I picked up a project bike last week. How do the stock cases hold up to a 96" build once bored? I'm going full S&S rotating, heads and cylinders.
Any info would be appreciated.

 

Lots of "Talk" about the '91 cases..
might be best to go full S&S or Chiwanese like tyhe Ulttima... probably Cheaper to go full Ultima, than rebuild what ya have... save even more by selling yer current mill....

 

I had a 93 FXR with a 96" S&S engine. It was a beast but I bought it like that. What's the word on 91 cases? bad castings? This thing doesn't leak a drop, then again, it's a stock 80" motor. I'd never buy Ultima, garbage. I'll keep this bike forever and use it for a bar hopper.

 

I recommend you talk to Scott at Hillside. An 89" in those cases is easy enough - been there with my 1990 FLHS - as it doesn't require any crankcase machining, but I would be wary of opening up the crankcase mouths to take larger bore cylinders. When I looked into enlarging my 89" further I concluded at the time that aftermarket cases were necessary, to provide reliability, also new cylinders, which added greatly to the cost. Hence my S&S 107".

 

I have never had problems with a well tuned 80 incher.. Course... I have a 1200 that has been 9 sec. at 135+...
Cubes are very fun... but, not everything!!!
I guess I would never need more than the 900 for a bar hopper... but, I do enjoy the 80 Incher...

 

Once the cases are bored there is not much meat left and the cases are prone to crack. It's not that they are bad castings. Better off to start with aftermarket cases, then you are spending.

 

I guess it's hit or miss. I've heard more cases (early 90's) then later years. I had my cases bored to accept the larger spigot for a 96" build and have not had any issues. I also heard that around 94 Harley went to Mercury Marine to build their cases (Mercalloy) and are supposed to be stronger than earlier years... I've had no issues to date. The biggest issue with going to the 96" build is that it's very difficult to find high compression Pistons... To get up to 11:1 for the cam I wanted to use (or anything over 9.7:1) I had to go with Axtell 30* Pistons and have them milled, then had to have the combustion Chambers reconfigured to accept the larger dome of the Pistons... Lots of money.... But lots of power as well.. An 89"er would probably be the cheapest way out or just purchase an S&S 111 or 124"er and throw it in...

 

Thanks for all the info everyone, greatly appreciated. Looking at a complete S&S 96" it would run about $6k.
S&S makes a Super Stock 80" but it's only a mild build, something I'm not interested in. Since i'm in Calif and the CARB and EPA are lunatics nowadays I think I'm going to give S&S a call and get some recommendations.

 

Don't waste your time with a 96"er get the 111 or 124 trust me.....

 

A 124" in a 540lb (wet) bike would be insane. Going with a Baker and Bandit setup and of course a chain conversion. I was just looking at a bike very similar to this at a FXR event in Sacramento a few weeks back. A 93 was for sale $28k! The wheels were RSD and cost almost $6k. I think it had a 124" motor. Like I said, this one I'll never sell so like any custom build I'll have way more into it than it would ever be worth.