Pulley's & RPM's

[Cody]

<font color=e87400>When setting up a machine what do the manufactures use as there guide for RPM/s

My honda GX610 18hp sports Max output of 18hp @ 3600 rpm's I've heard that's really only 90% correct, that you actually lose 10% hp somewhere, for some reason.

Do Manufactures use:
<li>Max HP Rpm's
<li>Max HP Rpm's less 10%
<li>Actual Rpm's @ Full throttle with No Load
<li>Actual Rpm's @ Full throttle Under Load.

I would assume that all the above are a bit different.

<hr color=e87400>
I ask because the orginal pulleys that I bought were according to the vendor the proper ones for my 18hp honda & TS 2021 pump. He sold me a 3" & a 6" <I>(3" for my motor 6" for my pump.)</I> According to “my†caliper they actually measure 3.055" & 6.25" -- I measured them on there outside diameter, I would imagine this is correct.

After doing some caluclations I have come to the conclusion that I really need a TACH!

If the pulleys are based on Max HP then the pulleys he sold me will turn my pump about 309 rpm's over the 1450 the pump is rated at.

If the pulleys are based on Max HP less 10% then the pulleys will turn the pump about 181 rpm's over.

Thus the Pulley's he sold me in either case will turn the Pump faster than it is rated for. I would guess this would damage my pump in the long term, perhaps the short term?
However I am not too sure about this either since General Pump doesn’t specify the keyword “Max†rpm’s anywhere in any literature that I could/can find. So maybe you can turn them a bit faster? <li>The question is how much faster?

My math, I had to sit & figure this out, tell me if I'm missing anything.
(Engine Pulley Circumfrence <i>divided by</i> Pump Pulley Circumfrence) x Engine RPM's = RPM's to PUMP

With:
-Engine Pulley – 3.055
-Pump Pulley – 6.25
-Engine Max Output RPM - 3600
-Pump Rated @ RPM - 1450

(3.055 x Þi) &#247 (6.25 x Þi) x 3600 = 1759 Pump Pulley RPM’s

<li>Is this too much?

I have until now always run GB units. These units, as I know it, run at a 2:1 ratio. If my Engine RPM’s are actually running @3600, or close to it, then I am turning these pumps that are rated for 1450 at or near 1800 rpm’s. In the past I have smoked at least 3 pumps which were attributed to overheating, the blame was placed at oil breakdown &/or water in the oil. Now I am not so sure. If the pumps are “rated at†1450 & 1450 is considered there maximum working capability then I have probably been overheating them due to excessive RPM’s.

What I need to find out here I suppose is what sort of tolerances GP has figured into their pumps.

So, that being put out there anyone have any thoughts?</font>

 

[Mark]

[GLOW=blue]Pump Education - Compliments of www.ARNorthAmerica.com [/GLOW]




Handy Charts & Formulas To Help You.. CLICK HERE!

 

[Cody]

<font color=e87400>Thanks Mark, but not what I am looking for.

I guess at this point the #1 question is: What is the result of running the pump at higher RPM's than it is rated at.

At some point there are limitations.
For instance if a pump is rated at 5.6gpm @ 3500psi @ 1450 rpm
Will it produce more gpm & psi at 1600 RPM, 1800 RPM? Or is 5.6 @ 3500 the most it can phycally accomplish. Then at what point will the Pumps Mechanical portion breakdown, rpm wise that is 1600, 1700 etc.

I understand that you probably won't know the answer to this, it';s a fair bet that no one here will. I have encountered it now & have been pondering on it for a while today & just figured I'd share it for food for thought.

Cody

PS <b>Mark</b> You never let me know what the warranty was on that 8gpm AR pump.</font>

 

[Mark]

The faster you turn that pump the more gpm it will produce.
At some point you will max it out, it is not advisable to turn it faster than the rated RPM.

Check out the charts on the AR North America site you will see how to determine gpm at a given RPM etc.

Sorry I forgot to post the warranty info on that AR pump model XWA8G35 for you, I was trying to find it online and copy & paste it..

