How can I make more power?

[David_JH 23]

I have a 1984 Workhorse GT-1100 with an 11 hp Briggs and Stratton engine. I'm wondering if there's a way to make it more powerful (like 20 hp or so) without spending too much money or endangering the well-being of the engine. Is there any kind of aftermarket carburetor that I could replace the stock one with? If I did increase the hp to 20 or so, would I risk breaking a connecting rod or lifting the head?

I don't want to make a crazy amount of power, but I would like to free up a few more ponies.

Thanks!

[peter lena 8,634]

@DAVID-JH , there a number of "  puller engine sites  "  that could help you out , simple would be a more tuned exhaust set up , detailed carb and ignition set ups. without getting into serious boring and balanced rotating assembles . it might be just easier to  look for a fresh rebuilt engine with more hp . don't know what you are looking for or planning to do , pete

 

[Handy Don 12,236]

 

[pfrederi 17,741]

 It would provably be cheaper in the  long run and more reliable to just get a bigger engine...

Edited June 20, 2021 by pfrederi

[8ntruck 7,016]

  Cubic inches are your best bang for the buck.

[ebinmaine 67,618]

"There's no replacement for displacement". 

Walter Owen Bentley. 

 

 

 

Seriously though.... My first question is... Exactly what do you want/need from  your machine?

How do you arrive at the 20 HP figure?

Do you simple desire more top speed?

Do you need a machine with more torque?

 

 

 

Most single cylinder engines are capable of roughly 1.5 times the original rating given a desire for some reliability and longevity. 

 

That's achieved by spending time and money as with any other power source.  

 

 

IMHO:

If you really want 20-ish HP.... Hunt down a larger beginning point such as a Kohler Briggs or Onan twin. 

 

Just my own opinion. 

 

[Skipper 1,788]

It will, within realm of reason, be almost weird magic, if you could just simply raise an 11hp to 20hp, and still have it running as intended for a GT, with just a few little easy fixes.

 

If you want it to still run as a reliable GT power unit, better go find a bigger engine. And don't get scared of loosing your WH PTO. Just snap on an electric clutch, and suddenly you have a plethora of engines to chose from. More modern types too.

 

just my 

[pacer 3,173]

I agree with replacement....... First off it would be VERY expensive and complicated to increase that amount of HP (if its even possible!!) 

As mentioned above there are MANY choices of replacement engines, with the older Kohlers beings the simplest  - and, probably the cheapest choices, and with the several options of new - like HF's Predator series, and others.

[Howie 886]

I seriously doubt you are going to be able to do that with bolt on parts. Even if you

could in my mind it is in my mind not going to be as reliable as it is now.

Think it would take an increase in displacement, camshaft, more compression

along with turning more rpm!

[Gregor 4,846]

On 6/20/2021 at 12:44 PM, David_JH said:

I'm wondering if there's a way to make it more powerful (like 20 hp or so) without spending too much money or endangering the well-being of the engine.

I think if that were possible to do, 90% of owners would have done it. The fact that no one has, should tell you something.

[953 nut 55,319]

On 6/20/2021 at 1:44 PM, David_JH said:

make it more powerful without spending too much money

That was every kid's dream when I was growing up. If you read the advertising in Hot Rod Magazine for various add on products you could get (up-to) a 10% increase with each one         so if you bought ten of them you should double your power, right?            

The first question has to be what is the condition of your engine? Has it been rebuilt with a cylinder rebore and a new oversized piston and new valves and guides? Older engines will have less than advertised power if the are in need of some serious TLC.

[Jeff-C175 7,202]

4 hours ago, 953 nut said:

every kid's dream

 

Yeah man... slap a cherry bomb and a Holley 780 double pumper onto your stock 305 and you were good to go... whether or not your little 305 could actually PUMP 780 CFM or not made no difference.

 

Oh, and don' t forget those silly a55 leaf spring shackles to lift the rear... now THERE's something that definitely made one go faster!  NOT!!!!

 

So many myths, so few myth busters.

 

Edited June 22, 2021 by Jeff-C175

[richmondred01 2,237]

On 6/20/2021 at 2:10 PM, pfrederi said:

 It would provably be cheaper in the  long run and more reliable to just get a bigger engine...

Any additional hp you can squeeze out of that will be negligible except to your wallet. 

Best suggestion I can throw into this conversation is to install a Kohler k321 or a k341.

You are about a hour away from me. I’ve got a rebuilt k321 wheel horse spec ready to drop in to that work horse.