MPG ~ 351W bored 0.030 over - Ford Muscle Forums : Ford Muscle Cars Tech Forum
FordMuscleForums.com is the premier Ford Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools
Old 01-24-2011, 08:25 AM   #1 (permalink)
Registered User
 
Join Date: Jan 2011
Posts: 117
MPG ~ 351W bored 0.030 over

Hey everyone,
I have been a little concerned lately with how much gas my old 351 (now 357 as it is bored 0.030 over) ci engine is going to suck up. I am planning on getting an Edelbrock Performer RPM intake manifold and an Edelbrock 600 cfm elec. choke carb, as well as a mild hydraulic (maybe roller) cam, and possibly installing some roller rocker arms. I'll be running 1 5/8" headers off of it through a 2 1/2" exhaust system.
Can anyone tell what I can expect for gas mileage for around town, and on the highway? Also, what can I do to make it more fuel efficient? With this setup, what kind of horsepower will it be making (stock 4V version is 290 hp.)
Thanks!
__________________
1969 Mustang Hardtop ~ In the works
351W 0.60 over, daily driver
rc450 is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 01-24-2011, 01:15 PM   #2 (permalink)
Subscriber
 
Join Date: Oct 2003
Location: NW PA Grandvalley
Posts: 4,010
Re: MPG ~ 351W bored 0.030 over

Overdrive will help. No one can tell you what you will get. Not enough info. I never saw a Winsor that wasn't a gas hog though. You may expect between 10 and 15.
__________________
"Tell it like it is or don't tell it at all" 1964 Falcon 2dr HT, 347V8 4V, dual exhaust, 5sp, pwr assist R&P steering, AM radio, heater with defrost and 2sp fan, electric windshield wipers, cigar lighter, dlx light group, bucket seats, console and full carpet.
retyler is offline   Reply With Quote Quick reply to this message
Old 01-24-2011, 01:17 PM   #3 (permalink)
Registered User
 
Join Date: Aug 2010
Posts: 249
Re: MPG ~ 351W bored 0.030 over

Quote:
Originally Posted by rc450 View Post
Hey everyone,
I have been a little concerned lately with how much gas my old 351 (now 357 as it is bored 0.030 over) ci engine is going to suck up. I am planning on getting an Edelbrock Performer RPM intake manifold and an Edelbrock 600 cfm elec. choke carb, as well as a mild hydraulic (maybe roller) cam, and possibly installing some roller rocker arms. I'll be running 1 5/8" headers off of it through a 2 1/2" exhaust system.
Can anyone tell what I can expect for gas mileage for around town, and on the highway? Also, what can I do to make it more fuel efficient? With this setup, what kind of horsepower will it be making (stock 4V version is 290 hp.)
Thanks!
In a word, or six "KEEP your foot out of it" , like that is going to happen. As far as mileage, is this in your '69 mustang? what gears? If you were driving the car before you did the rebuild, from the mods you listed I would say your mpgs should stay the same or mabey even get a little better. HP I am guessing 300-325.
firehorse5_0 is offline   Reply With Quote Quick reply to this message
Old 01-24-2011, 04:11 PM   #4 (permalink)
Registered User
 
Join Date: Jan 2011
Posts: 117
Re: MPG ~ 351W bored 0.030 over

It is in my '69, it has 3.10 rear gears, don't know the tranny specs though.
__________________
1969 Mustang Hardtop ~ In the works
351W 0.60 over, daily driver
rc450 is offline   Reply With Quote Quick reply to this message
Old 01-24-2011, 04:44 PM   #5 (permalink)
Tech Contributor Gold
 
Join Date: Dec 2009
Location: Carson City, Nv
Posts: 453
Re: MPG ~ 351W bored 0.030 over

Stick to a 2 brl carb, milder hyd cam, headers and dual exhaust with and AOD trans, using 3.55 gears. Over wise move closer to that pipeline Canada wants to built to Texas.
__________________
Getting her done after being FUBARed
rickyracer is offline   Reply With Quote Quick reply to this message
Old 01-24-2011, 05:03 PM   #6 (permalink)
Tech Contributor
 
