Teh Evolution of THe Evo Cases.

Discussion in 'Engine, Fuel and Exhaust' started by friscofrankie, Oct 20, 2009.

  1. friscofrankie

    friscofrankie Banned

    I done some searching. I've found some inconclusive articles and m=partial histories. I've read horror stories about case porosity, thin castings and bearing inserts parting company with their host castings. Does anyoen have the full story on this? Or can they pont me to a place (on the net preferrably) where I can find out what is true and what is rumor?
  2. Breeze3at

    Breeze3at Well-Known Member

    Frisco; Google "harley evolution engine case problems year by year". I saw one that looked like it might have what you want.
  3. Fossil

    Fossil Active Member

    In 1984 HD went from sand cast cases to die cast. They went the extra expense to make the cases look sand cast. This is the major reason 1984 Shovel Heads are the most sought after of all Shovel years. The same year the first EVO engines came out. I have heard of porous problems but have never seen it or heard of it from the owner themselves. I do know the very early EVO years did have a problem with the left engine bearing and seal coming loose and flooding the primary case with oil and often damaging the engine due to loss of oil pressure. This I have seen myself and HD was forced to honor warranties and do an assembly line fix. Through 1988 the rear cyclinder base gasket would get blown out and leak. HD came out with a flypaper like gasket that was sticky on both sides. That sure stopped mine from leaking. Get the book 'Milwaukee Marvel' by Sucher for an unbiased historical look at the MOCO. Fossil