Bobcat 630 Wisconsin VH4d with tapered shaft repower

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simply_peter

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Has anyone done a swap with a tapered shaft engine? I was thinking about getting a 31 HP Vanguard engine from small engine warehouse but the wisconsin has a tapered shaft and the Vanguard has a 1-1/8" shaft Has anyone fabbed up a 1-1/8" shaft to tapered shaft adapter? I was thinking about taking a 1-1/8th collar and welding it to some stock rod that was milled to the taper on the wisconsin moter. One other idea I had was to swap the pump from the 630 with a pump from a different model with a keyed shaft but this might be more complicated and expensive. I haven't taken anything apart yet and I don't have a parts diagram so at this point I haven't got a good look at the pump side of the motor and the pump setup. Does anyone have any advice or experience with this swap?
 

Tazza

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You should be able to get an arbor to change the shaft to the required mount for the new engine. If not, i can't see why you can't fab something up to take the shaft from the new motor. I wouldn't suggest swapping pumps, you should however be able to find another device to link the pump to motor. I'd suspect the pump has either a parallel key'd shaft or a taper key'd shaft. Both *should* be a standard taper. The 2 pump styles i have seen were a taper with a key.
Sorry i can't give you a definite answer on what to do...
 

jerry

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You should be able to get an arbor to change the shaft to the required mount for the new engine. If not, i can't see why you can't fab something up to take the shaft from the new motor. I wouldn't suggest swapping pumps, you should however be able to find another device to link the pump to motor. I'd suspect the pump has either a parallel key'd shaft or a taper key'd shaft. Both *should* be a standard taper. The 2 pump styles i have seen were a taper with a key.
Sorry i can't give you a definite answer on what to do...
That motor coupling is one thing that is not covered at all in my bobcat book. It must be a double u-joint same as the 632 or 631 as under engine removal it says "move engine back until drive coupling disengages". On the 632 the engine is connected to the u joint by a adapter block and it shouldn't be to hard to change the adapter from one engine style to another. Too bad the book does not cover this coupler.
 

bingo

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That motor coupling is one thing that is not covered at all in my bobcat book. It must be a double u-joint same as the 632 or 631 as under engine removal it says "move engine back until drive coupling disengages". On the 632 the engine is connected to the u joint by a adapter block and it shouldn't be to hard to change the adapter from one engine style to another. Too bad the book does not cover this coupler.
I have a 630 bobcat with a vh4d1 engine and want to swap it out to another engine,but dont know what you are talking about when you say a tapered shaft,mine comes out the engine to a u-joint hook up i think but i could be wrong. could you explain or post a photo.for me please. thank you
 

Tazza

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I have a 630 bobcat with a vh4d1 engine and want to swap it out to another engine,but dont know what you are talking about when you say a tapered shaft,mine comes out the engine to a u-joint hook up i think but i could be wrong. could you explain or post a photo.for me please. thank you
I think he is talking about the shaft from the engine to the U-joints. How is yours coupled to the engines shaft?
 
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simply_peter

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I have a 630 bobcat with a vh4d1 engine and want to swap it out to another engine,but dont know what you are talking about when you say a tapered shaft,mine comes out the engine to a u-joint hook up i think but i could be wrong. could you explain or post a photo.for me please. thank you
Mine is still assembled so I don't have any pictures. I have checked with a few people on replacement options and that is how I found out about the tapered shaft. As I understand it the back side of the motor has a shaft that is tapered instead of round with a key. The tapered shaft is what is inside of the u-joint hook up that you are talking about. When you separate the motor from the u-joint you should see the tapered shaft. When you replace the motor you either need to find one with a tapered shaft that matches the u-joint and you will have to reconstruct the u-joint so it will attach to the new motor. Or find something that you can swap with the existing u-joint. I was planning on reconstructing the u-joint, but I haven't taken mine apart and I don't have any manuals showing the parts. Is yours still running? Have you found a replacement motor yet or started to take it apart. Mine is still running it is hard to start and sometimes I have to run it with the choke on to keep it going. I had a mechanic look at it last fall and got it running but I hate to keep putting money into a 31 year old motor and I wouldn't mind getting one with a little more power. The motor is still in so I don't have any pictures to share. I wanted to figure out what to do with the shaft before I take it out of commission and spend the $ on a motor. Does this help? Where are you located? I have a lead on a possible motor here in town and they offer machine services so I am going to see if they could modify the shaft. They are out of town this week so if I find out more I will let you know.
 