Basically it is I believe 5 years against defects in material and or workmanship.

Most of the pump manufacturers are all offering the same warranty.

 

[Larry L.]

Cody,I'm not going to bore you b/c it seems your problems are abundant.I ran a 310 cat pump for 3 years,it was pumping 2800psi with a 2507 tip.I do not know how many gpm it was pumping b/c I never checked it,also it was loaned out for a year to another contractor.The 310 cat is rated at 2000psi and 4 gpm,I put a smaller pulley on the pump and left the ones on the motor alone.This was done useing a 16hp B&S,we never had any problems with it,ran like a charm and stills does,its retired tho for a spare.

 

[Cody]

<font color=e87400>Good to know <font color=green><b>Bigboy</b></font>

I managed to get a new pulley slammed onto that bad crank. I got one a tad smaller & beat it on with a sledge hammer, I think it will probably hold

Anyhoo, When I purchased it, I thought it was the same size as my previous one, but it's a little bigger. To make a long story short, according to the math, with my 18hp turnin 3600 the pump would be at 1871 rpm's. This is where I wish I had a Tach right now, I'd love to see what my motor is actually turning to see if I could run this sucker.

However, I think that with yours & Marks input, I might just try it out. I'll just keep an eye on it for thermal issues, if it blisters my hand I'll turn the motor speed down.

I have already shot GP an email re this, if they answer I'll post it.

 

[Mark]

Cody,

Sounds like you need a tachometer.

It is difficult if not impossible to determine what the gpm is with out some basics.

-1- You can determine pump rpm and then gpm if you start with some known factors such as: engine rpm 3200 engine sheave / pulley 2BK30
pump pulley / sheave = 2BK60 This would be a two to one ratio divide driver by driven to determine this would be turning pump at 1600 RPM

The General TS 2021 is rated 1450 RPM at 5.6 GPM (Or so they claim) so divide 1450 by 5.6 gpm etc. etc.

When you have no defined values it is tough to determine.



Good Luck, let me know if I can help.

 

[Larry L.]

a sledGH haMMER,should have put some slick willy on it,could you get the lock collar on it?.If not I dought it holding b/c of the kickback you get sometimes when shutting the engine off,no what I mean.It may last a hour or so or it could last forever,you never know how long a sledGH haMMER job will last.Next time try adding a little super glue before driving it on or heat the pulley before adding it to the crank,pour water on the crank as your forcing it on.

Heck man I don't see why you don't jusy buy you a band spanking new hotwater skid.They aren't that high money bags,buy a couple more pulleys and sleepless nights you could of had one paid for or set a gallon jug in the bars and stores that reads "Help Cody Buy a powerwasher"

 

[Cody]

<font color=e87400>LOL <font color=green><b>Bigboy</b></font>

I think I got it now. When I put that pulley on there I wasn't really thinking it was going to work. It's not the same as the one I was using before, it's the type with no hub, just 2 set screws. When I tried pushing it on a couple times to see if it would go, it only went on about 1/4inch. I ground down the welds that I had made there & tried on again, this time I gave it a good tap. With that it was on good enough where I could not get it off without a fw puller. I had planned on putting on some JB but since it was on so tight, I just figure "what the hell" just go ahead & pound it home. So, I did!

I'm going to buy a new something, just not sure what yet, I was geared up to go get a new engine on Monday, but now I'm not too sure. I keep going back & forth over a PTO setup. I had some concerns but a buddy of mine seems to think that the PTO would function fine. Muncie has a pretty decent PTO that I could rig up to run 1 maybe even 2 pumps off of. Only hold back is figuring out if everything is going to hold up. Muncie doens't really seem to know :\ . The PTO is a 39hp, intermittent, but you lose approximately 30% running it continuous. If that's a fact then I'd only get 27hp out of the thing. I'd prefer a little more, but this may be enough. I guess it'd run (2) 3500psi @ 5gpm, which inturn I could tee together for 1 3500psi @ 10gpm.

ahhhh decisions decisions

Cody</font>

 

[Larry L.]

