Left field question

[BMK]

I have just posted a new Thread over in the Shelby Inc site - Manufacturers. But notice that Posts and visits are few and far apart..

So thought I would ask the same - stupid - question about economy over here.

I say stupid question, but it is a consideration with fuel/ gas costs and this Australian Governments new Climate Change tax..

Fuel here is now $1.46 per litre - about $6.00 US a gallon. So short of running electric it is a costly exercise.

My GT40 runs a 302 stroker at 347 and returns average fuel/gas economy in light highway driving of 21 - 22MPG.

I am looking at buying a 427 Shelby aluminum crate engine for a Cobra project and was wondering what experiences you guys have had with these motors and plain old fuel economy - if this exists..

I would be interested in seeing your thoughts or your own experience with tuning for economy or stating the obvious that... I am dreaming that 427 and economy go in the same sentence..

Thanks guys for your thoughts on this. I could be convinced to go smaller with a stroker again..

Thanks

Bernie

[Jamo]

I don't run a gas gauge, so it's all good.

Also, since it holds nearly 40 gallons, I feel a certain moral superiority in knowing that in the event of a Zombie attack, we have a fuel reserve.

You're welcome.

[edit...typo]

[jhv48]

Average 10 MPG.

[Three Peaks]

If gas gets any more expensive down under or up here, we may all be installing a Ford 200 CI inline six before we're all done.......

I know of at least 3 people who have the 427 Stroker engines and none of them brag about their gas milage.

Bob

[Dennis O'Shea]

I have a 460 and the fuel mileage is bearly visable but its so much fun who cares

[Bill Wallace]

also 10 mpg w. a 482 ci keith craft built shelby block, edelbrock stage II heads, a quickfuel 4 bbl carb and a hydraulic roller cam

[Bill Bess]

It's pretty darn simple.....big cubic inches = bad as mileage. Small cubic inches = good gas mileage....speed costs money, how fast do you want to go?
Very fast is a good answer.

[BMK]

Thanks guys.

Yes I expected the answers but thought then again..

Jamo as always mate thanks.

With up to 200 miles between some fuel stops over here, it has me questionning the big cubes.

Not to mention the fuc#c!ng speed cameras that allow 2mph over and flash for the cash grab.

Anyone willing to sponsor me for a Green Card..

[COBRANIP]

If you've got horses......you gotta feed 'em.....

[RICK LAKE]

BMK Bernie It's a combo thing. Lets start with a biggie, FI system of carb?
Next we neex to look at the gear ratios of the trans and rear rear ratio. Tires with cost you about 1-2 mpg if they are real sticky to the road. Street tires with a wear of better that 200 will extend mph.
We don't have any spec on this motor. The big thing again is camshaft and LSA number. The last is the exhaust system, having at cruise speed about 2-4 psi of pressure will give the best mpgs.
Installing a torque( low rpm) cam will give you better mpg. your mileage can be from 10 to 22-25 mpg. It's how you want the car setup. If you go carbs, get to matching ones and setup one for cruising and the other for racing.
The last thing would be to install and A/F meter and watch this. Vacuum gauge will show you how to lite foot driving the car too. Fuel injection will give you a better drivability that carb for every day driving. Carb will get more power from the motor in the higher HP range of the motor.
Hydro roller cam is fine, look for a small one if you are going for MPG. 240-260 duration with the size of the motor. This motor will eat a little larger cam than the stock ones. My 482 has a small roller of 587-607. This is a good size for a 390-428 motor. The extra cubics have this running smooth with just a little idle noise and I mean little. My cam is also retarted 6 degrees for more bottom end power. The cam came with a 4 degree advance built in. I do have too much torque in the bottom end and will advance the cam in the spring. Specs on the motor will help. In see no problems with getting 17-20 mpg with a little work. Rick L.

[BMK]

Tnx Rick. Yes I need to get the better economy and will talk to whom ever I get to build the engine . Bernie

[Bill Bess]

How about a Ford Racing overhead cam 5.0, a stock 400+hp mustang motor, with a 6 spd. over drive trans and a 3.08 rearend, I would expect over 20 mpg with that set up.
Good luck, Bill

[Dimis]

Bernie,
Seeing as it's not likely to be your daily driver, chances are that it's unlikly to see enough miles to worry about it. Particularly with all those other toys you have in the garage

Further, if it does get to the stage where fuel does get that expensive, then there will be many more of us joining you on those bike rides

[Dirty Harry]

.030 over 351W with Edelbrock Performer cam, intake, carb., large valve heads with mild port job, T-5 with 3.25 rear end--pretty mild stuff, but enough to smoke the local boys

13-16 in mixed driving, 22-23 on the highway

I haven't heard of any big blocks coming close to those kind of numbers. You just have to choose.

