Ferrari Mailing List: Re: Engine problems

[Jim Conforti (lndshrk]

On 5/6/2011 9:39 PM, Robert W. Garven Jr. wrote:
> Lets talk about this
> 
> http://www.ferrarichat.com/forum/showthread.php?p=140497884#post140497884

  OK, at the risk of violating my own (and Benny Hill's) rule...

  Let's ASSuME that there are no "cracks" - no broken heads, pistons or
  cylinder walls.

  So where can air be leaking.

  1) The Piston/Ring/Cylinder interface
  2) Cylinder liner/Head interface (aka head gasket)
  3) Intake Valve
  4) Exhaust Valve
  5) Spark Plug

  To eliminate #1 - you put a squirt or two (not drops, but a good slug
  of oil - let's call it 3-5cc - into each cylinder and rotate the
  engine a few times before retesting.

  Note, this only eliminates WORN rings/cylinder liners - not STUCK
  rings.

  You can eliminate #3 easily by listening in each intake runner and
  comparing the sound of leakage.

  #4 is much harder unless you have the exh. manifolds off.

  If you have separate CO plugs that will actually come out, you can do
  that and listen to each as the cylinders are pressurized to compare.

  So we eliminate 2 the old fashioned way, run the motor for a few hours
  and then look for combustion gasses in/over the coolant using the
  proper (and very inexpensive) chemical tester which samples the
  gases and changes color.

  (Of if you have a CO meter you can do it that way)

  Essentially, the "head" of air over your coolant will rapidly become
  all sorts of CO2, and usually you'll have either oil-in-coolant or
  coolant-in-oil.

  You'll notice however that I also mentioned #5.

  How, I can hear the thoughts - "But Jim, he has the TESTER in the
  spark plug hole".

  Exactly, and if I had a $1 for every time a POS tester didn't seal
  properly in 1 or 2 plug holes, I'd also have an F430 Scuderia for
  track days ;)

  This is 33 years of building engines, and thus having to fix every
  family/friend/acquaintance,

  If your tester doesn't have a good gasket, add an o-ring around the
  snout that screws into the spark plug hole.

  If it DOES have a good gasket it's bright light and/or mirror time to
  see the difference between cylinder 3 and the others.

  If none, rule out #5.

  Also remember - that a simple gummed up ring can cause #1.  Nothing
  has to be "bad".

  In which case you can try running the motor, then squirting a little
  marvel mystery oil down each plug and rotating the motor warm a few
  times - letting it sit over nite - then restarting and immediately
  changing your oil.

  If it were me?  I'd give it an italian tune-up first.