Another Snowblower project

Tue Feb 09, 2010 7:13 pm

OK Fella's, I am on a quest to build a snowblower for my Cub. I picked up a JD 38" auger setup off of a JD lawn tractor. ($25, I couldn't not take it!) I am planning on using a Honda 8HP horizontal shaft motor and putting a pulley on the shaft to run the belt system of the JD auger. Does anyone have any idea what speed the auger should be running? I need to order a pulley for the Honda and want to get the right size. This should be a fun project, unfortunately we are scheduled to get 10-15" tomorrow, so I won't have it ready for that, but maybe the next one. Any suggestions or help would be appreciated. I was going to power it with a hydraulic motor, but to eliminate all of the hoses/plumbing I will fabricate the pulley system instead.

Re: Another Snowblower project

Tue Feb 09, 2010 8:21 pm


The impeller should be running about 1,000 rpm, auger about 300 rpm, if I remember correctly. Will search the posts and see if I can find it. Also, 3.5" pulley on the blower and 9" to 10" on the shaft. Let me verify that though..


Found it.... Snowblower Power

Rudi wrote:Eddie:

I just had a very nice conversation with Roger who has just come home from having his staples taken out. He had an full open field Gall Bladder surgery (not a laproscopy) on the 18th, and although he is recovering, he will be off of work for 4 - 6 weeks and then for the next 10-12 weeks is not able to lift anything. I was surprised he called back, but happy as well since he is sounding better than I expected.

He is quite familiar with what I am trying to do, and he tries to help me solve my puzzles. So.. Here is the gist of our conversation as it pertains to snow blowers and rpms.

Engines produce anywhere between 3,000 and 4,000 rpm at the shaft. Optimum rpms should be 3,200 to 3,400 rpm.

Typical pulley sizes on the shaft will be 3" to 3-1/2"
Typical pulley sizes on the cage will be 8" to 10-1/2"
Typically the reduction ratio will be on the order of 3 to 1 again depending on the size of the pulleys that manufacturers chose for each unit.

Discussing auger rpms.. Roger said that the auger rpms will be determined by shaft size, auger size and primarily gear reduction. Gear reduction can be nomially 2 to 1 for newer models and up to 4 to 1 for older models. This means that on average one should look for maximum auger rpms to be 500 rpm but more likely between 350 and 475 on the whole, again depending on which units are paired up.

I do not understand it all, but I got this much figured out. The 10 hp Tecumseh Sno King I have with a 3-1/2" pulley on the shaft mated to the 8-1/4" pulley on my cage with 16" augers, the older heavier 4 to 1 reduction should provide approximately 250 rpms at the auger. With the larger augers, he says I can actually reduce the size of the pulley at the cage to around 6" to increase the rpms without problem. No danger of blowing up the blower or the reduction unit.

Does that help?

Best I can do.. been trying for a long time to understand this and get answers. Most techs have no clue as to any of this, you really have to talk to the old timers.. so that is why it takes a while. I ain't no mechanic, :big give up: I just have a clue as to what I want to be able to do.. getting there however, it the real adventure :big smile: So far it has been at least a 2 year project with me, I want to be able to understand it and get it right. I don't want to blow anything up.

I sort of thought that the ratios between impeller and auger was more on the lines of 10 to 1, and mentioned it to Roger. He shot that one down real fast. That would make the the auger way too slow and could not provide enough snow to the impellers to actually move. On the older machines with the heavier gear reduction units, the ratios were 3 or 4 to 1 and the newer ones are closer to 2 to 1. Combine the smaller 12" auger size with the lower gear reduction ratios's and you can throw snow farther, in smaller volumes but farther.

I sure hope this is explained well enough.

Re: Another Snowblower project

Sat Feb 13, 2010 7:15 pm

Thanks so much for the info Rudi. That will be a big help. Surprised I didn't get much more response from this since we are all socked in with snow in one way or another. Well, I know you guys like pictures so we started the mock up today and made some good progress until dark. So these are just progress pictures, more to follow.And the wood 2X4's are just so we can get an approx. location for the engine. It will be mounted on a steel plate for the final set up. Hope they inspire others to jump in.

Re: Another Snowblower project

Sat Feb 13, 2010 8:06 pm

If you can't hit the blower auger to fan ratio correctly i seen the gravely tractors some with two different ratios. They were a 1 to 4 and a 1 to 10 on the similair two stage blower. I had a older gravely with the 7,6hp L engine with the 1 to 4 ratio open side blower and i could throw 4" of wet slush over the tops of the telephone poles it surprised all of us that day in the neighborhood. I actually ran the whole tractor into high drifts of snow with only the blown snow comming out of the drift with the handles sticking out.

Thats 1 turn of the auger to 4 turns of the fan that keeps the snow moving fast but it may load the newer engine more. The gravely's had very long connecting rods which means gobs of bottom end torque. The newer engines lack this torque feature. There more of a higher rpm engine now. All i'm saying is you made to adjust it so its right or you may hit it on the first shot. :D

I want a snowblower for my int154 with the creeper. I have a cub cadet 108 ready to go with the snowthrower on it but were not getting any deep snow now. I have 4 tractors set up with snow removal stuff and really no big blizzards yet. I guess i'm scaring the snow away.

Re: Another Snowblower project

Sat Feb 13, 2010 8:27 pm

David, looks like you're having fun and doing a great job. The only thing I can think of that may give you some issues----The one that George(IH48) had was hard to here the cub engine running slow, and the blower engine running fast. That darn cub engine is too quiet at idle. A low range unit would've been perfect. Maybe your Honda engine will solve the noise problem. Keep up the great fabricating and posting.


Re: Another Snowblower project

Sat Feb 13, 2010 9:24 pm

Rick, thanks for the tip! Hadn't thought of the noise problem yet! I may install a tach if I can find a 6volt one. I am away next week for school vacation and I am sure when I get back and finish it, we won't have any more snow!! Oh well, it is a fun project and I will be ready for next year. I will keep posting pics for those that are interested.

Re: Another Snowblower project

Sat Feb 13, 2010 11:03 pm


You are welcome. I am rather intrigued by what you have going here already. This is interesting. I for one will definitely be looking forward to more pics and narrative as you progress with this project. There have only been a few of these projects done that I know of, and I think Rick is the only one with a successful project on the forum so far. This looks well on the way to being the next one. :D