I was looking for some technical help regarding 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?
Will probably need the bigger throttle body?
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 tc88 wiring compatible with what I'd use on the 103?



really appreciate any help.

 

Why not just bore to 98" ? Don't think you're going to be that out price-wise.

 

Have to agree.... More economical to build your's to 98".... Some real strong 98"ers out there

 

No,, The ecm you have is fine but you will need to have the motor tuned to the new build.

I suspect that the throttle bodies are the same when compared to a 103 that is throttle by cable (not wire). The 103 throttle body might be a little bigger but you current TB will work..

You can use any motor out of a touring bike or Dyna (07 -up TC).

If the heads have acr, you might be able to wire them up to the current ECM.. If you were to change the ecm to something like a Tmax, it would be pretty easy.

AFAIK the wiring is compatible except that you can't use a fly by wire throttlebody.

Building the 88 to a 95/98 is definitely a possible way to go but unless you do a higher performance build, the 103 would likely be better with simply a cam.. You could also buy the 103 motor (or 96 ci motor for that mater) and and build it to a 107/110 to have some real fun..

 

you can make your 88 a 103 with a bigbore top end and a stoker crank if you are willing to pull the engine and split the cases. since your bike is an 06 and later head design, if you need a larger throttle body there is a SE version complete that will bolt right up, just tune it and be done, however, i would recomend that you consider doing some headwork while you are in there to get the best bang for you bucks.
m

 

Thanks everyone for your input.
Ive decided that im going to go with a 98" build based on your advice and cost comparison. to reduce down time Ive already acquired a set of heads, cylinders for extremely cheap, which I will be sending for a port, mill and bore. Ive already acquired some cams and I will be looking for a cylinder kit.


I just have 1 last question, do you all think a 98/96" is structurally safe for the 88" cylinders? I've seen some posts stating that 95" is the safest, but then again I've seen some running 98" without issues. Does anyone advise against this?


My goal is to get some more torque out of my bike. it handles really well and looks great, now I just need some more power.
thanks

 

Save a little for your rotor shell and charging system. 2006 rotor/compensator shell was held together by bolts and failed - especially on bikes people wound up. Looking at your bike, I see you will be that club one day. When it happens, you will just buy a complete kit for an 07. Done quite a few...

 

Do the 98" It's safe and has been done for many, many years...........

 

With out tearing into it you will never know how far the pistons will be down in the hole. Which will only give you a ball park figure on your comp. After you get the new cylinders bored and pistons fit. Mock it up to get piston depth then tear it back apart (if necessary) to have the base of the cylinder machined to get to .000" in the hole or zero clearance... Not only that you will at the same time have a set of jugs where the bottoms have been trued and less likely to weep oil...

 

Great torque combo that will work very well in that Dyna is;
Bore to 98"
Head work
Andrews 57 cams
t/body mods
10.0 cr.
No issues boring to 98".
We were one of the very first shops in the country, to begin boring to those dimensions back in 2006.
Scott