then consider an SBC with a power adder. Then you'll only burn the gas when you stomp on it. But remember, any engine guzzles gas when you stomp on it because power=fuel.


[This message has been edited by Glenn91L98GTA (edited November 27, 2000).]

mtx28

yea, but you konw how those ideas get so big ideally you cant ignore them i'd love to have one, but i know that it wouldnt be practical at all, and a stout 383 would haul major *** , but i still like to toy with the idea of EFI and lower gears giving me decent mileage (on a big block)

[This message has been edited by mtx28 (edited November 27, 2000).]

AlkyIROC

My engine could be better. The 10-12 mpg is daily driving in the city. I have 4.10 gears and a 4L80E overdrive tranny. Cruzing at 70 mph (110 kph) and just under 3000 rpm I can get 16-17 mpg.

During the summer when I occasionally take the truck to the track to burn off some nitrous, I'll get 8 mpg.