Trying to go bigger with the engine I have

It’s struggling because of the torque curve of the engine. Endless you run diesels you torque is created by the engines rpms 2500-3600 is we’re most small engines need to run because of there light rotating mass and short strokes.

@Innocentbystander can your expertise settle this debate? I don’t even know if I’m right now lol…

I remember you saying that you were pushing 9+ gpm when your motor was overrevving

I did??? Can you reference the post?

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With a number nine tip. Lol not 9gpm

I was off when I posted here on this thread about 3200 psi. I couldn’t quite remember just how much over on psi I was running. Apparently 4K lol

In order to push that PSI, through that tip, you need 9 gpm (just look at a chart). Plus the 1 gpm you were bypassing. So your pump was actually pushing 10+ gpm at that speed

This thread has turned into an awesome learning opportunity.

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Trying to explain this is making my brain hurt lol…

3k psi is if your motor is running at the correct rpm. I was 1,000 rpm too high. Putting me at a higher psi.

So I was 7 to 7.5 gpm coming out of the number 9 tip. And according to the cart that should put me at 3k psi or close.

Now crack the throttle up to 4,000 rpm (if it wasn’t an udor I’m sure I would have ruined it before I realized my rpm was that off) and you get more psi.

Plungers are turning faster trying to do what you are asking of it (even though it was possibly damaging an $800 pump)

Yea, learn to install a tachometer lol

I’m taking a nice hot bath and y’all got me so flustered I’m about to go put water in the rig and bucket test this on video.

But i think I’ll enjoy the water I’m in and not worry about spraying any today lol…

And yes I’m mentioning this just for @Innocentbystander

Where you at dude!

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There may have been other things at play creating that psi. Depending on we’re your gauge was.

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It was at the gun.

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Oh, man. You’ve got a lot of the facts, and you are just this close to getting it.

Study a nozzle chart for awhile.

Then think about what actually causes the pressure to raise or lower. Think about what causes the difference when you use larger tips. Then apply that to a different flow rate on the chart.

It’s the flow rate and orifice size that determine pressure. You were getting 4k psi out of your #9 tips because your flow rate had increased. There is no other explanation for it.

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Yes, as you said, you were asking it to put more GPM through the same number tip, which of course increased the psi, @florida_condo_cleani is right. don’t have to wait for @Innocentbystander for this, I guarantee you :slight_smile:

We’re all saying the same thing here just different ways lol. I am saying that the psi was increased because I was trying to force too much water.

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More of the story is know what your pump recommends for rpm and don’t run it higher or lower.

Run it at what it calls for with no deviation.

Don’t know your rpm? But a tachometer and install. Don’t know how to install a tachometer go to YouTube or join a small engine forum lol

Most pumps actually have only a max rpm and even that can be exceeded by 10 percent without issue. And you can usually run most pumps at half the max rpm without experiencing pulsation . Two of my machines run dual pumps @ 50 percent max speed most of the time

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But when you do that you are not running the motor at “wide open” or within the power ban which can be hard on a motor. You don’t leave a truck in overdrive towing a heavy load up a hill. Same principle I’m my opinion.

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