# More power!!!



## tsolisva (Feb 13, 2014)

Gents, I have an Ariens Model ST524 with a very old and tired 5 HP engine. I am considering buying a replacement engine and would like to increase the power output. How big of an engine can I buy to replace the current 5 HP. I was thinking about a ~ 8 HP engine. Does anyone know if the bigger engines will fit on the older ST524s? Any pitfalls to look out for? Is buying a bigger motor a bad idea?


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## Jackmels (Feb 18, 2013)

Predator 6.5 from Harbor Freight should be a relatively easy swap with Plenty of Power. You will, however need to get a sleeve from the hardware store, as you will need a 1" crank size to use the existing pulley on the original engine.
Grind a keyway in the sleeve and fab a larger key to bridge the crank, sleeve and pulley. These Engines work Great. I've done Many Repowers using this Engine. Inexpensive as well, $89 with this coupon.
http://www.dealsoff.com/images/habor-freight-0414.jpg


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## Shryp (Jan 1, 2011)

I would think the 5 HP ones would have a 3/4" crank to begin with, but Jackmels does this on a daily basis so he probably knows what he is talking about. Make sure your 5 HP engine is only a single shaft one as well.


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## scipper77 (Dec 4, 2013)

Thought the mid 70's Ariens used the same tractor section for all motors. For a situation like that I would say you could put up to an 8 horse on and not even be abusing the unit. However, I believe units with st designations are 1980's machines (starting around then that is). That means you might have two output shafts. It also means the units might self destruct if designed for 5 horse and supplied with 8. I wouldn't put more than a 6.5 predator on there or a 7 HP Tecumseh. 

Remove your shear pins and check to see if your augers are frozen to the shafts before you overpower the unit. If the augers are free then in theory your shear pins will fail before your gears are destroyed.


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## Jackmels (Feb 18, 2013)

The ST's use a 1" Crankshaft with Double Pulley. Even the 5hp is a 1" Crank.


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## scipper77 (Dec 4, 2013)

Jackmels said:


> The ST's use a 1" Crankshaft with Double Pulley. Even the 5hp is a 1" Crank.


Just to be clear for my sake. You are saying one output shaft with a double pulley and not two output shafts (Crank and Cam) with one pulley each.


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## HillnGullyRider (Feb 9, 2014)

I hope that is not a double shaft machine (pulley on the camshaft)


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## Jackmels (Feb 18, 2013)

ST Machines I've worked on have a 1"crank that used one double pulley on it. I'd say a rule of thumb is if it has the metal gear and worm style crank for the auger chute, it would have a single 1" Crankshaft. I have seen some double shaft configurations that were on later machines, but I think that started about the time the Auger Crank was attached High on the Chute rather than the low metal gear and worm.


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## scipper77 (Dec 4, 2013)

So its looking good for a predator conversion. I have yet to see anyone that is unhappy with a predator.


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## tsolisva (Feb 13, 2014)

Jackmels, How big is the Predator shaft (diameter)? Smallenginewharehouse.com sells conversion sleeves, with keys, so I need to know if I can buy one to fit the new engine and the existing pulleys.


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## nt40lanman (Dec 31, 2012)

I believe the predators are 3/4.


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## nt40lanman (Dec 31, 2012)

Now, being as you're going to throw more HP on there, and there's a shaft size difference, you *could* get individual pulleys, getting a slightly larger one for auger drive. That would speed it up and throw more snow more faster!! .


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## tsolisva (Feb 13, 2014)

Another quick question. I've noticed many older snow blower engines do not have an air filter. Why do they not have air filters? That always puzzled me. If I buy the Habor Freight Predator and it has an air filter, can I remove the breather element for snow blower usage? Thanks.


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## scipper77 (Dec 4, 2013)

Boats and snow blowers do not need air filters because they operate in an environment free from dust. You can keep the air filter in the predator if you like but there is no use for it.


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## danwinget (Feb 15, 2014)

*dual shaft conversion??*

Are you saying you can use a single shaft motor with pulleys to replace a dual shaft motor?


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## Jackmels (Feb 18, 2013)

tsolisva said:


> Jackmels, How big is the Predator shaft (diameter)? Smallenginewharehouse.com sells conversion sleeves, with keys, so I need to know if I can buy one to fit the new engine and the existing pulleys.


Predator is 3/4. ST pulley requires 1". If you need a double shaft engine, you can take the camshaft and side cover and use them in another similar engine to create a double shaft configuration. OR Scrap the thing and start Anew with something else.


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## nt40lanman (Dec 31, 2012)

Did Ariens use any double shaft motors? I've never seen it.


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## Shryp (Jan 1, 2011)

nt40lanman said:


> Did Ariens use any double shaft motors? I've never seen it.


For the compacts.


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## HillnGullyRider (Feb 9, 2014)

nt40lanman said:


> Did Ariens use any double shaft motors? I've never seen it.


Yes they certainly did, and on the models that used it, the drive spins counter clockwise (when viewed standing at the handles) so If repowered with a single shaft motor, one would end up with a machine with 5 reverse gears and only one forward (slow). The 932 3-5hp (small blocks) Tecumseh used dual output shafts in the 70's and 80's.


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## Toro-8-2-4 (Dec 28, 2013)

tsolisva said:


> Another quick question. I've noticed many older snow blower engines do not have an air filter. Why do they not have air filters? That always puzzled me. If I buy the Habor Freight Predator and it has an air filter, can I remove the breather element for snow blower usage? Thanks.


 My understanding for eliminating the filter is that it may collect water/snow and freeze impeding air flow. 
There are also heat boxes around the governor linages to prevent ice/snow from causing problems.

For those folks with experience using the Preditor engines as substitutes, has ice/snow build up on the linkages ever been an issue?

Thanks for sharing your experiences.


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## Shryp (Jan 1, 2011)

Toro-8-2-4 said:


> My understanding for eliminating the filter is that it may collect water/snow and freeze impeding air flow.
> There are also heat boxes around the governor linages to prevent ice/snow from causing problems.
> 
> For those folks with experience using the Preditor engines as substitutes, has ice/snow build up on the linkages ever been an issue?
> ...


Never an issue for me with no heat box added and air filter left in place.


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## scipper77 (Dec 4, 2013)

Shryp said:


> Never an issue for me with no heat box added and air filter left in place.


I second, no issues for me. I run with no air filter.


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## Jackmels (Feb 18, 2013)

Had 4 issues with Predators out of say, 50 swaps (20 or so Greyhound, which was the Previous Model)
1 Predator had no spark out of the box. 2 I had one carb float freeze, which flooded the entire motor. Motor was 1 week old, just returned it for another, rather than work on it.
3 Customer left old gas over the summer, and pulled the recoil until it broke.
4 Had one Greyhound Recoil break as well, I now keep a spare on hand. That machine was left outside uncovered-didn't help matters.


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## tsolisva (Feb 13, 2014)

*Predator in the House*

Gents,
I ordered the HF Predator and it showed up today...a day after the big east coast storm.  Anyway, I need to order the crank sleeve/key and the install begins. Does anyone have recommendations/gotchyas for the sleeve installation? I haven't found an exact fit but I was thinking about buying a 3 inch sleeve and cutting it down to size.


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## Jackmels (Feb 18, 2013)

I get Bronze sleeves Right out of the Drawer at my local hardware store for around 4-5 bucks. I make keys out of scrap using my Angle grinder.


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