About fresh air induction

[John Smith]

In my quest for mileage For daily use I have decided to re-install the factory air cleaner arrangement with the flapper doors for induction. It's the one thing I have thought about but have left out of the conversation over tuning and "durasparking".
I know the "wide-open" look of the chrome bonnet is kewl but since I have no hood scoop at the moment and run with the hood on, the factory setup will give cool fresh air with little on no engineering.

So,......best wishes to all in the choices that you make for your driving environment..

 

[drgrcr]

I have left mine intact. With the production fresh air tube connected. I have been trying to come up with a system that move the the top of the air cleaner lid away from the carb inlet and still maintain a cold air inlet. The biggest problem is the clearance between the hood and the air cleaner lid...

there is a service access panel for the windshield wiper arms located right behind the air cleaner that would give an access to a good high pressure ram air at the base of the windshield, just remove the panel and fabricate a kewl looking connection between the two...hmmmm....

 

[John Smith]

I like it...

keep thinking about it...

 

[dangerranger83]

Thats were water collects and drains too. Does give the chance of hydrolocking or getting water in the engine. Plus having a channel for it to flow wont help either. The factory inlet setup has the bends in it for a reason.

Of course driving in the winter time gives my engine plenty of cold air. Summer time, the air will be at min. as cold as you sticking your head out the window while driving.

I would figure that trying to have the engine suck what air that it can suck on its own would produce consistant results.

 

[rezmedic]

In my quest for mileage For daily use I have decided to re-install the factory air cleaner arrangement with the flapper doors for induction. It's the one thing I have thought about but have left out of the conversation over tuning and "durasparking".
I know the "wide-open" look of the chrome bonnet is kewl but since I have no hood scoop at the moment and run with the hood on, the factory setup will give cool fresh air with little on no engineering.

So,......best wishes to all in the choices that you make for your driving environment..

Correct me if i am wrong,
Wont warm air use less fuel? its thinner, so less fuel is needed to obtain proper mixture, at the expense of power of course.

 

[scooter]

Your wrong. Hot air is less dense, has less oxygen, runs rich.


Todd S.

 

[John Smith]

that's a good point actually..

Correct me if i am wrong,
Wont warm air use less fuel? its thinner, so less fuel is needed to obtain proper mixture, at the expense of power of course.

and I probably don't have an engineering answer myself, but a couple of problems seem to come up as I'm working with the timing...and leaning out is a little detonation. I think that fuel needs to be close to the IDEAL temp for good atomization and burning, hence the warm-up flapper door situtation around the exhaust manifold, but running air TOO hot may assist in detonation?..not sure really about that.. just trying to find the most Ideal settings w/o a puter...

I know that normally pre-detonation is more about igniting hot spots as you advance the timing..as you run leaner mixtures..and part of fine-tuning for me is running just under that detonation ceiling occasionally bumping it as driving conditions and fuel quality changes..

I know in an airplane at any cruising altitude you can lean till ideal EGT settings...and only worry about carb heat if "icing" conditions exist..or till beginning landing sequence...(on a carbed motor) I also know that as ambient air temperature increases the performance of a naturally aspirated motor decreases...(effective sea level rises as temperatures warm up)..so the quest for near sea level performance is always part of what Is needed to get the most performance from a motor..and you can lean out as your elevation rises..

Maybe someone will add an officlal "engineering answer"

 

[enginepaul]

Not a physicist, but I think you will find this is an age-old problem.
You want cold air because it is denser and has more oxygen to support the fuel burning.
The fuel vaporizes better when it is hot and that would make a more powerful, and even, explosion.
Many things have been tried to get the best of both worlds, but as far as I can see only a computer controlled fuel injected engine gets maximum power. While we are here, gas has an absolute limit on how much power it can put out when ignited. Nothing can make it have more power, you can only hope to get the most power per gallon, per pound or whatever measurement you want to use.
On a Ranger; about all you can do to maximize fuel burning on the standard engine is to get cold outside air into your air cleaner.
Incidentally, as a former plumbing engineer, I never thought calculating the flow of air or trying to modify it in any way was worth the effort.
(I'm on my last connector between the front air intake at the radiator and the air cleaner; after that breaks, I will run without it. I won't even bother looking for a replacement)

 

[adsm08]

Correct me if i am wrong,
Wont warm air use less fuel? its thinner, so less fuel is needed to obtain proper mixture, at the expense of power of course.

If the carb was actually making proper adjustments constantly like an EFI system you'd be closer to correct, but still wrong.

The problem is a carb system is, as stated by todd, it just runs rich. Also, the "expense of power" part kinda kills it.

Carbs flow more fuel as you increase the throttle angle. Less power = more throttle. More throttle = more fuel. More fuel = less MPG.

Once I drove from Williamsport to Harrisburg in my 78 Olds. 3.8L carbed, 350 3 speed, and 4.11 gears. It was about 30 degrees out. 1/4 throttle got me rolled up to 80 without even trying. In the summer, needed a lot more pedal to get that kind of speed.

