Date: Tue, 26 May 2009 15:33:17 -0400
Reply-To: VW Doka <vw.doka@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: VW Doka <vw.doka@GMAIL.COM>
Subject: Re: AMC valves, Boston Bob
In-Reply-To: <4A1C407E.3030209@comcast.net>
Content-Type: text/plain; charset=ISO-8859-1
Unfortunately, I've had the opposite experience. At least 50% of the
AMC heads I've removed from WBX'er engines have had damaged valve
stems at the keepers. Some have been really bad, others just a little
loose.
I'm guessing about 25 to 30 sets of AMC heads over the past 10 years.
We never leave the original exhaust valves in AMC heads when we
rebuild an engine. Just not worth the risk.
Just my experience...
Cheers,
Jeff
On Tue, May 26, 2009 at 3:18 PM, Ken Wilford <kenwilfy@comcast.net> wrote:
> 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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