# increasing engine rpm's ....is it worth it?



## nwcove (Mar 2, 2015)

thinking about spinning my chonda a bit faster than spec, its spec'd at the normal 3600 +/- 100 rpm, i'd like to let it run at 4000. not to worried about it grenading, but i do worry a bit about the added stresses on my old ariens . is it worth the extra 100 (?) impeller rpms, or will the result be lackluster.? 
:tempted:


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## ELaw (Feb 4, 2015)

I increased the auger + impeller RPM on an Ariens 32 I had a while back and it threw farther, but my goal was to try to make it process snow faster (so I wouldn't have to go in 1st gear with 6" of snow) and it didn't seem to help much. In that case I did it by replacing the pulley on the engine with a larger one.

But depending on what you call "older" I would not worry about stressing the machine too much. I put a 10 HP Honda motor on a 1960's Ariens that came with a 4 HP engine and with one exception it did just fine.

The exception was when I was seriously abusing it one time. It was spring and most of the snow had melted except this one large pile. I was trying to remove the pile (of repeatedly thawed and refrozen snow so very dense) and the wheels, with chains on them, were on dry pavement and getting incredible traction. So incredible in fact that both wheel hubs split where the keys were!

But honestly, and I know this is just opinion, I think the same would have happened with the original engine. The reduction ratio between the engine and wheels is such that if the friction disc is gripping well, the wheels can get a serious amount of torque.


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## YSHSfan (Jun 25, 2014)

What would be the torque at 4000rpm...? It is likely going to decrease I'd think.
Just like ELaw stated, I'd change the crank pulley to achieve a higher impeller speed.


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## Town (Jan 31, 2015)

The LCT 414 engine on my machine initially ran at 3,500 rpm and the impeller at about 1,040 rpm, but the spec is 3,600 +/- 100 rpm for engine and 1,083 rpm for the impeller. I increased engine rpm to 3,700 (top of stock spec) and the impeller rpm rose to 1,100 rpm. The most obvious improvement was in blowing the very wet slop (little snow and a lot of water) at the EOD without clogging. It does throw snow a little farther, but hard pieces of "ice" are thrown a lot farther so in an urban setting I have to be careful where the chute is pointed. I was going to increase the engine auger pulley from 2.75" to 3" but the dual pulley configuration is too difficult for me to carry out that change. 

The Ariens impeller is not wide enough to fill the 5" discharge opening with snow, so I widened the impeller at the end of last season and that improved the snow discharge volume. Engine speed is maintained under all conditions, so I am happy with all the changes.


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## ELaw (Feb 4, 2015)

Town said:


> ...I widened the impeller at the end of last season and that improved the snow discharge volume.


How did you do that?


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## Town (Jan 31, 2015)

ELaw said:


> How did you do that?


To correct my numbers: the stock impeller is 3.25" wide with a discharge opening width of 4.25". I widened the impeller to just over 4.5" wide with the side plate. The effective clearing width in the impeller housing from the back to just beyond the joint where the auger housing meets the impeller housing is 5".

Attached are some pictures showing stock setup and impeller mods. With the stock set-up you will notice that the paint is removed from the discharge opening only on one side after a year of use, the side closer to the engine. To make the impeller move more snow out the discharge throat the impeller can be widened and a side plate added to the side of the impeller at the auger.

The cup shaped impeller has an upward turn on the side of the impeller close to the auger. Bend that so it forms a gentler outward curve that extends the impeller width from 3.25" to 4.25" approx. Using an 1/8" thick angle iron bent to about 100 degrees, shape the end to match the curve of the impeller housing to allow 1/8" clearance to the raised auger side of the impeller housing. I used a piece of cardboard to fashion the curve and then transferred it to the metal. The 100 degree angle allows the new end plate to run at 90 degrees to the impeller housing, to keep snow from migrating into the auger housing on left side and making a mess. Drill 2 mounting holes in the end plates and hold them to the impeller with a locking pliers. Drill through the impeller blade and bolt together with two 1/4" bolts. You may need to adjust the curve of the end plate a little since my impeller housing is not perfectly round, an 1/8" clearance seems fine.

Hope this helps.


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## E350 (Apr 21, 2015)

Wow *Town*, that is a pretty cool mod! I read what you said about helping with wet snow. How about powder snow or medium density snow? Any improvement?

*ELaw* and *Town*, could you guys help this guy with recommendations for tires/chains etc. on his ST1032?

http://www.snowblowerforum.com/forum/ariens-snowblowers/98130-turf-saver-tyres-without-chains.html


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## Town (Jan 31, 2015)

E350 said:


> Wow *Town*, that is a pretty cool mod! I read what you said about helping with wet snow. How about powder snow or medium density snow? Any improvement?
> 
> *ELaw* and *Town*, could you guys help this guy with recommendations for tires/chains etc. on his ST1032?
> 
> http://www.snowblowerforum.com/forum/ariens-snowblowers/98130-turf-saver-tyres-without-chains.html


Not much dry powder last year, I had the widened impeller but not the side plates. There is improvement in all damp snow conditions and the EOD stuff ploughed up on the sidewalk but not sodden with the melt from salt and milder temperatures. In conditions where the EOD is just several inches of water it is all pumped a long way from the area to be cleared. So I think an overall improvement that you can actually see.


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## 43128 (Feb 14, 2014)

i have had the predator on my ariens 910018 running at 4400 rpm for about 2 years now. only mods are some cosmetic stuff and a richer main jet, in my case it made a huge difference in the machines throwing characteristics and it doesnt seem to be hurting the engine that is still running buttery smooth with no signs of wear, and the gearbox and chassis seem to be holding up fine as well, and even at 4400 rpms its still way quieter then my old hm80(or any tecumseh i have used or serviced for that matter)


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## e.fisher26 (Nov 6, 2016)

Theres a guy on YouTube that mounted rubber to the face of impeller paddles, to close up space between impeller paddles and drum wall. The result is NO clogs and throws slush and whatever he went through. Kinda same idea as what TOWN did just different placement.


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## nwcove (Mar 2, 2015)

e.fisher26 said:


> Theres a guy on YouTube that mounted rubber to the face of impeller paddles, to close up space between impeller paddles and drum wall. The result is NO clogs and throws slush and whatever he went through. Kinda same idea as what TOWN did just different placement.
> 
> 
> Sent from my iPad using Tapatalk


many members here have done the impeller mod, including myself, the overall performance gains are well worth it if your machines impeller to housing gap is 1/4 inch or more.


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## e.fisher26 (Nov 6, 2016)

What does everyone use for the rubber?




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## 43128 (Feb 14, 2014)

i use paddles for toro s200/s620 snowblowers, or if im scrapping out a single stage all pull the rubber off to reuse before scrapping it


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## Dauntae (Nov 10, 2016)

I'm planning to do this mod also, I have some rubber, Not sure which thickness to use though, I have 1/8 and 1/4 but thinking the 1/8 may be just enough to do the job.


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## ELaw (Feb 4, 2015)

I'd go with the 1/4" stuff. What would you gain by using thinner material?

My worry, if the rubber is spanning a large gap (which presumably it is or you wouldn't be installing it), is that under enough load the thinner material might bend backward at the outside edge and become less effective.


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