Check out the PTO pumps on the dump trucks or do you want one that big.You know about what those suckers cost,faint faint wow.Just think man if you blow a PTO hose which you may never but man oil oil oil on everything.Cost wise I think you would do better with a reg. hotwater skid,wouldn't the gas for the truck cost more for each job and if the truck breaks down your a foot again,no truck no pump.

 

[Cody]

<font color=e87400>I'd still have at least one standard PW on the truck. The PTO that I'm looking at now is under $1k I figure another $300-$500 for pulleys & what not to get the pumps powered. The truck uses little diesel when Idling so I don't see an issue there. This PTO is not hydraulic it's mechanical with a driveshaft. The shaft I would route under my truck then transfer that to belts going to my pumps.

As far as skids, I don't do skids . I run all seperate components. And build my own pressure washers, <i>the parts are much cheaper than the whole. I can get a 24hp honda for around $1200 a GP 2021 pump for $300 Unloader for $30 a gb for $125, now however I'll be using belt systems not sure what my prices will be on those since I just bought them this time w/o shopping prices but somewhere around $125 max I think. Carts $40 (Build my own) so I can build a 24hp honda 4000psi 5gpm for around $1700. Call around & see how much you can get one of those for! Next unit however I might bump up & try one of Marks 3500psi 8gpm AR pumps out, that'd be an extra few bucks. As far as heaters I prefer Propane, these only come in Vertical stand alone units (as far as I know anyway) thus I an set up for this type of heater. They run me about $1500 So now, I have a 24hp 4000psi 5gpm Hotwater unit for about $2900. Price that one out! </i>! Plus, by running sperate components it's much easier to set things up to work on. (For me anyway) I think that pretty much sums me up for my view on skid units. If I ever did/do buy one I'd probably do it to get one of the units that also makes steam, then again if I figure out how to build that myself I'd probably go that route</font>

 

[B.E YOUNG Sr]

Cody,

Not trying to stab you in the back but maybe you should consider buying a complete skid.

When buying a skid you pay for the engineering up front!

In the long run you might save a bundle of cash, a bunch of head aches, and do twice as many jobs.

Again I am not trying to slam you, but giving you the outside looking in view.

 

[Cody]

<font color=e87400>I just got in, that 18 ran like a champ.

Np B.E, the GB setup that I have been using was designed by an engineer, several depending on how you look at it. It's just a design incompatability, maybe it's the honda's fault, maybe it's the GB fault, who knows. It's not going to be a problem for me any longer since I am going to change over to Beltdrives.

IN addition, these problems that I am having right now, are just one of those things, grant it this is the worse run I have EVER had with crap breaking, but... sometimes poop just happens.

The problems are only an issue because they are all happening at the same time, it's just a Murphy thing. Problems like these are just a part of PW'g biz, <i>but like I said, just sux because I am gettin gangbanged with em all at once here</i>. Plus you need to understand that these motors that I have with bad cranks on them have THOUSANDS of hours on them. This 18hp unit probably has between 3K & 5K hours on it, thus my operating expense has only been around $0.25 an hour on it. I can live with that when it's made me at the very least $XX an hour on a bad day.

Had I foreseen the giagantic pain in the tush this was going to be I would have gone out & gotten a new engine in a heartbeat. Normally if repairs exceed 30% I just replace the broken item <i>with about the only exception being heaters (coils)</i> and retire the replacee to the parts pile for a later withdrawal . Here though I finally got tweaked about the trashed cranks with the GB's & decided to try a belt on it. Little did I know the crank would not want to hold it, an easy oversight for anyone I would guess. Now that I may have this nailed I may be able to yet put together another beltdrive or 2 from the parts pile. I think I am going to try to rebuild a pump too. I have a couple pumps that got thrashed on the insides, both have good pump heads, ones a fresh rebuild before the innards gave I'm going to see if I can use the 2 guts to get 1 working. I've never opened on up, so we'll see..

