rashin Posted October 14, 2011 Report Posted October 14, 2011 I'm in the market for a new top end (and crank). I was thinking of upgrading to a larger motor. What off the shelf setup will give me the most power with still using stock case, intake, and exhaust....? 421 4milll.....? Quote
4MiLLDraGSheE Posted October 15, 2011 Report Posted October 15, 2011 Well i think the most bang for your buck without having the cases trenched or bored would be a 421 cub from a reputable builder like herr jugs racing or the other site sponsors. But i would almost say i dont know how that would run on stock pipes you may be able to use stock carbs but pipes increase performance alot i would pick up a set. Quote
rashin Posted October 16, 2011 Author Report Posted October 16, 2011 I have fmf fatty pipes. I just want to make sure I can reuse those with the new cylinder... Quote
Jereme6655 Posted October 16, 2011 Report Posted October 16, 2011 I have fmf fatty pipes. I just want to make sure I can reuse those with the new cylinder... you can......you just wont have the absolute optimal setup......the fatties are good......dont get me wrong (i run em) but theyre not gonna get the performance you would our of R-2's or shearers or cpi's Quote
EvilBanshee Posted October 19, 2011 Report Posted October 19, 2011 I run a 421 68mm +4 stroker crank. It has FMF Fatties Here's a vid. Quote
Jereme6655 Posted October 19, 2011 Report Posted October 19, 2011 Evil......nice bike! ....from seeing how you shift like that though.....ever thought about a dunable over-ride? It'll let you backload it a bit....but also I noticed.....I hope you have a pancake bearing. Your holding the clutch in for a while while slowing down......if you don't your gonna eventually wind up welding your pushrod/ball together.... Bike sounds real strong though man... Quote
EvilBanshee Posted October 20, 2011 Report Posted October 20, 2011 Evil......nice bike! ....from seeing how you shift like that though.....ever thought about a dunable over-ride? It'll let you backload it a bit....but also I noticed.....I hope you have a pancake bearing. Your holding the clutch in for a while while slowing down......if you don't your gonna eventually wind up welding your pushrod/ball together.... Bike sounds real strong though man... No dude i dont. I never used to ride like that. But i have siezed an engine before just letting off the juice from WOT. Never again.. lol. Talk about heart breaker! And i dont have a dunable over-ride either? What is that exactly? Quote
Jereme6655 Posted October 20, 2011 Report Posted October 20, 2011 an over-ride allows you to shift without using the clutch while still under throttle......so you could pin it to win it and still shift but without using the clutch. HOWEVER....a normal over-ride will NOT like backloading (when you slow down in gear without the clutch pulled in)....it will actually destroy them. a DUNABLE over-ride WILL allow you to backload it.....both are more used in drag racing than anything else..... the pancake bearing goes in with your clutch rod/ball and keeps them from welding while your slowing down with the clutch pulled in. keeping that clutch pulled in for a long time (while rolling to a stop) is what causes them to fail and weld together......then you get the fun of splitting the cases to repair it.... Quote
rashin Posted October 20, 2011 Author Report Posted October 20, 2011 Question: Is it possible to build a basic (without porting) 4 mill stroker motor will stock cylinders, pistons and head using just stroker crank, and some type of plate spacer?? Quote
EvilBanshee Posted October 20, 2011 Report Posted October 20, 2011 an over-ride allows you to shift without using the clutch while still under throttle......so you could pin it to win it and still shift but without using the clutch. HOWEVER....a normal over-ride will NOT like backloading (when you slow down in gear without the clutch pulled in)....it will actually destroy them. a DUNABLE over-ride WILL allow you to backload it.....both are more used in drag racing than anything else..... the pancake bearing goes in with your clutch rod/ball and keeps them from welding while your slowing down with the clutch pulled in. keeping that clutch pulled in for a long time (while rolling to a stop) is what causes them to fail and weld together......then you get the fun of splitting the cases to repair it.... Cool stuff. Maybe ill look into that stuff when the winter hits. Thanks Quote
700vflash Posted October 20, 2011 Report Posted October 20, 2011 Question: Is it possible to build a basic (without porting) 4 mill stroker motor will stock cylinders, pistons and head using just stroker crank, and some type of plate spacer?? I have seen boss kits on ebay like that, but I don't know anything more than that. Quote
Jereme6655 Posted October 20, 2011 Report Posted October 20, 2011 while it is possible to do it without porting and with a spacer plate it is REALLY not looked highly upon..... 2 main reason..... 1) your port timings will be off because of the spacer plate... 2) you have just created another spot for an air leak in your motor.... but if you were to do it then it would run....but not as hard as your anticipating.... Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.