Re: ihc-digest V5 #134

[IHMagellan <IHMagellan@domain.elided>]

Jeff,

There's a severe interference problem with the domed pistons and the later
small combustion chambers.  The older heads use the dome to form the quench
area.  The newer heads' combustion chambers form the quench area between the
piston and the flat area around the chamber opening.  The dome is sticking out
of the block about 3/8" tall in exactly the same place that iron has been
added to the later chambers.  I haven't confirmed this yet, but after looking
through some piston part numbers and looking at some different heads, it seems
to me that the change is emissions related and occured with the addition of
the EGR valve.

Jerry Muncie

In a message dated 98-01-21 09:28:21 EST, you write:

<< Hey Howard,
 Given the huge amount of clearence, wouldn't domed pistons with newer heads
 give you a much higher commpression?
 I just can't see a problem there?
 
 Jeff Bade
 Chicago, IL
 1980 Scout ][, 304, 727, D300, 4" body, 4" spring, SS][ converted
 
  >>