17 hp engine bogs down with my new pump. Do I need a bigger engine?

   / 17 hp engine bogs down with my new pump. Do I need a bigger engine? #1  

chad22

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Nov 19, 2010
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Location
Kansas
Tractor
Sears Garden Tractor
Hello. I bought this new pump on ebay and it is a bit bigger than the haldex I had. The shaft is actually a 5/8" diameter instead of 1/2" but that was no big deal as I went and got a 5/8" Jaw coupler.

The problem is it wants to bog down and almost kill the 17hp opposed cylinder engine that's currently on my home made excavator.

eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

Do you think I need an engine with more hp? If so how much hp do I need to run this pump? lol

The listing says it's an SAE AA mount. But looks more like an SAE A mount.

Here's the specs per the listing on ebay.

Specifications



Rated pressure: 2900psi.

Displacement .3759 cu. In/rev

Shaft: ス keyed. (actually 5/8")

Ports: G1/2 inlet: G3/8俳utlet.

Rated RPM: 2000, Max RPM 4000

Part Number CB1A-F6SA

I'm thinking it may be a bit big for my 17hp engine to pull. But wanted to find out.

Thanks

Chad
 
   / 17 hp engine bogs down with my new pump. Do I need a bigger engine? #2  
A .4 cu in pump running at 3600 will produce about 5.5 GPM.

5.5 GPM at 2900 psi only requires about 11 HP.

You should be able to pump 8.5 GPM with a 17 HP engine using a .5 cu in pump at 3600 rpm and 3000 psi
 
   / 17 hp engine bogs down with my new pump. Do I need a bigger engine? #3  
Is the rotation of the pump the same as the old one?
 
   / 17 hp engine bogs down with my new pump. Do I need a bigger engine? #4  
What psi did you set the relief pressure?

If you run that pump at 2000 rpm, you will pump 3.25 GPM.

At a pressure of 2900 psi, it will take 6 HP

Have you install a hyd gage in the system?

What was the cu in of the pump you had before?

Was it a two stage?

What is the model number of the Haldex pump
 
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   / 17 hp engine bogs down with my new pump. Do I need a bigger engine? #5  
What psi did you set the relief pressure?

I was just coming back to ask that!
Chad, if you don't have a hydraulic gauge, go buy one. JJ told me to get one a year or so ago, I finally picked one up last month, and it can tell you a lot diagnostically.
 
   / 17 hp engine bogs down with my new pump. Do I need a bigger engine?
  • Thread Starter
#6  
Thanks for the help. Good to hear that the pump should work with my engine. I do have a hydraulic gauge. I ordered it quite awhile back. I never did get it hooked up though and have since misplaced it somewhere at our shop. :laughing:

I went searching for it today but couldn't spot it. If I can't find it I'll just get another one when I go to town probably Monday.

By the way. Where in the hydraulic circuit should I hook the gauge?

I'm not sure on the cu of the Haldex pump but will have to see if I can get some numbers off of it. I do know it was a single stage pump though.

Chad
 
   / 17 hp engine bogs down with my new pump. Do I need a bigger engine?
  • Thread Starter
#7  
   / 17 hp engine bogs down with my new pump. Do I need a bigger engine? #8  
I was also wondering about open center pump and closed center valves. When does it try to kill the motor? When does the pump try to kill the motor, is it when you pull a valve lever or just starting the engine up? With a bigger pump, how about hoses striating the flow? Just scratching my head here...
 
   / 17 hp engine bogs down with my new pump. Do I need a bigger engine?
  • Thread Starter
#9  
I was also wondering about open center pump and closed center valves. When does it try to kill the motor? When does the pump try to kill the motor, is it when you pull a valve lever or just starting the engine up? With a bigger pump, how about hoses striating the flow? Just scratching my head here...

The motor runs fine when starting up and as long as no valves are moved. It's just as soon as you pull a lever on the valve it sometimes bogs down and other times it just just wants to die.

Chad
 
   / 17 hp engine bogs down with my new pump. Do I need a bigger engine? #10  
You haven't told us what machine this motor and pump is on.

Can you post the flow path from pump to tank?

You can't mix open center hyd systems and closed center valves, as the open center valves passes the fluid from pump to tank with all valves in neutral.

Closed center hyd fluid flows to the valve and stops, waiting on a lever to direct flow, and then the used fluid is sent to tank.
 
 
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