logsplitter engine and pump?

[kallaste]

I just bought a homade logsplitter to fix up and sell. It has a good running cast iron Tecumpseh 14hp, a pump apx 7" accross (26 to 30 gal pm?) and a dozer cylinder.
Problem: The starter will start the motor but not when it is linked to the pump. I have tried a proven starter from my buddies motor and get the same results. it wont hardly turn over. If I remove the sparkplug it will turn over good. I have removed the spool valve to eliminate it as a possible blockage and went from the resivoir to the pump and back to the resivoir so no pressure could build. It still acts the same way. Do I need a pull start on this? Anyone have any ideas. I am really starting to get frustrated!!!:bang:

 

[turnkey4099]

I just bought a homade logsplitter to fix up and sell. It has a good running cast iron Tecumpseh 14hp, a pump apx 7" accross (26 to 30 gal pm?) and a dozer cylinder.
Problem: The starter will start the motor but not when it is linked to the pump. I have tried a proven starter from my buddies motor and get the same results. it wont hardly turn over. If I remove the sparkplug it will turn over good. I have removed the spool valve to eliminate it as a possible blockage and went from the resivoir to the pump and back to the resivoir so no pressure could build. It still acts the same way. Do I need a pull start on this? Anyone have any ideas. I am really starting to get frustrated!!!:bang:

This is too obviouis for you to have overlooked but...

Have you eliminated a problem with the pump? Sounds like it is nearly seized up.

Harry K

 

[kallaste]

This is too obviouis for you to have overlooked but...

Have you eliminated a problem with the pump? Sounds like it is nearly seized up.

Harry K

I have checked it as best I could. I can turn it by hand and it seem smooth. what I dont know for sure is which way it is suppose to be turning. Also the pump says nothing on it as far as inlet, outlet,gpm or who makes it. I have a Swisher splitter w/a 5.5 honda 27 ton and the pump is 1/4 the size of the pump on the homade splitter. I could be wrong but I thought that a pump only starts building pressure when it reaches a cetain rpm?

 

[drmiller100]

pumps make pressure from the get go, but if you have ran the pressure side straigth to the tank, it shouldnt be plugged.

obvious stuff. battery reads 13 volts? good solid cables?
when you crank it over, feel for hot spots in the cables and terminals.

 

[oneadam12]

possible alignment problem when coupled up?

 

[ericjeeper]

Does it appear to have ever been used?

or is this something someone started and gave up on? Maybe you could move the pump and go with two v-belt pulleys and an idler. Disengage the idler to start then rev her up and slowly engage.

 

[kallaste]

This splitter was never put into service. The other owner said that the hp motor wasnt enought to run the pump. I know this isnt right. The motor is linked to the pump w/ a lovejoy connector. I loosened the pump thinking that maybe it was binding , but that wasnt the case. I may have to turn it into a belt drive or put a pull starter on it. Does it make any difference which way the pump turns? All electric connections are good and wire size is suitable. I am using an 800 cca battery out of my truck to try to start it.

 

[turnkey4099]

This splitter was never put into service. The other owner said that the hp motor wasnt enought to run the pump. I know this isnt right. The motor is linked to the pump w/ a lovejoy connector. I loosened the pump thinking that maybe it was binding , but that wasnt the case. I may have to turn it into a belt drive or put a pull starter on it. Does it make any difference which way the pump turns? All electric connections are good and wire size is suitable. I am using an 800 cca battery out of my truck to try to start it.

Yes it makes a difference which way it turns. The few I have worked with all turned clockwise when you are looking at the input shaft. They also had either arrows showing the rotation or the ports were marked.

There should be no drag...well only minimal...at start up with the valve in neutral. Pressure would only build when there is resistance in thesystem, i.e., vavle in forward and trying to split something.

Hmmm. Just re-read your OP.

Quoteroblem: The starter will start the motor but not when it is linked to the pump. I have tried a proven starter from my buddies motor and get the same results. it wont hardly turn over.

