|
Sponsored Links (Register now to hide all advertisements) |
|
|
Thread Tools | Display Modes |
03-03-2017, 04:38 PM | #1 |
Junior Member
Join Date: Feb 2016
Posts: 13
|
Engine question...
I have a question for the Model A owners about my engine...
I have a 1930 Fordor Town Sedan... All stock... Stock engine with a stock head, stock transmission, and a stock rear end... I am getting 11 miles per gallon... Cylinder compression is 1-58, 2-56, 3-58, 4-56 lbs ... When I add oil to the top of the pistons and redo the compression test I get 1-60, 2-57.5, 3-60, 4-57 lbs... Not being an engine guru, could someone tell me if the rings are ok, or do I have something more serious going on here... I have read several places here that the Town sedans should be getting around 15 miles per gallon, and I’m trying to see what I could do to get my mpg’s a little higher... I do use Ethanol free gas, it is well timed, the car runs well and burns No oil... One more question... If I changed over to a high compression head (like a 5.5 to 1) would that increase the mpg or not? Many thanks ahead of time... Last edited by kqa3637; 03-03-2017 at 05:03 PM. |
03-03-2017, 04:57 PM | #2 |
Senior Member
Join Date: May 2010
Posts: 335
|
Re: Engine question...
I say yes and yes. A "wet" compression increase of only 2 lbs. indicates that the rings are good. a higher compression head should give at least 2 mpg. increase in my experience.
|
Sponsored Links (Register now to hide all advertisements) |
|
03-03-2017, 05:32 PM | #3 |
Senior Member
Join Date: Jun 2014
Location: Land of Lincoln
Posts: 3,131
|
Re: Engine question...
How are your plugs burning? What are the tire air pressures? What are your driving conditions, hilly, town driving with stop and go,etc! There are way to many variables that determine fuel mileage. Yes a higher compression head should help! Running a coolant thermostat will help! Dragging brakes will not help! Driving with the windows down will not help! How fast or slow your driving will cause mileage to vary! Good luck getting your fuel mileage up and have fun! :-)
|
03-03-2017, 05:38 PM | #4 | |
Senior Member
Join Date: May 2010
Location: Central, IL
Posts: 3,968
|
Re: Engine question...
Quote:
but yes your engine is good.
__________________
1929 Model AA - Need long splash aprons! |
|
03-03-2017, 05:57 PM | #5 |
BANNED
Join Date: May 2010
Location: Bucks County, PA
Posts: 11,454
|
Re: Engine question...
Is ur arithmetic Correct?
Ck your Stoichiometric / A/F ratio on a gas analyzer this will tell ya everything u need Last edited by Mitch//pa; 03-04-2017 at 08:11 AM. |
03-03-2017, 06:02 PM | #6 |
Senior Member
|
Re: Engine question...
Sponsored Links (Register now to hide all advertisements)
|
03-03-2017, 11:30 PM | #7 |
Senior Member
|
Re: Engine question...
How are you operating the spark control, the gas lever and the GAV? At what speeds are you shifting gears?
__________________
What's right about America is that although we have a mess of problems, we have great capacity - intellect and resources - to do some thing about them. - Henry Ford II |
03-03-2017, 11:34 PM | #8 |
Senior Member
Join Date: May 2010
Location: Southern California
Posts: 7,032
|
Re: Engine question...
Have you verified that your odometer is correct?
Charlie Stephens |
03-04-2017, 02:56 AM | #9 |
Senior Member
Join Date: Dec 2016
Location: Seattle
Posts: 129
|
Re: Engine question...
What sort of driving do you do? Long runs on the open road? Short runs? Stop/start in town? Some or all of the above? Without that detail mpg figures mean very little.
|
03-04-2017, 06:30 AM | #10 |
Senior Member
Join Date: Mar 2012
Location: lexington sc
Posts: 456
|
Re: Engine question...
myself I don't worry about gas mpg I just love to drive it and add fuel when needed
kevin 1930 tudor 1923 model t roadster p/u |
03-04-2017, 07:56 AM | #11 |
Senior Member
Join Date: Nov 2010
Location: Sebastian, FL
Posts: 479
|
Re: Engine question...
X2!
|
03-04-2017, 07:58 AM | #12 |
Senior Member
Join Date: May 2010
Location: on the Littlefield
Posts: 6,159
|
Re: Engine question...
