Coolant Bypass Line
 

I was thinking of removing the coolant bypass hose on the front of my motor. This is the hose that crosses the front of the motor and allows coolant to bypass the radiator and thermostat and re-enter the block.

I wanted to know what the purpose of this line was? Was it to provide coolant to the water pump when the thermostat was closed to prevent the pump from cavitating without a supply of coolant?

Quadcam removed it and said he has no ill effects, but I am thinking that driving around town at low RPM is one thing and that track use is another.

Anyone know the purpose of this line?

You make it sound like I drive like a little old blue-haired granny. :dunno: WTF???

You do live in florida...lol

You drive like a little biatch with your 400whp! Don't pretend like your a big dawg... becasue I'm about to ball this!

http://www.webwombat.com.au/entertai...kin-aces-2.jpg

I think coolant can bypass through the port on the side of the block next to the thermostat if needed. I don't have the bypass but I also am not running a thermostat right now. I am putting one back in though.

That's where the coolant bypass line goes. To the side of the block. So if you remove it what happens?

The hard pipe is still connected to the rear coolant pipe.

There is a reason they made the bypass hose. It's not there to be ornamental.

Remove it and let us all know the results.

Take it off. It serves no purpose on a track car, and very small purpose on a street car.

All you need is an upper and lower rad hose for a track car. And man, the engine bay will look so uncluttered without it. Also remove your oil filter heater/warmer hoses as well. One less hose to leak or blow out on you. :)

How do we block off the hard line.

cut and weld, or you can drill and tap if you so chose

well i can weld but i was tryin to avoid that just in case i want that hose back on someday. LOL

So what purpose does it serve for on a street car? And to be clear we are talking about that soft line that goes across the motor right?

Yes.... it's the soft line that goes in front of the motor. I'm still interested to know the purpose too.

I already threw his sh!t in the trash, last week. :thumbup:

to speed up the engine getting up to operating temperature so that the engine will produce the lowest amount of emission possible. as you know, during warm-up, the ecus are programmed to run rich which is bad for emissions. so, the faster that they can get the engine to operating temperature, the lower the emissions rating that nissan can get for the engine.

What kind of differnece in times are we talking about here? Seconds, Minutes?

I don't believe that. You don't need a bypass line to do that. Just let the coolant sit in the block it will get hot just as quick. If the pump is turning 3000rpm with insufficient amount of coolant flow it will probably cavitate. The bypass feeds the pump while the thermostat is closed. I believe that's the reason it's there.

That is what I was thinking, the only other source of coolant would seem to be the heater hose, this probably would not matter if you run without a thermostat