xviper

jehman, please don't take this as a flame, just my take on the subject. I think the danger comes when a significant amount of water or water vapour (heavy mist) finds its way into the cylinder and the piston tries to "compress" it. When water, whether in the form of liquid or heavy vapour is subjected to negative pressure as in your example, it will either vaporize or "gasify", thus allowing such piston movement. It's when water or vapour is "pressurized" like in the compression stroke, that vapour becomes more compact (more liquid). Liquid water of course, cannot be compressed any further and thus it is the compression stroke that is the most difficult and most dangerous and catastrophic.
With an 11:1 compression engine, I don't know how much vapour it would take to compress into a liquid before this liquid can occupy enough of the cylinder's space such that the remaining space can no longer be compressed during the piston's normal travel. ie. In our engines, what is the minimal amount of water it would take to stop the piston before it completed its full stroke up during the compression stroke? And can this much water be sucked up a 4" diameter pipe, through about 1.5 feet of travel, like in the AEM even though the filter is not completed submerged? These are the questions that need to be answered before we can determine the "probability" of a hydrolock condition in this car.
UL has already stated that it can take as little as 50cc. I think we can believe him on this. However, with the stated set-up, can this be possible?

cdelena

[QUOTE]Originally posted by xviper
[B]... And can this much water be sucked up a 4" diameter pipe, through about 1.5 feet of travel, like in the AEM even though the filter is not completed submerged?

dolebludger

cdelenda:

To check on the claim that the people at PRM made to me over the phone, I went out and drove a bit in 100 degree weather. The metal and other bits on the pax side of the engine bay near the hole to the fender cavity were quite hot. Then, I blew some ambient air into the grill, and ambient temperature air came out of that hole. So THIS part of PRM's claims I believe. My problem with the PRM is that it does not fit sealed to that hole, is about an inch back, and I can't see how it avoids pulling in hot engine bay air too. That's why I'm in the planning stages on a CAI using the stock airbox, putting a 3" hole in the left (facing the car front) side of it, running some kind of 3" pipe into that fender cavity hole, sealing it, and pulling some of that ambient air.

russ:

I'm a bit confused. PRM told me that their filter was a long and skinny thing that fit in the larger diameter part of the unit between the horn and the chrome pipe. If that's so, from the picture of the PRM on the first page of this thread shows that the closest part of the PRM filter is about the same distance from the TB as stock, and the furthest part is much further away. With the Comptech, it looks like the filter is at the pax fender part of the unit, putting it much further than stock from the TB.

Thanks,
Richard

jehman

[QUOTE]Originally posted by xviper
[B]jehman, please don't take this as a flame, just my take on the subject.

cdelena

[QUOTE]Originally posted by dolebludger
[B]cdelenda:

Then, I blew some ambient air into the grill, and ambient temperature air came out of that hole.

xviper

[QUOTE]Originally posted by jehman
[B]Suffice it to say, that hydrolock is possible but isn't a very common thing, happening to less than ten (I'm guessing) people for all of the S2000's out there?

dolebludger

cdelena:

Not at all. I've pretty well decided that the fender cavity is a good place to pull in some air that is no hotter than ambient. (PRM and Comptech seem to agree.) But I know that benefits from this will be greatly diluted to near zilch if something isn't done about the stock inlet pulling in hot air right over top of the radiator. Can't just block it off, as I doubt 7+ inches of cross section area a 3" pipe gives is going to cut it. Thinking about using a combination of fender cavity air, plus using xviper's Rad blanket and maybe a "spoon type" device. Think that combination might work?

Thanks,
Richard

ultimate lurker

Dolebludger, a short, fat pipe has minimum resistance, but it does not have an ideal resonance point for maximum resonance supercharging in the normal operating range of the engine. That's the tradeoff the various intakes make. You have to decide what you want. The Mugen intake is probably one of the freest flowing encapsulated filter intakes with excellent flow all around the filter. The stock airbox does not have this (flow tends to be concentrated through a relatively small portion of the filter).

On the topic of hydrolock, one might look at the physics involved. Let's say that you have to pull a column of water 20 inches from the lowest point of the intake to the TB (we're not initially concerned with horizontal travel, only vertical rise). The intake pipe is about 3 inches in diameter. This gives us a total volume of water that we must pull up of about 150 cubic inches, which will weigh about 5.5 lbs.

Now, the engine can draw a vacuum of about 24" maximum. This equates to about 12 psi of pressure differential from atmospheric. It will act against about 7 sq inches of surface area of water (the cross section of the tube). This will allow it to exert about 84 lbs of force against the column of water. More than enough to move it.

Of course, in the real world, you need to consider all the water being moved (usually for every 10 ft you move horizontally, you add another ft to the vertical distance as a rough estimate), the resistance of moving it through a pipe and the fact that an internal combustion engine doesn't generate a constant vacuum, but rather pulses.

Nonetheless, IMO, there is more than enough suction to bring water into the engine. Even if we halved the vacuum, doubled the weight of water, etc. I do agree thought that its rare that you'd see a solid column of water as it would require complete submersion.

Personally, I don't worry about hydrolock. I did get a little water induced misfiring on an CAI equipped Integra during the El Nino storms in SoCal back in 1997, but it just required a sec to "clean out" the engine (probably steam cleaned my cylinders too) with a little revving. If it rains any heavier than that, I won't be driving, I'll be looking for a boat.

UL

dolebludger

UL:

Could yoou provide me with a site to a seller of the Mugen intake systems? I tried to search under "Mugen" and all I could find was a site in Japanese!

Thanks,
Richard

Ruined 2

One question, one comment.

Xviper, what and where is this "back-up" fuse you were talking about awhile back? Any more info on what you were talking about?

And, like a lot of people, I also know someone who "hydrolocked" his S. In his case, it was a combination of a high rate of speed and RPM, and an unseen deeper than usual puddle. The car didn't die immediately but sputtered and slowed down after exiting the puddle, then came to a complete stop. The engine was pretty much toast, and no, Honda did not cover it. His insurance company did, however.

It wasn't stupidity for the most part as it was not raining at the time, just not enough attention to the road ahead. AEM intake, by the way.