bingo

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Mine is still assembled so I don't have any pictures. I have checked with a few people on replacement options and that is how I found out about the tapered shaft. As I understand it the back side of the motor has a shaft that is tapered instead of round with a key. The tapered shaft is what is inside of the u-joint hook up that you are talking about. When you separate the motor from the u-joint you should see the tapered shaft. When you replace the motor you either need to find one with a tapered shaft that matches the u-joint and you will have to reconstruct the u-joint so it will attach to the new motor. Or find something that you can swap with the existing u-joint. I was planning on reconstructing the u-joint, but I haven't taken mine apart and I don't have any manuals showing the parts. Is yours still running? Have you found a replacement motor yet or started to take it apart. Mine is still running it is hard to start and sometimes I have to run it with the choke on to keep it going. I had a mechanic look at it last fall and got it running but I hate to keep putting money into a 31 year old motor and I wouldn't mind getting one with a little more power. The motor is still in so I don't have any pictures to share. I wanted to figure out what to do with the shaft before I take it out of commission and spend the $ on a motor. Does this help? Where are you located? I have a lead on a possible motor here in town and they offer machine services so I am going to see if they could modify the shaft. They are out of town this week so if I find out more I will let you know.
mine was doing to same thing, that yous is and it went south or quit running, it first blowed both head gaskets and i replaced them and torqued them down and tryed to start it but it would not start so i took a compression test and 1 and 2 cyl has only about 40-45 lbs and 3 has 70 lbs. and 4 has 60 lbs not enough to start it it was running real bad before that too.thinking about replacing it with another but dont know what engines will work in it this is the first skid loader i have ever owned and it has the wisconsin vh4d1 in it also. im like you dont want to sink a lot of money in this engine when theres better engines out there that are a lot cheaper and parts for them are cheaper to replace..so if you know of any engines that will work let us know... open for all options...I would think the u-joint issue could be fixed to connect to about any engine but im just guessing....
 
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simply_peter

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mine was doing to same thing, that yous is and it went south or quit running, it first blowed both head gaskets and i replaced them and torqued them down and tryed to start it but it would not start so i took a compression test and 1 and 2 cyl has only about 40-45 lbs and 3 has 70 lbs. and 4 has 60 lbs not enough to start it it was running real bad before that too.thinking about replacing it with another but dont know what engines will work in it this is the first skid loader i have ever owned and it has the wisconsin vh4d1 in it also. im like you dont want to sink a lot of money in this engine when theres better engines out there that are a lot cheaper and parts for them are cheaper to replace..so if you know of any engines that will work let us know... open for all options...I would think the u-joint issue could be fixed to connect to about any engine but im just guessing....
I have been looking at the 31HP Vanguard engine and the other one I am checking on is a 30HP Generac motor. I would also consider a diesel, but I can't find a deal on one to make it worth doing. The best price I have found on the 31 HP is around $1799 with exhaust. I think the motor will be shorter with any of the options so one other thing you may want to plan on is making a stand to lift the motor up and adapt it from the current bolt pattern. One thing I have noticed is that while the HP numbers are higher on these motors the torque foot lbs seem to be lower than the Wisconsin engine. Should this be a concern? Does anyone know if the u-joint is tapered on the pump side or if it is a keyed shaft? I wonder if you could use the shaft from a similar model?
 
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simply_peter

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I have been looking at the 31HP Vanguard engine and the other one I am checking on is a 30HP Generac motor. I would also consider a diesel, but I can't find a deal on one to make it worth doing. The best price I have found on the 31 HP is around $1799 with exhaust. I think the motor will be shorter with any of the options so one other thing you may want to plan on is making a stand to lift the motor up and adapt it from the current bolt pattern. One thing I have noticed is that while the HP numbers are higher on these motors the torque foot lbs seem to be lower than the Wisconsin engine. Should this be a concern? Does anyone know if the u-joint is tapered on the pump side or if it is a keyed shaft? I wonder if you could use the shaft from a similar model?
One more concern I noticed is that the Wisconsin engine is 500 LBS while these v-twin replacement options are closer to 125 lbs. Will I need to add weight in the rear to keep the balance and tipping loads close to the same? There is a Generac motor on ebay for $1800 that is rated for 40 HP that I think would be my choice if I go with the swap. bingo: Do you have plans yet to pull your motor? I haven't touched my since I still need to use it. Just curious to hear if you learned more about the connections to the pump. I found where you can buy a keyed coupling so I was thinking about welding a short rod to the end of it and machining a taper on it to match the end of the taper on the engine. That way it would still use the same connections as the old motor. Just a first idea, still not sure what's best since I don't know for sure what it looks like.
 

Tazza

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One more concern I noticed is that the Wisconsin engine is 500 LBS while these v-twin replacement options are closer to 125 lbs. Will I need to add weight in the rear to keep the balance and tipping loads close to the same? There is a Generac motor on ebay for $1800 that is rated for 40 HP that I think would be my choice if I go with the swap. bingo: Do you have plans yet to pull your motor? I haven't touched my since I still need to use it. Just curious to hear if you learned more about the connections to the pump. I found where you can buy a keyed coupling so I was thinking about welding a short rod to the end of it and machining a taper on it to match the end of the taper on the engine. That way it would still use the same connections as the old motor. Just a first idea, still not sure what's best since I don't know for sure what it looks like.
It won't simply tip over, it will lower the ROC of the machine though with less weight in the rear. This will also depend on how far back the engine sits. You could always add a little weight at the back to counteract this.
The replacement engine thats rated at 40HP sounds like it will be way over powered, at least you shouldn't be able to stall it.
As for the shaft, if you are going so far as to weld to it, I'd machine it parallel so its a *standard* mount for the new engine. Matching a taper isn't as simple as it may first appear....
 
