cams / big bore kit
Elite HDF Member
Joined: Apr 2007
Posts: 4,919
Likes: 23
From: Seattle, WA
I was wanting to do cams on my 2011 fat bob. My bike guy said that most likely the crank shift will have run out and need to be replaced costing close to 3k or more. Then we started talking about my options from there he said we could go to a 106 or 117 s&s. But I have a hard time changing out the motor at only 25k miles on it. I wanted to see what others have done and what to expect from cost to experiences. Also some one was saying they thought that going to a 117 would destroy the frame belt and other things ( I think is a load of mularky).
Any input from experiences is great.
Thank you for you're time
Jeff
Any input from experiences is great.
Thank you for you're time
Jeff
The problem was that the gears are much more sensitive to lateral movement of the drive shaft (crank shaft) ... these year bikes had better manufacturing tolerances (on average) so usually not a problem ...
'06-later Dyna Twin Cam motors switched to a hydraulic cam chain tensioner system and the tensioner shoes are much less of an issue ... also easier to replace ...
Coincidentally, in the later models, the MoCo relaxed the tolerance for run out of the crank shaft ... (for the most part, this is not a problem) ... but, if for any reason, someone wants to use a gear drive setup, there is a greater probability that the crank shaft run out will not be within the tolerance specs (if I recall correctly, 0.002") ...
My point is ... I agree with Apollo ... no need to do anything with the crank ... just do not do gear cams ... plenty of good options for your motor ...
I would recommend Andrews 48 cams ... or Woods 555
Good luck with the build ...
R/
'Chop
Last edited by SURFOR Chop; Aug 7, 2012 at 02:01 PM.
The '99-'05 Dyna Twin Cam motors had a spring-type cam chain tensioner system in which the tensioner shoes were susceptible to excess wear and the risk that at relatively low mileage they would wear out and cause damage to the motor ... at the time, a popular alternative was to replace the chain driven cams with gear drive cams ...
The problem was that the gears are much more sensitive to lateral movement of the drive shaft (crank shaft) ... these year bikes had better manufacturing tolerances (on average) so usually not a problem ...
'06-later Dyna Twin Cam motors switched to a hydraulic cam chain tensioner system and the tensioner shoes are much less of an issue ... also easier to replace ...
Coincidentally, in the later models, the MoCo relaxed the tolerance for run out of the crank shaft ... (for the most part, this is not a problem) ... but, if for any reason, someone wants to use a gear drive setup, there is a greater probability that the crank shaft run out will not be within the tolerance specs (if I recall correctly, 0.002") ...
Definitely would love to follow suit in splitting cases and throwing some more stroke down ... not sure I'd follow suit on the gear drive / cams (but, not knocking your selection) ...
Good luck with the build ...
R/
'Chop
The problem was that the gears are much more sensitive to lateral movement of the drive shaft (crank shaft) ... these year bikes had better manufacturing tolerances (on average) so usually not a problem ...
'06-later Dyna Twin Cam motors switched to a hydraulic cam chain tensioner system and the tensioner shoes are much less of an issue ... also easier to replace ...
Coincidentally, in the later models, the MoCo relaxed the tolerance for run out of the crank shaft ... (for the most part, this is not a problem) ... but, if for any reason, someone wants to use a gear drive setup, there is a greater probability that the crank shaft run out will not be within the tolerance specs (if I recall correctly, 0.002") ...
Definitely would love to follow suit in splitting cases and throwing some more stroke down ... not sure I'd follow suit on the gear drive / cams (but, not knocking your selection) ...
Good luck with the build ...
R/
'Chop
Don't forget that after 2002 the crankshafts went from forged to cast, which was where I was going with my original comment that the 2002 and earlier have a more stout crank and a timken bearing.
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Cruiser
Joined: Jan 2012
Posts: 159
Likes: 2
From: Mesa, AZ
ok found the break down if I want to do geared and the crank has some run out then there is the issue. If that is the case for now I'll go with chain driven I can't see changing out a motor at only 25k! My pockets aren't that deep yet.
Tourer
Joined: Jan 2011
Posts: 290
Likes: 2
From: wayland ny
Just did the big bore on my bike all and all in the end i will have about $800 into it. $630 for the kit and and about 200'ish in misc. parts and dyno. i figure i did good my bike only had 15k miles on it.
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Cruiser
Joined: Jan 2012
Posts: 159
Likes: 2
From: Mesa, AZ
Sounds super cheap what did you do (go from and to)?
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