20 MPG Big block??
Safety Car
Joined: Aug 2000
Posts: 3,711
Likes: 43
From: San Antonio TX
Re: 20 MPG Big block?? (ykp53)
Sure. You build the engine for VE at a very low rpm and gear accordingly. If you want more than that, visit http://www.feuling.com/ and read some of the engine tech he was working on before he went HOG wild.
A 25 pound monkey can get 20mpg from a BB 'Vette as long as that's really what you're trying to do.
A 25 pound monkey can get 20mpg from a BB 'Vette as long as that's really what you're trying to do.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Re: 20 MPG Big block?? (American Boy)
Well, as ever I suspect any reasonable tuner will reply, 'it depends on where the power curve is'.....
so given that on any level....the most efficient engine will sport a DPFI closed loop system on top....nuff said.....
IMO tune carbs all day long, and rebuild to any standard...but nothing beats that computer.....not with an O2 sensor input anyway....
GENE
so given that on any level....the most efficient engine will sport a DPFI closed loop system on top....nuff said.....
IMO tune carbs all day long, and rebuild to any standard...but nothing beats that computer.....not with an O2 sensor input anyway....
GENE
Race Director
Joined: Sep 1999
Posts: 11,360
Likes: 382
From: Plano TX
Re: 20 MPG Big block?? (ykp53)
I should be able to tell you in late may. Going on a road trip to the forum cruise in (about 800 miles each way). I have a 454 with EFI and 5-speed with 0.68 OD. We'll see what kind of mileage it'll crank out.
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Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Re: 20 MPG Big block?? (zwede)
ZW, please do, for sure ....as I would love a BB vette, but the thing is the total cost of a conversion....accessories and DPFI, and the aluminum heads and so forth....freaking thing would have to get some decent MPG for that kind of price.....
GENE
GENE
Melting Slicks
Joined: Apr 2000
Posts: 3,286
Likes: 8
From: San Jose California
Re: 20 MPG Big block?? (ykp53)
I took my L88 on a run up to San Franciso and back one night last year, about 150 miles total. Cruising between 70 and 80 mph depending on traffic, but being very gentle with the throttle (no secondaries), I averaged 15mpg. This is with a factory spec L88, Richmond 6 speed with a 2.54:1 overall gear ratio.
I am hoping that with the new roller cam and some jetting changes, numerous fuel ionizers and other gadgets from JC Whitney & Co. that I can win some "beer bets" with over 20mpg's.
I do believe that a more modestly cammed BB than mine with a well tuned carb and ignition system would easily get 20mpg's on the highway with gearing in the high 2's, maybe even with 3.08's and 27" original diameter tires. I have found that high compression engines, i.e. 11:1, deliver much better mileage than engines with only 8.5:1, everything else being equal. I think I recall reading that the difference can be as much as 20%.
Chuck
I am hoping that with the new roller cam and some jetting changes, numerous fuel ionizers and other gadgets from JC Whitney & Co. that I can win some "beer bets" with over 20mpg's.
I do believe that a more modestly cammed BB than mine with a well tuned carb and ignition system would easily get 20mpg's on the highway with gearing in the high 2's, maybe even with 3.08's and 27" original diameter tires. I have found that high compression engines, i.e. 11:1, deliver much better mileage than engines with only 8.5:1, everything else being equal. I think I recall reading that the difference can be as much as 20%.
Chuck
Burning Brakes
Joined: Oct 2001
Posts: 1,146
Likes: 0
From: Milford NH
Re: 20 MPG Big block?? (ykp53)
Sure, I do not think it is impossible. Like it has been mentioned, an efficeint engine, fuel injection and good driving habits (probably the most important), you should be able to get 20 MPG once.
Pro
Joined: Jul 2002
Posts: 723
Likes: 0
From: North Port, FL
Re: 20 MPG Big block?? (ykp53)
On my last road trip to Indiana and back (about 1000 miles total) I averaged 19.6 mpg. I attribute the milage to the .6 ratio of the Richmond transmision and the tune of my 850 DP carb. The carb was tuned using an Inovate Motorsports wide band o2 sensor. I run a 15.4 a/f at cruise a 12.6 a/f at full throtle and a 14.7 a/f at idle.
Thread Starter
Racer
Joined: Jul 2001
Posts: 341
Likes: 0
From: macon, ga
Re: 20 MPG Big block?? (ZL1powr)
Zl1Powr do you have a oxygen sensor mounted to the side pipes? if so where? and how? i know its a big block its not supposed to get good gas milage, but hearing the wife complain about $35 a week in gas is gettign old.
Race Director
Joined: Nov 2000
Posts: 11,872
Likes: 12
From: Waterloo ontario Canada
Re: 20 MPG Big block?? (ykp53)
I am regularly pulling down 15 mpg on mostly open roads with a little city driving thrown in. I would like to take a trip with strickly open roads to find out how good it gets. I do run extremely lean at cruise, over 15 to 1 and drop to 13-1 on hills and passing. I do have an oxygen sensor.
This is with 2 850 double pumpers and a blower
This is with 2 850 double pumpers and a blower
Melting Slicks
Joined: Jul 2002
Posts: 3,128
Likes: 3
From: Deltona (son of Deland and DAYTONA) FL
Re: 20 MPG Big block?? (ykp53)
anyone remember those ads in the Sunday paper in "Today" section that would turn your V8 into a V6? :lolg:
I think it kept the valves shut on 2 cylinders.
I think it kept the valves shut on 2 cylinders.
Safety Car
Joined: Dec 1999
Posts: 3,599
Likes: 837
From: PA
Re: 20 MPG Big block??
is it possible? if so what would it take to do this?
You might want to check out back issues of Super Chevy from the early 1980s I believe. They had a project Monte Carlo with a 454 that was getting around 26 mpg in real life driving.
That's 26 mpg with no fuel injection and no overdrive transmission...
Regards,
Pro
Joined: Jul 2002
Posts: 723
Likes: 0
From: North Port, FL
Re: 20 MPG Big block?? (ykp53)
Zl1Powr do you have a oxygen sensor mounted to the side pipes? if so where? and how? i know its a big block its not supposed to get good gas milage, but hearing the wife complain about $35 a week in gas is gettign old.