----- If I remove the sparkplug it will turn over good. --------

Now that is really strange. Why would a motor turn freely (connected to the pump) with plug removed but won't do it with plug in? Beats me.

Harry K

 

[Old_School_Nut]

This splitter was never put into service. The other owner said that the hp motor wasnt enought to run the pump. I know this isnt right. QUOTE]

what makes you think that? if its a big pump that came with the cylinder it might be to big, a pump that size that is one stage IS to big for that little engine. to much drag from the pump and the starter may not turn her over fast enough to get her to fire, or run. I would run her with the pump disconnected and see how she runs, work out any mixture problems,(make her run strong) then hook the pump back up and try to run her, a warm engine is also easier to start so if it now will run the pump you have an idea that it does not like the drag of the pump during startup. if you have time you could hook one end of the pump to a bucket of oil and turn the pump input shaft tell you fill one gallon. count the number of full rotations required to fill one gallon. with that you should be able to figure out how many GPM you will be pumping at full engine speed (more than likely 3,600 rpm), the math is simple. this works on a constant displacement gear or vane pump which i am betting yours is. once you find your GPM you can figure out your HP requirement for that pump, then you need to add buffer, i like to use 25% but many engineer's use a smaller number...

lets see some pics.


-Leo-

 

[kallaste]

This splitter was never put into service. The other owner said that the hp motor wasnt enought to run the pump. I know this isnt right. QUOTE]

what makes you think that? if its a big pump that came with the cylinder it might be to big, a pump that size that is one stage IS to big for that little engine. to much drag from the pump and the starter may not turn her over fast enough to get her to fire, or run. I would run her with the pump disconnected and see how she runs, work out any mixture problems,(make her run strong) then hook the pump back up and try to run her, a warm engine is also easier to start so if it now will run the pump you have an idea that it does not like the drag of the pump during startup. if you have time you could hook one end of the pump to a bucket of oil and turn the pump input shaft tell you fill one gallon. count the number of full rotations required to fill one gallon. with that you should be able to figure out how many GPM you will be pumping at full engine speed (more than likely 3,600 rpm), the math is simple. this works on a constant displacement gear or vane pump which i am betting yours is. once you find your GPM you can figure out your HP requirement for that pump, then you need to add buffer, i like to use 25% but many engineer's use a smaller number...

lets see some pics.


-Leo-

The 14 hp motor runs very good. I have tried warming it up and then linking it to the pump. I get the same results. I do have a twin cylinder 28 hp Kohler motor that I may have to use if I cant get a belt drive system to work or a pull starter. I will post Pictures soon as I get a chance to take some. Seems funny that the pump has no markings on it at all.

 

[Old_School_Nut]

The 14 hp motor runs very good. I have tried warming it up and then linking it to the pump. I get the same results. I do have a twin cylinder 28 hp Kohler motor that I may have to use if I cant get a belt drive system to work or a pull starter. I will post Pictures soon as I get a chance to take some. Seems funny that the pump has no markings on it at all.

yeah with a belt drive you can turn the pump at a lower speed and give the engine more leverage over the pump, what size pullys you need tho depends on how many GPM the pump pumps. its easier to do the math than go by trial and error...

if you use the 28 hp engine you still may not have the power to run it WELL when directly coupled if its a one stage pump.

like you i have a pump with no tags or anything, makes it a pain dont it...
good luck...

 

[sawinredneck]

Big pump, 14 horse motor, and a belt drive? This is getting better all the time! Pics indeed!! It sounds like the pump is way to big for the motor!

 

[Old_School_Nut]

Big pump, 14 horse motor, and a belt drive? This is getting better all the time! Pics indeed!! It sounds like the pump is way to big for the motor!

yeah, gets interesting don't it? would be less trouble to get the right sized pump... no belts to slip, wear out, no shafts to move around and get misaligned, no side load on the pump....

