Engine Pulley difference

[bizon 30]

Hi everyone, when surfing on different forums and websites i came on a topic where someone sayed that the enginepulley of a hydro is a5" and a manual belt gearbox is a4"  

i' m  speaking about a 416-8  

 

now before buying another pulley i would ask the experts first so i anyone will set this straight ? 

 

Or another example of a bit larger pulley?  I want to speed it up a bit with a vario pulley on the tranny  and a bit larger on the engine   Not to much it is not a racer but driving half a mile on high enginerpm isn't very pretty 😊

[ebinmaine 68,401]

I don't know the exact sizes but that information is just about correct.

One thing to remember is that the belt guard system must still be usable or you're clutching mechanism as a whole might not work correctly.

You can only get away with a slight increase in size on the engine pulley without needing to modify the belt guard so that it will still maintain status as a belt guide.

 

It might be easier and less expensive 2 shrink the size of the transmission pulley instead of increasing the size of the engine pulley.

There are sheave and pulley size and RPM calculators online that will help you get to your desired level of speed.

 

 

 

[bizon 30]

@ebinmaine thnx !   I was first thinking to only chanche the rear (gearbox side)pulley  but  it seems to do less than we expect .. ?  With that websites you can calculate the ratio but  there still is the gearbox  wich cange a lot..  

 

i was thinking trying t9 mount a variable pulley from a mtd on the gearbox   They have 5-7 levels  so if i put it in 2nd  and than mount the belt like it should with the original clutch   It must work .. i guess/hope ?   Just to become that i can put it in gear, drive and speed up by shifting gears while driving (shifting the vario i mean)  

 

we will go driving on  road conditions with 2  the other one has a mtd so he can shift while driving  much more comfotable and quicker..  

[ebinmaine 68,401]

I'm quite curious to see what you come up with.

 

Please post what your results are.

 

As far as the use of the pulley calculator, I would stick to the final drive ratio, so to speak.

if you know that the tractor will do 7 miles per hour let's say. Try to find a pulley that will make it do 10 or 11. Doesn't sound like much but that's a huge increase.

 

I'm not familiar with that variable pulley. If you wouldn't mind, post some pics of it. Sounds interesting.

[Achto 27,795]

@bizon I've thought of trying a similar thing with a . My thought was to adapt a variable-drive from a John Deere or Massey Ferguson garden tractor. This would allow me to select a gear on the original transmission and then have multiple selections on the variable drive. Unlike the  transmission, which should only be shifted when the tractor is at a complete stop. The variable drive can be shifted while in motion.

 

 

[bizon 30]

@ebinmaine i will do !  And i also go search and try a calculator  but ihere in belgium it is hard to find pieces without partsnr   So i prever to use original parts so i can order them by a dealer without questions like why changing...  

 

@Achto  john deere or massay are very rare out here  do you know how it works ?  I have seen one on the internet for sale with this system and that is where i stole the idea 😎

[Achto 27,795]

2 hours ago, bizon said:

 I have seen one on the internet for sale with this system and that is where i stole the idea

 

It uses a double taper idle pulley between the engine and transmission. The center piece on this pulley can move side to side. As you move the pulley away from the engine it force that belt down towards the center on one side of the pulley. This make the belt from the idler to the transmission climb to the outside on the other side of the pulley.

 

Maybe this video can explain it better than I can.

 

 

Edited April 11, 2019 by Achto

[Achto 27,795]

@bizon Adding a vari-drive would be a fun project, that will take some time. If you are just looking for a higher road gear, I would probably change to a smaller pulley on your transmission. If you do this you will have a faster tractor and you should not have to alter the belt guard. I think it would make the low range gears a bit more useable also.  

[ebinmaine 68,401]

1 minute ago, Achto said:

@bizon Adding a vari-drive would be a fun project, that will take some time. If you are just looking for a higher road gear, I would probably change to a smaller pulley on your transmission. If you do this you will have a faster tractor and you should not have to alter the belt guard. I think it would make the low range gears a bit more useable also.  

I agree with that. That's what I would do as well.