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| | | | Joined: Jun 2011 Posts: 24 New Guy | | New Guy Joined: Jun 2011 Posts: 24 | Hi guys... I know a lot of you have followed my saga over the last couple weeks or so. Yesterday I posted that after I tuned up the 235 and rebuilt the Rochester B, I went from 10 to 20 MPG. Not true. Today I drove it 115 miles and filled the tank... it took 10.7 gallons...and is getting, oddly enough, 10.7 MPG. So I don't know what to think now. My assumption is that I have a 4:11 rear end - that, with the 235 should be giving me 15 MPG or so, right? Maybe I have an even lower geared rear end -- how could I determine this? We're talking about a 1950 3100, with a a '54 235 in it. I just wonder what the rear end options were in 1950 for Chevy trucks. It was definitely a 'farm truck' - had that ignition switch that you could remove the key from and still turn it off an on...The differntial is 10 bolts. Please, can someone enlighten me? The truck is running nice and smoothly - loved being on Hiway 5 in Ca. with all the cars whizzing past me. But that fuel guage just kept moving down down down... anything you can suggest I'd appreciate. Thanks,
Hank | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 |
Hank,
If you have the stock rear-end (enclosed driveshaft rear end) for a 1950 3100 it is 4.11
What was your average speed?
| | | | | Joined: Jul 2001 Posts: 3,887 Cruising in the Passing Lane | | Cruising in the Passing Lane Joined: Jul 2001 Posts: 3,887 | I'd say with a stock setup [I think 4.11 was standard in 50], you're dreaming to expect more than 12 or 13 at highway speeds - and remember back in the day "highway speed" was about 45 .... if economy is what's important, an old truck isn't the ticket  Bill | | | | | Joined: Jun 2011 Posts: 24 New Guy | | New Guy Joined: Jun 2011 Posts: 24 | I was going around 60 most of the time. Yes, I have the torque tube - enclosed driveshaft. | | | | | Joined: Jun 2011 Posts: 24 New Guy | | New Guy Joined: Jun 2011 Posts: 24 | Well, I'm happy to get what I should get.. if 10 - 11 MPG is what I should be getting, then so be it. In previous posts though, I had several guys say they were getting around 15 with same set up. Plus, I had a '53 years ago, and got around 15. I'm just wondering if I missed something in my tuneup and carb rebuild. No gas leaks...brakes are not dragging. | | | | | Joined: Jun 2011 Posts: 24 New Guy | | New Guy Joined: Jun 2011 Posts: 24 | I'll check it out on back roads going around 45 max.... less RPM... should be better mileage....again, just want it to be right. | | | | | Joined: Jan 2009 Posts: 1,644 Shop Shark | | Shop Shark Joined: Jan 2009 Posts: 1,644 | I just rebuilt a 55 power glide 235 engine and put it in my 52-3100 all else is stock and I'm getting between 12 and 14 MPG it depends on where I'm driving and how fast ,I don't go over 55 MPH and stay off the highways also I rebuilt a carter 4480s carb changed it to port vac. and installed that and it made a big differance in overall performance.
Pete | | | | | Joined: Jun 2011 Posts: 24 New Guy | | New Guy Joined: Jun 2011 Posts: 24 | thanks Pete...love your gallery pic and story!
Hank | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 |
60 mph with a 4.11 rear end and 28" tires, you'd be at about 3,000 RPM
12 mpg might be possible but 10-11 is not bad.
Please let us know what MPG you get at 45 MPH (2,200 RPM).
| | | | | Joined: Jun 2011 Posts: 24 New Guy | | New Guy Joined: Jun 2011 Posts: 24 | Actually, I have 26" tires, giving me even a higher RPM, right?
Will keep you posted.
Hank | | | | | Joined: Jan 2001 Posts: 5,337 'Bolter | | 'Bolter Joined: Jan 2001 Posts: 5,337 | I know I posted it before but, are you sure your vacuum advance is working and you have the right carb base gasket.
See the USA in your vintage Chevrolet! My Blog | | | | | Joined: Jun 2011 Posts: 24 New Guy | | New Guy Joined: Jun 2011 Posts: 24 | I have the right gasket and I see the distributor advance upon acceration - so I assume the vacuum is working - is there something I should be looking for besides that? | | | | | Joined: Oct 2006 Posts: 1,847 'Bolter | | 'Bolter Joined: Oct 2006 Posts: 1,847 | a few years back you got real gas too. the alcohol just kills gas mileage. however it still cost the same. I don't know as if I would actually worry about mileage in one of these things. Its kind of like buying an escalade and then complaining it doesn't get good mileage. You just aren't going to get fuel economy from one of these things.
Last edited by brokenhead; 06/19/2011 12:17 PM.
| | | | | Joined: Jun 2004 Posts: 8,597 Riding in the Passing Lane | | Riding in the Passing Lane Joined: Jun 2004 Posts: 8,597 | I think you should change the rear gears to 3;55 or put in an o-drive trans. Then you will get decent gas mileage & go down the highway at a respectable rate. You cant expect decent gas mileage with 4:10 gears 26 " tires & 60 MPH.
