I wanted to share In idea I had with everyone to see what they think. I had an idea to make a Bypass Valve from simple items from the hardware store for under $15. I designed one yesterday and made an valve operation gif. The valve will plug into a tee connector before the MAF sensor as opposed to an inline bypass valve sold on the market. Im also working out an idea to add a sensor so that when the valve opens even alittle, it will trigger an audible tone and illuminate an LED on the dash. I need some input. Ideas? Concerns? Tell me what you think...







Edit: I appologise if I came off as trying to make a "DIY: Bypass Valve" Thread. What I meant was I was designing a BP valve and I could make a NON-Operational concept from items bought at the hardware store, which I did. It's assembled and works in theory. I just needed to have a physical concept to see what could be done to improve the design.

Nobody wants to elaborate on this idea??

What exactly are you trying to accomplish with this? If you are trying to make a fake BOV, it won't work. Your NA engine isn't making boost so there won't be anything to push your "valve" out. Remember, when an engine is naturally aspirated, it runs under vacuum.

I think he's referring to a CAI bypass valve to prevent hydrolock.

My problem with bypass valves are, what is the point of having a cold are when air will be taken from the path with the least resistance, being the bypass valve. but that is just my view on bypass valves in general.

My suggestion would be build it with good materials, like some sort of spring maybe instead of a rubber band.

Ah, I guess that makes sense. This part makes me think otherwise.

Guess I'll wait for the OP to clarify.

The idea is for a bypass on a CAI system. The design is an initial idea (concept). A spring would be a better idea but you would have to know what the engine produces in terms of vacuum ( which I believe is measured in Hg) and what that translates to in spring tension. From my boost/Vac gauge, I know my intake produces about a 19-20 Hg vacuum. Obviously if the vacuum increases to say 25 or 30, something is wrong. The problem is that I know very little about the acual numbers when it comes to hydrolocking. I if I decide to get serious about this idea I will take a standard tibby intake and hook a shop vac to it and produce a "typical" vacuum with a filter and work out what acually happens during a hydrolock. Any ideas, advise, experiences would be helpful.

the pressure in the intake piping will be essentially 1 atm. The pressure you want to determine is that in the pipe whilst the engine is trying to ingest water. You must find if this hydrolocking can occur from large amounts of water mingled with air, or by a column of water trying to move up the intake. In the latter case, you could say that the engine will soon deplete the air in the piping and cause a 0 vacuum condition which would draw the water up, as long as the intake piping is not 22 ft deep . To be safe, you could find the spring that will open under 0.7 or so atm, of course finding a suitable value may require some trial and error.

Thats my concern. The question is, what amount of water in the cylinder constitutes the term "hydrolocking"? A droplet? A teaspoon? At what point, does any amount of water, start causing damage to the engine.

I thought of another idea just now. What if you had a moisture sensor downstream of the MAF that when too much water accumulates on the sensor, a circuit trips an emergency open valve to the bypass valve.

Soda fountains @ fast food restaurants have those liquid sensors that stop the flow of soda...

Hydrolock is when the engine locks up because it tried to compress water. If it gets that far into the engine, one drop is enough. I question the preciseness of your rubberband. You should buy a bag of them just in case.

Oh, is the aem valve not sufficient. It's pretty damn cheap and already made. You won't have to buy sodas, coffee filters, or rubberbands....all things that don't belong in an engine bay unless you're reenacting a scene from MacGyver, the A-team, Survivorman, etc.

^^^ That bolded part. Why reinvent the wheel. One is already made.

I literally spit my coffee out when reading your last sentence mwahahaha kudos!

I still dont get it

This is...in general...a BAD idea.

Good theory, and good try, but hit this too low quality to even hold together. Doesn't the pressure get quite high in a bypass valve?

As I said before, the idea is concept. Obviously, the acual product is not going to have rubberbands but rather an extension spring. There will be safties in place in the event that the spring fails. Though it is unlikely, if it does fail, there will be a screen to catch the valve. It's not going to be made of paper coffe filters and rubberbands. Those are there to demonstrate the mechanisim in action. I'm working on a design of what the product may look like. When I'm done I'll post it.

That path of least resistance will be the filter. Breechan pointed out that...
...which is invaluable advise. There is a spring out there with the right tension that will keep the valve closed until water starts coming in. Perhaps the tension will have to be calibrated for each persons engine. Meaning that, if say I get a maximum vac. of 21 inHg when coming down from a high RPM, water starts making its way up the intake and the vacuum hits 24 inHg, I want to make sure that the bypass valve opens at 22 inHg and the water wont reach the TB.

Bypass valves are a bad idea or my design is a bad idea? What pressure? The BP valves are designed to open under vacuum....

Here is an idea for a basic water sensor design...



The blue spots represent water vapor or mist into the engine. The senosr is placed inline with the air intake before the MAF sensor. The sensor is sandwiched between two non-conductive screens that will concentrate water mist into water droplets. Should one of these droplets contact and bridge a red and black wire, it will trip a circuit that first lights an in-dash indicator, then trips an action such as opening a bypass valve or a circuit that cuts ignition to all cylinders in an extreme situation.

just run a short ram intake or stay away from puddles, simple as that lol

The heat in the engine bay means the rubber band & cheap plastics won't last long.

Bypass valve's are a fine idea, it's the negative pressure generated by the vaccume. Ever seen how easy it is to crush a pop can with suction?

And putting a rubber band anywhere neer heat is a bad idea. Not to mention they dry out and crack quite quickly.

cut your intake tube so that filter sits up high - right up against the hole where the pipe comes from engine bay (just like ebay cai does ) and no hudrolocking....unless you are in the 2 feet of water.

Or if you that paranoid - cut your intake pipe right before it makes a turn to go into the fender-well - intake will sit right behind the headlight.

For the third time.....the rubber band and soda can bottom is a CONCEPT. I'm not saying to put those in your engine. I made that as a visual so people can understand the design and its mechanics. Please go back and read the first post lol!

I wouldn't be surprised if there were already inline air pipe water sensors that are proven to work. If you're going to try this, I at least wouldn't reinvent the wheel and just try to find a premanufactured sensor, or if you can't find one for sale, just copy an existing design.

I'm sure there is, I've not seen any for automotive applications though.