> Kai Rad[ic]ke is a machinist
Vance, I think you must have misheard, what Kai actually said was "I rebuild
cars that use leather and bits of wood for oil seals, I must be a masochist".
Stan
-----Original Message-----
From: owner-6pack@Autox.Team.Net [mailto:owner-6pack@Autox.Team.Net] On Behalf
Of Navarrette, Vance
Sent: Monday, August 27, 2007 7:45 PM
To: Greg Dito; triumphs@autox.team.net; Triumph 6 Pack
Subject: RE: [6pack] Valve Guide Fit, Intake Port Size
Greg:
1. You should not enlarge the ports on a TR6 head, according to
David Vizard (my hero) in "The theory and Practice of Cylinder Head
Modification". He claims that the TR6 ports are slightly too large
already. Yes, it is possible to make the ports too big. The bigger the
port, the lower the air velocity in the port, and the more likely fuel
is to fall out of suspension. In addition, you want to take advantage of
inertia to "ram" additional air and fuel into the cylinder. Big ports
reduce the "ramming" effect. If you are porting the head, smooth and
blend only, do not enlarge on the TR6. Don't even do a gasket match - a
waste of time on anything but an extensively modified racing engine.
Blend in the short side radius and blend in the last 1" of the port next
to the valve seat.
2. You should NOT be able to press the guide out with finger
pressure. I would say that it should require 300 lbs minimum to press
out the valve guide. HOWEVER, the valve itself should move freely
through the valve guide, and should have no detectable side play (you
cannot wiggle the valve from side to side). When held vertically, the
valve should fall out of the valve guide by itself. Typical clearance is
0.001 to 0.0015 inch.
Kai Radke is a machinist, and can give you definitive numbers on
the pressure required to press out a valve guide.
Cheers,
Vance
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