13hp or 22hp for ts2021

So I am certain a question like this has been posed before but the answer always seems a little unclear so...

I have (had) an 11hp and ts2021 doing 3000 @ 4 belt drive and I destroyed the engine. I am going to get a predator but not sure whether to go with the 13hp or 22hp. Its the basic pulsar unloader. What psi and gpm would I expect to get if I kept the pump and unloader as is and just swapped out the engine? What other considerations do I need to make?

Daniel Simmons
Pressure Washing America, LLC - Houston, TX
http://pressurewashingamerica.com
 

JBurd

New member
GPM is determined by how many rpm's the pump is spinning. You should get about 5.3 gpm I think out of that pump if you spin it the right rpms no matter what engine you use. You could slow it down with larger diameter pulley, but why do that? You were probably getting 4gpm cause the engine was bogging down.

There is a formula to calculate PSI with given HP and GPM, but I don't have that on hand, I'm sure someone else will chime in with that. From my experience, 13hp will not give you max psi (which is fine if you don't need it), and 22hp might be overkill (shouldn't hurt anything just a gas waster). The formula will tell you a target PSI, and from there you need to get the right tips and set your unloader using a pressure gauge.
 

Matty P

New member
The 420cc predator should be fine if you're doing Residential. I'm actually building that exact unit right now along with a 22hp predator that will be running a tsf2021.

Remember... You're getting 30cc more out of the predator the a gx390. I'm expecting to see 2600 psi out of it which is fine for residential work. If it weren't January I'd put it all together tomorrow to see exactly where it's going to be at.
One other thing.... The predators are now shipping with a 1.7 gallon fuel tank. Check the box at the store and it will say on the side if it has the 1.7 tank.
 
The 420cc predator should be fine if you're doing Residential. I'm actually building that exact unit right now along with a 22hp predator that will be running a tsf2021.

Remember... You're getting 30cc more out of the predator the a gx390. I'm expecting to see 2600 psi out of it which is fine for residential work. If it weren't January I'd put it all together tomorrow to see exactly where it's going to be at.
One other thing.... The predators are now shipping with a 1.7 gallon fuel tank. Check the box at the store and it will say on the side if it has the 1.7 tank.

That's what I don't get - why would bumping up to 13/14hp drop it below the 3000psi and 4gpm it was getting with the 11hp? What gpm are you expecting?

Thank

Daniel Simmons
Pressure Washing America, LLC
http://pressurewashingamerica.com/
 

Matty P

New member
I'll get 5.5 or so out of it. The gpm stays static in regards to horsepower, it's the psi the goes down with lower hp.

If you only got 4gpm on a belt drive with a ts2021 then the pulley was the wrong size or something else was amiss.
 

JBurd

New member
That's what I don't get - why would bumping up to 13/14hp drop it below the 3000psi and 4gpm it was getting with the 11hp? What gpm are you expecting?

You shouldn't base your expectations off of an engine that got burned out. Here's the formula (quoting Russ from a 2012 post)

Actually, to find desired horsepower, I prefer ( [gpm X psi] / 1450) X 1.5
So let's use 5.5 gpm and 3,500 psi for an example...
( [5.5 X 3,500] / 1450) X 1.5
( 19,250 /1450 ) X 1.5
13.28 X 1.5 = 19.91 hp.
Many use the formula (gpm X psi) / 1100. This formula will work, but pushes the engine to it's limits constantly. A slightly larger engine will last longer.

With 18 hp and 8 gpm, I wouldn't run over 2,200 psi, 2,500 psi max.
 

Sirocco Jerry

Active member
definitely 2 ways to look at this.. max out the 13hp,
.. either with pressure (3500psi at 4.2gpm) or Volume (5.7gpm @2500psi).

Or with the larger engine.. max out the pump,
.. at a lower QUIETER engine speed with belt drive.

V-twins are inherently quieter than single cylinder "thumpers".
..and running at lower speed is quieter.
Quieter does a more compelling Demo ! Quieter gets bigger contracts !
 