I used to get 15 or so, then I replaced the worn cam with a used but not worn "B"cam, put in valve seats because of too many seat grindings, and a thermostat-- top speed went from 52to 67, and fuel mileage over20, on a long trip I averaged 23 at speeds over 60,-- stock head, gear ratio, same untouched carb and dist--- with the old cam I could get spark knock, after never even with full advance in any conditions, both ways the plugs (repro 3X)would burn light tan--- the valves sunk in the block and the cam not lifting the valve out of the hole as much as it should restricts flow
Adding the thermostat was good for 1.5 mpg The jets in my carb are original, have never been flow tested, but I have done loaded emission testing when it was done for NJ inspections--- both before and after the addition of ethonal, and the ethonal dies lower emissions. My carb is a little rich on regular gas, a little lean on 10%ethonal--- with ethonal the car would have passed emissions as a 2002 Honda Civic--- I had to run it as a later car, no old cars in the database Last edited by Kurt in NJ; 03-04-2017 at 08:07 AM. |
03-04-2017, 09:08 AM | #13 |
Senior Member
Join Date: Jan 2016
Posts: 2,101
|
Re: Engine question...
Kurt, how or why would a thermostat increase mpg. Dumb, enquiring minds want to know
|
03-04-2017, 09:54 AM | #14 |
Senior Member
Join Date: May 2010
Location: on the Littlefield
Posts: 6,159
|
Re: Engine question...
A cold engine needs a richer mixture, i could close the GAV sooner, ---before the thermostat I had to have 1/4 turn, after I could close it, and the oil stayed cleaner longer because it got up to temp quicker too---thinner oil less friction moving the oil
|
03-04-2017, 10:00 AM | #15 |
Senior Member
Join Date: May 2010
Location: Mpls, MN
Posts: 27,582
|
Re: Engine question...
My 1999 Olds 88 runs in the 195* to 205* range because that's where the engine gets it best fuel economy. I use a 180* in my Model A.
|
03-04-2017, 11:44 AM | #16 | |
Senior Member
Join Date: Nov 2015
Location: Tennessee
Posts: 714
|
Re: Engine question...
Quote:
Old timers used to fill up early in the morning when the air and the gas in the ground was cooler. My Grandad said it improved mileage. |
|
03-05-2017, 02:15 AM | #17 |
Senior Member
Join Date: May 2010
Location: Between Seattle & Tacoma
Posts: 2,354
|
Re: Engine question...
Do you know the actual rear end ratio? Simple things first. As mentioned, what color are your plugs after warmed up and ran at speed?
|
03-05-2017, 09:00 AM | #18 |
Senior Member
Join Date: May 2010
Location: on the Littlefield
Posts: 6,159
|
Re: Engine question...
Another thing to look at is --are the brakes dragging, how easy is the car to push, fuel economy is not just the engine
For the people that say --fuel mileage doesn't matter, it does, running too rich dilutes the oil, increases cylinder wear, carbons the rings,valves, pistons |
03-05-2017, 09:21 AM | #19 |
Senior Member
Join Date: May 2010
Location: Bucks Co, Pa
Posts: 3,740
|
Re: Engine question...
It sounds like your engine is in good shape with all compression numbers within ten lbs of each other. I would not be happy with the stock HP of a mod A, but then I live in a very Hilly area. Myself, I would want to put a high Comp head on it and port and polish the manifolds.
This probably increases the HP about 8-10 or some 20- 25% with out putting more gas in the cyls. Terry |
03-05-2017, 11:56 AM | #20 |
Senior Member
Join Date: Apr 2013
Location: Columbia, TN.38401
Posts: 422
|
Re: Engine question...
check all piston, to see how high they are. they will differ some.
|
03-05-2017, 12:14 PM | #21 |
Senior Member
Join Date: May 2010
Location: Fountain Valley, Calif.
Posts: 937
|
Re: Engine question...
I have a well-running Town Sedan, and get about 22 mpg when on hiway tours & cruising, but it drops off to about 15 in town with lots of stop and go driving. Town Sedans are the heaviest Model A and will get somewhat less mileage than the other models. I agree that a HC head is a really nice add, both for mileage and better acceleration.
|
|
|
Sponsored Links (Register now to hide all advertisements) |
|