TM Gurus inside please.

[Jayson]

Here is where I stand. I have a EZ truck mount with a liquid cooled Carburated 28hp Kohler spinning a direct coupled tuthill 4007 blower. It has fresh plugs, air filter is fine ( ran with it out also ),
Coming off the waste tank I Y'ed the 2 2" ports to a stainless Y to a male cool cuff connection. With this set up @ 3,600 rpms it only show a 3hg loss threw that set up.
Now when 100% blocked off it boggs down 500rpms to the 3000-3100 rpms range when vac relief is set @ 11-12hg. The relief is the standerd brass-spring-bolt deal that came on Nicks older machines. When the lift is set higher it will bogg down further below 3,000 and keep getting worse and worse untill the wand is lifted off the carpet.
So whats the issue? Can I only run 10-11hg on this motor blower set up or wold a fuel issue cause this as well.
I'm just baffled. It just seem like the engine is not making enough HP to keep up with the higher loads. Nicks has been helping trouble shoot this but I'm still out of ideas right now. I also have a kunkle in my garage that I threw on for giggles. It's set @ 16hg and just about stalled the engine after 3 to 4 cycles on the relief.
Also. Should I move the rpms up to 3,600 when all is connected or before the vac hose is attached to the port? Maybe it's just a throttle adjustment issue?

 

[KBRENNY]

I cant think of anything that comes to mind but I do not think it is a throttle issue. Sounds like you have plenty of HP to drive the system but I would not adjust the throttle as you have stated. Most of the engine manufacturers recommend 3600 rpm with no load so adjusting the throttle to reach 3600 while under load may result in premature engine wear or possible failure.

 

[Jayson]

The governor also seems to operating fine. Seems to function when a load is introduced.
I'll guess I'll just clean at a spitfire 10hg and call it a day. I love the damn machine but dont understand why it would bogg so bad. From what I've been told...even from Nick is that 100-200 rpm drop is all that I should be seeing.
How crucial is exhaust plumbing? Mine necks down due to space limitation and also has 3 90* bends. So I know it creates excess heat but would it cause it to bogg under load?

 

[GRHeacock]

When the wand is on the carpet, and doing it's cleaning work, is that when it bogs down, or when it is all blocked 100%?

If the bogging down is only when 100% blocked, I would think when cleaning, it is OK, because when cleaning, it is not blocked 100%.

Yes, it is normal to drop a few hundred rpms while working.

Gary

 

[Jayson]

So a few hundred rpm is ok? I have not noticed an issue on cut pile nylon. Seems to bogg more so on glue down with more vac lock at the wand.
400-500rpm drop when 100% blocked @ 13hg
250-350rpm drop while "normal" cleaning 10 hg or so.

 

[GRHeacock]

There is "X" amount of air flow through the carpet into the wand. More on some carpets, less on others. The air flowing through the carpet is what allows the water and solution to clean the carpet.

If totally blocked, there is no air flow, and no cleaning going on.

So, it sounds OK to me.

Gary

 

[Bob Foster]

Sounds very similar to my unit when it is turned up beyond 12inches. Except at that point it blows clutches.

 

[Jayson]

Sounds very similar to my unit when it is turned up beyond 12inches. Except at that point it blows clutches.

Whats the motor and blower set up on yours?

 

[Larry Cobb]

Jayson;

Direct-coupled to a #47 is a substantial load on the 28 HP engine.

Anything that lessens power output from the engine would cause the RPM drop.

Could be fuel or ignition issue.

Larry Cobb

 

[Lee Stockwell]

Get a fuel pressure meter, around $10 at AutoZone. With 1/8" ntp brass plumb it in just between the valve cover and carb.

I suspect low fuel pressure, via kinked or undersized feed line...or possibly the fuel pump in the wrong place. The fuel pump must be mounted very near the pickup, under the van, so that it can PUSH gas instead of pull it.

Hot weather operation takes its toll on fuel delivery systems, especially at high throttle.

Thanks,
Lee

 

[The Cleaning Artist]

The horsepower is too low for the rpm you are running with one wand. Try this. When cleaning with one wand run machine @ 3100 rpms. Your engine will carry that rpm very well at the stated hg. When you dual wand run it at 3600 and again with the available hp you have it will carry the rpm much better with both wands running. Make sure your filters are clean and the blower is not gummed up. Might want to flush the blower. Replace all sharp 90 degree bends in the suction side with sweeping ones. I used PVC and they are holding up well.

