Re: [T3] ? Mystery of the Clacking Valves ?

["Jim Adney" <jadney@vwtype3.org>]

On 14 May 2011 at 10:37, Bobsnotch@aol.com wrote:

> Jim, most of today's modern engines have roller lifters, and cams designed  
> to use them. This change to rollers basically eliminated the need for the 
> ZZDP  in the oil. Also, when talking to a GM tech (at the dealer), he said 
> that by  eliminating the ZZDP, the catalytic converter gets a longer life (the 
> stuff  inside it). This was the reason they were getting rid of their EOS 
> (Engine Oil  Supplement), which contains ZZDP.

The roller lifter explanation is also what I got from a co-worker 
that I asked about this yesterday. I hadn't realized that this was 
common today. It makes sense, but that sure leaves a LOT of older 
cars out there SOL.

> I think there are a couple of people working with either roller cams and  
> lifters , or ceramic lifters for our engines. Jake Raby is one of the few  
> that I know of, as he's been dabbling in both.  

If would be great if ceramics could fix this. I hadn't thought of 
that. There are companies that do ceramic coatings to ordinary metal 
parts, but I would expect this to be a pretty hard thing to get to 
work right.  

-- 
*******************************
Jim Adney, jadney@vwtype3.org
Madison, Wisconsin, USA
*******************************

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