how mucher water pressure does an i/o produce?

[lime4x4]

Over the winter i will be rewiring and replacing all the gauges. I have a 86 mercruiser 260 with an alpha drive. I was thinking of making an alum coupler to install in the feed hose from the outdrive. Is there enough pressure there to register on a pressure gauge? Just want it for an early warning setup

 

[Howard Sterndrive]

Re: how mucher water pressure does an i/o produce?

technically, 0 psi

the pump produces flow, not pressure

Pressure is made by restriction to that flow. So pressure is determined by everything else - heat exchangers, block, thermo hsg, manifolds...

And I have seen see 25 to 55 psi at WOT.
As passages clog with age, I'm sure it could get higher.

The OMC stringers could probably run over 75 psi if restricted. They have a big impeller.

Depends a lot on the exhaust manifolds I find. Also depends on drive ratio, and steering cooler.

 

[cr2k]

Re: how mucher water pressure does an i/o produce?

I would suggest placing it on the seawater side of the heat exchanger if you have one. This would tell you 2 things, your operating pressure and a temperature spike would warn you of restriction in the heat exchanger such as failing impeller or such.

As to what pressure? Install it run it and see what it runs. This will be your baseline.

 

[lime4x4]

Re: how mucher water pressure does an i/o produce?

My current setup is raw water cooled. I was going to install it right where the hose goes in to feed the p/s cooler. I will also be installing a new impeller next spring. So it should give me a good base line. This is the gauge i'm looking at it. it reads from 0 to 35

http://www.danamarineproducts.com/P...=1666ac8-ee7d7821-1c81-45e9-a2b3-bf620b5f52c6

 

[45Auto]

Re: how mucher water pressure does an i/o produce?

The water pressure tap on my Bravo (belt driven seawater pump) is on the output side of the pump, reading the feedline pressure just like the OP is proposing. It reads 25 PSI at about 3000 RPM and 8 PSI at idle with a brand new impellor, drops to about 15 PSI at 3000 and 4 PSI at idle after the impellor is a month or so old. A 2 year old impellor also reads 15 and 4. Never had one older than that, I change it every other year.

I would expect the readings from the Alpha to be similar.

 

[lime4x4]

Re: how mucher water pressure does an i/o produce?

I'm basically looking to install something that will give me a heads up to a potential and expensive repair and/or failure. I'm also installing 2 temp gauges to monitor each exhaust riser