How much pressure does a raw water pump put out?

[Luhrs28]

I have a Sherwood G7B typical rubber impeller pump on my GM 6.2 Diesel V8, and I'm thinking of putting a pressure gauge just downstream of the pump to aid in diagnosing any future problems. My question is what pressure range should the gauge have? I'm thinking something like 0-30psi but I'm not sure. I've found specs on the 'Net saying it flows about 30GPM at high engine speeds but I haven't seen any data on the pressure.

Do any of you guys know approx. how much psi I should see at the pump outlet running under normal conditions?

Thanks,

Bert

 

[45Auto]

Re: How much pressure does a raw water pump put out?

The raw water pump on my 8.1L Bravo III shows 3 PSI at idle, and about 15 PSI at 3000 RPM. It'll show 25 PSI for an hour or so just after a new impellor is installed.

The 0-30 should be perfect for your application.

 

[vxtech]

Re: How much pressure does a raw water pump put out?

pumps are rated by flow because its your system's design that creates pressure, to establish a good known pressure will probably ruin impellar,install a tee fitting on output hose with pressure gauge (scale of your choice) also install ballvalve after tee fitting , run motor with ball valve open and observe psi , if everything is new and no retrictions psi should be low, as you create restriction with ballvalve closing you will see pressure rise up , once ballvalve is fully closed (couple seconds) just to read max reading as impellar will be probably be ruined, that is your max pressure, but there are many variables to how restricted you system maybe altering known good readings hope this helps

 

[Bondo]

Re: How much pressure does a raw water pump put out?

The 0-30 should be perfect for your application.

Ayuh,... I'd think that'll cover All of Us,...

I've got the gauge,... Hope to hook it up on this next motor...

Being an open cooling system,... It's the resistence, rather than actual Pressure We're lookin' at...
Still should be a Good indicator of whether the impeller is Ok, or if the risers were pluggin' up....

 

[Luhrs28]

Re: How much pressure does a raw water pump put out?

OK very good. I understand it's actually the resistance of everything in the system that creates the pressure. I'm not talking about deadheading the pump to see what the max. pressure is. I just want a gauge so I can keep track of what normal is so one day if the cooling system is acting weird I can at least see if the pressure is normal or not. Thanks for all the replies.

Bert