Hi!
Just thought I'd ask about something...
I've got a grand marquis, a heavier car than a mustang for sure,
so when I rebuilt the engine as a school project and upgraded to an HO, I put an explorer camshaft in it. I also put explorer gt40 heads on--got lucky at the junkyard. The explorer camshaft, since it is geared more towards low-end torque, which I badly need for my heavy car. A higher ratio differential is next on my wishlist.
My fuel economy before the conversion, as I'd owned the car for a year, was 18-20mpg over the summer, and 15mpg over the winter. Importantly, I was commuting in 20mile trips on the highway.
Since the conversion, I've got a different job too, and I'm only commuting 5 miles, half of it highway, if that even counts when you accelerate onto the highway and get off less than 2 miles later!
Since the HO conversion, my second tank was 12.5mpg.
Can this be explained by the change in driving habits?
Can this be explained by a certain break-in period for the engine? It's got 400 miles on it now; all bearings, seals, valve sleeves, rings, etc. replaced.
But I also wanted to check if the explorer cam is really very close to the HO cam, or, if using the HO computer to run a car with an explorer cam could be causing it to run way too rich? If it's working on the assumption of an HO cam, could it be assuming significantly more air than it's getting...?
I've got speed density btw.
If they're really not that different, then I won't worry any more about it.
It really might just be the shorter commute.
But man, 12.5mpg is just depressing. Not a number to brag about when I live in a family that owns priuses and subcompacts.
Just thought I'd ask about something...
I've got a grand marquis, a heavier car than a mustang for sure,
so when I rebuilt the engine as a school project and upgraded to an HO, I put an explorer camshaft in it. I also put explorer gt40 heads on--got lucky at the junkyard. The explorer camshaft, since it is geared more towards low-end torque, which I badly need for my heavy car. A higher ratio differential is next on my wishlist.
My fuel economy before the conversion, as I'd owned the car for a year, was 18-20mpg over the summer, and 15mpg over the winter. Importantly, I was commuting in 20mile trips on the highway.
Since the conversion, I've got a different job too, and I'm only commuting 5 miles, half of it highway, if that even counts when you accelerate onto the highway and get off less than 2 miles later!
Since the HO conversion, my second tank was 12.5mpg.
Can this be explained by the change in driving habits?
Can this be explained by a certain break-in period for the engine? It's got 400 miles on it now; all bearings, seals, valve sleeves, rings, etc. replaced.
But I also wanted to check if the explorer cam is really very close to the HO cam, or, if using the HO computer to run a car with an explorer cam could be causing it to run way too rich? If it's working on the assumption of an HO cam, could it be assuming significantly more air than it's getting...?
I've got speed density btw.
If they're really not that different, then I won't worry any more about it.
It really might just be the shorter commute.
But man, 12.5mpg is just depressing. Not a number to brag about when I live in a family that owns priuses and subcompacts.