Join Date: Jan 2002
Location: Ontario,Canada
Posts: 6,420
Garage
Re: MPG ~ 351W bored 0.030 over

The camshaft and final rear gearing will have a huge influence on what kind of mileage you will get(as well as performance)...An overdrive trans like a T-5 will work awesome for getting you good mileage...An automatic tends to suck more fuel and is less streetable when you start to modify it for performance...
__________________

1968 mustang 408W Hybrid..Burns gas and rubber!
11.59@120.95 with 1.68 60ft
frdnut is offline   Reply With Quote Quick reply to this message
Old 01-24-2011, 05:42 PM   #7 (permalink)
Registered User
 
Join Date: Aug 2010
Posts: 249
Re: MPG ~ 351W bored 0.030 over

Quote:
Originally Posted by rickyracer View Post
Stick to a 2 brl carb, milder hyd cam, headers and dual exhaust with and AOD trans, using 3.55 gears. Over wise move closer to that pipeline Canada wants to built to Texas.
2 bbl is not much different (mpg wise) than 4bbl if you keep your foot out of it... near impossable, when you have the HP you tend to use it. X2 on the OD and steeper gears. It broils down to whay you want most.. HP or MPG????? If you want more of both you can go to fuel injection.. lots of work, but it works. My Cobra will "sh*t and get" and still gets 22 mpg crusing @ 70-80 mph with 3.73s.. my 2 cents.
firehorse5_0 is offline   Reply With Quote Quick reply to this message
Old 01-24-2011, 06:14 PM   #8 (permalink)
Registered User
 
Join Date: Jan 2011
Posts: 117
Re: MPG ~ 351W bored 0.030 over

How hard would it be to swap out the 3:10 gears for, say, 3:55, would this make a big difference and how much would this cost?
__________________
1969 Mustang Hardtop ~ In the works
351W 0.60 over, daily driver
rc450 is offline   Reply With Quote Quick reply to this message
Old 01-24-2011, 08:58 PM   #9 (permalink)
Registered User
 
Join Date: May 2007
Location: Orting, Washington
Posts: 1,122
Re: MPG ~ 351W bored 0.030 over

Here are three examples for you.

On a round trip to Reno I got 17 MPG in a 1970 Sportsroof Galaxie, it was powered by an all factory Windsor with the exception of an OEM 4V intake, 1850 Holley, dual exhaust and recurved distributer. It had a C6 and factory rearend ratio. We ran the car 65-75 most of the trip both ways.

I have a 86 Mustang coupe powered by a 410W, on a round trip to work which is 22 miles I used roughly 4 gallons! A lot of it was sideways if you get my drift...LOL.

I have a1964 F500 powered by a 69 4V 351W, I used to joke it was $10.00 every time I started it, that was back when gas was $2.00 per gallon.

I've owned many 351Ws over the years, most drink gas.

A 302 on the other hand can be a great little mileage maker.
My son beats hell out his 5.0 coupe and swears it get over 20 MPG
most of the time.
McCutcheon4 is offline   Reply With Quote Quick reply to this message
Old 01-25-2011, 04:08 AM   #10 (permalink)
Registered User
 
Join Date: Jun 2009
Location: MA
Posts: 57
Re: MPG ~ 351W bored 0.030 over

Another sample for you. My ride is a 393 EFI w/ aggressive cam, TKO600 5sp with the highway friendly 0.64 5th gear, and 3.27 rear gears. About 450 HP. I get a pretty miserable 9-10 mpg around town, but get about 20 on the highway at 70-75.