They say money can't buy happiness. It can buy old Chevy trucks though. Same thing. 1972 Chevy c10 Cheyenne SuperIn the Gallery Forum | | | | | Joined: Jun 2011 Posts: 24 New Guy | | New Guy Joined: Jun 2011 Posts: 24 | Yeah... the picture is pretty clear now. Sounds like there is nothing wrong with my truck; what it is is what it is. For now I will just slow down and enjoy the ride. Today I will be loading my wife, dog, cooler, beach chairs, and a couple of books into Ol Blue, and spend a happy fathers day out on the Sacramento River. We'll cruise out there at a leisurely 45 MPH or so! HAPPY FATHERS DAY TO ALL YOU BOLTERS TOO!!!
Hank | | | | | Joined: Aug 2005 Posts: 6,377 Ex Hall Monitor | | Ex Hall Monitor Joined: Aug 2005 Posts: 6,377 | My '38 coupe with the original 216 & 3.73 rear gear gets 15 on a good day @ 55 MPH. If I kick her up to 60 I get 12-13. The best I ever got was putting home on the back roads from a show in Wichita @ 50 & got 18.
Save a life, adopt a senior shelter pet.
The three main causes of blindness: Cataracts, Politics, Religion.
Name your dog Naked so you can walk Naked in the park.
| | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 |
I'd like to hear about gas-mileage from Cosmo or anyone else that has over-drive. I have the 3.55 rear-end gears and 1:1 transmission in high gear and I get about 19 MPG at 55 MPH. At 65 MPH, I get about 12 MPG. I attribute this to the the higher RPM (2500 compared to 2100 RPM) and to the fact that I am driving a box (wind resistance).
| | | | | Joined: Feb 2011 Posts: 1,362 'Bolter | | 'Bolter Joined: Feb 2011 Posts: 1,362 | In my younger days, dads 57 3100 that we put a 327 in with a carter WCFB carburetor, 4sp and stock rear gears, got 24 mpg on the road. If everything is done right, I don't see why a 235 old truck can't get into the 30 mpg area or better. And its not going to be all stock as far as internals and gearing.
Though a small block sure gives more choices of efficiency improvements over the 235.
Kicking self for selling off my Taskforce trucks.
Still looking for an LCF or conventional big bolt in decent shape.
As of 10-26-2022, A 55.2 Taskforce long bed now the work begins
| | | | | Joined: May 2005 Posts: 487 'Bolter | | 'Bolter Joined: May 2005 Posts: 487 | Hank,
How much ethanol is mixed with your gas?
Here in the DFW area we have E10 which seems to be good for about a 10% reduction in fuel economy. (I'm purposefully avoiding a digression into discussing government interference and trying to stick to the thread topic)
regards,
Leon | | | | | Joined: Jan 2001 Posts: 1,423 ODSS President | | ODSS President Joined: Jan 2001 Posts: 1,423 | I'd like to hear about gas-mileage from Cosmo or anyone else that has over-drive. I have the 3.55 rear-end gears and 1:1 transmission in high gear and I get about 19 MPG at 55 MPH. At 65 MPH, I get about 12 MPG. I attribute this to the the higher RPM (2500 compared to 2100 RPM) and to the fact that I am driving a box (wind resistance). Here we have dual deuces mounted on a vintage Edelbrock intake... Note the cast linkage arms...a Grigg treatment, borrowed from the Diesel world. The arms have the same on center measurement as the old home-made arms that came with the intake. Grigg sleeved the heim joint side of the arms for a tighter fit. Overhead shot of engine bay with Tom Langdon's 'lamp-top' air cleaners. I replaced the threaded rod (metric) with SAE so I could use the polished brass finials. Driver's side pic. Buffalo Steve fabbed on the four bolt plates on this 50's period Edelbrock intake. Note the horseshoe used to negotiate around the rear electric choke. This rod cannot be eliminated as it provides support to the inner and outer fenders and helps to allign the hood. Heat provided to the intake via a home-made plate on the bottom of the Edelbock intake, this plenum was plumbed to the Fentons. This project could not have been accomplished without the invaluable help of Sweet (who kept me from losing my mind at times, and was there from start to finish) and Grigg III who had constructive suggestions and technical help throughout the project. For more thankyous on the project see the ODSS Homecoming post in the Events Section. I recently returned from a 1K round trip from Charlottesville, VA to upstate NY and averaged 18.7 mpg at mostly 65-75 mph. So worth the effort.
~ Cosmo
1949 Chevy Half Ton
Rocinante, like Don Quixote, he is awkward, past his prime, and engaged in a task beyond his capacities.
"...my good horse Rocinante, mine eternal and inseparable companion in all my journeys and courses." ...Don Quixote, Cervantes
"If you come to a fork in the road, take it."...Yogi Berra
"Rudeness is the weak man's imitation of strength." ...Eric Hoffer
| | | | | Joined: Feb 2001 Posts: 4,095 'Bolter | | 'Bolter Joined: Feb 2001 Posts: 4,095 | I have a not so original set up with 15 inch tires with 2.73 rear end and dual carbs and just driving around at 35-40 mph i get 12-13 mpg. on the highway using the 5th gear i can average 20 at 60-70 mph and have seen a high of 23.5 a few times.
Ron, The Computer Greek I love therefore I am.1954 3100 Chevy truckIn the Gallery 2017 Buick Encore See more pix1960 MGA Roadster Sold 7/18/2017
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