Quote: I don't think a lighter rotating assembly is going to save you any noticeable mpg. Acceleration will be better, but cruising, you are already spinning the rotating assembly. It sounds like you are building more or less how the 318s came from the factory in the 80s, w/ a tiny solid cam.
The problem those cars had with intown miledge was gettin everything moveing, they got good miledge on the highway. The light weight stuff should help a bunch in town. I will be removeing at least 1600 grams from the rotateing assy plus removeing weight from the crank to balance it roughly 1200 more grams for a total of 2800 grams Now consider that weight in first gear has to accelerate 7.5 times as fast as the car it will be like removeing 21,000 grams from the vehicle, or almost 50 lbs everytime the engine speeds up or down. I also remember reading the weight actually goes up exponetialy not lineraly so it would rev even easier. And also my car is already 500lbs lighter than those dippys and 5th aves.
Compresion will be at least 1.5 higher ratio and should be good by itself for %4 more power from the same fuel or %4 more miledge. Also the tighter quench will cause a lot more turbulence resulting in a faster and more complete burn so I can run less advance to get les negative work on the piston before TDC. Even if the headers don't hit there tuned RPM the engine will do less work forcing the gasses through them than the 3 cats and very restrictive single exhaust the mid 80s cars had. I will have no EGR valve to slow the part throttle burn rate either.
The cam is a couple degrees smaller so a tad less overlap and solids have slightly less friction than a hydro mabey a tad more than a roller but I can tune the valve lash for a little more efficency.
If I can find a dual port intake it should also help build mixture velocity at low speeds around town.
I can run it a little leaner (14.7 is the goal)without worying about burning up the cats or NOx emmisions.
I am expecting to beat my current best MPG by at least 5 mpg while I am really hopeing for 10mpg better. My current best ever was 23mpg mostly highway driving. Strictly in town I would usually get 17mpg.
I think it should be a drastic improvement from the 80s
I am not causing global warming, I am just trying to hold off a impending Ice Age!
Now consider that weight in first gear has to accelerate 7.5 times as fast as the car it will be like removeing 21,000 grams from the vehicle, or almost 50 lbs everytime the engine speeds up or down. I also remember reading the weight actually goes up exponetialy not lineraly so it would rev even easier. And also my car is already 500lbs lighter than those dippys and 5th aves.
