318 mpg

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usdart

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I finally got my 318/904 dialed in with a new 500 cfm Eddie carb and an SP2P intake. I was getting about 16Mpg before the swap with a cast 2 bbl on it. Anyone curious what the change might be?

If so I will let you know in a coule of weeks of monitorng driving 40 miles a day mostly freeway at 65 Mph.
 
Power LOSS so far. Smoother running and better response though. This intake was made for economy and I think Vic Edelbrock meant it.
 
usdart said:
I finally got my 318/904 dialed in with a new 500 cfm Eddie carb and an SP2P intake. I was getting about 16Mpg before the swap with a cast 2 bbl on it. Anyone curious what the change might be?

If so I will let you know in a coule of weeks of monitorng driving 40 miles a day mostly freeway at 65 Mph.
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Cleaner burn and 21 miles to the gal if you drive it nicely O:)
 
If you LOST power, you aren't dialed in. The SP-2P was an economy oriented intake, and below 4000 RPM, should do far better than the single plane iron stocker. A 4 barrel shouldn't hurt economy (unless you are constantly using all four barrels). If you are running an Eddy 1405, think about going 1 or 2 jet sizes leaner. Make sure you are running plenty of timing advance. A 318 with the stock cam likes at least 10 degrees static. Make sure you have a functioning vacuum advance, and hook it to timed vacuum (passenger side nipple on an AFB/AVS/Eddy carb). Down the road, if you start looking for a little more power, scare up a regular Performer or an old LD4B, and dont go nuts on the cam..

My 72 Swinger, with a dead stock 318 with a gazillion miles on it got 20-22 MPG on the highway and 16 or so in town (without a/c on). Unfortunately when I quit running that engine, it was getting an abysmal 400 MPG on oil. So it was truly an "Add oil and check the gas" ride. I think I spent more time cleaning my tail lights at
 
I have a 1403 Eddie carb on it. Timing is adjusted just short of ping on load. Maybe not dialed in for performance cause that is not I was after. This is just my beater for work. I have not driven it since I got the throttle and stuff worked out, so , maybe a I will have better performance.
 
The intake is good for economy but the 500cfm/2bbl carb isn't designed
to save fuel. A small Edelbrock/AFB style carb should get you 20mpg. on the highway if you drive it smart. Mike
 
It has to be better than those 3 different 2 barrels I tried. I always got a black soot spot on my driveway at startup. They took a long time to warm up anc never quite ran right. I tried two Holly's and a reman-Carter.
No more smoke at starts and all issues melted away.
 
do you have dual exhaust yet?

Electronic ignition?

Those will both help with gas mileage,
so will making sure your tires are inflated to the max
PSI recommended on the tire sidewall.

I have a 318 in my '64 Valiant, and get from 17-21 mpg on the road,
and I have a bigger than stock cam.
 
VERY NICE car!
I am in West Richland Wa.
The car is a 79 Volare, lean burn gone and shows 99999 on the clock. Exremly smooth runner but, uglier than Ole cooters ex wife.
 
usdart said:
It has to be better than those 3 different 2 barrels I tried. I always got a black soot spot on my driveway at startup. They took a long time to warm up anc never quite ran right. I tried two Holly's and a reman-Carter.
No more smoke at starts and all issues melted away.
Click to expand...


Was the intake manifold exhaust crossover heat block, that will cause the spark plugs to foul out unless its only driven when its hot outside and hard.
 
Dunno.. old intake and carb are on the floor of my garage now.
I still have some fine tuning to do on the kickdown lever. Still no down shift for passing.
 
Be careful, you can burn the trans out if its way out of adjustment. I used to set it so it was all the way back when the throttle was open all the way. Sounds like its not going back far enough, that will cause the trans to slip and burn up.
 
I put the adapter on the carb yesterday..there is a good 'seat of the pants' improvement in overall performance! This car was strong before even with issues and now it is probably the best 318 I ever had. Even better than my brand new 72 Demon I had back in 73.


