dmfisher71 Posted April 15, 2011 Report Share Posted April 15, 2011 ok i kinda got a dumb question i been out of the game for a while and my mind is blank i know that a stock banshee cylinder max bore size is 66.5mm but what is the decimal (ex. .020 over) measurement of 66.5 bore. Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted April 16, 2011 Report Share Posted April 16, 2011 ok i kinda got a dumb question i been out of the game for a while and my mind is blank i know that a stock banshee cylinder max bore size is 66.5mm but what is the decimal (ex. .020 over) measurement of 66.5 bore. .100over Quote Link to comment Share on other sites More sharing options...
MorrisJL Posted April 16, 2011 Report Share Posted April 16, 2011 I'm new to the banshee and with dmfisher71 on this. The Banshee I bought has was rebuilt last summer, the pervious owner told me it had been ported for racing, I think .90 over is what he told me. I don't know what that means exactly or how much its been bored out. I would like to know because when I find its time to do a rebuild I'll know if I need to buy new cylinders and pistons first. I also don't know what 4mil means... read it a lot. Maybe the someone could start a thread with words, terms and acronyms... defined. Quote Link to comment Share on other sites More sharing options...
Larry's Shee Posted April 17, 2011 Report Share Posted April 17, 2011 4mil refers to a crakshaft with a 4 mm longer stroke, requires some mods/pieces to use it. To OP , most prefer not to run at .100 over, say the liner is to thin. hope this helps Quote Link to comment Share on other sites More sharing options...
spurdy Posted April 17, 2011 Report Share Posted April 17, 2011 I'm new to the banshee and with dmfisher71 on this. The Banshee I bought has was rebuilt last summer, the pervious owner told me it had been ported for racing, I think .90 over is what he told me. I don't know what that means exactly or how much its been bored out. I would like to know because when I find its time to do a rebuild I'll know if I need to buy new cylinders and pistons first. I also don't know what 4mil means... read it a lot. Maybe the someone could start a thread with words, terms and acronyms... defined. 0.040" or 40 thousandths is equal to 1 mm. So 0.090" over is 2.25 mm over stock bore or 66.25 mm. 66.50 is the max to go on stock cylinders. The cylinder wall is very thin at that point. That means your looking at new cylinders or new sleeves likely next time your top end needs work. SP Quote Link to comment Share on other sites More sharing options...
MorrisJL Posted April 17, 2011 Report Share Posted April 17, 2011 How would you measure what your cylinder is bored to... is it as easy as taking the head off and measuring your cylinder, or is it more involved then that..? I know the shop where the last rebuild was done I think I will double check with them before taking anything apart... Further... Are sleeves a cheaper option come time to rebuild...? Are sleeves reliable? If I just replace with new cylinders and pistons... what can I expect from a performance stand point going back to stock size... Should I have to worry about replacing any rods or crankshaft components? Would it require jetting...? I know some very basic questions... I would think I have the correct answer for most, but I've learned, unless you've did it... trust but verify. Quote Link to comment Share on other sites More sharing options...
BigRed350x Posted April 17, 2011 Report Share Posted April 17, 2011 How would you measure what your cylinder is bored to... is it as easy as taking the head off and measuring your cylinder, or is it more involved then that..? I know the shop where the last rebuild was done I think I will double check with them before taking anything apart... Further... Are sleeves a cheaper option come time to rebuild...? Are sleeves reliable? If I just replace with new cylinders and pistons... what can I expect from a performance stand point going back to stock size... Should I have to worry about replacing any rods or crankshaft components? Would it require jetting...? I know some very basic questions... I would think I have the correct answer for most, but I've learned, unless you've did it... trust but verify. There will be almost no noticeable difference between the bored out cylinder and a stock bore cylinder. Very minimal. If you're going to buy sleeves and get the work done to re-sleeve you might as well just buy new stock cylinders and send them out to get re-ported for your 4mil. As long as you don't have a catastrophic failure your crank and rods will probably be fine. Just check for up and down play when you take the cylinders off. If you get sleeves, by the time you buy the sleeves, pay to have them pressed in, and get them port-matched to your previous porting and buy a new top end you're going to be into them as much as a new set of stock cylinders and a new port job. - Jared Quote Link to comment Share on other sites More sharing options...
spurdy Posted April 18, 2011 Report Share Posted April 18, 2011 might as well just buy new stock cylinders and send them out to get re-ported for your 4mil. As long as you don't have a catastrophic failure your crank and rods will probably be fine. Just check for up and down play when you take the cylinders off. - Jared If you port new cylinders for a 4 mil your not going to use your stock crank. (Wasn't sure if you knew that but based on earlier questions I didn't want you getting confused). No re jetting for new top end. Only performance gain would be higher compression from a new top end. SP Quote Link to comment Share on other sites More sharing options...
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