Vintage Mustang Forums banner

1 - 8 of 8 Posts
G

·
Guest
Joined
·
0 Posts
Discussion Starter #1
Hi all,

I have Ford Mustang '66 with 289 V8 and like to know how much typical fuel consumption might be with these parts:

- Edelbrock 600cfm carb
- Weiand Stealth intake
- Edelbrock RPM heads (1.94/1.60)
- Edelbrock RPM cam
- Crane's roller rockers
- Ford Motorsport push rods
- Keith Black 9.7:1 pistons
- Stock block, crankshaft etc.
- 4-speed manual
- Tri-y headers, 2.5" pipes
- 8" 3.55:1 rear with locker

Now fuel economy is quite poor, about 20 litres / 100km = 11.8 miles / gallon

How can I improve fuel consumption? I already have Edelbrock calibration kit, but it don't help much because engine goes too lean if I change jets/rods to one or two stages leaner. Can anybody help me, waiting for advices.

Regards,

Ari





Ford Mustang HT '66 A-code 289, 4-speed manual. Hi-po parts: Edelbrock RPM cam/heads,Crane roller rockers,Ford Motorsport push rods,Weiand Stealth intake,Tri-Y headers with 2.5" pipes/Flowmaster 2-chamb. mufflers. 8" 3.50:1 rear with detroit locker.
 

·
Registered
Joined
·
5,205 Posts
I think 9.7:1 compression is pretty high on that 289... But 12-15 miles per gallon ought to be about right with all of those modifications.

try running on a higher octane,
 

·
Registered
Joined
·
3,047 Posts
Hi, just back from Tampere, on the way there I was running 2500rpm and return 2000rpm(=100km/h, those 2.7? gears!). I haven't refilled since, but I would estimate something like 13-14 L/100km. Engine differs from yours with (most likely) stock heads, not too hot cam. What tires you have? What's your timing? What type of driving that 11.8mpg included?

Door handle first when cornering
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #4
Hi Arto,

I have 195*70*14 tires and timing is ~10 deg (idle) 34-35 deg 3500rpm. Driving is mixed city drive with no(not much) hard accelerations :) . I suspect that timing and distributor settings are not good to my setup. Well, we see it when I go next friday to Jääli where is 500hp dyno. There I should find good setup between fuel economy and power. I just hope engine can take that punishment without falling a parts. (this is first engine that I have built myself)

Ari

Ford Mustang HT '66 A-code 289, 4-speed manual. Hi-po parts: Edelbrock RPM cam/heads,Crane roller rockers,Ford Motorsport push rods,Weiand Stealth intake,Tri-Y headers with 2.5" pipes/Flowmaster 2-chamb. mufflers. 8" 3.50:1 rear with detroit locker.
 

·
Registered
Joined
·
10,287 Posts
Your car has similar but not exact mods to mine. I have 3.25 rear gears, 4 speed, etc. I get about 12 mpg city and about 19 highway (taking it easy).

Adjusting for the 10% steeper gears you have you are a little worse than what I am getting.

Paul
1965 Mustang 2+2
1989 Mustang GT Convertible
MCA #27261
MCA certified judge for 65's and late models
 

·
Registered
Joined
·
3,047 Posts
Dyno is good. Are limiting the pull rpms to below 6000?
Timing shouldn't be that far from optimal. I have 12 initial and according to distributor specs should be 36 at 3000rpm. I am just wondering whether that RPM package is that much to blame. Did you have vacuum advantage? That might give 1mpg more.
Get more tire. 100km/h is now something like 2900-3000rpms. Just changing to 215/70/14 will drop that by 125rpms.

Door handle first when cornering
 

·
Registered
Joined
·
911 Posts
I run a 289 with a mild cam, Edelbrock preformer intake and a 600cfm Edelbrock carp and a pertronix unit and I get 22mpg on the highway in 5th gear on my T-5. After I upgrade to a MSD ignition I expect that to go up a bit. You can definitly get better gas milage out of the 289 then 11mpg.

Mustang Parts makes a great addiction.
 
G

·
Guest
Joined
·
0 Posts
Discussion Starter #8
I might change different tires but 6" wide wire wheels are not very good to wide tires. Front end of my car is now so low(shelby mod & gt springs) that 195*70*14 is maximum. To rear it might be possible to change 215*70*14. I'm using vacuum advance and I just yesterday read my distributor manual (Accell Superstock breakerless) how to change mechanical advance. Well, I think biggest reason so bad fuel economy is that RPM cam. I had mild street cam before that and fuel consumption was in mixed driving 15L / 100km (15 miles / gallon) Now when fuel is so expensive I'm thinking to get back to milder cam.

Ford Mustang HT '66 A-code 289, 4-speed manual. Hi-po parts: Edelbrock RPM cam/heads,Crane roller rockers,Ford Motorsport push rods,Weiand Stealth intake,Tri-Y headers with 2.5" pipes/Flowmaster 2-chamb. mufflers. 8" 3.50:1 rear with detroit locker.
 
1 - 8 of 8 Posts
Top