[BMK]

Dimis

Sadly I have ridden the bike even greater distances than I have driven over the last few months.

If my power weight ratios were comparable to the cars I would be economical..


Than again it is cheaper to buy a Shelby 427 than one of the damn bikes..

[Varmit]

i can describe my my 427 simply as "thirsty"

[Hammer65]

Here's some data from a Roush 427SR in a Superformance MKIII

Date Miles Gallons Cost $/Gal MPG Average
5/10/2008 63 14.64 $60.57 $4.14
5/15/2008 154 8.12 $34.11 $4.20 11.2 11.2
5/17/2008 290 12.89 $54.38 $4.22 10.6 10.8
7/9/2008 652 14.69 $68.71 $4.68
7/13/2008 748 8.87 $41.51 $4.68 10.8 10.8
7/17/2008 879 14.03 $63.41 $4.52 9.3 9.9
7/20/2008 1002 11.15 $50.16 $4.50 11.0 10.3
8/4/2008 1128 11.97 $53.62 $4.48 10.5 10.3
8/7/2008 1259 11.88 $52.00 $4.38 11.0 10.5
8/18/2008 1351 8.56 $36.62 $4.28 10.8 10.5
8/29/2008 1481 12.44 $52.46 $4.22 10.5 10.5
9/7/2008 1587 8.88 $36.21 $4.08 11.9 10.7
9/16/2008 1715 13.89 $57.49 $4.14 9.2 10.5
11/23/2008 1815 9.62 $24.51 $2.55 10.4 10.5
3/29/2009 1939 12.68 $33.47 $2.64 9.8 10.4
4/25/2009 2080 13.08 $34.79 $2.66 10.8 10.4
5/17/2009 2226 13.58 $38.83 $2.86 10.8 10.5
8/19/2009 2621 13.23 $42.58 $3.22 9.6
9/17/2009 2732 12.42 $41.96 $3.38 8.9 9.6
3/22/2010 2849 11.61 $39.01 $3.36 10.1 9.6
5/13/2010 2975 13.10 $45.31 $3.46 9.6 9.6
7/7/2010 3138 14.45 $50.86 $3.52 11.3 9.7
7/28/2010 3292 13.24 $45.01 $3.40 11.6 9.8
30/2010 3430 12.44 $43.04 $3.46 11.1 9.9
10/19/2010 3557 15.17 $52.15 $3.44 8.4 9.8
5/20/2011 3689 12.32 $52.95 $4.30 10.7 9.8

[BMK]

There is the opportunity to build with both the performance and economy approach. Guess I just need to talk more with the supply and engine the builder.

[BMK]

Thanks for the Posts guys. It is appreciated.

I understand the HP and cube argument but just wanted to get some ideas on the best way to go.

I will be doing a lot of driving and wanted to find the better combination of cubes and economy.

From the outset I will let the builder know what I want to achieve and then pass on all the information I have been sent via email from the forum - links etc. to builders and parts suppliers.

This has been ideal as I have been able to see options.

Pace in Queensland who are the Kirkham suppliers and agents in Australia have also been very helpful in supplying links, ideas and advice.

Having run strokers (351 to 380+ ) in my Cobra and GT40 (302 to 347) I can see that small blocks can soon run out very thirsty and far less economical than going straight to a 427+ straight off and building for a little better economy.

Ultimately I would prefer the aluminum Shelby block and will start here.

Again the ideas given to me have helped me understand the whole cube and economy argument a little better - now to build it.

Thanks again to all.

Bernie

[Buzz]

Bernie, a fuel injected big cube torque monster of an engine coupled to an overdrive tranny and a numerically low rearend gear ratio could probably give surprisingly good performance and fuel economy numbers in a light car like our Cobras. If the engine was cammed to make max power at a reasonably low RPM, you could still have satisfying acceleration when needed and relatively economical higher speed cruising on the open road. Remember that many of the truisms that apply to normal cars are not necessarily applicable in Cobras because of the massive power to weight ratio we enjoy.