Outstanding!
Chrysler went to the 2.21:1 ratio gears for fuel mileage and for emissions.
In a perfect world, I can see fuel mileage going up on an engine that doesn’t have to spin as much.
In the real world – it doesn’t work that way. Torque multiplication is lost with the high gear ratio and engine is constantly working hard to “maintain” which puts carburetor in the “power” mode full time (or under-load circuit).
The basic systems to every carburetor are: float (fuel level), idle, off-idle, main (primary venturi’s), power/load and accelerator pump. Then some have additional circuits if it has a 4-bbl.
As MoparKidD-4 has demonstrated, getting rid of the 2.2 ratio gears is the first step if you want any sort of power. BTW, thank you for your report.
I think it is odd that police cars almost always come with 2.94 gears. They get the same fuel mileage as 2.2’s and are a lot easier to drive – but factory kept installing the 2.2’s for the masses.
Now I have a couple of questions for you: What did you use for a propeller shaft?
The propeller shaft for an 8¼” is shorter than a 7¼” differential is (1.6”).
A vibration is normally caused by loose U-joints 9 out of 10 times – but if propeller shaft has been removed recently – a ding or dent in it can also cause a vibration,
If a driveshaft shop shortened a propeller shaft, they will balance it afterwards.
If car has new U-Joints and shaft was balanced (and not damaged) – then the most likely cause is tires (balance or defect in tire). There should not (ever) be a vibration present when everything is done.
M-bodies do weigh in at, or about, 4000 pounds.
On the 4-bbl changeover – you have a lot of choices (carburetor brand, square vs. spread bore, intake brand, fuel injection, and so forth. One thing that is hard (or not cheap, depending on how you look at it) to find is the transmission kickdown linkage setup.
I like and prefer the mechanical linkage – but with current prices, availability and the chances of getting a complete (and correct) set is not easy. I’ve seen a lot of people purchase a “so called set” and end up with another 2-bbl setup - or a lot pieces of a mismatched set. I recommend that you get a cable setup. It will be cheaper and that way you don’t have to worry about getting incorrect parts.
If transmission linkage is not used or is not set up correctly – you WILL have premature transmission failure (this is not an if, or a maybe, but a WILL HAVE).
The next item will be air cleaner. If car is to be driven in town and highway every once in a blue moon, and you live in South California, South Texas or Florida (ie: a warm area), what you use for air cleaner won’t matter much.
If you will be doing much highway driving, then getting an air cleaner with fresh air will help your fuel mileage out, at lot.
If you will be driving in below freezing wearer often (like in Ft. Collins, CO), then an air cleaner with exhaust manifold heated air is also beneficial to have.
An air cleaner like this one would fit the bill, nicely http://www.forfmjbodiesonly.com/classicmopar/threads/lean-burn-air-cleaner.6601/ Either use your computer or get a piece of steel to fill the hole on side of air cleaner (it doesn’t need to be a professional job – unless you have plans on entering into a car show).
Once you pick what intake manifold you are going to use, let me know. I have a couple of used ones for sale, cheap (I keep tripping over them in my garage). I just don’t want to recommend which one for you to use.
If you have some extra money in your pocket – you might want to at least look at fuel injection. I have plans on injecting both of my cars – but my money tree is just not putting out enough, nowadays.
One last question (in regards to future 4-bbl changeover). Can you measure your diameter of exhaust pipes for me (after main cat and also the tailpipe (one that exits the car)), please?
BudW
Chrysler went to the 2.21:1 ratio gears for fuel mileage and for emissions.
In a perfect world, I can see fuel mileage going up on an engine that doesn’t have to spin as much.
In the real world – it doesn’t work that way. Torque multiplication is lost with the high gear ratio and engine is constantly working hard to “maintain” which puts carburetor in the “power” mode full time (or under-load circuit).
The basic systems to every carburetor are: float (fuel level), idle, off-idle, main (primary venturi’s), power/load and accelerator pump. Then some have additional circuits if it has a 4-bbl.
As MoparKidD-4 has demonstrated, getting rid of the 2.2 ratio gears is the first step if you want any sort of power. BTW, thank you for your report.
I think it is odd that police cars almost always come with 2.94 gears. They get the same fuel mileage as 2.2’s and are a lot easier to drive – but factory kept installing the 2.2’s for the masses.
Now I have a couple of questions for you: What did you use for a propeller shaft?
The propeller shaft for an 8¼” is shorter than a 7¼” differential is (1.6”).
A vibration is normally caused by loose U-joints 9 out of 10 times – but if propeller shaft has been removed recently – a ding or dent in it can also cause a vibration,
If a driveshaft shop shortened a propeller shaft, they will balance it afterwards.
If car has new U-Joints and shaft was balanced (and not damaged) – then the most likely cause is tires (balance or defect in tire). There should not (ever) be a vibration present when everything is done.
M-bodies do weigh in at, or about, 4000 pounds.
On the 4-bbl changeover – you have a lot of choices (carburetor brand, square vs. spread bore, intake brand, fuel injection, and so forth. One thing that is hard (or not cheap, depending on how you look at it) to find is the transmission kickdown linkage setup.
I like and prefer the mechanical linkage – but with current prices, availability and the chances of getting a complete (and correct) set is not easy. I’ve seen a lot of people purchase a “so called set” and end up with another 2-bbl setup - or a lot pieces of a mismatched set. I recommend that you get a cable setup. It will be cheaper and that way you don’t have to worry about getting incorrect parts.
If transmission linkage is not used or is not set up correctly – you WILL have premature transmission failure (this is not an if, or a maybe, but a WILL HAVE).
The next item will be air cleaner. If car is to be driven in town and highway every once in a blue moon, and you live in South California, South Texas or Florida (ie: a warm area), what you use for air cleaner won’t matter much.
If you will be doing much highway driving, then getting an air cleaner with fresh air will help your fuel mileage out, at lot.
If you will be driving in below freezing wearer often (like in Ft. Collins, CO), then an air cleaner with exhaust manifold heated air is also beneficial to have.
An air cleaner like this one would fit the bill, nicely http://www.forfmjbodiesonly.com/classicmopar/threads/lean-burn-air-cleaner.6601/ Either use your computer or get a piece of steel to fill the hole on side of air cleaner (it doesn’t need to be a professional job – unless you have plans on entering into a car show).
Once you pick what intake manifold you are going to use, let me know. I have a couple of used ones for sale, cheap (I keep tripping over them in my garage). I just don’t want to recommend which one for you to use.
If you have some extra money in your pocket – you might want to at least look at fuel injection. I have plans on injecting both of my cars – but my money tree is just not putting out enough, nowadays.
One last question (in regards to future 4-bbl changeover). Can you measure your diameter of exhaust pipes for me (after main cat and also the tailpipe (one that exits the car)), please?
BudW
