[QUOTE=negcamber,Nov 22 2007, 11:49 PM] Yep...a local member just ditched his V2 because he sucked enough water to stall the car durning a period of heavy rain where he drove though a deep puddle slowly.

 

[QUOTE=RED MX5,Nov 23 2007, 12:00 AM] If they knew that hydrolock was a potential problem with the V2 they'd probably offer a bypass valve for them, or at least give warnings about the potential.

 

[QUOTE=negcamber,Nov 23 2007, 01:53 AM] Thanks for the info on the bypass.

 

[QUOTE=RED MX5,Nov 23 2007, 02:06 AM] I can't point you to anything on their web site about the V2 and hydrolock, but when I called them to order a replacement bypass valve for my V1 (after busting the old one) they told me that if I had a V2 I didn't need to worry about hydrolock, becuase of the two individual chambers.

 

Hahaha, some of the noobs are going to think you and I are having a heated argument, because they don't have a clue how long we've known each other or how well we get along, so before I jump back into this I want to make a "General Announcement."

PUBLIC NOTICE: Negcamber is one of the guys I look to for solid and dependable information regarding the S2000, and I also do the best I can to provide solid and dependable information to my fellow S2000 owners. I actually depend on guys like Negcamber, Billman, MikeGarrison, and others, to call me to task when I get my facts wrong or am unclear; We have to do this kind of thing to help us sort out things we don't fully understand (or have misunderstood), and this kind of discussion ultimately benefits everyone. It may look like an argument, but in fact, it's just a search for truth. Negcamber and I are hashing this out so we can both provide others with the most accurate information we possibly can.

Negcamber, you might start out your next response by confirming what I said in the previous paragraph.

OK, back to the argument ... I mean ... discussion. j/k

You know I've done a lot of testing to prove or disprove things that have been posted here on S2kI, and there is no way I'd ever trust my engine to somebody else's testing and verbal guarantee. I ran a V1+BPV for about two years, but I had both the BPV and a cover over the filter to keep water from puddling in that little dip down near the filter. Before I found out about the dip and puddling, I am sure I started my car several times with water in the pipe, and the BPV does keep it out of the engine. You've probably seen the video where they take the AEM V1+BPV on an NSX, rev the car to redline, and then poke the filter down into a tank of water. The blatter in the valve inverts, and there is just no way for the pipe to hold the water anymore, so it can't possibly get into the engine. However, in their tank test, the car isn't moving, and it would be a mistake to say that hydrolock is "impossible" with the BPV installed. Even AEM doesn't make this claim. They say that the BPV *virtually* eleminates. What that means is that the odds of having a hydrolock problem are so low as to be inconsequential. Of course, that's just a manufacturer and their tests, and we have to decide what the actual risks are for ourselves. Having torn a BPV apart and understanding how it works, I have every reason to believe that AEM is not fibbing, and that the BPV does *virtually* eleminate the risk of hydrolock. This is also supported by the fact that there has never been a case of hydrolock on a car with a BPV.

The V2 is a different animal, so we have to look at it differently. We can speculate about the fluid dynamics, and I'll do that shortly, but I think it's better to start with whatever hard facts we have available. Unfortunately, hard facts are somewhat limited. We know for a fact that at least CAI's can cause hydrolock; We know for a fact that nobody has ever reported hydrolock in UTH or anywhere else while running either a V1+BPV or a V2. We could speculate that we've only never seen it with a V2 because nobody with a V2 has ever left their car parked in a downpour, but I think that's highly unlikely. It's more likely that the lack of hydrolock problems with the V2 has something to do with the fluid dynamics of the multi-chamber design.

Your speculation about the step in the pipe size is logical enough, given the factors that you've taken into consideration, and I'm not enough of an expert in fluid dynamics to say that it's wrong. I do however know enough about fluid dynamics to say that it's not necessarily as simple as it seems on the surface. Both the V1 and the V2 use acoustical prenciples in an attempt to produce a little more peak power. The V1 has a single resonance (and harmonics) and the V2 has two primary resonances (and their harmonics). The V1 is like a non-terminated, non-tapered, acoustic transmission line, and the V2 operates more like two resonators in series. The airflow dynamics in the V2 are far more comples, and I can't see any reason to believe that the dynamics of a liquid moving through the system wouldn't be as different as the dynamics of the air flow and acoustic waves. There will be acoustic waves in the liquid too, and at best, this clouds the issue. AEM does flow testing, so they have a better grip on this than I do, and I'm no more certain about it than you are, but your skepticism of their claims and your argument to support it are, IMO, over simplified and *may* be misleading. Since I don't know for sure, I'm left looking at the available hard data, and the fact that we have never seen a hydrolock with a V2 is more convincing than anything else we know for sure, and certainly that's got to be more dependable than our speculations.