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simply_peter

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It won't simply tip over, it will lower the ROC of the machine though with less weight in the rear. This will also depend on how far back the engine sits. You could always add a little weight at the back to counteract this.
The replacement engine thats rated at 40HP sounds like it will be way over powered, at least you shouldn't be able to stall it.
As for the shaft, if you are going so far as to weld to it, I'd machine it parallel so its a *standard* mount for the new engine. Matching a taper isn't as simple as it may first appear....
The foot pounds of torque on the v-twins are much lower than that of the VH4D. That was the reason for the increase in HP. I probably just need to wait to see what it looks like and see how it goes together before I figure out the shaft.
 
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simply_peter

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The foot pounds of torque on the v-twins are much lower than that of the VH4D. That was the reason for the increase in HP. I probably just need to wait to see what it looks like and see how it goes together before I figure out the shaft.
I found a VH4d motor with less than 100 hours that I can get for under half the price of a v-twin. Is it worth trying to change motors when I can can just replace for less money. I only use this bobcat at home so I don't rely on it for income. I would like to have more reliable starting especially in the winter, but I am not sure if that's a low compression issue or just reality running a 30 year old motor.
 

Tazza

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I found a VH4d motor with less than 100 hours that I can get for under half the price of a v-twin. Is it worth trying to change motors when I can can just replace for less money. I only use this bobcat at home so I don't rely on it for income. I would like to have more reliable starting especially in the winter, but I am not sure if that's a low compression issue or just reality running a 30 year old motor.
From what i was told, the VH4d is an excellent engine. If the old one lasted 30 years, thats pretty good!
I personally would keep it original, saves a lot of hassles.
 
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simply_peter

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From what i was told, the VH4d is an excellent engine. If the old one lasted 30 years, thats pretty good!
I personally would keep it original, saves a lot of hassles.
I just did a compression test on my current engine. I had two cylinders at 90, one at 80, and one at 60. Does anyone know what they should start out as? I am guessing the 60 is the one causing my problems... Sorry for all the questions but this has been very helpful! p.s. how do I skip a line when I type?
 

Tazza

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I just did a compression test on my current engine. I had two cylinders at 90, one at 80, and one at 60. Does anyone know what they should start out as? I am guessing the 60 is the one causing my problems... Sorry for all the questions but this has been very helpful! p.s. how do I skip a line when I type?
I believe the "normal" range for a petrol engine is about 120PSI and they have to be within i *think* 15% of each other.
Your 60PSI pot does sound like its your problem, a new set of rings or a valve job may get you out of trouble, but you need to measure the bores to know where you stand.
Click on your profile and where it says use Use HTML editor (free text box), click that box and your paragraphs will work.
 
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simply_peter

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I believe the "normal" range for a petrol engine is about 120PSI and they have to be within i *think* 15% of each other.
Your 60PSI pot does sound like its your problem, a new set of rings or a valve job may get you out of trouble, but you need to measure the bores to know where you stand.
Click on your profile and where it says use Use HTML editor (free text box), click that box and your paragraphs will work.
Does anyone know how long the shaft is on the Bobcat version of the VH4D? Is it the same shaft for all 600 series? 600, 610, 630? I found a deal on a low hour motor, but it's a military version with a tapered shaft. The shaft is 5 inches long and I think the bobcat version is closer to two inches. Does anyone know?
 

BobMelroe

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Does anyone know how long the shaft is on the Bobcat version of the VH4D? Is it the same shaft for all 600 series? 600, 610, 630? I found a deal on a low hour motor, but it's a military version with a tapered shaft. The shaft is 5 inches long and I think the bobcat version is closer to two inches. Does anyone know?
Going from memory I want to say 2-3/4 - 3-1/4, somewhere around there. That's about what the VF4D in my 600 was anyway. Just a stubby little thing. I swapped the VF4D out for a straight shaft engine and bored the variable pitch sheave out to accept it. Just had to cut the shaft on the engine to the same length. Hope this helps :/
 

sterlclan

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Going from memory I want to say 2-3/4 - 3-1/4, somewhere around there. That's about what the VF4D in my 600 was anyway. Just a stubby little thing. I swapped the VF4D out for a straight shaft engine and bored the variable pitch sheave out to accept it. Just had to cut the shaft on the engine to the same length. Hope this helps :/
the shaft on my 630 is straight with a key about 2.5 inches long
 

tsanders

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the shaft on my 630 is straight with a key about 2.5 inches long
the coupler on my 632 bolts to the engine flywheel and slides onto the splines of the pump. i have the 4cyl ford engine but a friend has a 4cyl wisconsin engine on a bobcat,trencher and a waterpunp and he swears by them. like tazz says it would be easier to stay orignal than to rigg something up. ps your 630 dosen't have a place for a radiator. good luck any way you go.
 
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