In any event. It's not a big deal really, just frustrating. As far as the skid units, like I said they don't fit to my design. And besides with "most" skids that I see out there they are nothing to jump up & down about. They are just an Engine, a Pump, an unloader, a wrapped set of coils & a beckett burner. Pretty basic stuff! The only thing that really seperates them is their housing ie; Cart Frames, Steel Frames, Stainless Frames, Stainless Window Dressing, etc etc... I may be wrong here though but this is all I see & I have seen many of them. I've been to a few of the PWNA annual seminars with all the vendors there & their stuff there too look at too. Which reminds me

One year at a PWNA seminar Delco was there sporting one of there new hotwater skids. The owners son was there or maybe it was larry's son, I forget his name. Anyway, he was talking to me about this new machine. It had a little banner on it stating "20% more fuel effiecent" he was boasting about the effiecency & so where the other reps there.
I asked the guy, <i><b>"What kind of mileage does it get"</i></b>
He responded <i><b>"What do you mean. "</i></b>
Me <i><b>"I mean, how much fuel does it burn"</i></b>
Him <i><b>"It burns 20% less fuel than any other burner on the market"</i></b>
Me <i><b>"Well how much is that"</i></b>
Him <i><b>"20% less"</i></b>
Me <i><b>"Look dude. You want me to purchase this thing, I use propane burners that use approximately 1.5g per hour @ $1.1 an gal. If you want to sell me on this thing getting better economy then you need to tell me how much fuel it burns!"</i></b>
At this time he pretty much blew me off. What should have been a REAL easy question to answer he either couldn't or wouldn't which leads me to wonderin!

That goes down in my books as one of the all time worse salesman that I have ever seen.

Cody.</font>

 

[B.E YOUNG Sr]

Cody,
Ah finaly good news on the 18 HP!

How was a GB lasting you?

Can I assume you would not reccomend the use of one?

 

[Cody]

<font color=e87400>Well, that's a tough question. For a limited user I think the GB would be fine. I got anywhere between 1000 to 8000 hours out of the ones I had. The 1000 hours was on a 18hp machine, if you remove that one, the next would be around 4000 hours. <i>hours like that is equivelent to 100K - 200k miles on a car</i>

There's alot to be said for GB units. They last, belts don't break, they are a sinch to set up. For me, I am tired of parking motors just because the crank is messed up. Not to say that I won't go back to them though. I may. We'll see how well the belts hold up.
Hell the only reason I ever have to park a machine is when a crankshaft gets too bad to put a gb back on. There's alot to be said for Honda's.

I'd say that the limited user would be ok. The serious commercial user, probably not. Now this problem could be limited to an issue with the Honda cranks. Other motors (briggs, Kohler, etc) may have harder cranks that would not be affected the same way, If I knew this were the case I might be inclined to try one of those motors out to keep on running gb units. On the same hand however that could open up a whole new can of worms if the other motor doesn't hold up as well as my Hondas.

 

[Mark]

Cody,

I have seen the same kind of damage to Kohler, Briiggs & Honda crankshafts, on both gearbox driven pump units and direct drive units.

When you go on & off with the gun, you creat a load / no load situation something needs to give so on direct drive & gear box units the engine output shaft / crankshaft usually takes the abuse at the key slot.

(I have noticed the same on flow or lock up unloader units.)

On a belt drive unit the belts stretch & wear and the sheaves / pulleys wear.


I will take a belt drive unit any day.




2 days until the 4th and a long weekend!

Have a Safe & Happy 4th!

 

[oguard]

Ahh Cody to reinvent the wheel.

First you need to know a couple of things...

Horsepower and torque ratings on small industrial engines do NOT meet any SAE or other technical specificatio0n because there are none. The manufacturer rates them based either on an average of recorded test results or test mules under ideal conditions.

NO small industrial engine is designed to run at full rated RPM for any application. You need to look at both the BSFC and torque rise to determine the ideal range to operate the engine. This is determined through working with the engine manufacturer and experience to arrive at the right combination of pulleys to do what you want.

Overspeeding a pressure washer pump will void the warranty and give you greater flow. however, pump ratings are at maximum so exceeding them will cause undue stress to the component.

