96" S&S conversion in an evo

Discussion in 'Engine, Fuel and Exhaust' started by kedoba, Sep 16, 2010.

  1. kedoba

    kedoba Member

    I have a '93 FLHS with 60 K miles. The top end was done about 16 K ago and bored .030" and currently the cam seals are leaking as well as the bottom of one of the jugs. None of the oil ends up on the floor though. The exhaust puffs smoke and I go through about a quart of oil in about 1500 to 2000 miles. I am thinking of putting an S&S 96" kit in it which has 10.2:1 compression. The guy that works on my bike says he won't do it because the bottom end won't hold up to the bigger cubes and more power. I have read that by increasing the stroke as with one of these kits it caused the piston to hit the cylinder at a sharper angle which causes a more frequent rebuild. I read it's about 35 K miles instead of 50 K miles. Does anyone have experience with this conversion and what are your thoughts about it? Thanks.:unsure
  2. Jack Klarich

    Jack Klarich Guest

    Built lots of Shovel Strokers using S S kits very reliable, increase in piston speed and more side loading and thrust on the pistons, that said still very reliable builds IMO Evos take good stroking , you can find the right combo in The Big Twin Hibh Perfomance Guide, Hopple has my copy right now it gives good combinations for motor builds, good luck if you want more inches STROKE IT:s
  3. karlsbike

    karlsbike Active Member

    I am late here, but anyway (I was born late;)
    I have almost the same as you - my '91 is getting old and worn - leaking everywhere. I am therefore building a full S&S 96" kit this winter (I didn't buy the complete engine, as this started off when I saw a set of big-bore cases for 50% off...)
    I knew I was not keeping the old cases, as I got scared reading all about EVO case failures after boring them.
    You see, the S&S 96" kit is not a stroker only kit, but a 3 5/8" bore (+1/8"), 4 5/8" stroke (+3/8") kit. This means that the cases needs machining leaving too little material for comfort especially to the studs and one of the lifter blocks. I think the H-D cases were beefed up a bit in 1994? (not 100% sure of the year)
    Adding a standard S&S EVO stroker kit (yielding 89") should be ok - as Jack notes above.
    Otherwise, the only difference between the 96" kit and mine are the cases - which I am sure you can score for a reasonable price these days. Adding a good cam and 10:1 compression (what I am aiming for) - should give you plenty of power AND all you want in terms of reliability.