I'd guess you should get around 10-15 around town and low to mid 20s on the highway if you have OD. Obviously, gas mileage is highly dependent on how much you use your right foot.
sm351 is offline   Reply With Quote Quick reply to this message
Old 01-25-2011, 12:14 PM   #11 (permalink)
Tech Contributor
 
Join Date: Jan 2002
Location: Ontario,Canada
Posts: 6,420
Garage
Re: MPG ~ 351W bored 0.030 over

Quote:
Originally Posted by rc450 View Post
How hard would it be to swap out the 3:10 gears for, say, 3:55, would this make a big difference and how much would this cost?
It depends on what trans you are running..If you have overdrive you can go with a lower rear end gear..If the gears are too high with overdrive you can actually get worse mileage as it makes the engine work too hard..
__________________

1968 mustang 408W Hybrid..Burns gas and rubber!
11.59@120.95 with 1.68 60ft
frdnut is offline   Reply With Quote Quick reply to this message
Old 01-25-2011, 06:04 PM   #12 (permalink)
Registered User
 
Join Date: Jan 2011
Posts: 117
Re: MPG ~ 351W bored 0.030 over

Quote:
Originally Posted by frdnut View Post
If the gears are too high with overdrive you can actually get worse mileage as it makes the engine work too hard..
How? overdrive gears are already higher gears, so wouldn't adding higher ratio rear end gears make it even better? I can't see how that would make it work harder...but, I am far from being an expert on this
__________________
1969 Mustang Hardtop ~ In the works
351W 0.60 over, daily driver
rc450 is offline   Reply With Quote Quick reply to this message
Old 01-25-2011, 06:58 PM   #13 (permalink)
Tech Contributor
 
Join Date: Jan 2002
Location: Ontario,Canada
Posts: 6,420
Garage
Re: MPG ~ 351W bored 0.030 over

Quote:
Originally Posted by rc450 View Post
How? overdrive gears are already higher gears, so wouldn't adding higher ratio rear end gears make it even better? I can't see how that would make it work harder...but, I am far from being an expert on this
Most engines have a rpm range where they are happy and will produce the best gas mileage possible..If you have an already high rear end ratio like a 2.79 or 3.0 and then you add over drive it will probably pull your rpms down too low and it will take the engine below its "sweet spot" in the rpm range..For example I used to have an 82 F100 with a 300 six banger..It had 3:1 gears in the rear end and when the 3 speed trans died I swapped in a 4 speed overdrive trans..In almost all conditions it would get worse gas mileage in overdrive than in 3rd gear..It was just working the engine too hard to pull it in overdrive..
Now if you have a relatively low gear like a 3.70 you can have lots of acceleration and the engine does not have to work hard to get the car moving..Out on the highway you put it into overdrive and it drops your rpms down to rpms similar to what you had when you were running a 3:1...You can have your cake and eat it too!
__________________

1968 mustang 408W Hybrid..Burns gas and rubber!
11.59@120.95 with 1.68 60ft
frdnut is offline   Reply With Quote Quick reply to this message
Old 01-25-2011, 08:36 PM   #14 (permalink)
Registered User
 
Join Date: Aug 2008
Location: Prince Albert, Saskatchewan, Canada
Posts: 1,885
Re: MPG ~ 351W bored 0.030 over

I always thought my car did rather well, especially for a car this big. I would always get a little over 20 mpg on the highway, loaded to the mud flaps, or completely empty with my stock, original 351W 2V, but with dual exhaust. I still have plenty of tuning to do on after the rebuild, but I did a short highway trip this summer and managed 18.5 mpg. These mpg numbers are with the imperial gallon, which is ~20% bigger than the US gallon, so everything goes farther on a gallon of gas north of the border.
__________________
1970 XL, 351W originally 2V, now 4V
670 Street Avenger, Edlebrock Performer intake, Comp XE262H, Flowtech Headers
70XL is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Ford Muscle Forums : Ford Muscle Cars Tech Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Ever get bored of a car? 19mach69 The Garage 23 06-04-2008 09:23 PM
390 bored .060 over? Sinister Galaxie Pages 16 11-22-2007 04:23 AM
Bored, bored, bored Murff The Garage 20 11-10-2007 04:17 PM
FS: 289 bored .040 over 702FairladyZ Mustang Pages (1965-1973) 3 10-02-2007 08:06 PM
I was bored.... TorinoStyle2 Torino Pages 2 03-26-2006 04:13 AM


All times are GMT -7. The time now is 10:28 AM.



Powered by vBulletin® Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Friendly URLs by vBSEO 3.6.0
 

Garage Plus vBulletin Plugins by Drive Thru Online, Inc.