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Date:         Thu, 28 May 2009 00:24:31 -0700
Reply-To:     Zolly <zolo@FOXINTERNET.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Zolly <zolo@FOXINTERNET.NET>
Subject:      Re: AMC valves, Boston Bob
Comments: To: Robert Keezer <warmerwagen@YAHOO.COM>
In-Reply-To:  <627822.48461.qm@web33505.mail.mud.yahoo.com>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
              reply-type=original

The valves don't necessarily "have to" be replaced, but the keepers must be made to hold the stem without being loose. The old ones are now subject to metal fatigue. The AMC heads have better aluminum alloy material, not that hard and they don't crack as easy. Zoltan

----- Original Message ----- From: "Robert Keezer" <warmerwagen@YAHOO.COM> To: <vanagon@GERRY.VANAGON.COM> Sent: Thursday, May 28, 2009 12:00 AM Subject: Re: AMC valves, Boston Bob

What makes AMC heads so great then if the the valves need to be replaced? Is this recommended in the sales brochure by the Andalusian Matadors Confederation?

Robert 1982 Westfalia

--- On Wed, 5/27/09, Jerry <jbvelo@BELLSOUTH.NET> wrote:

From: Jerry <jbvelo@BELLSOUTH.NET> Subject: Re: AMC valves, Boston Bob To: vanagon@GERRY.VANAGON.COM Date: Wednesday, May 27, 2009, 6:43 PM

There are different processes for completing a correct valve/head job. I personally would never trust the valve work from other than a reputable mechanic. If I were to order the AMC heads from a vendor without knowledge of their technique or abilities, I would make sure that very good quality valves are used. This would mean total disassembly of the heads, replacing the valves, checking spring tension, etc.

I do know that Bob Donalds guaranteed his AMC heads. He replaced the AMC valves with OEM valves. He also checked spring height and tension. I had a long discussion with Bob in March 2008 about his method of completing valve work. The best method of doing a valve job is known as "interference angle". The valve seat angle may be 45 degrees. When you do interference angle you would grind the valve face at 44 degrees. This method ensures a positive seating angle for the valve face. The other important factor is the valve seating width. Normally you want the valve seating width to be around 1/16 ". And you want the valve seat to be in the middle of the valve face. You obtain this valve seat dimension and width using three different stones (interference angle). You use a 60 degree stone to widen the throat area. This will move the seating position toward the outside of the valve face. You use a 15 degree stone on the top of the valve seat to move the seating area to the inside of the valve face.

So, your optimal valve sealing area is approximately 1/16" in the middle of the valve face. The valve sealing area needs to be narrow so there is a good, effective seal. The sealing area also needs to be wide enough to transfer heat and provide cooling for the valve head.

Bob took time to do a valve job the correct way. I don't know about other people but Bob Donalds knew what he was doing.

I did valve jobs on diesel engines and I always used the "interference angle" method. It's the only way to correctly complete a valve job and have confidence that the valves are sealing they way they should.

Bob also identified problems with AMC valves and the valve keepers. You damn sure don't want a valve dropping at 4000 RPM because of a bad keeper or valve stem.

JB 88 GL KY

On 5/27/09 1:03 PM, "Marc Perdue" <mcperdue@GMAIL.COM> wrote:

> Given the widely diverse experiences you all are having/have had, I'm > beginning to wonder if there's a difference in your processes, i.e., > what exactly you do when you replace the heads, set the valves, what > specs things are set to, etc. On the surface of it, you'd think there > couldn't be a difference; after all, how many ways are there to do the > job? However, all other things being equal, i.e., if the AMC heads > each of you get are essentially identical, then how is it you could be > getting such different results? This is just sort of the systems > analyst in me talking, with a hypothetical ponderance... > Environmental considerations certainly could come into play, I > suppose, but I suspect there's something else going on . . . > > Marc > > On Wed, May 27, 2009 at 1:51 PM, VW Doka <vw.doka@gmail.com> wrote: >> "Doesn't exist"?? That pile of scrap AMC heads that I took the >> recycler must've been a mirage... >> >> Perhaps it's a "west coast" thing... >> >> Jeff >> >> >> >> On Wed, May 27, 2009 at 10:37 AM, Ken Wilford <kenwilfy@comcast.net> >> wrote: >>> Jake, I am with you on this one. I have done many, many head gasket >>> replacements and head replacements over the years. I don't know the >>> exact number but it is well over 50 at this point (maybe over 100 I >>> don't know). I have used the AMC heads exclusively for the past 11 >>> years. Out of all of those jobs I have never had one come back due to a >>> bad valve. Actually out of all of those jobs I have only ever had to >>> redo one and that was at the very beginning of my business and due to a >>> bad spot on the case that I didn't properly address (live and learn). >>> Beside that I have never had a head gasket or head replacement job ever >>> come back or have a problem that I know of. That is a pretty good track >>> record. I am a small shop, I hate returns way worse that you ever could >>> since I do this job many times a year not just once. If I thought for a >>> moment that this was a problem I would change the valves myself so that >>> I could avoid a come back. It just has never happened so I don't feel >>> like treating a disease that doesn't exist. I am just sharing my >>> experience here. >>> >>> Ken Wilford >>> John 3:16 >>> www.vanagain.com >>> >>> >>> Jake de Villiers wrote: >>>> >>>> I'm with Jeff. If an 'improved' head with better valves and tweaked >>>> keepers >>>> is only $100 more than an AMC head that is good for ~30,000 miles, why >>>> would >>>> I want to cheap out? >>>> >>>> The labour to re & re the head that swallowed a valve will be at least >>>> $1000, you and they'll want to check the other side too that's $2000 >>>> plus >>>> towing etc. >>>> >>>> Why wouldn't you want to do it right the first time? I know which shop >>>> I'd >>>> get my heads replaced at - the one that does the best job *ONCE*! >>>> >>>> On Tue, May 26, 2009 at 3:17 PM, Jeff <vw.doka@gmail.com> wrote: >>>> >>>> >>>>> Ken, >>>>> >>>>> Actually, the wholesale cost of a bare (no valves, springs or keepers) >>>>> AMC >>>>> head is substantially below $300, so a $499 "upgraded" head is easily >>>>> doable. >>>>> >>>>> Even the wholesale cost of a complete AMC head is below your example >>>>> below >>>>> of $389. >>>>> >>>>> As for valves... wholesale cost of "better" exhaust valves is less >>>>> than >>>>> $25, >>>>> intakes are less than $10. When I say "better", I'm referring to TRW >>>>> valves >>>>> that are made in Germany. >>>>> >>>>> And these are my prices. A large company that purchases in bulk will >>>>> get >>>>> much better pricing. >>>>> >>>>> >>>>> One thing that we commonly do is to reuse the original VW valves (if >>>>> they >>>>> are within specifications) on new AMC heads. >>>>> >>>>> >>>>> Cheers, >>>>> >>>>> Jeff >>>>> >>>>> >>>>> >>>>> >>>>> -----Original Message----- >>>>> From: Ken Wilford [mailto:kenwilfy@comcast.net] >>>>> Sent: Tuesday, May 26, 2009 5:32 PM >>>>> To: VW Doka >>>>> Cc: vanagon@GERRY.VANAGON.COM >>>>> Subject: Re: AMC valves, Boston Bob >>>>> >>>>> Jeff, >>>>> OK, let's pretend that you are going to replace your exhaust valves >>>>> with >>>>> "better" ones that are around $35 each. This is just exhaust valves >>>>> however there are two of these per head ($70) then you are going to >>>>> want >>>>> to use "better" intake valves which run around $20 each ($40 per >>>>> head). >>>>> So just in valves you are talking about adding $110 in cost per head. >>>>> Now look at what folks are charging for the heads with the "better" >>>>> valves. A certain company who shall remain nameless is selling their >>>>> "better" valve heads for $499 each. This would mean that they would >>>>> have to buy their heads at $389 each just to break even (not making >>>>> any >>>>> money and not factoring in their labor). The heads just aren't this >>>>> cheap. Even if they could get the heads for $300 (way below what >>>>> anyone >>>>> can actually get them for wholesale) you are talking about only making >>>>> $89 per head which wouldn't be worth it. That might cover your labor >>>>> in >>>>> removing, installing and lapping the valves but that is it. No profit. >>>>> The math just doesn't work. The only way it works out is if you take >>>>> the AMC valves out and put something else in that is relatively cheap. >>>>> I know one particular rebuilder who shall remain nameless who was >>>>> replacing the AMC valves with aftermarket stainless ones that he could >>>>> get pretty cheaply. This was working well for him for a while until he >>>>> ran into a bad batch of these aftermarket valves that had improperly >>>>> heat treated stems and had valves start failing on him. So the very >>>>> "problem" that he was supposed to be fixing by replacing the valves >>>>> was >>>>> the thing that started happening. Ironic, isn't it? >>>>> >>>>> So if people wanted to pay a premium for heads with OE valves >>>>> installed >>>>> I would have no problem with that. People can pay a premium to get >>>>> premium valves. However when a company says their heads are better >>>>> when >>>>> they are putting in aftermarket valves which may or may not be any >>>>> better than what they are replacing I just don't think this is right. >>>>> Just my opinion. >>>>> >>>>> Ken Wilford >>>>> John 3:16 >>>>> www.vanagain.com >>>>> >>>>> VW Doka wrote: >>>>> >>>>>>> From my experience, they start to show significant valve stem wear >>>>>> around 20k miles. Failure around 40k miles. >>>>>> >>>>>> The bad batch story is just that... a story. The AMC heads sold today >>>>>> still use the same cheap, crappy exhaust valves as the ones from 5 >>>>>> years ago. You can buy the same valves brand new for about $7. A >>>>>> good exhaust valve for the WBXer runs about $35. >>>>>> >>>>>> Not conjecture, not really opinion... just my experience. >>>>>> >>>>>> Cheers, >>>>>> >>>>>> Jeff >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> On Tue, May 26, 2009 at 4:13 PM, Robert Keezer >>>>>> <warmerwagen@yahoo.com> >>>>>> >>>>> wrote: >>>>> >>>>>>> Very logical . After all, how would a company like this stay in >>>>>>> business >>>>>>> >>>>> year after year with notoriously bad valves? >>>>> >>>>>>> It just did'nt make sense. >>>>>>> >>>>>>> I think Kens' answer is reasonable fro me to go by. >>>>>>> >>>>>>> One bad batch has perpetuated this myth all these years. I never >>>>>>> >>>>> believed it . >>>>> >>>>>>> Most of my Vanagons sold with AMC heads and never a complaint. >>>>>>> Which is why I asked, how long do they last? This bad batch head? >>>>>>> >>>>>>> If they went bad in 5 years, I would'nt expect to hear from the >>>>>>> buyer . >>>>>>> One year or less maybe . Less than 6 months probably. >>>>>>> >>>>>>> Robert >>>>>>> 1982 Westfalia >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> --- On Tue, 5/26/09, Ken Wilford <kenwilfy@COMCAST.NET> wrote: >>>>>>> >>>>>>> >>>>>>> From: Ken Wilford <kenwilfy@COMCAST.NET> >>>>>>> Subject: Re: AMC valves, Boston Bob >>>>>>> To: vanagon@GERRY.VANAGON.COM >>>>>>> Date: Tuesday, May 26, 2009, 12:18 PM >>>>>>> >>>>>>> >>>>>>> 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 >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>> >>>> >>>> >>>> >>>> -- >>>> Jake >>>> >>>> 1984 Vanagon GL >>>> 1986 Westy Weekender "Dixie" >>>> >>>> Crescent Beach, BC >>>> >>>> www.thebassspa.com >>>> www.crescentbeachguitar.com >>>> http://subyjake.googlepages.com/mydixiedarlin%27 >>>> >>>> >>> >>

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