 

[scooter]

The fuel vaporizes better when it is hot and that would make a more powerful, and even, explosion.

I think your wrong.... Alot of drag racers put "ice cans" in there cars. Its coiled fuel line in a can full of ice.
Ever have a car/truck "vapor lock"? The fuel turns to vapor before it can burn.

gas has an absolute limit on how much power it can put out when ignited. Nothing can make it have more power.

I think your wrong again. (im no engineer)
You can add lead, Oxygenate the fuel, up the octaine level or COOL IT DOWN.

I know from Motocross racing we were always fighting the hot fuel problem. The radiators are are attached to the friggn fuel talk, so the fuel was always heating up. We waited till the last minute to fuel up our bikes.


Todd S.

 

[enginepaul]

Cooling almost anything will make it denser. Cool fuel would allow more to enter the cylinder. That doesn't mean that it would burn better; check some physics sources for their opinion. Sometimes people do what is workable in the real world rather than work on theories.

Adding something to change the chemical make-up makes it something different. Gasoline, or anything else that burns will only have a finite amount of energy.

Do a Google on the subject, I'm sure there is a lot of info on the web; it's a lot easier than reading all the books that I have read over the years. Start with a physics site.

I doubt if anyone would claim that cool fuel of any kind would vaporize better than hot fuel, but if it works for you, great.

 

[scooter]

Cooling almost anything will make it denser. Cool fuel would allow more to enter the cylinder. That doesn't mean that it would burn better.

Really????
I never said it burned better. I keeps it from vaporizing too soon (predetanation) !!!!!
Cam lift, valve size and vacuum dictate how much fuel enter the cylinder.

Adding something to change the chemical make-up makes it something different. Gasoline, or anything else that burns will only have a finite amount of energy.

No shit, but its still gasoline.......

I doubt if anyone would claim that cool fuel of any kind would vaporize better than hot fuel, but if it works for you, great.

I dosent vaporize better, never said it did.
As your piston compresses the air/fuel, it heats up and vaporizes. If your air/fuel it allready hot, it will PREDETONATE ! ! !
You want your spark plug to start that process exactly when its supposed to. Cool air/fuel mix allows the spark plug to start it.


Start here.
http://www.vpracingfuels.com/page469659.html#Section15613004


Todd S.

 

[John Smith]

good comments from all..

It seems to be clear that the right air temp for good combustion is needed for optimum fuel burning..and the cooler the better coming into a hot combustion chamber.

Cooling the fuel helps as well...again ..on a warmed -up engine.

How critical this all if for a grocery getter? Maybe not as critical as we might think..untill we try push the envelope to get more power, or better the fuel mileage etc.

A carb will never be a better solution than a computerized fuel injected motor, especially for pushing the power-and efficiency envelope,

But it gives a simple acceptable solution to fire a simple motor..and on a good note...you never will have the problem of overheating a head or piston for a failed fuel injector...or have to be concerned about some other failed sensor keeping you in "limp" mode...

now when it comes to heat...anyone remember wrapping a fuel line with a cold water-soaked rag to deal with vapor-locking? Now that takes you back...some cars..(Fords) the steel fuel line was so close to the block/head..you didn't want to shut it off during a hot day driving w/o having a plan for the potential vapor-lock problem..

 

[rezmedic]

Never looked at it like that..

If the carb was actually making proper adjustments constantly like an EFI system you'd be closer to correct, but still wrong.

The problem is a carb system is, as stated by todd, it just runs rich. Also, the "expense of power" part kinda kills it.

Carbs flow more fuel as you increase the throttle angle. Less power = more throttle. More throttle = more fuel. More fuel = less MPG.

That makes alot of sense. I never took into account the fact that a carb will just dump fuel in the air without knowing how dense the air is and how much O2 is in it.

 

[drgrcr]

Here in AZ hot fuel vapor lock is always a problem in the summer. On my project carburated Ranger, the fuel line has been rerouted to run next to the AC vapor line and then wrapped in header type wrap the keeps header heat out of the engine compartment. I have access to thermocouples and a data recorder, I had a thermocouple on the fuel line skin temp at the fuel pump outlet, I observed that when the fuel line skin temp would get around 200' that is when the engine would start vapor locking in city traffic. So that is when the fuel line was routed next to the AC vapor hose, the one that runs over the top of the radiator. but....it would still vapor lock after a 20-30 minute heat soak, like driving through traffic to the parts store, go in the store do business, then do a drive away. The engine had a bad sag until the cooled fuel got into the fuel bowl.

As far as getting rid of the cold air system, never. maybe disconnect it in the winter, but there is added power and fuel economy to be had even with the factory stuff. After working in the automotive testing business for over 30 years, I have learned that the factory does not add anything they have too unless there is a good cause....

As soon as I get my Ranger back from daughter I will post a picture of the fuel line.

Why would I put a thermocouple on a 83 Ranger? cuz it what I do... It has been a hobby since I was a teenager...