athena big bore kit?

[BANSHEE HP]

a 4mm long rod motor has 7mm more up stroke then stock.(+2mm for the 4mm crank and +5mm in longer rod)

 

a 795 series piston will take away make up the the 5mm longer rod, leaving you still with 2mm to make up with spacer plates/gaskets/domes.

on bores less then .080 66mm this would be the piston youd use.

 

at 66mm you have the blaster piston(573mo6600) that becomes available. its pin height is 6mm higher then stk banshee piston and 1mm higher then the 795's.

 

if someone is suggesting going straight to 66mm,(we know its not because boring is makeing more hp). with a 4mm long rod setup(+2mm for the crank and +5 longer rod)  the piston would be out of the bore 7mm's again but your able to take away 6mm's this time with a 573mo660 blaster piston. leaving you with just 1mm to make up with gaskets and domes.

 

another thing that isnt mentioned but is relavent, is that a 513 std pin height banshee piston and a 795 series long rod piston share the 13* squish angle. a blaster 573's series piston has a 9* angle.  youll probably get different answers from different ppl, but the less angle on the squish band the more power the engine makes( and im not getting into why). hence why some builders/manufacturers use a flat top style piston in engines.

 

 

sooooooo, the reason i'd figure a builder would suggest going straight to 66mm, imo would be the 1mm less theyd have to make up with domes and gaskets and the 9*  squish angle of the piston.

 

[trickedcarbine]

Interesting..... Maybe take the thing to 66 and nickasil it after porting

[sheerider11]

Got it, when you say blaster piston the 795 pops into my gead( blaster style) your talking about a actual blaster piston 573

[trickedcarbine]

Yeah, makes sense now. I like the fact that the piston comes out less on the 573 style to