[samhain]

New to the forum, just want to know if anyone has put on the 103 kit to a FXSTi. been going nuts trying to check. My dealer's Parts man says yes, but the cat. and web site say no. If no, is it because of the balance shafts. Any insite will help.

Thanks, Samhain

 

[csoday]

You most certainly can. Many of us, myself included have.:banana: See my signature.

 

[Bubblehead Lifer]

Looking into possibly doing this to my 04 FXSTi also. Any input on a good kit to get started with. I am pretty sure I that I have scissored crank, haven’t tore into it yet. Do I need to change out anything in the crank area. Not really interested in doing a stroker. Looking for lower to mid range torque. My “need for speed” was over about 20 years ago. Mostly ride back roads and highways. Blue Ridge Parkway is in the future. I am a decent wrench monkey so plan on doing assembly myself, send out any machine work and such.

 

[Uncle Salty]

You win 1st place for the oldest thread revived today contest! Go collect your bag of cookies. If you want to turn a 88" Twin Cam into a 103, you're doing a stroker. If your crank is bad, it's gotta come out anyway but I'd consider a S&S crate engine before doing all that unless you have the parts laying around.

 

[Bubblehead Lifer]

Thought I jump start this thread because it was the perfect lead in for my question. As for the stroker, Hell’s Bells, I had a buddy with a stroker in a Corvette, nothing but trouble. Now the S&S create engine. You are the second person to recommend going that routine. Maybe I’m searching for the wrong thing but have not found one that will fit a 04 Softail frame. I read somewhere that S&S was sued by HD for cloning the Twin Cam motor or maybe it was just the TC88. But anyway I can only find S&S Evo motors or 07 and newer Dyna and touring bikes. Like I put in the first post, decent wrench monkey but when it comes to the brain side to put things that work together not so much. “Mongo Like”. If someone could dumb it down a little the slow guy might catch on.

 

[Uncle Salty]

The "X" just zipped by me and the B engine design didn't sink in. I don't know of a S&S crate engine for a Twin Cam B but TT or Therm may have some ideas for you.

I'm still confused by your statement, "I am pretty sure I that I have scissored crank, haven’t tore into it yet. Do I need to change out anything in the crank area." and also inquiring about a 103 but don't want a stroker. Apparently, I don't have the foggiest idea of what you want because going to what is commonly called a 103 requires increasing the stroke.

 

[Don Dorfman]

It takes a motor out overhaul to accomplish this and it is easily done by a qualified shop. The crank and pistons are the part changed that will get you there. S&S makes a strong crank for the B motor. With a case bore and the same parts plus new cylinders the same motor can be a 117"

 

[Bubblehead Lifer]

Sorry, what I am asking for may not be possible that is why I have come the well of knowledge. A little history. Took a wad of cash to the local HD dealership and got a 04 FDSTi with 90,000+ miles on it. Rode for a couple months and life was good. Then lost oil pressure before I could get off the side of the road lifters started banging. Opened the cam chest and one of the georotor in the oil pump had exploded. Posted some pictures on another thread and got a lot of scissored crank answers back. Looked into the HD long block program thinking this engine probably tired anyway when a rider from church suggested building it into a 103 if I was going to have to put out another wad of cash. I didn’t know that a 103 would require a stroker, which with my limited experience was not good so I was trying to steer away from them, buddies Corvette but he was an idiot so it may have been him and not the motor. What I am really looking for is first: more low to mid range torque so that when the better half is on the back we have better take off and hill climbing power. Second: maybe some “Wow” factor to show for two wads of cash I have in it.

 

[Don Dorfman]

You won't get what you want through the rebuild program. This will take the help of a dealer or independent shop custom building the engine for you. Harley never made an early version B motor 103 in a production bike with a 5 speed. Said it before, just rebuild what you have. A 103" upgrade from 88 is worthwhile at that time. A good running 103" is miles ahead of a stock 88" and does not cost "wads of cash". But it does take a new crank which you need anyway.

 

[Bubblehead Lifer]

Thanks Don, I think you hit me a couple times on the other post about pinion damage. I know this maybe premature until I can get the garage cleaned up and break the motor down. But do you have any suggestion on cam, piston, rod etc combinations that work well together for that low to mid range torque I’m looking for. As I have mentioned “wrench monkey”. I can take apart and put back together just about anything but when it comes to knowing what cam works with which piston that is over my head. Don’t really want to take it to shop unless it is something like boring out cylinders. Not because of the money but I use it as therapy after a bad day. That or kill Aliens on PS3.

 

[Don Dorfman]

Sure. Use an S&S 103 4.375 stroke crank, Andrews 48 cam, Harley adjustable pushrods and hybrid camplate and oil pump (part number provided already), KB 103 stock replacement flat top pistons at 1st oversize and bore your cylinders. Put new bearings everywhere and replace the balancer parts as needed. It will be a very good running motor. A sizable difference from the 88" but not as strong as a higher compression 103 with a little more cam and headwork.

 

[LNB]

Sure. Use an S&S 103 4.375 stroke crank, Andrews 48 cam, Harley adjustable pushrods and hybrid camplate and oil pump (part number provided already), KB 103 stock replacement flat top pistons at 1st oversize and bore your cylinders. Put new bearings everywhere and replace the balancer parts as needed. It will be a very good running motor. A sizable difference from the 88" but not as strong as a higher compression 103 with a little more cam and headwork.

Hey, I have a 103 that I’ve built from a 08 96ci engine. I’ve done head work and pistons and all the above. I am not really a high speed rider, low end pull is what I was looking for. Never got into the cases. I can smoke almost all 110ci and just about anything under that. Even am able to keep up with slightly bigger ci bikes. My point is, 103 built motor is more than satisfying. Can’t go wrong with it as long as you do it right or have someone who knows what they are doing. Go for it!!

 

[johnny_red]

A word of warning. If ordering a 1999-2006 4.375" stroke flywheel set from S&S specify the weight of currently available pistons, or they will supply a crank balanced for the heavier pistons of the 99-06 era that are no longer available.

 

[Sturge]

My '02 went 95ci at about 35K miles. Also had mild head port (BigBoyz) and added Andrews 37 cam at 9.8:1. After break-in, I had dyno tune at Big Boyz and what a difference...super fun build. At about 55K miles crank pinion sprocket shifted throwing counterbalance out of whack (FXST has balanced engine). I looked into crank repair but decided to go with an S&S 4.375 stroked crank and bored to 107. Used same Andrews 37 cam and Dan Vance tweaked heads/compression a bit to keep me in the sweet spot.

As stated above, you're into bottom end anyway so get an S&S crank and be done with it. Much more robust design than HD crank. For a little more you can go 117 but requires case machining and new cyls. I considered this but ultimately stopped at 107 which is as big as you can go with stock cyls.