Sirocco Jerry

Active member
Quietizing your system, where horsepower is available

When I am "leading" a new customer wanting to grow his business,
we talk about building an Advantage over their competition..
A new guy can say he's got Newer more powerful equipment,
a smart guy can boast his certifications,
and ANYbody around residential,
hospitals & hotels,
.. or working at night, can sell.. "Quieter"
 

Sirocco Jerry

Active member
General TS2021 pump ..at full tilt.

the TS2021 was re-rated to..
5.6gpm @ 1450rpm ..and 3500psi
plus, it has alternative versions to 6gpm so..
you can run it up to 1550 rpm for the full 6gpm,
.. as long as you reduce pressure to not overheat those rods..
.. 3000psi would be fine,
.. and tank-fed, as long as you dual-feed it.
 

Sirocco Jerry

Active member
..and JBurd, your formula makes me dizzy..
this one is easier for these new guys to use, and very accurate..
for continuous Hp..
5.6gpm x 3500psi x .0007 = 13.2 HpC ..or electric motor horsepower.with gas engines.. Intermittent Hp..
HpC x 125% = 16.5 Minimum intermittent Hp or HpI
So.. with the 5.6gpm pump at 3500psi requiring 13.2HpC ..
..the 22HpI engine would be running at 60% ..nice 'n cool.

and you NEVER want to run an engine at over 80%
..this is why a 13hp 4gm 4000psi engine is so Loud..
it is Screaming mad at running HOT..
4gpm x 4000psi x .0007 = 11.2HpC
.. /13HpI = running at 86% = overloaded
 

JBurd

New member
the TS2021 was re-rated to..
5.6gpm @ 1450rpm ..and 3500psi
plus, it has alternative versions to 6gpm so..
you can run it up to 1550 rpm for the full 6gpm,
.. as long as you reduce pressure to not overheat those rods..
.. 3000psi would be fine,
.. and tank-fed, as long as you dual-feed it.

I love learning these secrets of the pumps. So is the 6 gpm at 1550 rpm a special version, or does that apply to all ts2021? Also, is the tsf2221 really rated for max 3000 psi?
 

JBurd

New member
..and JBurd, your formula makes me dizzy..
this one is easier for these new guys to use, and very accurate..
for continuous Hp..
5.6gpm x 3500psi x .0007 = 13.2 HpC ..or electric motor horsepower.with gas engines.. Intermittent Hp..
HpC x 125% = 16.5 Minimum intermittent Hp or HpI
So.. with the 5.6gpm pump at 3500psi requiring 13.2HpC ..
..the 22HpI engine would be running at 60% ..nice 'n cool.

and you NEVER want to run an engine at over 80%
..this is why a 13hp 4gm 4000psi engine is so Loud..
it is Screaming mad at running HOT..
4gpm x 4000psi x .0007 = 11.2HpC
.. /13HpI = running at 86% = overloaded

Excellent point about those loud 13hp setups! Regarding the formula, it was Russ', not mine. One question though...if you end up multiplying yours by 125% to get intermittent rate (for 80% engine load) why not use GPM x PSI x .0009 = HPi? Yet even then Russ' formula is about 15% more conservative (resulting in 15% more horse power required). Anyway, it does seem that your formula Jerry is closer to what my equipment is currently running at.
 

tomtucson

New member
I believe a ts2021 could run fine at 1750. And can we just have ( Gallons x psi ) and divide by ONE NUMBER, the RIGHT number, whatever that is?? All the rest of the dividing and multiplying, just work that out to the ONE number to divide by. And then don't forget that the labeled horsepower is not the running horsepower (except for Generac engines, that I know of)
 

ben skipworth

New member
It seems like 1100 would get you pretty close? 4gpm x 4000psi=16000 / 1100=14.54hp
5.7gpm x 3500 / 1100 = 18.13hp
But I am not an expert. lol
 
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