Screamer!

[rodkillah2002]

I know all the really fast guys are running big atv and motorcycle engines but I want to do a little something diffrent. I want to start with a big single cylinder or even a twin and build the we out of it just to see what I get. I have a 15.5 b&S but I really want something in the 18 to 20 hp range to start with. any build threads or tips would be great. I have no idea what Im doing so it should be really fun to see what happens. Thanks you GUYS!

 

[r_chez_08]

Worst invention ever, single ply tolit paper!

I would install a better air filter and exhaust, and rejet. Then up the compression to around 11:1, and maybe remove the governor.
That should gain a few HP.

 

[gixxerkart]

Lol just spray it with naaawssss brah. Then you'll snap a speedo in 9sec flat. Frah shah brah.

..... Whoa, where am I?

 

[gixxerkart]

Hey since my last post was nonsense, Ill add a thought in here since r-cheez mentioned higher compression. Has anyone tried adding material to the combustion roof of the head to increase compression? They do it IRL on race engines.

 

[Doc Sprocket]

Lol just spray it with naaawssss brah. Then you'll snap a speedo in 9sec flat. Frah shah brah.

..... Whoa, where am I?

Given your location, I'd say too much sun...

 

[exenos]

While I want to suggest a opposed twin you'd be better off getting a large v-twin and building that up.I just love the old opposed twins for some reason. From what I have heard, it doesn't cost too much to get a 25hp twin up to 75-100. Look up lawn tractor pulls. That's where all the high hp industrial engines are.

 

[Bluethunder3320]

i believe that 18hp briggs and kohler's are built up for lawn tractor pulling, theres many fast parts for them they are just $$

 

[slideways]

Briggs Vanguard Vtwins are plenty reliable and have a big aftermarket. The Kohlers are even stronger but much more expensive.

For example: a 16hp Vanguard can be had running for $200-300. Exhaust $50 (DIY), a 2bbl carb from a 20hp $75, cam $150-200, mild porting on the heads and intake system (free) and you should be in the 25-30hp area. Just don't go over 5500 or so with the stock rods. If you want billet they are about $120ea. Same with pistons.

 

[gixxerkart]

Would He get tire spin with 16hp?

 

[exenos]

You can get tire spin with almost any engine with he right gearing. Heck I spin the tires with my 6.5 clone. Its more, can he spin the tires and have a decent top speed, which I don think he will do with 16hp, a modified 16hp, yes but stock no.

 

[rodkillah2002]

Well Guys, thanks for all the input. Im thinking of getting something not running that way I will not fill bad about tearing it apart. Milling the heads. billit internals, a big carb and cam. I know its a lot of cash but Im looking at a long term project. What do you think about a built peerlees 700 with a 40 or 44 series TAV? Will it work?

 

[crazyman]

I sold and delivered a clattering Tecumseh 15.5 hp vertical shaft motor to a guy on here.

During conversation, he said he converts them to horizontal and runs them on gokarts in racing. His last Tecumseh made more than 45hp... Lots of money is the key to getting huge power out of little engines. You are better off getting something close to your expected horsepower and then tweaking cheaply.

The biggest HP gains in any engine are the int/ex ports, and the camshaft. Bigger is not always better. Cheap is a free flowing exhaust and a high flow air filter, then jetting.

I put a 27HP liquid cooled Kawasaki onto my 18HP simplicity sovereign. True duals, jetted one barrel, and all I can do is slip belts in 3ft tall grass. It just won't die.

http://www.youtube.com/watch?v=yFvL_IvtB8o&feature=plcp