Hey folks, pretty new to these forums, and I've been out of the business for over 10 years. Allow me to preface, that I worked in the business from franchise dealerships to even owning an aftermarket hd shop as well as just wrenching in the garage from the early 80's to late 90's. Divorce cost me everything so I've been out of it.

I'm now considering getting a bike again. I prefer the old FXR frame over the Dyna. I always like the better handling FXR, the lighter weight, short wheelbase, and twisting the throttle hard on them was always fun.

So my question now is, if buying a used FXR frame bike, will any of the dual cam motors fit this frame and do they hold the same rear motor mounting to trans position?

I haven't looked into any of it at all tbh. Just trying to get an idea as there is no shot that if I did buy an FXR that I would keep stock displacement. I can however build/design motors from scratch ( I wouldn't buy a shop built kit motor), so buying S&S or Delkron cases etc to build a motor for said frame isn't an issue.

Thanks for your responses.

 

Delkron makes evo style cases that take twin cam top ends. I think they are called fatsos or something. I am not an engine builder and dont know any one who has done it but it looks like a good way to get a big powerful evo

 

Thanks Matt, I'll look into it. So I guess they are no longer calling the HD motors evo's either?

When I went upside down I was in the process of building a 4" x 4 1/4" single cam motor for a custom drag style one off frame I had. I had S&S cases, STD heads, S&S cyls w/JE 30degree domed pistons, S&S wheels, Andrews 630 lift cam, S&S G carb with both an alcohol bowl and gas bowl (for obvious different uses). This was when the 4" bore stuff was brand new and I was building using the best configuration I felt I could design at the time. Sadly it went south with the business & divorce. But I'm getting the urge again to build one last ride for myself.

 

There quite a few twin cam fxrs running around. There might even be a thread on this site. Do a search on google as there are a couple write ups on how and whats needed to make it work.

 

few friends of mine buy wrecked roadking , strip them , cut the neck and set rake 1 1/2 inch back and 28 degrees rake and make 6spd twincam fxrs

 

if you can get chopperguys on the phone good luck but they can help you with any mounting questions.

 

I apologize in advance for my "purist" attitude, but the thought of putting a twinkie motor into a FXR sort of makes me feel nauseous.

To answer your question...a twinky motor will not just plop into a FXR frame without some tweaking. My question is...why would you ever want to do this?

An 80" Evo motor with some easy mods will surprise the hell out of most twinkie riders out there. Nevermind if you stroked the motor, cammed it, ported the heads, put on a Thunderjetted S&S Super E or a Mikuni 42, and threw on a Thunderheader, you could turn it into a twinkie killer.

 

My Thoughts exactly Bro .. Hell will freeze before see a Twin Cam in this beautifully running EVO ..

 

a twin cam will bolt right in with a motor to trans adaptor plate , the problem with using a late complete running gear out of a touring bike is the oil pan on bottom of trani . easier to just build one out of a road king . why would someone want one ? because some of us actually ride our bikes and need parts on the road . try finding an inner primary for an 85 fxr in kansas or oklahoma most of these bikes are 20+ years old and parts break

 

sonnydaze do you have any pictures of some FXRd Kings by any chance?