A tale of 2 Xterra's

[702krawler]

No, air is "sucked" into the pipe due to lower pressures generated on the intake stroke of a given cylinder. Otherwise you'd stall at a stop light. Is the "ram" air better? Sure, a little. Without it you might see a minimal HP loss, but overall nothing to worry about.

 

[wreckdiver1321]

No, air is "sucked" into the pipe due to lower pressures generated on the intake stroke of a given cylinder. Otherwise you'd stall at a stop light. Is the "ram" air better? Sure, a little. Without it you might see a minimal HP loss, but overall nothing to worry about.

What he said. The ram air effect is not actually necessary to keep the engine running. No matter what, the low pressure from the cylinder will suck air in. The ram air effect just makes the engine breathe a little easier.

So like I said, in heavy snowfall, just turn the head around. That's what I did during heavy snow on my 2003 Frontier. Zero issues.

 

[702krawler]

Thinking about this more, I'm not sure you really need to be that concerned with even turning it around, unless you're just scared the snow will clog it. A little water in the engine from rain or snow won't hurt it. Massive amounts of water (a larger volume than will fit in the cylinder in the piston's fully compressed state) will.

If you drove around without your hood and an open air box in heavy rain, you'd be fine. It is when water inundates the intake (think when it is underwater) that hydrolock with its inevitable bent piston rod or other expensive failure occurs.

 

[wreckdiver1321]

Thinking about this more, I'm not sure you really need to be that concerned with even turning it around, unless you're just scared the snow will clog it. A little water in the engine from rain or snow won't hurt it. Massive amounts of water (a larger volume than will fit in the cylinder in the piston's fully compressed state) will.

If you drove around without your hood and an open air box in heavy rain, you'd be fine. It is when water inundates the intake (think when it is underwater) that hydrolock with its inevitable bent piston rod or other expensive failure occurs.

^This

 

[Dalko43]

No, air is "sucked" into the pipe due to lower pressures generated on the intake stroke of a given cylinder. Otherwise you'd stall at a stop light. Is the "ram" air better? Sure, a little. Without it you might see a minimal HP loss, but overall nothing to worry about.

Maybe I am using the wrong terms. The issue I was more concerned about with turning the snorkel around was no air period getting into the intake.

I did some google searching on this topic, which inevitably led to other forum posts. There were some vendors and forum posts claiming that if you turned the ram air snorkel around and drove at higher speeds, you in effect created a vacuum which deprived the engine entirely of any air (allegedly). For this reason, they were recommending that you not turn the air snorkel 180 degrees away from your primary direction of travel.

Some of these searches also yielded several anecdotal stories of vehicles, with similar snorkels, getting lots of water in their intake air box, to the point where their MAF sensor was getting thrown off and the engine started to lose power.

Again, I don't know if any of this is valid or not. It was simply something I was looking for feedback on.

Thanks to all for the input on this.

 

[702krawler]

I will buy that there could be an area of slightly lower pressure created, perhaps leading to slightly decreased horsepower, but nothing approaching a true vacuum. And definitely no way it will prevent all air from getting into the engine. Even if somehow all air were prevented from entering the engine, what consequences are they concerned about other than the engine stalling?

As for standing water in the air box, I doubt that too. If it got in, it is probably just as likely to get sucked into the engine and come out the exhaust as steam. Now if you were to leave the top off with the engine NOT running, I could see where that could accumulate enough water to perhaps cause you issues.

 

[702krawler]

Check out this thread: http://www.expeditionportal.com/forum/threads/55274-About-the-backwards-facing-snorkel-conundrum

You'll notice Scott Brady says his snorkel only faces backwards. He may be half man, half amazing, but I doubt even he has figured out how to make his internal combustion engine run without air.

 

[wreckdiver1321]

^ Hahahaha

I might point out something. One of the most popular snorkels made for the LR Disco II, the Mantec, has a fixed rear-facing head. This is what Scott is referring to in his post in the thread above.

Think about it, and try this as an experiment. Next time you're riding as a passenger and going down the highway, stick your head out the window and look backwards. Take a breath. If you can breathe (you can, ask me how I know ), then your engine, which creates a much more powerful vacuum than you can, will have no trouble at all.

 

[Dalko43]

Check out this thread: http://www.expeditionportal.com/forum/threads/55274-About-the-backwards-facing-snorkel-conundrum

You'll notice Scott Brady says his snorkel only faces backwards. He may be half man, half amazing, but I doubt even he has figured out how to make his internal combustion engine run without air.

Thanks for posting the link to that thread.

^ Hahahaha

I might point out something. One of the most popular snorkels made for the LR Disco II, the Mantec, has a fixed rear-facing head. This is what Scott is referring to in his post in the thread above.

Think about it, and try this as an experiment. Next time you're riding as a passenger and going down the highway, stick your head out the window and look backwards. Take a breath. If you can breathe (you can, ask me how I know ), then your engine, which creates a much more powerful vacuum than you can, will have no trouble at all.

Yeah, but is that a fair comparison? Isn't a more valid comparison to stick your head out the window of moving car, turn your ahead away from the prevailing wind (primary direction of travel) and try to breathe in air through a long straw?

That essentially is what the engine is trying to do with the snorkel setup turned around.


Maybe I am being paranoid on the air deprivation issue as it relates to the snorkel setup, but I do think I will have to be careful with the snorkel during heavy snowfall (which is a normal occurrence in this state).

Thank you both for the feedback and answers...they are certainly helpful.

 

[702krawler]

You're welcome. If it makes you feel better to turn around the snorkel head in the snow, then go for it. It won't hurt anything.