MR FDO
01-30-2005, 06:24 PM
I would like to take a few moments to shed some light on some of the most common stroker questions.
#1: Will I lose my reliability ? If the stroker package is correctly designed and assembled , it should have a very productive life .That is , assuming that you don't buzz it like a 2 stroke way beyond it's useful rpm range . Also, when ever you add H.P. you add stress . So, the condititon of the parts you start with [ transmission,clutch,cases etc.] can play a big part in how long it lives.
#2: Will my cases crack ? In my experience I have only seen this in big displacement , high H.P. , improperly or non balanced engines .
#3: What kind of H.P. can I expect ? Using the selection of kits that are available for the 400ex as a reference , you will usually see big improvements in low & mid range with modest gains on top . Some will give more low end and others will give more mid .I t will depend on stroke [4,6,7, or 8mm] and the bore & stroke combination .
#4: Can a stroker be made to rev quick and high ? Yes . The quick revs can be accomplished by lightening the rotating assembly and balancing it . As for higher rev's ,this can be accomplished with balancing , a longer connecting rod and the correct head mods & camshaft.
#5: How do you ad stroke to a crankshaft ? When you stroke a crank , you move the crank pin away from the centerline of the crank , exactly , 50% of the desired amount of additional stroke . Here is an example : Stock stroke = 70mm = 35mm above the crank c/l [tdc] + 35mm below crank c/l [bdc] . 6mm x 50% = 3mm +35mm = 38mm above c/l 38mm below c/l =76mm . Before I go any further , I want everyone to understand that the above infomation is a result of my own experiences over the last 25 years in the perfomance industry. This , is not , carved in stone . I felt that this might help some of the younger riders the ,less, mechanically inclined that might be considering a stroker .
#1: Will I lose my reliability ? If the stroker package is correctly designed and assembled , it should have a very productive life .That is , assuming that you don't buzz it like a 2 stroke way beyond it's useful rpm range . Also, when ever you add H.P. you add stress . So, the condititon of the parts you start with [ transmission,clutch,cases etc.] can play a big part in how long it lives.
#2: Will my cases crack ? In my experience I have only seen this in big displacement , high H.P. , improperly or non balanced engines .
#3: What kind of H.P. can I expect ? Using the selection of kits that are available for the 400ex as a reference , you will usually see big improvements in low & mid range with modest gains on top . Some will give more low end and others will give more mid .I t will depend on stroke [4,6,7, or 8mm] and the bore & stroke combination .
#4: Can a stroker be made to rev quick and high ? Yes . The quick revs can be accomplished by lightening the rotating assembly and balancing it . As for higher rev's ,this can be accomplished with balancing , a longer connecting rod and the correct head mods & camshaft.
#5: How do you ad stroke to a crankshaft ? When you stroke a crank , you move the crank pin away from the centerline of the crank , exactly , 50% of the desired amount of additional stroke . Here is an example : Stock stroke = 70mm = 35mm above the crank c/l [tdc] + 35mm below crank c/l [bdc] . 6mm x 50% = 3mm +35mm = 38mm above c/l 38mm below c/l =76mm . Before I go any further , I want everyone to understand that the above infomation is a result of my own experiences over the last 25 years in the perfomance industry. This , is not , carved in stone . I felt that this might help some of the younger riders the ,less, mechanically inclined that might be considering a stroker .