how much water to hydrolock an engine?

[LOUISSSSS]

i'm aware that if water gets into the engine, it will lock it up and then your engine would be gone for good. is this true?

if yes, how much water would be needed to be pulled in by the intake to "hydrolock" the engine? an drop? an once? a cup? a gallon?

if it matters my car has a Honda v6 J30

 

[Zenmervolt]

The smallest amount theoretically able to hydro-lock an engine would be just slightly greater than the volume of a single cylinder when the piston is at top dead center.

If you have a 3.0 litre V6, the swept volume of each cylinder is 500ml. If you have a 10:1 compression ratio (close enough of a guess for a back-of-the-envelope calculation) then the total volume is 500ml/0.9 or 555.55 ml, so hydro-locking the engine would take about 56ml of water in a single cylinder.

In practice, it would take more since it's extremely unlikely that all the water would go into one cylinder.

Also, someone please check my math, I'm in a bit of a rush and am not 100% sure that what I've put down is accurate.

ZV

 

[Vic]

Heh. I looked it up, and it just so happens that the Honda J30 does have a 10:1 compression ratio.

 

[MiataNC]

You can't compress a liquid, so if you do get "too much" water in a cylinder you can bend a rod, damage a rod bearing, damage a piston, and even blow the piston out the side of the block.

It really is just a question of how much is "too much", and that will depend on the engine. Ingesting liquids is bad mmmkay?

 

[exdeath]

A single cup of water is more than enough to completely lock a small 4 cyl and a least a couple cylinders in a large V6 or V8, provided it all goes directly into the cylinders in a single compression cycle and doesn't atomize and mist it's way through as vapor over time.

 

[andylawcc]

Originally posted by: Zenmervolt
The smallest amount theoretically able to hydro-lock an engine would be just slightly greater than the volume of a single cylinder when the piston is at top dead center.

If you have a 3.0 litre V6, the swept volume of each cylinder is 500ml. If you have a 10:1 compression ratio (close enough of a guess for a back-of-the-envelope calculation) then the total volume is 500ml/0.9 or 555.55 ml, so hydro-locking the engine would take about 56ml of water in a single cylinder.
ZV

:thumbsup:

 

[zerocool84]

Reason why I won't get a CAI

 

[exdeath]

Originally posted by: zerocool84
Reason why I won't get a CAI

Depends on the design and how low the filter is to the ground or where water can easily splash. All modern OEM intake systems draw "cold" air through the fender well already.

 

[amdhunter]

Originally posted by: LOUISSSSS
i'm aware that if water gets into the engine, it will lock it up and then your engine would be gone for good. is this true?

if yes, how much water would be needed to be pulled in by the intake to "hydrolock" the engine? an drop? an once? a cup? a gallon?

if it matters my car has a Honda v6 J30

lol, what do you have planned?

 

[jagec]

Originally posted by: MiataNC
You can't compress a liquid,

A good approximation for most reasonable conditions, but I make a living out of compressing liquids.

But yeah, it will easily screw up an engine beyond your ability to cheaply repair it.

I once got really close to hydrolocking a jet ski. We were tuning the carb (it was having trouble starting), and I attached the hose to the flush fitting and turned it on before trying to crank it a few times. It seemed to be turning over slower and slower, so for some reason I took out the spark plugs and cranked it...and shot water straight up into the air. Took a while to get all THAT dried out...

 

[Demon-Xanth]

Originally posted by: exdeath

Originally posted by: zerocool84
Reason why I won't get a CAI

Depends on the design and how low the filter is to the ground or where water can easily splash. All modern OEM intake systems draw "cold" air through the fender well already.

Definitely depends on where it's at. If it's breathing through the hood or upper grill, you'll likely need to nose the car into a pond before it gets enough water in at once not to just pass it through. If it's one of the type that goes down to the bottom of the valence, a large puddle can have you sucking water in. With my OEM intake, I'd have to submerge the passenger side headlight. (at which point, I'm likely not driving out of it anyways...)

An engine will handle a spray well since it doesn't have to pass gulps, it may just run odd since the air fuel mixture will be all jacked up once you start really getting up there. Saab even had a method where they used windshield washer fluid as an intercooler, and people have experimented with water injection, as well as cleaning the engine with seafoam, both of which involve passing non-fuel liquids through the engine. Most are passed through as steam from the heat of combustion.

 

[exdeath]

Originally posted by: jagec

Originally posted by: MiataNC
You can't compress a liquid,

A good approximation for most reasonable conditions, but I make a living out of compressing liquids.

But yeah, it will easily screw up an engine beyond your ability to cheaply repair it.

I once got really close to hydrolocking a jet ski. We were tuning the carb (it was having trouble starting), and I attached the hose to the flush fitting and turned it on before trying to crank it a few times. It seemed to be turning over slower and slower, so for some reason I took out the spark plugs and cranked it...and shot water straight up into the air. Took a while to get all THAT dried out...

Aluminum and iron "compress" easier than water, thats the bottom line in this discussion

 

[exdeath]

Originally posted by: Demon-Xanth

Originally posted by: exdeath

Originally posted by: zerocool84
Reason why I won't get a CAI

Depends on the design and how low the filter is to the ground or where water can easily splash. All modern OEM intake systems draw "cold" air through the fender well already.

Definitely depends on where it's at. If it's breathing through the hood or upper grill, you'll likely need to nose the car into a pond before it gets enough water in at once not to just pass it through. If it's one of the type that goes down to the bottom of the valence, a large puddle can have you sucking water in. With my OEM intake, I'd have to submerge the passenger side headlight. (at which point, I'm likely not driving out of it anyways...)

An engine will handle a spray well since it doesn't have to pass gulps, it may just run odd since the air fuel mixture will be all jacked up once you start really getting up there. Saab even had a method where they used windshield washer fluid as an intercooler, and people have experimented with water injection, as well as cleaning the engine with seafoam, both of which involve passing non-fuel liquids through the engine. Most are passed through as steam from the heat of combustion.

Purposeful water injection is in fact quite handy under high boost

 

[LTC8K6]

I once drilled a 3/4" hole in the side of my air filter box on the bottom side of the filter so that air coming in the hole would go through the filter and the meters, etc.

The purpose of the hole was to prevent the engine from being able to pull water through the low end of the air intake plumbing if the low end got submerged.

The theory being that the small hole up high had no effect on the engine normally, but would prevent enough suction from developing to pull water in through the low end of the pipe if I drove into deep water.