what type of water pressure gauge to test engine water pressure

[snake91876]

I have had a few issues with engines that i thought were still not getting adequate flow
after water pump installations. I would like to test them with water pressure gauge, what type of gauge would be best. where would most motors be tested.

 

[Moody Blue]

Re: what type of water pressure gauge to test engine water pressure

Talking in generalities, and assuming you are talking about an outboard, the actual water pressure is quite low. A water pressure gauge is readily available for this purpose. Many owners prefer a pressure gauge over a temperature gauge. Typically, gauges come in two ranges, 0-15PSI and 0-30PSI. From my own experience, at idle I see around 2PSI and at WOT I see about 12PSI after installation of a new waterpump assy and impeller. Of course, depending on the specific motor, results will vary somewhat.

As for where to plumb the gauge, again each motor is different. You do want to tap into the cooling system within the powerhead, and there is typically a port available to do so. In other cases, it may be possible to tee into the telltale outlet.

 

[j_martin]

Re: what type of water pressure gauge to test engine water pressure

On most mercury outboards, the tell tale is not the place to tap in.

 

[Silvertip]

Re: what type of water pressure gauge to test engine water pressure

On most mercury outboards, the tell tale is not the place to tap in.

It works fine on 75 - 90 triples.

If all you are trying to do is build a pressure test unit, the plumbing dept at your local hardware store, Lowes, Home Depot etc can provide an inexpensive water pressure gauge for any water system. You grab a handfull of small brass pipe fittings and a length of hose and you are in business. However, a water temp gauge alone, and a water pressure gauge alone do not provide a complete and comprehensive cooling system test. The water pressure gauge tells you whether or not the pump is working. That's all it tells you and that alone is no guarantee the engine will not or does not overheat. The temperature gauge tells you the engine is or is not overheating. The water pressure readings should be taken immediately after a new pump is installed. Over time, if and when one sees pressure readings degrade, you know its time to replace the pump.