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Anybody with any other size engine, 208cc and up, that suppose to run at 3850 + - 50 rpms at no load, have a tach to verify that it does??...Just irks me why the 254cc is set lower at 3600......Never got a answer back from LCT...
 

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Anybody with any other size engine, 208cc and up, that suppose to run at 3850 + - 50 rpms at no load, have a tach to verify that it does??...Just irks me why the 254cc is set lower at 3600......Never got a answer back from LCT...
The spec's for the LCT engines specify 3,850 +/- 50 rpm as the governed engine speed. Ariens use the LCT engine but spec it as 3,600 +/- 100 rpm. I have a 2015 model year 414cc AX engine that ran at 3,450 rpm when new so I bumped the governor up to 3,700 rpm in the first year. Subsequently to 3,900 rpm for the last several years. Those measurements were with a laser tach. For this season I added a Runleader hour/tach that also shows 3,900 rpm and how the rpm drops under load. Attached is a pic.
1 Tach on 17 Jan 2021.JPG


The machine has just over 50 hours on it this season so far, but the snow is half the normal amount this season.
 

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My 2018 Deluxe 28 SHO has 306cc and runs at 3600 RPM (Runleader tach installed).

This was the factory setting. I have not adjusted the speed, as I am happy with the performance of the machine at 3600.
 

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A person could twist up the revs on the 254cc and see how it goes. It most likely will be just fine. If things go badly and the experiment ends with a loud noise which followed by a long quiet noise, then I see a guy on Ebay sells new 254 LCT engines for $179 with free shipping.
 

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Discussion Starter #5
The spec's for the LCT engines specify 3,850 +/- 50 rpm as the governed engine speed. Ariens use the LCT engine but spec it as 3,600 +/- 100 rpm. I have a 2015 model year 414cc AX engine that ran at 3,450 rpm when new so I bumped the governor up to 3,700 rpm in the first year. Subsequently to 3,900 rpm for the last several years. Those measurements were with a laser tach. For this season I added a Runleader hour/tach that also shows 3,900 rpm and how the rpm drops under load. Attached is a pic. View attachment 176380

The machine has just over 50 hours on it this season so far, but the snow is half the normal amount this season.
Well looks like yours was set at 3600 org. but the spec. is 3850..,so we will never know the real story behind this..Did you notice any difference from the org. setting to what you increased it to?...
 

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My understanding is that at higher revs, the engine oil system becomes ineffective so you run the risk of a connecting rod failure (?). :unsure:

I have set my predator engine at 3900 RPM, figuring a $120-ish replacement cost will not be the end of the world.
 
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Most snow blower engines run at 3450-3600 rpm. That is where they produce the most power and won't blow up. Now, a modern engine will make some more power above 3600rpm (I would say another 1/2 horsepower at most), but you are running into the risk of it blowing up. If not, it is not good for any engine to run at extremely high rpm. They will wear out faster. Also, the bigger the engine, the less you can rev it. At rpm above 3800, it is very likely that you will see a power drop, not a power gain.

But, why are we making our engines rev higher? Simply, it is the cheapest way to gain more performance. It turns the impeller faster, which throws snow farther. I don't think it will make your engine bog down less. If there is any power gain, you would be using it to turn the impeller instead.

Most engines can rev above 3600 rpm just fine, but for how long? Even my Tecumseh 8hp flathead is running okay at 3670 rpm.
I think Town is a little crazy with his engine rpm, but his engine, he does what he wants. You want to follow him then go ahead. When we do that, we are ready for a new engine.
 

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As far as ariens having 3600 rpm specs. Might be because ariens machines carry over engineering from previous models that were designed with 3600 rpm tec motors.


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Well looks like yours was set at 3600 org. but the spec. is 3850..,so we will never know the real story behind this..Did you notice any difference from the org. setting to what you increased it to?...
Yes, I was disappointed with the performance at 3,450 rpm, it felt weak. Increased the rpm to 3,700 and there was a profound improvement in snow throwing. Increased the crank mounted impeller pulley from 2.75" to 3.25" and the rpm from 3,700 to 3,900 rpm and still an improvement. Neighbours noticed that my machine threw the snow father. It has been several years running like that so probably 150 engine hours.

The engine sounds much better at 3,900 rpm than at lower rpm. We are only talking about a 300 rpm increase over the Ariens AX spec of 3,600 rpm. So an 8% increase, not exactly crazy fast.
 

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Discussion Starter #11
Yes, I was disappointed with the performance at 3,450 rpm, it felt weak. Increased the rpm to 3,700 and there was a profound improvement in snow throwing. Increased the crank mounted impeller pulley from 2.75" to 3.25" and the rpm from 3,700 to 3,900 rpm and still an improvement. Neighbours noticed that my machine threw the snow father. It has been several years running like that so probably 150 engine hours.

The engine sounds much better at 3,900 rpm than at lower rpm. We are only talking about a 300 rpm increase over the Ariens AX spec of 3,600 rpm. So an 8% increase, not exactly crazy fast.
Well sounds like yours worked out with no problem..I will see , since mine continues to get more stronger with each run...counting a one more Big Daddy, would be a good test..
 
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