Sender: "Marvin Kaye" <marv@lancaironline.net>
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Date: Mon, 06 Dec 2004 22:20:50 -0500
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From: Tom Thibault <tthibaultsprint@earthlink.net>
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Subject: Re: [LML] LNC2 Forward Facing Induction
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My engine started life as an IO360-B1F (updraft, 180 HP).  I bought the 
Performance Aero Engines replacement sump, the required new intake tubes 
and rubber connector tubing, plate to cover old induction opening, 
gaskets, etc.  Total cost $786.  As I understand it, this sump is from a 
-B1E engine.  This was an aft facing installation.  The mod is to cut a 
round hole in the bottom of the -B1E sump in order to gain access for 
welding in a new stainless spider aimed toward the front instead of the 
rear.  The rest of the mod is to weld on a cover for that hole, weld a 
flange on the front for the fuel servo, and finally provide a cover 
plate for the aft opening.

Unfortunately, the sump was not tapped for the oil quick drain, so I had 
to pay a machine shop to do that for me.

I then had to buy a replacement custom exhaust system (none of the 
systems from Lancair fit this layout).  This I got from Custom Aircraft 
Parts, in El Cajon, CA.  They are a first class operation, but the new 
system cost $1500 .   I chose a four-into-two-into-one configuration, 
with a 2.75 exit pipe turned down 45 degrees at the end.  This slip 
jointed system has about 150 hours on it with no cracks and requires no 
support brackets whatever.

Finally, I reshaped the cowling to look much like a Legacy (one tunnel 
down the pilot's side and very little below the fuselage profile).  This 
resulted in an exit opening of about 8" by 2.5", plus the 5" ID tunnel 
surrounding the exhaust exit.  The air inlet is a straight shot of scat 
with no filter.  Resulting CHTs are very good.  My Arizona summer time 
climb temps are 390-400 F and cruise is usually 370-380.  Summer oil 
temps (front mounted cooler at cyl 2) are 200 in the climb and 170 
cruise.  These are WOT, lean to peak EGT at 12K feet plus.  At low 
speed, my oil temps zoom, so summer touch and gos are a problem.  I 
suppose that is partially due to no inlet ramp in front of the oil 
cooler causing turbulent flow.  With only 2" from inlet to cooler and 
the cooler being an inch below the inlet lip, I wonder how you can 
follow the 11 degree rule for the angle from inlet to ramp.  If anyone 
has photos of a ramp that solves this problem and results in good low 
speed oil cooling, I would love to see them.

The performance improvement was very small.  There was a small increase 
in manifold pressure over the updraft without filter.  I can make 19.5" 
MAP at 12.5K feet.  At best, my TAS increased 5 knots.  Quite an expense 
and effort for so little of a performance gain.

Tom Thibault
N4XB, "Eagle Dancer"