I was looking for some technical help regarding increasing power and compatibility when doing a motor swap.


I have a 2006 Dyna Streetbob with a TC88 FI motor with a newly rebuilt 6 speed tranny and the newer SE compensator. I was going to do the heads, cams and then I thought maybe Ill increase the cylinder size as well while I'm at it. while putting together a cost comparison, it looks like it may be comparable/cheaper and more dependable to acquire a 103 from an ebay vendor and swap my 88" for a 103".


I was wondering what I would need to do this swap?


Do I need a new ECM, Ill probably need the bigger throttle body and can I use a 103 out of a Touring Road/Street Glide in my Dyna mated to my 6 speed?
If the heads have ACR, could I probably wire it to the starter?
Is wiring going to be a nightmare or is my current wiring compatible with what I'd use on the 103?




really appreciate any help.

 

Disclaimer: I'm no expert. But I would think that it would way more cost effective and easier to go to a 98" build and pretty sure that a built 98 will outperform the 103 all day. Maybe I'm wrong and the swap would be a piece of cake but I think just for cost of acquiring a used 103, that's in what condition?, would be more than a decent 98" build.

 

I'm not sure there were many models of TC88 that had a 103" engine. The TC96 model range has more models with a 103", but your trans won't bolt up to them, so that isn't going to work. In addition, Beagle's suggestion above will bring you many benefits over a stock 103", even if you have a slightly smaller capacity.

We have engine builders in here who you can contact for expert help, to actually perform mods and supply new parts. Pop into the Tech Engine section and consider contacting Scott at Hillside Cycle. Tell him you're a member of HDF! A proven aftermarket package should really light up your bike!

 

Scott will fix you up. He won't sell you anything you don't want/need. Great guy to work with.

 

A later Twin Cam will bolt to the 2006 Dyna trans GR, that was the year the Dyna got the hydraulic tensioners and 6 speed transmission with the pass thru oil passages. Still a 4" stroke on the engine though.

 

Your ECM will work. IIRC, '06 and up cable operated T/Bs are 46mm, so your T/B may very well be the same as the donor motor but not sure about the T/B size from a 103" motor but if larger, you could run it. FBW T/Bs are larger but no good in your situation. Any Dyna or Touring motor from an '07 up Twin Cam will swap out. You can wire the ACRs to the ECM but may require a new harness; not sure about that but you could also wire to the starter as you suggested.

I think I would plan and build a 98" motor. I have seen some strong 98" motors making near 120TQ/115HP; just need the right components and a good tune.