At 21:40 27/04/98 -0400, you wrote:
>-- I was was/am planning on bronze guides and stellite or SS valves. Is
>stellite or SS better??
I think Stellite is harder. It is used in artificial heart valves.
>What do you think about replacing the valve
>springs since I have them off? The originals are over 30 years old ...
Definitely. And you should consider getting uprated ones (you'll be able to
redline higher, or be more confident about going to your spec'd redline).
>--That is a good question. How do I tell? Do I just measure the
>total head thickness with a caliper? I have a pretty good one
>of those. You are right, I do not want to boost the compression too
>much. I have a problem with run-on as it is.
If in doubt, you should measure the clearance of your pistons at TDC, and
the valves. You can do using the old head gasket - just don't give it quite
as much torque as normal. Oil the tops of the pistons and bottoms of the
valves, and put plasticene on top of the pistons (under the valves). Turn
the engine over once by hand, take off the head, and carefully peel off the
plasticene and measure the thicknesses. This will tell you how much you can
skim off the head and how much extra valve lift you can run (if you're
considering a cam grind). At this point, you can also calculate your
compression ratio (after measuring the volume of the combustion chambers).
Graduate School of Biomedical Engineering
University of New South Wales
Sydney 2052 Australia