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65cruiser
05-24-2005, 09:38 AM
Okay, my gas mileage is not where I would expect it to be. It's a 65 Cruiser, 194 six (McKinnon). It's recently tuned to factory specs and has (at one time) had a rebuilt Holley 1 barrel installed. It runs perfectly, accelerates nicely, no hiccups. But, the best I can squeeze out of her is around 14.5 miles per gallon. The spark plugs look good and I'm not getting soot out of the exhaust. The choke is set according to the manual.

Any ideas? Anybody else got a 194 or 230 I can compare this too? Most of my driving IS 60-65 mph. The car cruises just fine, but am I pushing it too hard and causing gas mileage to suffer?

________________________
Mark Anderson
http://home.alltel.net/anderm
1965 Studebaker Cruiser

studegary
05-24-2005, 02:44 PM
You are not pushing it too hard. What transmission do you have and what is your differential ratio? If you have an automatic and around a 3.31:1, your fuel mileage isn't out of line considering the use of todays gasoline. Keep in mind that you are moving about 3000 pounds in a not very aerodynamic box shape. Above about 50 mph, that wall of air that you are pushing has a bigger effect on the effort to move your vehicle. IIRC, the resistance to motion goes up with the square of velocity (speed). Also, be sure that you don't have any drag from things like brakes or wheel bearings. Tires, and their pressure, also enter into the equation.

Roscomacaw
05-24-2005, 04:26 PM
The next question is what gears there are in the rear axle.:)

Miscreant at large.

65cruiser
05-24-2005, 06:43 PM
It's probably my gearing. It's an automatic and it has a 3.73 Dana 27 TT rear end. It would probably do better with a 3.31, but it's pretty peppy with the 3.73 and I like that. I'm pretty sure I don't have any drag going on. As I said, the car runs great. I drive it daily 17 miles one way and my speeds are around 60-65 mph. The car likes it:) It's got radials and they're at the proper pressure.

I'm not trying to beat any mileage runs, but was hoping for 18 mpg or so.
________________________
Mark Anderson
http://home.alltel.net/anderm
1965 Studebaker Cruiser

1949commander
05-25-2005, 10:30 AM
Remember that 194 six is 3.2 liter in todays terms. If you took your modern car and ran it in direct drive or even second so it was turning the same RPM it would only get 15-16 as well. That is why Studebaker sold so many cars with the Overdrive, it makes a huge difference in mileage. It could be that the economiser system in the carburetor is out of wack causing a richer mixture when cruising. Also have you set the timing, you want to set it like the book says set it to a spec then advance it until it pings then back it off just until the ping goes away. Also check the throttle shaft for play if it has the slightest bit of play that messes with the idle vaccum which inturn screws up the economiser workings since it works off of vaccum. If you want to find out how good it is runing go to Summit and order a air/fuel ratio meter. All you have to do is have a fitting welded into the exhaust pipe close to the manifold, you screw the O2 sensor in it and a wire or two to the gauge. It can help you fine tune the engine so it is running lean enough when cruising and rich when it is under load. All things set right you should see 16-18 mpg but not much better with the GM 6, automatic and 3.73 gears.
[8D]

Restore it, don't replace it.Keep the Studebaker reproduction industry going

65cruiser
05-26-2005, 10:41 AM
Okay, clue me on on where this "economizer" is. Looks like a garden variety 1 barrel Holley to me.

________________________
Mark Anderson
http://home.alltel.net/anderm
1965 Studebaker Cruiser

1949commander
05-27-2005, 11:59 AM
The economizer or load enrichment is a little vaccum controled valve inside the carburetor. It's job is to allow the engines main jet to be set lean for low engine load operation i.e. cruising down the road or when vaccum is high. Then as load increases the vaccum acting on this economizer valve decreases, a counter spring that works opposite the vaccum overcomes the reduced vaccum as load increases and opens another jet to enrich the mixture. Most carburetors have a little piston and linkage that controls this valve. If the piston is worn then this valve will not function as intended and will cause a richer mixture. The other thing that affects this valve is a slightly worn throttle shaft on the carb. As the shaft wears the maximum vaccum that can be achieved is reduced, thus the economizer begins to open under less load. One way you can tell if your throttle shaft is worn is to check the idle screw setting. If it is turned out farther than the factory spec it may be due to a worn throttle shaft. Also if you adjust the idle screw and little change in idle is noticed then the shaft may be worn. If you check a brand new carb you will notice no slop in the shaft. Another source of poor fuel economy is an inopertive manifold heat riser valve. This controls the temperture of the intake manifold to allow for quick warm up from start and also keeps the carburetor from icing up in cool weather. If this is stuck in the bypass mode no heat from the exhaust manifold reaches the carburetor and choke assembly. This means that the choke will take much longer to open, plus the carburetor will not warm up to help vaporize the fuel.

Hope this helps:D

Restore it, don't replace it.Keep the Studebaker reproduction industry going