Hello,

I have a Dyna 2006, bored to 3.938” with JE-pistons and with Andrews 26, S&S lifters, Feuling OE+ camplate and oil pump.

Eventually I think I got the tuning right, (Dynojets tune with local tuner’s VE, plus 4-5 autotune sessions and 18 % timing retard on that). Bike has 9.2:1 (190/190 psi) and runs well, (except for some lower rpm vibration mainly due to the Predator front motor mount, I think).

My concern would this winter be to upgrade to the SE Compensator and to check the crankshaft runout again. Last time was two years ago, before the cam change. Then it was 0.0021” plus the gap of 0.0007”.

If when measuring the runout I discover it has increased too much, I guess I would have to replace the crank. S&S seems to be a good choice. It will give a longer stroke, from 4.000” to 4.375” and my displacement would increase, I think from 98 to 106 ci. Looking at Big Boyz Calculator I see that the compression will increase as well and that I may have to replace the cam.

Anyway, if anyone here has experience of changing to longer stroke on a big bore Dyna 2006, or any 99-06 Twin Cam A, answers will be much appreciated.

Best Regards

Oak Mountain Rider

 

You'll also have to replace the pistons..

I've stroked a 2000 fxdx but also used 4 inch bore cylinders that required case boring. Unfortunately that motor blew up about 2 years ago.. It's now a 107 all bore with 4 inch stroke.

If you still have the riveted alternator rotor, replace it.. You'll have to anyway if going to a SE comp.

What does 0.0007" gap mean?

 

Hi Max, thanks for answering.

Ah, so I need to replace the pistons as well? (I never thought about that.)

The gap is when you push and pull the crankshaft from and against the feeler gauge. That was ordained by the Feuling manual and the gap should then be added so I had 0.0028” by this method. (The Feuling limit for using a gear cam is 0.005”, if my memory is correct.) But looking at the Harley manual I see that they do not count any gap there and that by Harley standard I then had 0.0021”. The acceptable runout stated in the 2006 Dyna manual is 0.003, as far as I can remember.

Around 1:st of November, depends on the weather of course, I will take bike in for the winter and then pull the cam cover. Hopefully I am under 0.003”.

By the way, is your FXD 2000 running well now? I had a Superglide 2000 with Mikuni on it. I miss it.

 

Yes. The distance between the piston pin and the top of the piston is different to accommodate the longer stroke.

So the gap is simply measuring the play in the right crank bearing..

The FXDX is running great.

 

If you change to the Screamin' Eagle compensater you will also need to change the stator. The '06 stator is a smaller diameter, and will not maintain a proper charge. Use a stator from an '08 Dyna and it will plug right into your '06 wiring harness.

 

Thanks a lot.

 

Glad to hear that. You have the older, and better constructed, crank on your 2000, don’t you?

 

Yes.