I run 27hp/47 blower with very little bogging @ 20 hg with the above rpm's. My next is to try some 2.5 in hose but replacing 500 ft is going to cost some bucks.

I would not worry about what the machine does when the port is completely blocked off as that is not relative to actual cleaning.

 

[Jay D]

OK, I have a similar machine Ez2747 and now a 30hp instead of the 27hp. I have the "Freeflow" system on it set at 15 HG. Backup, freeflow w/27hp cleaning at Larry Cobbs shop with commercial gluedown, 100 ft of hose, 3550rpms no restricktion, 3350rpms hoses and wand attached. started cleaning and I went to the truck and noticed the rpms at 3050 or so. I changed to the 30hp kohler recently set at 3550rpms no load, 3425 with wand and hose attached and about 3200rpms cleaning residential carpet. I use a glide, 2" wand, and a wye 10'out from the van cleans fine but under load. Complete blockoff on any aircooled will probably kill the motor. Brute watercooled like the NIssaN probably different story. I dont know. Just my observation. also very few(except harley) get a full 15 hg with the wand on the carpet .

 

[Jayson]

The horsepower is too low for the rpm you are running with one wand. Try this. When cleaning with one wand run machine @ 3100 rpms. Your engine will carry that rpm very well at the stated hg. When you dual wand run it at 3600 and again with the available hp you have it will carry the rpm much better with both wands running. Make sure your filters are clean and the blower is not gummed up. Might want to flush the blower. Replace all sharp 90 degree bends in the suction side with sweeping ones. I used PVC and they are holding up well.

I run 27hp/47 blower with very little bogging @ 20 hg with the above rpm's. My next is to try some 2.5 in hose but replacing 500 ft is going to cost some bucks.

I would not worry about what the machine does when the port is completely blocked off as that is not relative to actual cleaning.

Let me try to understand this... LOWER my RPMs to 3100 to start with and it will not bog as much under a full load @ any desired Hg? Wont the engine make less HP at lower RPMS and compound the problem even more?

 

[Steve Toburen]

Jayson,
Before you do anything else let me suggest an add-on to Lee Stockwell's idea. I almost never comment on technical/ repair issues but his post brought back memories of my slide-ins and yes, high ambient heat definitely would cause our stock fuel pumps to not deliver enough fuel. We added auxiliary electric fuel pumps down by the tank and it solved the problem. Cheap and easy fix.

Steve

PS Gotta love cleaning in these 100 degree days. Plus if it is 100 in the shade what is it inside your truck with the machine running???

 

[The Cleaning Artist]

Yes the engine will make a little less hp at lower rpms. At this rpm your blower and pump will also require less hp too. What I have noticed with my machine is that running the machine wide open(3600) and trying to pull 450+ cfm through a single 2" hose requires more hp @ 20 hg than my little engine can munster. S0 I run it @ 3100. When the wands hits the floor It only drops about 60 rpms. When running @ 3600 and the wand hits the floor, it will drop to about 3250. I think 3100 is peak torque for my engine and thus runs very smooth there for one wand.
You might want to try this too. Run machine at 3600 without any load. Then hook up 150 ft of hose and watch the lift climb and the rpms fall. This will show you what kind of strain just the hose is putting on the system.
My machine came with a smaller blower and I installed the 47. At 20 hg and 3100 rpms the wand will SCREAM and you feel a hard pull to the fiber even with a glide.

If you are having a fuel issue(which I don't think so) it means you would be running lean And I'm sure with any amount of time or strain and you would burn a piston, head gasket or valve or worse yet beat the rod out from detonation.

 

[Becker]

What does Mr. EZ say?

 

[The Cleaning Artist]

I just read Jay's post and when the wand hits the floor, my gauge reads 18" constant and will climb to 19/20 on commercial carpet. The high lift is what gives me the heat. If I set the relief to 15 It'l drop 25/30 degrees to around 240/250.

 

[Lee Stockwell]

We ran two 2547's for almost six years on a pretty hard ride. Usually full throttle (3450 on the tach). Why? Because any engine will drop a few rpms under load (as well as draw more fuel).

The peak in the torque curve of that Kohler engine is above 3000 rpm, thus the goal of having the machine "settle in" to the high end of that curve when actually cleaning under load.

Our experience taught us that if we ran the machine below the peak in the torque curve we would be more likely to bog than if if we ran slightly above it.

