Hi anyone considering doing this big bore upgrade? I'm very interested as I have a deposit on a 07 Fatty.
You think they will they have to mill the case out?

 

Nobody? Any HD techs out there?

 

Not sure, but I noticed they are selling a new case boring tool. Based on this fact alone I suspect the cases must be bored.

 

Starting planning early on this one. I have an 07 Duece on order right now and I'm actually looking at the other route of forced induction. I know a supercharger or Turbo can be done fairly easily and going by the Dyno it seems like te way to go. I've never riddin a Harley with forced induction though, so I'm still in the looking around stage right now

 

Whoa! Now that's a way to go. I wonder what the powerband will look like on a 96" blown motor.

 

Cases do not need to be bored....

Just a bigger bore, as the motor is already stroked.....

With that kit, you will get a new set of heads with ACR's built in.....

Similar to the S&S version.. Haven't seen them yet.... like to see how they are wired up.....

 

Are you completely certain about not needing to bore the cases. Reading the 110" kit it does not specify the need, but reading the case bore tool it sure does. This is from the case bore description.

The Screamin' Eagle® Case Boring Tool takes the guesswork out of boring Twin Cam engine cases to accept oversize cylinders. Designed to be used with a heavy-duty 15" drill press or milling machine, the fixture holds and aligns the cases for accurate machining. Ideal for installing a new '07 Twin Cam 110 cubic inch Stage Kit .

Boring the cases isn't for a longer stroke but for the larger dia. jugs for as you stated the larger bore. 4" bore to be exact. Regular TC 88" engines need a case bored for 4" pistons I would bet the new TC 96" inch does also since they use the same jug size as a TC 88".

 

Going by what the Svc Mgr relayed to us when he returned from the dealer show.....

Havent seen any of the kits, as they are on order, as well as the stand.....

 

Since the cylinders haven't changed, the spigot holes in the cases must be the same as well. The stoke is increased to 4.380" to obtain the 96" displacement with 3.750" cylinders. The Big Bore cylinders are 3.875" still. The combination of big bore cylinders and the 4.380" stroke yields a 103" engine. In order to go to 110", you need to use the Bigger Bore cylinders at 4.060". These will not bolt on. They require opening up the cases and machining the spigot holes to accept them.

 

Great Info ! Just what I was looking for.
I think I will cruise it and break in the engine as a 96" and have something to look forward to and compare the performance when going up to a 103" or 110".
Boring the cases has to be costly. I was hoping not to have do the complete engine breakdown. [&o]