Water Brake Dynamometer Set-up

[ibanezplayer]

This year we're planning for more in depth engine work, and properly calibrating our ECU, so we've decided to set up a water-brake.

I've searched around the forum and found everything I need to know, except how to physically plumb the brake. The water brake that we have is of a different design to the ones I've seen on the forum.

Any one have any advice?

Thanks!

http://img112.imageshack.us/img112/5789/dsc05062smallxi2.jpg
http://img150.imageshack.us/img150/9647/dsc05064smalltz3.jpg

[Wesley]

The one parallel to the rotational axis should be water input, the one radial should be output. I don't remember why there are two exits... I think I've been up too late.

[ibanezplayer]

Thanks Wesley;

So if I understand correctly, number 1 is the water input and number 2 is the output.

Any idea on the small hole, number 3?

Thanks!
http://img211.imageshack.us/img211/9633/dsc05064smalltz3op7.jpg

[360 Research]

If you are refering to a picture, I do not see it, But the -4 AN fitting is the vent line. This must be free to vent to atmoshphere. The Line should be run uphill, so water does not build up inside.

[mech5107]

Originally posted by ibanezplayer:
...
I've searched around the forum and found everything I need to know, except how to physically plumb the brake. The water brake that we have is of a different design to the ones I've seen on the forum.
...



Could you please give the link for the forum that you found?

[360 Research]

You could try:
http://forums.land-and-sea.com/

[360 Research]

now I see the picture.
1 is the drain. 2 is the inlet. Make sure you mount the brake so the drain is at 6 o'clock so it will gravity drain.

[Wesley]

Yep, 3 is a vent. Shouldn't it run downhill so water doesn't build up?

[360 Research]

The purpose of the vent is to allow air to escape the brake while it is filling with water, and allow air back into the brake while it is draining the water. Sometimes under high loading, the vent will fill with water. If the vent is run downhill, you can run into a situation where the brake is draining, but it has to lift the water in the vent line before it can start taking air in. The symptom of this with an auto-load control system is usually rpm ocsillation.
The best solution is to use a Tee fitting, run one line downhill, the other line uphill. Then any water that gets in there will drain out, and there will always be air available when the brake wants it.

[ibanezplayer]

Originally posted by mech5107:
Could you please give the link for the forum that you found?

This forum (www.fsae.com) has plenty of information on water brakes, connections to engine output, water supply requirements, etc.

Thanks a bunch Wesley and 360 Research, think I've got everything now. I'll be sure to utilize that t-fitting on the vent.