However we never attempted to attain 20 hg with this setup. We got great results in the 13 to 15 hg range. I felt it was abusive to the overall machine to scrunch it down like that.

If you noticed, I suggested a diagnostic tool first. The fuel pressure meter. Unless you can confirm adequate fuel delivery the rest of your troubleshooting is in the dark.

Have fun, we're here to help. Actually, as Steve T noted, we've already made your mistakes for you. Learn from them.

Thanks,
Lee

 

[The Cleaning Artist]

Lee there is lots to be gained going from 13/15 hg to 20. Not many machines are built to run that high but ours is. 300 ft out and the glide still sticks to the carpets.

Jays findings about hp and rpms are inline with mine.

 

[KBRENNY]

I personally believe the problem is in the fuel system or engine also. That blower only draws 19 to 20 hp. Even if the solution pump is drawing around 5 hp there is still plenty there. I am running a 20 HP honda on a sutorbilt 4mp at 16.5" HG and it only drops 100 to 150 rpm while cleaning and drops 300 to 350 when totally blocked off and opening the vac relief. Part of the reason you do not see as much drop in rpm when you run at 3100 is the power required to drive the blower at 3100 vs 3600 is different. If you would like to contact you local roots distributor I am sure they will tell you it takes around 80% to 85% of the power needed at 3100 as it will at 3600. Also roots does not recommend a vac level over 15" HG continuous on that model blower as shown on the following PDF

http://www.dresser.com/internet/busines ... 20URAI.pdf

I spent over an hour on the phone with roots while selecting the blower for the machine I am building and learned quite alot from the tech person I talked to. I decided on a 56 dsl and will run it at 16".

While I agree lift is an important part of the total package, so is flow. As you increase lift your flow will decrease, as you increase flow your lift will decrease. Finding that balanced and magical sweet spot is the challenge.

I have an automotive vac pump that can reach 30" hg on a 1/8" tube with little to no cfm, it won't clean carpet.

 

[The Cleaning Artist]

An open flow system with high lift has more cfm at the wand than with one with lower lift!
And just because you raise the lift doesn't mean your decreasing the cfm.

My blower was under warranty until it's time ran out.

WhiteMagic is now advertising 20hg. Mmmmmmmmmm

 

[KBRENNY]

If a system with high lift flows more cfm then explain to me why every major blower manufacturer's spec sheets show lower cfm levels with increased lift? the above mentioned pdf is a perfect example. This is not only true with roots, it is the same with tuthill and sutorbilt. There is no question that the blower will produce more heat with higher lift. That is part of the reason most manufacturers will not warranty a blower pushed past it's recommended max lift. Higher lift not only causes an extreme raise in temp (your seals are not designed for) it puts a larger stress load on the timing gears of the unit.

I do not know 1/100th about blower than they guys that design them and everything I have said here was information given directly to me from engineers at roots and sutobilt.

here is the link to sutorbilt's spec sheet:

http://www.gardnerdenverproducts.com/up ... Brand_(148)/PDF_Folder/Blower_Vacuum/PD_Blower_PDF/PD-SB-L_1st_12-06.pdf
Same thing, the higher the lift the lower the CFM.

 

[The Cleaning Artist]

KB, Sorry to offend you but my machine is in a class of it's own. My blower is water injected to keep it cool @ 20 hg. Do some searching and you'll see that the lift don't effect the shafts or lobes as they can take it. I'm going on 3000 hrs without any problems with the 47. And yes I have more cfm and LIFT at the wand than most other machines with the same size blower and probably more than larger machines at long distances..

What you are seeing on there charts is restriction built into the system that raises the lift. Totally different on a free flowing system which is what a good designed cleaning machine is UNTIL the wand hit the floor.

 

[KBRENNY]

The water injection was not mentioned before and that places in in a whole different ball park. OK your blower does not get hot, I understand that. Maybe if I can explain it to you in the terms used by the lead engineer at dresser roots: "a positive displacement blower will only move "X" amount of air volume per revolution, the only way to increase the volume of air displaced by the blower is to increase the operational RPM the blower spins at. Once you reach the maximum recommended RPM you have reached the maximum potential for moving air that the blower is capable of. The amount of lift increases as a restriction is introduced into the inlet side of the system. If you have no restriction on the intake side there will be no lift, just CFM. A restriction will cause a raise in lift because the air can no longer flow as freely through the system. The greater the restriction the higher the lift" Now that is how he explained it to me because I was heading in your direction and he pointed me in the right direction.

