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When you flow bench test, you want a smooth tone, no bubbling sounds, no up and down sounds to the port.
Notice in these pictures of ports I've done on a bbc (flowed high 570's cfm) and the intake that there are areas that are smooth as well as areas that are rougher. This is for fuel air mixture, anti seperation of the mixture as well as best air flow with as few port/runner cc's as possible for best power. The heads are bbc, if i remember right they were 380ish to 385ish cc's on intake port sizes. Engine made over 1600 hp n/a. Here is also an intake i did that gained 42hp over a rough as cast version on a 358 sbc;
ok
I wish I had the money to test mine then I could quote figures.
I watched that Mythbusters episode where they proved that the golf ball dimpled surface of a car increased its gas mileage. That's the direction your experimentation should go.
My youngest son (now a mechanic) when in his younger days rigged up a blower to force air thru the carb. Gas mileage was way over 20 mpg on a Chev El Camino.
Things were great until he fried a piston for being TOO lean. Extra air is nice but you also need extra gas. He learned a valuable lesson.
Do understand the need for the intake manifold to be in a curve as air flow will NOT go around 90 degree corners very well.
Air/Fuel turbulance is needed at a specific spot in the intake/induction system. I have never tried the swirl/glacing method discussed here. Suppose it might be feasable under some R&D conditions.
In drag racing my heads were air bench flowed with the intake manifolds attached (a matched set).
R&D is the word unless a person is willing to pay $$$$ to a specialist.
I am in agreement with a couple of others here. Seems to me Hot Rod magazine, or something similar, tested smooth/textured intake ports in an article. this was some time ago maybe ten or more years ago. They actually had the dyno numers to support thier theory. The roughed up ports may not flow any better, but the fuel atomization was better due to the swirling effect the rough ports had on the air/fuel mixture. As someone else stated, this is not new technology.
I watched that Mythbusters episode where they proved that the golf ball dimpled surface of a car increased its gas mileage. That's the direction your experimentation should go.
On a 140 mph drag car, it's worth another 3 mph. On a 1999 Pro Stock Firebird, it was worth a tenth quicker E.T. and another 5 mph. However NHRA and the IHRA would not allow it. Then they caught us on the vortex generater we made on the rear qtrs with 12 Mark Williams decals on each side. Imagine that, a rule written over my idea.
I am in agreement with a couple of others here. Seems to me Hot Rod magazine, or something similar, tested smooth/textured intake ports in an article. this was some time ago maybe ten or more years ago. They actually had the dyno numers to support thier theory. The roughed up ports may not flow any better, but the fuel atomization was better due to the swirling effect the rough ports had on the air/fuel mixture. As someone else stated, this is not new technology.
THis is exactly why when I do port work, some areas are smooth and other areas are rough. There are some areas that is nothing but just a need for the volume at high rpm and those areas are smooth. I've had 2 types of head ports on the bench and flow with in 3 cfm of each other, but the mixed port (smooth and rough) heads made 150 more horsepower.
I think you are going about this wrong, you are ignoring to many other related components and variables. Now lets see this quote: " have improve fuel efficiency under highway driving conditions, I have experienced as high as 60 mpg (4.71 L/100km) over a 220 km journey on a hot summer's day cruising around 80 km/h. I can also get 15 mpg as well." That tell me under perfect test condition you get 60 mpg, as any car can...under test conditions. Otherwise you get 15 mpg. You are just running extremely lean, hence the knocking and pinging, and as someone said the final result will be a piston coming out of your hood.
Intake shape and valve shape are only two components of gas performance. The other is the carburator, probably the most important piece as the gas and air are introduced there and the size and shape of the venturi influence the atomization and metering of the mixture. I don't see you doing anything to modify the carburator. Also timing - which you touched on a bit, compression - which you covered, vacuum, exhaust, etc. And then you have external components such as temperature and humidity. I am suprised you haven't incorporated any air/fuel guage at the output (in your exhaust pipes) in your testing.
But, regardless, you are using 30 year old obsolete technology (I have a carburated car as well, so I don't think it's all bad). Current technology uses computers to mix the fuel varing the timing and mix based on external temperature, etc. If you really want to advance automotive fuel consumption technology, you have to work on today's technology...but then you are competing with the massive resources and budgets of the scientists employed by Ford, Chevorelet, Toyota, etc.
Just an update.
Have been doing some fine tunning and have a rough city consumption of 45 MPG (imp) ~6.2 L/100km.
Improving gas mileage is nothing new. Have you had your tail pipe emissions tested to see how bad your pollutant's are? Usually better mileage = worse for the air. We were able to balance both with fuel injection.
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On a 1999 Pro Stock Firebird, it was worth a tenth quicker E.T. and another 5 mph. However NHRA and the IHRA would not allow it. Then they caught us on the vortex generater we made on the rear qtrs with 12 Mark Williams decals on each side. Imagine that, a rule written over my idea.