Any intake, even the stock setup, can ingest water under the right (or wrong) circumstances, so warnings are appropriate, but before we get into that, let's talk about your buddies car, and more importantly, hydrolock itself.

Sufficient water in a cylinder will stop the piston on the compression stroke, because the water will not compress like air. The *water* *locks* up the engine, and instead of saying water-lock we say hydrolock. There is only one definition, so if your buddies car depends on definitions, then he did not have a hydrolock problem. Interpreting it as such is simply a mistake. There are a number of ways moisture can cause the car to stall and not restart immediately that are in no way related to hydrolock, and since I wasn't there, I couldn't say what was going on with your buddies car, other than to say (for sure) that it was not hydrolock.

What concerns me about your friends car is the water in the oil pan, and to some extent I think it's may be more important to discuss this than to hash out this hydrolock business, so I'm going to veer off topic for a second. If the oil was light brown and tacky, there may well be an oil water mix coating the inside surfaces of the engine, and it won't come out with a simple oil change. I don't know how much water was involved, or how long the car was run with an oil/water mix in the crankcase, so maybe it's not a problem afterall, but an oil/water mix can leave a NASTY mess inside an engine, and if it was me, I think I'd pull the oil pan and have a look. It would also be extremely interesting to try to figure out the route the water too to get into the crankcase, especially if it was a large volume of water, but I suspect that we are a little short of info to be able to be sure what the route was. Anyway, did you guys take a look at the inside of the engine yet, or was there not enough water in the oil to make that necessary?

Now, back on topic ...

I can only speculate when it comes to AEM's history, because they were selling BPV's before I ever even heard of the company. However, CAI's and the potential for hydrolock has been around since the 60's. It use to be so rare that most people didn't even know what it was, but most of us weren't using smooth tuned CAI's back then, so that's understandable. Carbs with velocity stacks use to fill with rain water and hydrolock the car on startup, and we use to stick rubber balls in the stacks to keep the rain out. Once the engine is running it's not a problem, but if water is allowed to accumulate in the intake, it can trash the engine. When you buy velocity stacks nobody will ever tell you that they point upward and will act like a funnel when it rains, because anyone can look at the things and see that they'll funnel water right into the intake if they're left open in the rain. Likewise, anyone using a smooth, single diameter pipe for a CAI can see just by looking at the thing that if they stick the open end under water, it's going to suck it up into the engine. I don't think it's wrong for companies like AEM to expect their customers to have a little knowledge and/or common sense. Perhaps the warning should be "don't modify anything if you don't know what you're doing."

I think that's a little extreme though, and people who think they know what they are doing would still screw up their cars, so we have to come up with something better. So, in an effort to do that, how about I suggest something, and you suggest any corrections or imporovements, and we'll work out something that is consistent and sound to pass on the next time this quesiton comes up.

Q: I'm thinking about putting a CAI on my car, but I'm worried about hydrolock. Is that something I really need to be worried about?

A: The surest way to avoid problems is to stick with the stock intake. If you want more induction noise, you can get it with a short ram, which puts the filter high enough for hydrolock to be virtually impossible. (BTW, we have a short ram on the MX5. ) You could also use an AEM V1+BPV with confidance, because nobody has ever had hydrolock with a genuine AEM BPV in their CAI, and the valve makes hydrolock extremely unlikely. The V2 is more of a question mark, but not because we've seen hydrolocks with the V2. So far that hasn't happened, but one of our members knows a guy who had his car stall, and got water in his oil pan, after running through a puddle with a V2 on the car. This single incident may have been a fluke, but before deciding on a V2 (or any other intake or mod) you need to seriously consider this kind of potential downside.

Saying that I've read about all this V2 hydrolock stuff in UTH and the V2 is trouble is actually inaccurate, because there has never been any such discussion in UTH (unless I somehow managed to miss it, which is of course always a possiblity). The V2 intake has a clean record so far, and speculating about what might happen if the fluid dynamics work the way one of us thinks it works, is sketchy at best. It's like the people who have speculated that the BPV lets warm air into the intake, defeating the purpose of the CAI, and equally likely to be right (or wrong).

Can we agree on what the facts are, and come up with consistent advice for those who ask?