Good point on the assembly lube. I also found that the Kendall oil was
great when I was running the turbcharger business. In fact I was doing some
stuff for the NASA people and when I put them onto the Kendall diesel motor
oil their turbo bearing failures completly went away. That is very cool that
you are testing the tappets. Any cam worth much will probably have a tapered
lobe cause that is about the only way you are going to get the tappet to
rotate.
----- Original Message -----
From: "Greg Solow" <gregmogdoc@surfnetusa.com>
To: <WEmery7451@aol.com>; <jmwagner@greenheart.com>; <kaskas@earthlink.net>
Cc: <rjmunns@btinternet.com>; <FOT@autox.team.net>
Sent: Sunday, January 27, 2002 4:54 PM
Subject: Re: Camshaft failure? :(
> Tappets have been a problem for some time. We will not install any tappets
> that have not been hardness tested. The minimum hardness that we will
> install in a street engine is Rockwell C scale 51, and for racing we like
to
> use tappets that are harder than 56 Rc. We send a lot of tappets back to
> our vendors as defective.
> When we have tested original (installed by Leyland) tappets, we have
> generally found them to be in the 52 Rc to 55 Rc range. The replacement
> tappets available today have varied from 19Rc all the way up to 60 Rc. The
> last batch of "Triumphtune" tappets went from 41 Rc up to 56 Rc. They all
> look the same. They are made to go on a cam that does not have tapered
> lobes. We have found that if the lobes of the cam are tapered and the
> tappets are machined to match and are hard enough, with the proper break
in
> and use of Moly based assembly lube, the failure rate is almost nil. We
use
> Kendall GT-1 racing oil in our race engines and Chevron in our street
> engines. The Kendall is superior to most other oils in keeping iron to
iron
> wear to a minimum. It is also excellent where there are bearings. Other
oils
> we have tried have worked well in the bearings and crank area, but not
> wherever there is iron to iron, non pressure lubed situations. These areas
> are the cam and tappets, the rocker shaft, valve stem to rocker arm,
timing
> chain to tensioner, and cam to oil pump drive gear.
> These experience are based on TR-3, 4, and 4A engines and may not
apply
> exactly to TR-6 and Spitfires.
>
> Regards, Greg Solow
>
> The Engine Room
>
> Santa Cruz, Ca.
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