PTO drives are all transmission driven in one way or another. This requires you to lock the throttle at a set RPM in order for the diesel engine to devlop the power required. Remember that 1 hour of idling time reduces the running time of a diesel engine by 2 hours. PTO drives do not have enough built-in cooling capacity to sustain long term operation either. (I used to sell Mack Trucks years ago).

While you may be able to buy components at lower costs than a manufacturer it will not be consistent. You will not have the warranty support from the component supplier for example. Honda actually requires that they test every new model pressure washer that comes to market with their engine unless you are grandfathered in like we are.

In short, I would be extremely interested in finding out what you do in order to make our skid unit better for professional cleaners.

We have CSA certifications, liability insurance, R&D that will increase our costs; however I doubt you could buy a Honda as well as we do let alone a pump.

Feel free to contact me via email or telephone.

Cheers.

 

[Cody]

<font color=e87400>Thanks for the reply Mark & Onguard.

<b>Mark - </b>

Thanks for the input on the Kohler & the Briggs. I assumed the crankshaft would still have to get damaged from this but wasn't sure. You never know for sure unless someone tells you that's around it or until you see it. So I am happy I chose to stay with my Honda's. And I fully do understand why it has happened <i> the constant triggering</i> since that constant triggering is loaded solely on the key on the GB & DD units with zero give, as you would get in a belt. You mentioned the unloaders having an adverse affect, now that I am converting to belts this should not be an issue should it? I use the 607 unloaders.

<b>Onguard. -</b>

Thanks for hopping in here.

You mentioned that the diesels get 2 hours for every one of idling. This concerns me a little bit. When I initially purchased this Diesel it was under the pretense that diesels were optimal for idling, idling for hours it need be, & without any damage. I was told by dealers, truckers & others that idling a diesel is no big deal & would not adversely affect the vehicle. Now, not knocking you, you say this may not be the case. I had spoken with Ford service center about what I was going to do with this truck as far as a PTO when I had originally purchased it & they seemed to think that idling it, or running it up some would be fine & not limit the trucks lifespan in the least, as long as I kept good oil in it anyway.

Orginally when I purchase it I had planned to put a Chelsea 941 splitshaft dual output PTO on it. I changed my mind on this because the folks that were going to set it up for me changed the configuration on it when I finally took it to them to install. They added another $4k to the price tag on the service thus pissing me right the hell off so I did an about-face on them & never looked back! In any event, at that time I had done a lot of research on PTO's & idle issues on my truck. Idling was not an issue. If you have some direction to point me to learn more about this thing idling & where it would decease my trucks life span as much as you said I'd appreciate it if you could point me too it so as I can learn it first hand.

As far as the small engines working at full rpm. Well I suppose that I knew this but just did not look at it the right way. I'm not a motor head. Outside of pressure cleaners I know nothing about combustion engines, & I know very little about these. I know of the problems that I have had over the years & enough to overcome those & that's about it. My engines have really "rarely" failed to where I had to work on them much anyway. With that said, I guess that the rpm's were just confusing me. I wasn't relating anything to the performance drop of my engines, like the standard 85% efficiency rule. I was just looking at the specs & figuring that was it & then running the pulley math. Bad ME! I have a tach now so in the future this won't be an issue for me.

I sort of understand the performance drops this is why I have opted to get a 24hp motor this time rather than the 18hp. For my pumps I need close to 18hp. I figured that a 24hp motor will run at about 19hp after a 10% standard performance drop & 10% after I convert it to propane. If it isn't right, It should at least get me into the right ball park!

