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425cc stroked motor....


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the pin is moved x distance on the crank. this allows the piston to go farther into the jugs and create more displacement.

 

It also adds more torque because when you move the crank pin farter out from the center of the crank it gives the rods more leverage on the crank.

 

It is like putting a cheater pipe on a wrench when you have a really tight bolt.

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thanks alot banshee-man and jbookey makes alot of sense now.

 

 

So tell me this for a 425cc displacement the pin would have to be moved.... (answer here) ???

 

It is probably not a 425cc. A 421cc is a real common engine. Most of the time you see 421 cub. It uses a 68mm bore (+4mm over the stock 64mm Bore) and a +4 mill stroker crank. Stock stroke I belive is 54mm so a +4mill stroker crank would be 58mm. The Crank drops right in with no modifications to the cases.

 

The cub cylinder is an aftermarket cylinder that is drag ported right out of the box.

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i doubt he is getting 145hp out of it though. 100hp is a desent built 421 cub.

 

After you bolt on a cub cylinder the HP you gain per dollar you spend drasticaly goes down.

 

 

I am not real familiar with different drag setups and power out put. I am thinking that you would have to have a pretty worked up 10 mill stroker motor to hit 150 hp if you could even reach that. Isnt 130hp a desent number for a 10 mill?

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So tell me this for a 425cc displacement the pin would have to be moved.... (answer here) ???

 

It would have to be moved out 2mm farther from the center of the crank shaft. That 2 mm will cause the piston to travel 2mm farther up the cylinder, and cause the piston to fall down 2mm farther in to the cylinder. Grand total of 4mm.

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