No Mike not yet! I am waiting on my unloader to come in! Should be here any day!!! Sorry I have not posted any results. Between being busy as hell and waiting on the unloader I have not had time. Hey, I ordered a green spring unloader, what type do you use?

I'm going to start using the green spring, everyone says it's the best.

I use the AL607 black springs.

Here's a good link. GPM, HP, PSI, & Nozzle size calculator.

http://www.barens.com/cgi-bin/calc

It's been colder than a well diggers azz lately. Can't do squat. So I've been on the computer a lot lately calculating stuff.

Here's a good guide for engine/pump combinations and two bar surface cleaners.

20" surface cleaner: 13-20hp 4-5.5gpm @ 4000-3000psi

24" surface cleaner: 20-26hp 5.5-10gpm @ 4000-3000psi

28" surface cleaner: 24-40hp 8-13gpm @ 4000-3000psi

36" surface cleaner: 33-53hp 13-18gpm @ 3500-3000psi

http://www.barens.com/cgi-bin/calc

I used this chart and also measured the area of a circle.
From my experience this HP-GPM range for each setup (slow-fast) is pretty accurate.
You will be able to move each one about the same speed for it's range.

A= pie X radius squared.

20" = 314.159 inches squared
24" = 452.389 inches squared
28" = 615.752 inches squared
36" = 1017.875 inches squared

Your HP & GPM should be directly proportional to the surface area your machine will cover.

28" circle is 2.00 times larger than 20" so you need 2.00 times the HP & GPMs.
36" circle is 3.25 times larger than 20" so you need 3.25 times the HP & GPMs.
36" circle is 2.25 times larger than 24" so you need 2.25 times the HP & GPMs.
36" circle is 1.65 times larger than 28" so you need 1.65 times the HP & GPMs.

Looks like you need a heroic machine for a 36 inch surface cleaner, huh ?

Yes, I join mine together. 20hp 8gpm + 13hp 5gpm = 33hp 13gpm @ 3000psi

I'd really like to have Spencer's rig.

24hp 8gpm + 16hp 5gpm = 40hp 13gpm @ 3500psi and HOT WATER!!!

Thats My Boy Spencer, kicking curbs, and blasting Gum.
He better leave that Deep Fried Turkey alone, or his Big Surface Cleaner is gonna "Gobble" him up ?