 

[JeffHK454]

Hyd. pumps make oil flow, resistance makes pressure. The pump or valve body should have a prevision to divert flow back to tank when fluid power is not needed.

Jeff

 

[turnkey4099]

yeah, gets interesting don't it? would be less trouble to get the right sized pump... no belts to slip, wear out, no shafts to move around and get misaligned, no side load on the pump....

Sorta getting sidetracked. Granted the motor might (probably is) too small but that doesn't have anything to do with the starting problem. With the valve centered (neutral) there should only be minimal drag on the motor. The oversize pump (load) would only apply when it was driving the cylinder.

.....

Hmm. I wonder if the valve is okay?...nope. motor plus pump spins freely without the plug in. Won't go with it in. This is one wierd problem.

Harry K

 

[kallaste]

Sorta getting sidetracked. Granted the motor might (probably is) too small but that doesn't have anything to do with the starting problem. With the valve centered (neutral) there should only be minimal drag on the motor. The oversize pump (load) would only apply when it was driving the cylinder.

.....

Hmm. I wonder if the valve is okay?...nope. motor plus pump spins freely without the plug in. Won't go with it in. This is one wierd problem.

Harry K

I eliminated the spool valve by tying the inlet and outlet to the spool valve together. fluid was being pumped from the tank thrue the pump and back into the tank , so the only restrictions could have been the hose size which is 3/4 inch.
I think I might put a pulley on the pump, run a belt from the pump to my wheelhorse tractor start the tractor, ingauge the clutch and see what happens. If my 10 Kohler on my tractor turns it, it may explain alot.

 

[sawinredneck]

I kinda get what you are saying Harry, but, if I am thinking this through, they may have a pulley reduction system on it, that waould increase the load as well. Without pics or a better description, it's kinda hard to know what really is going on!

 

[kallaste]

I kinda get what you are saying Harry, but, if I am thinking this through, they may have a pulley reduction system on it, that waould increase the load as well. Without pics or a better description, it's kinda hard to know what really is going on!

Currently the motor is linked to the pump with a lovejoy connector.
The system has no gear reduction on it. all the specifics were posted earlier.

 

[redprospector]

I'm betting that a smaller 2 stage pump would cure the problem. Your other splitter has a 5.5 hp engine, which means it has an 11gpm, or at the most a 13 gpm 2 stage pump. This old pump is 4 times that size, it could be a 30 gpm pump (who the heck knows). Believe it or not it takes a lot of energy to just pump the fluid through the neutral valve position, and back to the tank.
You really can't run a very big single stage pump with a 14 hp engine.

Andy

 

[Old_School_Nut]

I agree with the other guys, and untell you know how many GPM your pump is you will not know if you are waisting your time or not.

step one: do like I said in my past post and see how many times you need to turn the input shaft to get one gallon, I mark the shaft and housing with a marker, then I start pumping into one bucket with a drill to get the air out, then switch to another and start counting...

step two: plug it into this formula

HP required for a normal single stage gear pump= Flow rate(gpm) x system pressure(PSI) / 1714 x pump efficiency

For those of you following at home with a 2 stage, your hp requirement is 1/4 that of the one stage, or 25%, thus the beauty of a 2 stage...

most gear pumps are 85-95% efficient, if you do not know what your pump is then use 85% to be safe.....

Like I said before, I like to add 25% buffer to the final HP requirement, many people and enginears use less, like 20% it doesnt matter, the idea is just to give your engine a reasonable life span and give the operator faster speed (not as much bogging)

once you know your GPM you can figure the rest out...

BTW FYI, their are many gear pumps not rated for the max speed of most small geas engines, I have seen many for sale with a max speed of 2,000 RPM.

my pump:
128.57 turns=1 gallon
my engine runs at 3,600 RPM sooo

3,600 RPM / 128.57= 28 or in other words, 28 gpm easy ehh



-Leo-