318 engine, MPG and what makes it better

[mopar 3 B]

THis is wrong. A wider tire has a larger contact patch. The extra traction also means more drag.

His stock wheel well will not allow that wide a tire.

 

[rumblefish360]

A ‘74 Satellite has narrow wheel wells?!
LMAO, no way! Get atta here!
I’ve seen 275/60/15’s as almost common. Ya gotta be able to fit bigger *I think?*
Regardless....

Back to the MPG issue at hand.....

 

[mopar 3 B]

A ‘74 Satellite has narrow wheel wells?!
LMAO, no way! Get atta here!
I’ve seen 275/60/15’s as almost common. Ya gotta be able to fit bigger *I think?*
Regardless....

Back to the MPG issue at hand.....

Its going to be really hard to justify that or anything larger with only the 318 to power it.

 

[JB400]

The recipe you need:

1. Efficient engine. Air needs to flow easily in and out of it with good fuel burn.
2. Right gear set. You want low rpms at cruising speed. I pay attention to where the trans shifts at and run the engine at that rpm on highway.
3. Light weight. Every little bit helps. Less weight, less fuel used to get to speed.
4. Tires need to be narrow and hard for least resistance. No deep wheels either. This combo will not be fun for going around corners.
5. Aero. Lose the spoilers as most just increase drag. You will also want to lower the car. You don't want much air going under the car.
6. Vacuum guage. It tell you how much air your engine is gulping. If it's sucking air, it's sucking fuel. Easy way of adjusting your driving habits.

This should get you a good start.

 

[levicah]

How about a pic of the rear end? I have my doubts that it is a dana whereas I bet it's probably 8 3/4.

How wide of tires are you running?[/QUOTE

I can remember 4 mpg but gas was $0.35 per gal. . Cost a whole $5 to fill the tank.

Oky doky, Tires are 215/75/15's. The guy never said "dana" but did say 9 3/4 and the word "upgraded" ...makes no sense.
The rear end has a very removable rear cover with 10 bolts. The cover also is round or slightly oblong with a big *** contour hump off to one side. It lacks any of those trapezoidal straight edges that I've seen on pictures of Dana's.
A bolt tag has "271" stamped on it. 271 gear ratio...I have no idea what he was aiming for. The rear end is a rabbit trail I think, but I am learning. I downloaded the manual for the carb, so Ill tune tune tune and try to figure out what the previous owner was thinking or not thinking as I go. Like the wheels...he spent some real money just to put modest tires on the car.
As for facts, I've listed the obvious things in the first post. They arent guesses. 14 years of storage, the sucker started right up with fresh gas and continues to run very nicely. I just think the mpg sucks. To this day, I'm not sure what "pinging" sounds like. I havent heard anything that "sounds like a "ping" though.

 

[JB400]

8 1/4 rear end is oval with 10 bolts

 

[levicah]

Its going to be really hard to justify that or anything larger with only the 318 to power it.

Mopar 3B...that is the mystery in a nutshell. The guy couldnt make up his mind between having a numbers perfect satellite or a hot little roadrunner clone. The paint job and alloy rims are worth more than the 1500 hundred I payed for it.

 

[mopar 3 B]

10 bolts = 8.25 housing and normal for a 318 car.

 

[mopar 3 B]

Dont feel bad when you finally figure out what you bought. I have seen knowledgeable chevy and ford people get snowballed when it comes to Mopars.

 

[levicah]

8 1/4 rear end is oval with 10 bolts

Yeah, I thought about that, I'll look at it closer tomorrow, the gas tank and my bad eyesight made it hard to see...but I'm assuming that wouldn't be an upgrade right? Actually, it closely resembles a 10 bolt GM rear end. At a 271 ratio, what sized tires should be on there?

Please Do Not Post eMail addresses or phone numbers in posts - Send that info in a private conversation​

 

[beanhead]

 

[YY1]

I was going to say 9 1/4.

 

[rumblefish360]

Its going to be really hard to justify that or anything larger with only the 318 to power it.

I never suggested it nor would I suggest it. Thanks you.

 

[levicah]

His stock wheel well will not allow that wide a tire.

lol, I could raise a family in those wheel wells

 

[levicah]

View attachment 620231

Yeah, I've been staring at that one for 2 days now. Still looks more like a round 10 bolt GM rear end with the convex contouring left of ctr. So, we've learned that traction bars are not needed on a 318...would a axle swap in anyway have need of, or involve installing traction bars? I honestly dont know.

 

[YY1]

On most 72-74 8 1/4 was standard unless big block or 4 barrel, then 8 3/4 and then very late 9 1/4.

Not a super easy swap as the frame width changed in 71 and only certain C body or wagon axles are a drop in.

Does it look like the spring perches have been moved...any evidence of them being welded on somewhere else, or non factory looking welds?

 

[rumblefish360]

There are zero reasons to install traction bars.

 

[moper]

If you're looking for milage you have to get into the tuning. These cars don't tune themselves like a modern car so you need to dig into how to set and control the timing curve, and then how to tune the carburetor. You should have the vacuum advance connected, and you should know exactly what the initial timing is, and the centrifugal amount and what rpm it starts and finishes at. Once that's set you can plug in the vacuum advance and set the carb. Chances are it will be lean which when combined with the timing you gives you the pinging. You will need the Edelbrock strip kit for that carb. Always do timing first, carb last.

 

[levicah]

If you're looking for milage you have to get into the tuning. These cars don't tune themselves like a modern car so you need to dig into how to set and control the timing curve, and then how to tune the carburetor. You should have the vacuum advance connected, and you should know exactly what the initial timing is, and the centrifugal amount and what rpm it starts and finishes at. Once that's set you can plug in the vacuum advance and set the carb. Chances are it will be lean which when combined with the timing you gives you the pinging. You will need the Edelbrock strip kit for that carb. Always do timing first, carb last.

Thank you, I'm a learnin. I'm waiting on a tachometer.
Do the upgrades to this 318 (performer intake, 600c/ 4 Bbl carb, headers & glaspacks, 727 trans, unknown cam)
change any specs or numbers as far as timing and tuning?

This car had less than 500 miles on a rebuild before being put up on blocks 15 years ago when I bought it. A month ago, I rebuilt the dried out transmission, added some fresh gas and it purrs and roars like it did 15 yrs ago.

It just has a short lived "diesley raspy rattle" when I punch it on a hill. Like a hot car or a vacuum issue. Until now , I assumed that was "pinging". Hopefully the carb already is calibrated or well matched. I dont know.

 

[rumblefish360]

Detonation or pining sounds like a metallic rattle and/or a hammer on top of the pistons.
It can be a rattle nearly as fast as a rattle snakes tail shake or slow like a rapid secession or hammer stikes on loose parts bin.