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Mileage Question
https://slantsix.org/forum/viewtopic.php?t=44485		 Page 1 of 1
Author:  bob_o [ Tue Apr 12, 2011 11:06 am ]
Post subject:  Mileage Question
Howdy everybody! Not only am I new to this Forum, but I'm new to Mopar's as well. I recently acquired a '66 Valiant more-door with a 225 and a 904. The car had sat for a long time (the car still had bias ply tires on it!) and needed ALOT of work to get her road worthy again. I've been driving it daily now for a couple of months. Anyways, here's my question... I rebuilt the single barrel Holley on it in hopes of getting some better mileage. While the car does run a whole lot better now, I'm still only getting about 10.5 mpg (?!). And that's driving around town and doin about 60-65 mph on the freeway. That works out about to about 190 miles per tank. No bueno. Did I mess up the rebuild? Could the motor be tired? Could it just be the way the car is geared? How can I identify the ratio? Any ideas? Suggestions? Like I said, I'm new to Chysler products (I grew up with GM stuff) so any and all help would be appreciated. I'm hoping you guys have some "slanted" tricks up your sleeves! Thanks in advance :)

bob_o
Author:  Doc [ Tue Apr 12, 2011 11:14 am ]
Post subject: 
Confirm some other things before going further with the carb.
- Is the distributor's mechanical and vacuum advance working correctly?
- Is the valve lash set to specs? (.010 on the intake valves, .020 on the Exhaust)
- Do you know the cranking engine compression in psi?
DD
Author:  bob_o [ Tue Apr 12, 2011 12:26 pm ]
Post subject: 
Awesome, thanks Doc. I'll start checking into those suggestions!
Author:  The_Duke [ Tue Apr 12, 2011 5:03 pm ]
Post subject: 
Hey bob-o,

Have a go using the search function at the top of the board for terms like 'MPG' or 'fuel economy'. There's a wealth of info on how to get that 190 miles per tank to over 400.
Author:  bob_o [ Wed Apr 13, 2011 8:20 am ]
Post subject: 
I'll do that Duke. Thanks man :)
Author:  ESP47 [ Wed Apr 13, 2011 8:20 am ]
Post subject: 
This is a good link to get started on

http://www.slantsix.org/forum/viewtopic ... ht=#138010
Author:  SlantSixDan [ Wed Apr 13, 2011 9:11 am ]
Post subject: 
Tune-up parts and technique suggestions in this thread. Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download. Make sure your 1920's power valve hasn't fallen apart (see here).
Author:  The_Duke [ Wed Apr 13, 2011 3:38 pm ]
Post subject: 
.... and are you still running a points distributor?

Easy GM 'HEI' mod to electronic ignition is recommended.

Again, just search for HEI and you'll find what you need. 8)
Author:  bob_o [ Thu Apr 14, 2011 8:45 am ]
Post subject: 
I've made a list of all the suggestions you guys have given me, and I'm gonna start goin through them this weekend :)

Duke, the car still has a points-type distributor in it. I was actually thinkin about tryin to locate an HEI for it, so thanks for that!
Author:  wjajr [ Thu Apr 14, 2011 1:35 pm ]
Post subject: 
Before spending a wad of dough, make a quick check of the point’s gap. If the engine runs well after adjusting, you have found the problem.

Where your car sat for a long time, the points could just be corroded, or closed up a bit. File or clean, and reset them. Don’t forget to put a little Vaseline on the six sided cam that opens & closed the points. If left un-lubed your points will fall out of adjustment rather quickly from wear.

We are spoiled these days with electronic ignition equipped autos. Before those orange boxes became the norm, one had to inspect their points ignition about every 6 months, or 6,000 miles, and perform a full tune-up once a year or 12,000 miles.

Today, doing any ignition related tasks once every 100,000 miles is more like it, making 12,000 mile service interval seam excessive.
Author:  Slanted Opinion [ Thu Apr 14, 2011 5:00 pm ]
Post subject: 
Don't be satisfied until you're getting better than 20 mpg... 23+ if you're babying it at all.
Author:  Ross [ Thu Apr 14, 2011 5:16 pm ]
Post subject: 
after i did a tune up on mine i got 18, and thats a truck. Just recently when i filled up i was getting 12.3. I went a week babying it as much as my lead foot would let me and managed to get 14.4 mpg just by babying it some and bringing my shift points down a few hundred rpms. Im hoping i can get back up to 18.
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