Strongest 4c block?

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Tony01

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Nov 28, 2012
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What's the strongest 4-stroke motor block between 140cc and 212cc? What can handle the highest compression?

Pretty much,

Honda GX160 vs GX200/HF212
Briggs 5hp vs similar size OHV?

Looking for a suitable candidate for reliable supercharging.
 

cannonball2

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Oct 28, 2010
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If you want the ultimate, build a block for the 5hp Briggs called a Blockzilla. I have been out of kart racing a good while but these engines dominated the open class. The open class Animals which I ran, were fast catching them. Don't even know if they are still made, but they gotta be out there. Also The JR Dragster class might have used them. There was one that used a 4" Chevy piston as I remember.. These blocks handled high compression(for flat heads)/combustiom pressures no problem
 

Tony01

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Nov 28, 2012
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Damn! Those would definitely be nice. But they are so expensive... More expensive than the entire budget. The big blockzilla3 has a 3" bore and tons of meat to the head bolts... I could see that thing taking 2bar.

What about something more affordable?

I was looking at the clones which only have 4 head bolts, then at the Briggs 5hp fh, with its 7? bolts.. Does this make a difference? Is the flatty better despite its outdated design?
 

Tony01

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Nov 28, 2012
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You could read this http://gardentractorpullingtips.com/index.htm Then find a 7 hp Kohler and do some of the mods. A 7 hp Kohler is about the same size as 5 hp Briggs, and are heavy, some goes for Wisconsin.

They take the 14 Kohler blocks and get close to 60 hp out of them ..............Curt
Wow... that link. I saw it yesterday and spent an hour reading the info.. I think I only made it less than a quarter of whats on that site.. thanks for the link. The day of starting to buy stuff for the build is a ways away as I try to figure everything out on paper before jumping in for $1500 but will keep my eyes open. An iron block may be what I'm looking for. I bet those things can handle more than 20psi of boost!
 

curtisfox

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Dec 29, 2008
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There were some cast iron Briggs also, but think the were bigger, not sure. Could make a head cradle like the Kohler pullers have to help hold it together and still keep the stock head. The 7 hp Kohlers are out there roto tillers, old snow blowers. Just got to snoop,i have a 4 hp Kohler and it's not any bigger then a 1 1/2 hp briggs. Sounds like a fun project...................Curt