If you think you know more about CFM, lift or blowers in general than they guy who designs them then I have had my laugh for the evening.

 

[The Cleaning Artist]

your quoting specs for a bare blower with no plumbing attached. Well we all know that is not how the blower is installed in the machine not to mention the 200 ft of hose your trying to pull water, soil, solvents and air through. Blower slip also plays a big factor. I have spent many hrs talking with TUTHILL about blowers and their respected applications not to mention water injection.

You'll figure it out, Maybe!


The most restriction is 200 ft out at the WCI. What will move more air, A system capable of reaching 20 hg or one that cuts off @ 15?

I'd suggest doing more research before you build that machine if you want performance!

Once you reach the maximum recommended RPM you have reached the maximum potential for moving air that the blower is capable of

This is also not true as you can also overdrive the blower to get more cfm's. Several manf do this.

 

[KBRENNY]

I AM IN NO WAY SAYING LIFT IS BAD! I will run my new blower at the highest lift it is rated for. My argument is: I know that your blower (no matter what brand or make) can not move any more volume than it can at max RPM regardless of lift. Unless you are saying that the displacement per revolution on your blower magically changes when you go to higher lift. The higher lift helps with system restrictions to "force" the air through the system, this is why we have great people like Greenie so we can get maximum flow by using larger hoses and more efficient system to move the air more effectively.

I would like to hear someone else opinion on this:

4MP blower spun at max RPM of 3600 with 200' of 2.5" hose

4MP blower spun at the same speed with 200' of 1.5 hose

Now, Which one will read higher lift on the gauge?
Which one will move more air?

Hint: The answers to each of these questions are different.

I would like someone else with knowledge in this department such as Greenie or Les Jones to make some comments on what they think.

 

[The Cleaning Artist]

your still not getting it. In the scenarios you mention, the restriction is the hose size.

I WILL REPEAT, IN A FREE FLOWING SYSTEM, THE MOST RESTRICTION IS THE WCI. THE UNIT CAPABLE OF THE HIGHER LIFT WILL MOVE MORE AIR AT THE WCI!!!

Might Greenhorn or Matt splain it to ya!

Ok my last for tonight.

Two identical systems, both with 200 ft of same size hose, both running at the same rpm. One's relief is set at 20hg and the other at 15. Which one will move more air and pull harder to the carpets when the wand's glide makes contact to the carpet(WCI)?


GOODNIGHT!

 

[KBRENNY]

I have already come off in these post to be arguing with you and I do not want that. If you can, please explain it to me so I will understand.
This is what I understand now:
1. A blower moves the same amount of air per revolution
2. Once a blower is spinning at its highest RPM it is moving the most air possible
3. If there is no restriction in the system there will be much less lift than if there is a restriction
4. Restriction will cause a higher lift reading.
5. Restriction will reduce the Volume of air moving.

I agree that lift is important to get the water/dirt out of the carpet but once it is out of the carpet and in the hose it must travel to the recovery tank. Once inside the hose the lift does not help it travel through the hose, the CFM does.

I chose a 56 over a 59 when choosing blowers because the recommended lift rating on the 56 was considerably higher. I am not against lift but I believe increasing lift decreases volume.

If your vac relief valve is opening quite often when cleaning then you are definitely losing cfm. While I am cleaning my vac relief (16.5")very seldom opens and when it does it is for a very short time. A vac relief valve set at 20" would open much less and therefore lose less air flow to the hoses. My question would be where is the restriction enough to cause the vac levels to reach 20"? Even on CGD my vac relief seldom opens and my gauge is normally around 14" to 15".

Seriously, if I am wrong explain it to me so I can understand.

I mean that sincerely and that is why this board is so great. We can all learn from each other and become better carpet cleaners in the process.

 

[R W]

My Genesis 59 will bogg after reaching about 15hg or more, and it produces about 50 HP. It seems to run it's best at about 2600 rpm's and 12 hg.

 

[The Cleaning Artist]

RW in all seriousness, When the machine is out of warranty start eliminating all the restrictions in the plumbing you can. As you do this you will free up hp, cfm and available lift. You will also relieve un-needed strain on the belts, blower and engine for use when you need it. I looked at the 59 but it is underdriven and too restricted for my liking.


KB I typed two different pages and both were lost in cyberspace when I clicked submit. You can call me. 352-732-3855