Super charger

[Handy Don 12,235]

33 minutes ago, Achto said:

As long as we're on the safety subject, let's sit back, relax, & watch a few million $ go up in smoke.

 

Stopped watching when a safety official went up to a blown, fuel all over, burning tractor with a 2 lb fire extinguisher! Seriously?

[kpinnc 12,083]

1 hour ago, Achto said:

sit back, relax, & watch a few million $ go up

 

Why is that so satisfying? I don't know why I like it so much! 

[fast88pu 3,324]

16 hours ago, kpinnc said:

As someone who loves modifying dang near everything- I really don't want to say this.

 

...However,

 

If you modify any small air cooled engine to operate over 3600 RPM- it's best to start with a bare performance block and build up with high performance components. Otherwise you own a bomb that requires a hammer to start it. 

 

There is no if. It will fail catastrophically, and you might hurt yourself or someone else when it happens. 

Stock kohler k or magnum can safely turn 4500 with no issues. I stock 212 predator will safely turn 5200 stock. Build a kohler and spin 7k. I have a 212 built to turn 10,500. And my 670 predator is built to turn 6500. 

[fast88pu 3,324]

7 hours ago, Bill D said:

@fast88pu has the most experience of anyone here with superchargers for small engines.  Built an M16 and a Onan N52 with superchargers.

Also a 522xi

[kpinnc 12,083]

33 minutes ago, fast88pu said:

Stock kohler k or magnum can safely turn 4500 with no issues. I stock 212 predator will safely turn 5200 stock. Build a kohler and spin 7k. I have a 212 built to turn 10,500. And my 670 predator is built to turn 6500. 

 

I will absolutely defer to your experience. My point was that no one should just bolt on a supercharger or for any reason spin stock engines over 3600. 

 

And though cast iron Kohlers and engines with aftermarket kits can exceed this, they don't do so without extensive modification. 

[Bill D 1,926]

3 hours ago, fast88pu said:

Also a 522xi

Sorry I forget about that one.  Also, your machines all have turbo chargers, not super chargers.

[Pullstart 62,905]

10 hours ago, Bill D said:

Sorry I forget about that one.  Also, your machines all have turbo chargers, not super chargers.

There is sure some difference, but matching fuel to boost and handling boost appropriately… boost is boost 

[Horse Newbie 7,073]

On 6/17/2022 at 2:09 PM, TJ Salyers said:

It was a joke.

You don’t joke with these guys when it comes to “more power” !  

[fast88pu 3,324]

On 6/16/2022 at 1:25 PM, Maxwell-8 said:

Definitely possible, but you will have to get a blow-trough carb or do fuel injection.

 

Would be easier to make consistent boost then using a turbo. The AMR 300 and 500's where used on small Asian  engines that have a max displacement by law of 600cc.

 

The question is, how much boost can a Kohler or Onan take before the rods leave the party.

I'm running 15psi on my m16, but it's built. Running 6psi on my kohler 22 twin stock rods and pistons. Then my onan I had up to 8psi and it was scary to ride lol. Now it makes 4psi, it's also a 52ci onan.

[Snoopy11 5,714]

21 hours ago, fast88pu said:

stock 212 predator will safely turn 5200 stock

Sir, I would appreciate it you elaborate on what you mean by "safely turn" those rpm's, I do disagree in part... regarding safety... and here is why:

 

 

37 minutes ago, Horse Newbie said:

You don’t joke with these guys when it comes to “more power” !

Power... ...or safety...

 

Don

Edited June 18, 2022 by Snoopy11

[Maxwell-8 4,277]

Those cheap engines mostly have a rev limiter in the form of valve float lol

[Achto 27,600]

17 hours ago, Maxwell-8 said:

Those cheap engines mostly have a rev limiter in the form of valve float lol

 

Chevrolet incorporated the exact same rev limiter into their stock small block V8 since 1955.  

[Snoopy11 5,714]

19 hours ago, Maxwell-8 said:

Those cheap engines mostly have a rev limiter in the form of valve float

Not only that... but most 3,600 RPM engines use 'soft' valve springs to avoid cam wear... as the lobes on the cam of those engines are just hard enough not to wear with the soft springs... not to mention the fact that the cam stem itself nor the followers aren't the strongest material known to man...

 

In other words... if you introduce heavier springs into an engine with a stock cam... you might very well have issues with valvetrain/cam wear...

 

So much goes into legit engine building... it will make your head spin...

 

Introduce boost to that equation... you are pressuring all those components THAT much more.

 

Don

Edited June 19, 2022 by Snoopy11

[Snoopy11 5,714]

I should finally add, as my last laugh in this thread...

 

People who consider boosting any application that does not have active pressure lubrication... oil pump... etc... proves that:

 

1. They know nothing about small engines.
2. They don't care if the engine grenades.

Anyone legitimately contemplating boosting a small engine will invest in a full pressure lube engine, and the durable parts to go along with that engine.

 

Anyone who doesn't do those things... well... let's just say... I don't have very nice things to say.

 

This thread was a dead-end from the start... and I really don't think there is anything left to say... certainly nothing that hasn't been said before... so...

 

I'm out.

 

When someone has a literal project that they want to boost or modify, I'm here to help.

 

Otherwise... may this thread...

Don

[kpinnc 12,083]

I look at it like this: it's all about what an engine is engineered to do. Traditional air cooled engines (older ones, of course) were made to provide a set range of power and longevity. Statistically, they worked very well. Thousands are still in use as long as 50+ years now. Many were overbuilt to a point, and this certainly shows with the likes of Kohler Ks and Magnums and Onans, and even some Teccys and Briggs.

 

Newer engines were designed to barely endure thier power bands for a short period of time- and only then when serviced properly.

 

Aftermarket components can allow older and newer engines to massively exceed thier original output power. Those components are engineered for that, but require constant adjustments and maintenance. Makes me think of the difference between a stock truck and a NHRA funny car. A stock vehicle will last for years with regular servicing and use. On the other hand- a highly modified machine requires constant teardown and in-depth maintenance because so much of it is operating at or near the maximum endurance of all of its components.

 

So the short answer that sums all of this up is this: if you want solid dependable low maintenance reliability, then leave it stock. If you have time, patience, and financial ability- then modify your engine to the max. I'll watch from a safe distance as soon as I finish mowing and put my tractor up.