Date: Tue, 26 May 2009 15:18:22 -0400
Reply-To: Ken Wilford <kenwilfy@COMCAST.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Ken Wilford <kenwilfy@COMCAST.NET>
Subject: Re: AMC valves, Boston Bob
In-Reply-To: <ED8CE9CF91284BCB82DD7E524FF412F4@ZoltanPC>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
I spent a bunch of time on the phone with Bob talking about this subject
as well, but I believe all of this fear and loathing about the AMC
valves is due to a bad batch of these heads back about 6 or 7 years
ago. I have never had a failure like the one Bob always warned me about
and I never changed the valves from the stock ones. Recently I had a
pair of AMC heads that I installed on an engine about two years ago come
back into my possession (engine threw a rod). The heads had about 18k
miles on them. I took the heads to a machine shop to have them checked
and a valve job done before selling the heads to a list member. I asked
the machine shop about the condition of the valve keepers, grooves on
the valve stems, etc. He said that he had inspected them and they were
like new condition and that they valves themselves were also in like new
condition. I can say that I have never had an AMC head fail in 11 years
of installing them. I have never had one that I have sold to a customer
fail due to a bad valve either. Anything can fail if you abuse it, or
improperly install it, or don't correctly adjust the valves, etc.
However I have never found the stock AMC valves to have any issues. If
you want to spend extra money on "better" valves and install them only
to have them fail (I have known this to happen) that is your choice.
However the stigma against using the AMC heads out of the box is totally
unfounded as far as I am concerned.
Just my experience,
Ken Wilford
John 3:16
www.vanagain.com
Zoltan wrote:
> One important fact I learned from Bob, was that the AMC heads have loose keepers. The two halves meet each other to touch, thus grabbing the valve stem, being loose, they travel up and down until they break through the grooves and the valve free to move deeper inside and then operated by the piston to have it pushed up.
> So, the first thing I recomment to anyone I meet is to have the keepers ground at their sides until they don't touch each other.
> Bob was very happy with the AMC heads and tossed the old ones for their metal fatigue. In his experience, it was not worth chancing all the troubles by putting the old ones back.
> He liked the better material the AMC heads are made of.
> So, the keepers must be fixed first.
> Zoltan
>
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