C130 Chief said:
If you LOST power, you aren't dialed in. The SP-2P was an economy oriented intake, and below 4000 RPM, should do far better than the single plane iron stocker. A 4 barrel shouldn't hurt economy (unless you are constantly using all four barrels). If you are running an Eddy 1405, think about going 1 or 2 jet sizes leaner. Make sure you are running plenty of timing advance. A 318 with the stock cam likes at least 10 degrees static. Make sure you have a functioning vacuum advance, and hook it to timed vacuum (passenger side nipple on an AFB/AVS/Eddy carb). Down the road, if you start looking for a little more power, scare up a regular Performer or an old LD4B, and dont go nuts on the cam..

My 72 Swinger, with a dead stock 318 with a gazillion miles on it got 20-22 MPG on the highway and 16 or so in town (without a/c on). Unfortunately when I quit running that engine, it was getting an abysmal 400 MPG on oil. So it was truly an "Add oil and check the gas" ride. I think I spent more time cleaning my tail lights at
Click to expand...
 
Ooh, now I can't wait to do my 4-barrel swap! I'm going with a ThermoQuad and cast-iron 360 manifold off an '83 Dodge truck. Timing advance makes a big difference too, I went from 5 degrees AFTER TDC base timing to around 10 degrees before TDC, and the car runs like a dream now. I think the carb is still kinda dirty since it still hesitates for a split second if I hit the gas at a stand-still, but it's nowhere NEAR as bad as before. Gas mileage has just about doubled too.
 
T-Q's are a great carb,,if you get a good one or you or someone you know is good with them.
I tried two and am just too dumb to make em work right.
That cast iron intake is really good. I ran 14.32 with a basically stock 360 in a Dart with the stock intake. All I had was a different cam and Speed pro 10 to 1 pistons and MSD on it.
 
Whats your mileage now? Can't be so good that you haven't burn a tank of gas by now, right? We like to know how those wimpy-but must be great for mileage-intake and carb are.
 
I have a 318 with a 500cfm eddie 4-barrel with performer intake. Im lucky to get 13mpg in the city. Block is .30 over with a 340 cam among other things. But runs great. With the stock 2-barrel I was getting close to 17mpg in the city. However I have been told that the reason I am getting low mpg's is becuase of my weak rear-end. It's still the stock 8 1/4 with 2.76 gears. It's almost like they are dragging the engine down a bit since it needs to be upgraded to be up to the engine/tranmission's rebuild. 3.23 sure grip will come this summer. Headers would probably help me a little as well as far as gas mialage.
 
The 340 cam in conjunction with the 2.76 gears around town are killing you.
If you wanted mileage, you should back down on cam and hit the Hwy. Yes, headers will help.
Performance wise, thge 3.21's will be cool, so long as tire height doesn't grow much.
 
Spent the week putting in a new Radiator, Starter, Brakes, and Master Cyl. I am determined to make this thing Safe and Depenable for work. Still has the full tank of gas in it from last week.
I am gonna start driving next week to check the wimpy parts.
 
dodge freak said:
So whats the verdict?
Click to expand...

Oh helll, I can't tell a difference, it's 20' and a foot of snow so longer warm ups and different driving habits.
I guess I will have to wait for some good weather to get a good reading. So far it seems like no change, all seems the same on mileage. I have to think it would have improved cause the car was running so poopey with the 2 barrel on it.
 
Well 16 mpg is not bad, if it is the same and it has more power, you done good, really good.

I am thinking the camshaft makes the differences, because I went from 318 heads, to 360 heads, still the same-well I lost 1 mpg Then after from a single plane intake, to a dual plane intake and my mileage went back to 10 mpg but I am sure it runs better--with 3.91 gears.
 
Well it's about 13 MPG in this weather..it should pick back up as weather gets better. I idled it for an hour last Sunday to get it thawed out and I idle 15-20 minutes in the Am to get er goin.
 
dodge freak said:
Whats your mileage now? Can't be so good that you haven't burn a tank of gas by now, right? We like to know how those wimpy-but must be great for mileage-intake and carb are.
Click to expand...

It looks like 18 MPG with the wimpy 500 cfm Eddie and the even more wimpy Eddie SP2P intake.
I am happy with that, performance picked up and I no longer have starting and idling issues. It is a pleasure to drive now, cruises like I remember the big cars used to do.:toothy10:
Only problem now is, What to work on next. It was my hobby fixer uppper for a grocery getter (beer runs) and work commuter.
 
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