>
>Yesterday, I was adjusting my valves, and while opening each valve, I
>noticed that not all of the valves opened the same amount. Is this a
>pretty fair indication of worn camshaft lobes and lifters? I know that
>the lift is not the same for exhaust as for intake valves, but these
>varied even among the same type of valve. My idle is also a little
>rough, despite all efforts to tune it, if this helps. I don't know how
>old the camshaft is, and I have a little evidence it may be a
>higher-performance unit than factory. I really don't want to tear into
>the engine until I have to pull it for something serious, but I'm
>looking for similar experiences from others.
> On a related note, what determines an engine's redline? I always
>thought it was a combination of things, but the most recent Moss catalog
>has a set of valve springs and caps that they say will extend your
>redline above 7000RPM. Is valve float really the only thing that limits
>safe RPM?
>Scott
>
>
In my case, it was a worn camshaft. The engine seemed sluggish during
accelerations, and when I went to adjust the valve timing, I noticed some
of the valves didn't move.
When I pulled the cam out, several lobes were completely gone. But this was
an Isky reground cam with less than 40,000 miles on it. Isky claimed that
MG cams were inherently weak. Fortunately, I had a spare cam handy.
This was a performance cam, with different intake and exhaust settings
(stock uses the same 0.015" gap on intake and exhaust). So you may have the
same problem.
I should have known better. When I sent my original cam to Isky to be
reground, I sent one of my worst ones. And to get the extra lift, they had
to add to the lobes somehow. All I know is that whatever they added, it
didn't last long - lobe failure in under 40000 miles.
David Councill
dcouncil@imt.net
71BGT
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