In a message dated 04/18/1999 6:56:53 AM Mountain Daylight Time,
ianmiller9@hotmail.com writes:
<< First of all the reason I tore my motor apart was it was only running
on 3 cylinders. I figured out why fast enough. Once the head was
removed I saw one of the valves wasn't closing. One of the retaining
bolts on the airfilter back plate had fallen out and been sucked
inside my motor and was holding the spring open. The good news is I
can't see any where that the piston was touching the valve. So my
first question is should I pull the valve springs and check for wear
on the valve stem? Then what constitiutes a "valve job" and how do I
do it? Where can I get the proper valve seals? Secondly on my motor
I have a cast iron head (66), but on the spare motor I have (67)I have
a aluminum head. Is this normal? should I switch heads?
Thanks Ian Miller
>>
Ian,
If you really want to do the head right, take it to a good machine shop and
have them see what all needs to be done. While it's off it would be a good
idea and go ahead and do a complete valve job. That would consist of
replacing all the valve seals, grinding the seats and valves checking the
head for flatness and pressure testing it for leaks. Now, if the head is
original it will have the brass valve seats and they should be replaced with
ones that are compatible with unleaded gas. The brass ones are not very hard
and they recede into the head so the valves sink deeper and deeper in.
Another problem I had with them (twice) is that the brass and aluminum expand
and contract at different rates and they eventually loosen up and fall out.
Then you have a valve stuck open, which can damage the piston. Last time I
had mine off (had dropped a valve seat) I had all the valves, guides, seals,
and seats replaced and the head resurfaced. I believe it cost around $450
and made the car run a lot better and I don't have to worry about the seats
receding with unleaded any more.
Joseph Berkenbile
70 1600
Albuquerque
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