As far as my tossing together my own machines. Well I look at it like this. In the Honda warranty paperwork there is nothing about any voided warranties if I use this for a pressure cleaner. My warranties are the same for the pumps whether I purchase them as a whole unit or alone. Your right, Honda does verify machine setups for manufactures, well look where that has gotten me. I have several units with gnarled up crankshafts because of improper design which are the very designs that Honda has approved. So Honda’s approval is kind of a moot issue to me

As far as my units being better than skids, I don't think that I really said that. What I did say is that the way I configure my equipment is better for "me". I prefer stand alone systems. When I look at a skid unit, heater & washer combined, all I see is service issues. Even changing out packings is a pain in the neck because the pump is buried, working on the engine & heater components is the same. Everything is kind of buried. With my configuration everything is right there. If I have a pump blow packings on the job I can replace them & be back running in about 7 minutes. If my heater blows a transformer I can have it running in 3 minutes. If I blow my heater coils I can have them replaced in 30 minutes back at my shop. If I lose an engine I can replace the engine in 15 minutes, maybe not now with belts. I can do an oil change in 5 minutes. You see a pattern here, everything I have is laid out for accessibility & ease of maintenance. There's little that I cannot do quickly.

Now I know that the skids are not necessarily that horrible to work on, however I absolutely HATE to spend any additional time than necessary doing repairs or maintenance. Time is money & time is life, thus any additional time that I have to spend fixing something is time that is TOTALLY lost. So, I set up everything I can for maximum efficiency for time. In addition, I think that having my components set up the way I do also provides maximum simplicity. I don't have any bells & whistles to these systems. No little lights, no additional fittings. I have the engine & pump, unloader feeds 7ft to my heater & bypasses to the tank, heater runs about 3 ft to the hose reels. That might be unnecessary to mention but I have seen some pretty complicated looking skid units, units that have odd looking fittings here & there, & lights for this & that. Much of which I see as completely unnecessary stuff.

Besides all that, most skids are diesel driven heaters. As far as I know, propane burners have to be vertical units. The propane skids that I have seen are pretty much a waste of money sinces the configuration is such that anyone could do it sinces there is no frame, a propane "skid" is just that, a skid, just a deck with a motor, pump & a vertical heater mounted behind them & you pay an extra $500 it set up this way.

Propane I believe is far superior to diesel, & yes I have used both. Propane is cheaper and cleaner. I've had to change out coils on diesel heaters, omg what a mess. On a propane heater you don’t even get dirty form it. On propane you don’t have all that nasty soot, that alone is enough for me to stick with propane.

Lastly Prices. The prices that I stated before is what I pay for those things. If you are a manufacture & paying more then wow! I don't know who you are so calling you would be tough, from your post I suspect you’re a vendor, I never knew that. Feel free to <a href="mailto:cody@cfl.rr.com">email me</a>.

For me all of the little problems I am having right now are really sort of a good thing because I am learning a few things that I never knew about pumps, engines, flows & whatnot. So although it's been a monstrous pain it's been enlightening. I think that this experience will help me make things a little better in the future.

Cody</font>

 

[oguard]

In GENERAL a diesel engine idles at ~75% better effieciency than a gasoline engine. BUT... running a diesel engine at idle for an hour is equivalent to running it down the road for 2 hours. Diesel engines benefit from extreme levels of thermodynamic efficiency so they do not generate heat at idle. A cool engine will not allow for proper flow of coolant and oil to prevent damage; hence the 1 hour idle = 2 hours running. Idling is a problem for truckers and the smart ones do two things: they add a shutdown timer so that when they stop for any reason they can set the timer to turn the engine off after 5 minutes or so of idling. This prevents differential heat soak which will cause fatigue cracks and oil coking. The other thing they add is an auxillary heater/air conditioner. In other words a class 8 diesel engine burns up to 1 gallon per hour where an auxillary heater will burn 1 gallon in 8 hours. All thoise trucks you see sitting by the side of the road idling for hours on end are wasting money and creating long term costs that can be avoided.

For a PTO to work properly you need a certain engine RPM depending on where the take-off is located to drive the hydraulic pump. This is difficult on almost all diesel engines but especially so for the length of time you would require for washing. I would suggest you start with a local heavy-duty truck dealer who specializes in wet lines for dump or other applications to get some real knowledgeable advice. I prefer Mack dealers for stated reasons.

Honda supplied keys are too short to properly mate the shafts so this is the most likely reason why you have had the troubles you have.

I agree that LP is a preferred wa to do things but some people are loathe to change from what they know.

Cheers.