Just bought an 84 tercel wagon, need help finding an intake

[walrus]

So I'm now in the 4x4 tercel club, and I gotta say-I'm pretty excited. I really enjoy this car.

I'm looking for one of these hoses as the one in mine is missing

http://www.villagetoyotaparts.com/produ ... 15050.html

Does anyone know of an auto store that would have this so I don't have to wait for it to ship? I asked at advance auto parts and they said they don't have it.

Also, is it an issue temporarily driving without it?

Thanks!

[dlb]

that plastic cold air intake is not necessary at all, and they are super common at wreckers. any tercel wagon and any hatchback from 83-86 uses the same carb and engine so you can grab that intake tube from them. should only be a couple bucks at a wrecker.

[Petros]

welcome to the forum,

where are you located? that flex hose is not necessary for it to run okay, it is the cold air intake plenum that goes from next to the head light, I have several extras from various parts cars if you can not find one locally.

If you are in an area with icy cold mornings there is a flex hose that comes off the shroud on the exhaust manifold that takes heated area from around the exhaust pipe and runs it into the under side of the air cleaner. this prevents carb icing on cold mornings (until the engine warms up and the manifold is heated up).

That flex hose can be bought in any auto parts stores and is a generic part, not too costly, must be trimmed to fit. I have mine removed because we seldom get cold enough weather to cause carb ice, and cold air intake usually gives slight better power and fuel economy.

[Mark]

My wagon was missing one originally, but I installed one since the warm air creates better atomization of the fuel, providing better fuel economy. The valve to supply this warm air opens at around 20-something degrees Celcius or 70-something degrees F. (the temperature in the air filter housing, not the outside air temp.). It's debatable if the better atomization of the fuel when the air is warm is more beneficial than the more oxygen in the denser air when it's cold. The horsepower crowd like cold-air intakes for the extra oxygen (better volumetric efficiency) and therefore a bigger bang, providing more power. I can see this working in a fuel-injected engine, where the injector is responsible for most of the atomization, but in a carbureted engine, air temp might have a much bigger effect on fuel atomization (better atomization = better horsepower, fuel economy and lower emissions).

[Mark]

Oops. I just looked at your link and noticed I was thinking of the wrong hose part #17881 not 17882. Everything I said in the above post probably has nothing to do with you now.

[dlb]

many serious hypermilers use warm air intakes to improve fuel economy. i haven't gone to that extent yet but i have noticed over the last few years of regular fuel use tracking that mileage in winter months is regularly 10-15% worse than in the summer. for instance, i averaged over 14-14.5 km/L (34-35 mpg) through the entire summer but with temps around freezing recently, i have averaging 12-12.5 km/L (29-30 mpg) for the last month. part of that is cold oil and bearing grease but even on highway drives where those things are warmed up, you will still not see the same mileage as you will in the summer. it may also have to do with the temperature of the gasoline in your tank and its expansion. i haven't looked into that yet though, just a thought.

[Petros]

fuel atomization is a common misconception, all of the mythical 100 mpg carburators (that do not exist except in urban legends) claim that improved atomization results in better efficiency and better fuel economy.

Engine laboratories in both universities, and all of the major car companies around the world, have proven that myth to be false. It turns out, by experimental observation, that a vapor to liquid droplet ratio of about 40 percent vapor to 60 percent droplets, give the most efficient combustion. If all the fuel is 100 percent vaporized before the intake valve is closed (in the intake manifold, IOW), the density of the fuel air charge goes down, the atomized fuel displaces too much oxygen in the mix, efficiency drops off. You have to carry most of the fuel into the combustion chamber in the form of small but much more dense droplets rather than a vapor. the 40 percent vapor is necessary to initiate combustion (only fully vaporized fuel will burn), the droplets than, after combustion starts, very quickly get heated and vaporize during the combustion process. Even fuel injection puts the majority of the fuel into the intake manifold in relatively large droplets. I have done some manifold design tests when I worked for Nissan, using clear plastic mock-up intake manifolds with working injectors in them, to observe with a high speed camera what happens to the fuel mixture down stream of the injector. it looks almost like a garden sprinkler of fuel drops for the first 4 or 5 inches downstream in the manifold, and broken up into smaller droplets or vapor about 8 or 9 inches down stream from the injector.

So the intake air temperature, the heated intake manifold, the length and shape of the manifold and the ports (the amount of turbulence), all contribute to the amount that the fuel droplets are broken up and partially vaporized. fiddling with any of these will change that ratio, and affect efficiency. And the ideal ratio is likely different for different operating conditions, temp, altitude, etc. even fuel mix (ethanol blend for example)

That ladies and gentleman, and fellow Tercelonaughts, is a piece of "inside" scientific engine fact that is almost unknown by the average mechanic or shade tree tuner and gear head.

[Mark]

I just had a few beers (Phillips IPA, which is probably the best beer in the world, by the way) so I'll attempt to continue the conversation. In diesel engines, using injectors obviously, the quality of atomization definitely does matter. When the injector tips start to get worn or obstructed with carbon and the spray pattern/atomization is not within specs, combustion is inefficient and there is unburned fuel leaving the cylinder on the exhaust stroke. The big diesels I work with show this as increased cylinder temps in the cylinders with crappy atomization. The fuel in these cylinders continues to burn as it enters the exhaust manifold. All internal combustion engines have an ideal stochiometric ratio of air to fuel where, in an ideal world, all oxygen and fuel is combusted before it leaves the cylinder. I could be wrong, but in a non-turbocharged gasoline engine, this ratio is about 14-1. You're saying that if the fuel is all vaporized, then the ratio would be more like 10-1 for example, because the vaporized fuel displaces some of the air (and oxygen). The 4-stroke cycle happens so fast, there isn't much time for the fuel droplets to ignite and completely burn. If the droplets are too large, it takes too long for them to vaporize and be able to be burned. Dividing the fuel into smaller droplets increases the surface area of the fuel allowing it to vaporize quicker and more fully combust in the tiny fraction of a second that it's in the cylinder. I guess ideally, with all the fuel vaporized in the cylinder, there should be about 1 part of vaporized fuel to 14-or-so parts of air (with 20% oxygen). Alright, I'm done.

[Mark]

Back on semi-topic: I wonder what the point is of the hose that the original poster is looking for. Is there something wrong with sucking air from the engine bay? Maybe in very hot climates, the air drawn in would be too hot if it came from under the hood? I can't see it mattering in my climate.

[Jarf]

Mark, where you live it shouldn't make much difference at all.

But, have ever opened your hood, on a summers day and felt a blast of hot air escape as you opened it?
Those are the days when that little tube will fulfil it purpose.

[Petros]

Mark,

you have confused something unrelated: the fuel air ratio is unrelated to the vapor to droplet ratio of the fuel that does enter the combustion chamber. Fuel air ratio is still important for good economy, power and low emissions. the vapor to droplet ratio affects combustion efficiency, which is only a very small part of the total efficiency of the engine (about 1 or 2 percent, overall efficiency including all loses is about 35 to 39 percent). so there are a lot of other, much larger factors, that affect overall efficiency, power and economy.