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Anyone know if 800 cylinders will bolt in place of 600 cylinders. Also, what is the stroke of 600/800. Thanx
 

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800 jugs will bolt right up as far as the pattern and case but the piston will not make it to the top of the cyl becuase the differnt stroke of the 600 and 700, you have to shave the bottom of the cyl's off to make up the difference or deck the tops depending on the application or usage,done a few 800 bottoms with 600ho jugs to make stroker 600 motors but not to many 600 bottoms with 800 jugs ,those are hard to dial in.
 

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dyna-tek racing said:
800 jugs will bolt right up as far as the pattern and case but the piston will not make it to the top of the cyl becuase the differnt stroke of the 600 and 700, you have to shave the bottom of the cyl's off to make up the difference or deck the tops depending on the application or usage,done a few 800 bottoms with 600ho jugs to make stroker 600 motors but not to many 600 bottoms with 800 jugs ,those are hard to dial in.
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No way will they bolt right up.. !!!! While the bolt pattern is the same, the diameter of the skirts on the bottom of the 800 cylinders are 2 mm's too big in diameter.. the 800 jug will not drop into a 600HO or 700 block.. You first have to open the bore in the top of the upper crankcase the 2 mm diameter first. And that is just the start of the issues.

The 600HO and 700 twins have a 73 mm stroke.. while the 800's have a 75.7 mm stroke..

Then when comparing port timing there is other juggling that needs to be done.. following that solution.. you need to either get some domes for an aftermarket head like RKT that drops the chamber into the cylinder.. or you need to cut the top of the cylinders down.. not that it hasn't been done.... a lot of work for 755 cc's of smooth vibrationless power (800 cranks are shakers - while 600HO/700 cranks are pretty smooth). Just my two cents worth on the issue...

The easy thing to do with your 600HO is to put 700 cylinders, pistons and head on.. but best get them ported first as for the 100 cc's you gain, the ports on the 700's are more conservative then the 600HO.. But ported 700 cylinders and you 600HO comes alive..
 
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