gotta_goatsfast Posted August 24, 2012 Report Share Posted August 24, 2012 Okay, allow me to rephrase that question; What does it takes to make a stock 350cc motor to go up to a 410cc motor? Is this where the 4mm crank comes into play? the 4mm crank does increase displacement, but it also provides a little "extra" leverage for the piston to drive the crank. It also benefits (when using a 115mm rod) a better rod angle. Some could also argue, the piston's "dwell" time with the 4mm extra stroke helps promote cylinder filling/evacuating. You won't see 410cc with a 58mm stroke (up from 54mm stock) with stock jugs. Depending on your bore, it will be around 385cc +/-15. The 410 motors I believe are using a 68mm bore cylinder in place of the 64mm stocker. Its not so much the size of the engine that matters, its the matching of parts and the talent behind the porting. Quote Link to comment Share on other sites More sharing options...
traxx2003 Posted August 24, 2012 Author Report Share Posted August 24, 2012 the 4mm crank does increase displacement, but it also provides a little "extra" leverage for the piston to drive the crank. It also benefits (when using a 115mm rod) a better rod angle. Some could also argue, the piston's "dwell" time with the 4mm extra stroke helps promote cylinder filling/evacuating. You won't see 410cc with a 58mm stroke (up from 54mm stock) with stock jugs. Depending on your bore, it will be around 385cc +/-15. The 410 motors I believe are using a 68mm bore cylinder in place of the 64mm stocker. Its not so much the size of the engine that matters, its the matching of parts and the talent behind the porting. "gotta_gofast " I really appreciate your inputs! and you are correct, after posting this question I did some more search and was able to find information about the engine cc's depending on cylinder bore and crank combinations. You are correct in order to get 410cc with a 4mm crank, you would need to be running a 68mm bore cylinder. I found a table that had a lot of possible combinations of bore sizes and cranks and it would say what cc you would have. Now I can't find it. But like I said Thank you for taking the time to answer my question!!!! Quote Link to comment Share on other sites More sharing options...
gotta_goatsfast Posted August 24, 2012 Report Share Posted August 24, 2012 I wouldn't get too hung up on displacement though. A guy I rode with pieced together an Ebay special 4mm kit and bored his 64.5mm cylinders all the way to the service limit!!! and just ran it as-is with no porting, stock carbs, and T5s. He thought it was bad ass because it was somewhere around 400cc. After a lot of smack talk, a cammed and piped 416ex ran side by side with him in a drag race! He sold it and bought a 450r. He hates banshees because even a "400" banshee couldn't beat a honda EX. Not relavant, but I completely spanked his 450 last year after I had gotten my 421 serval dialed in. haha, moral of the story is simple. The size of the engine has little to do with the final performance of said engine. Port work and parts combination are the foundation. Ability to tune, riding skill level, and suspension setup are all of equal value. Quote Link to comment Share on other sites More sharing options...
yzrmbsg Posted August 24, 2012 Report Share Posted August 24, 2012 I wouldn't get too hung up on displacement though. A guy I rode with pieced together an Ebay special 4mm kit and bored his 64.5mm cylinders all the way to the service limit!!! and just ran it as-is with no porting, stock carbs, and T5s. He thought it was bad ass because it was somewhere around 400cc. After a lot of smack talk, a cammed and piped 416ex ran side by side with him in a drag race! He sold it and bought a 450r. He hates banshees because even a "400" banshee couldn't beat a honda EX. Not relavant, but I completely spanked his 450 last year after I had gotten my 421 serval dialed in. haha, moral of the story is simple. The size of the engine has little to do with the final performance of said engine. Port work and parts combination are the foundation. Ability to tune, riding skill level, and suspension setup are all of equal value. This! Quote Link to comment Share on other sites More sharing options...
94BANSHEE Posted August 25, 2012 Report Share Posted August 25, 2012 Guys...with a great port job by kevin etc. on stock jugs with .40 over bore and fresh pistons and a 4mil. crank...would T5 pipes be sufficient for that upgrade? Also using stock carbs and V3 reed cages thx Quote Link to comment Share on other sites More sharing options...
sheerider11 Posted August 25, 2012 Report Share Posted August 25, 2012 "gotta_gofast " I really appreciate your inputs! and you are correct, after posting this question I did some more search and was able to find information about the engine cc's depending on cylinder bore and crank combinations. You are correct in order to get 410cc with a 4mm crank, you would need to be running a 68mm bore cylinder. I found a table that had a lot of possible combinations of bore sizes and cranks and it would say what cc you would have. Now I can't find it. But like I said Thank you for taking the time to answer my question!!!! Quote Link to comment Share on other sites More sharing options...
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