Goodparts makes a beffy replacement TR6/Gt6 pedestal with its roller rocker
setup. Not a plug - never used it, but I have had my stock pedestals egg
out a bit under the nuts /washers. I now have some high quality studs and
hardened washers and nuts from ARP.
----- Original Message -----
From: "Michael Porter" <mdporter@dfn.com>
To: "marty sukey" <trmarty@hotmail.com>
Cc: <fot@autox.team.net>
Sent: Monday, May 19, 2008 10:25 PM
Subject: Re: [Fot] Pedistal studs
> marty sukey wrote:
>> Ken,Jack, all. Is this a problem specific the the TR4 engine or is this
>> something the TR6 and Spitfire folks should keep in mind?
>>
>>
>
> The TR6/GT6 engines have the rocker shaft supports at the ends of the
> shaft, so that's a plus. Nevertheless, the pedestal studs are a bit
> wimpy. One of the things I've been thinking about is the tendency of
> the pedestals to walk back and forth with increasing valve spring
> pressure. As one adds stiffness into the valve train--stronger and
> stiffer pushrods, stronger rockers, etc., there's usually little done to
> the pedestal studs, and that means the weakest part of the valve train
> is the one to flex.
>
>
> In looking at the pedestals, it's apparent that they are mostly hollow,
> with a collar cast into the tops, which fits somewhat loosely around the
> stud. That means the pedestal, under load, can sort of squirm underneath
> the nut and washer, which might be one of the reasons for the nuts
> loosening up.
>
>
> What I'm thinking about doing is boring that collar out to a slightly
> larger size, enlarging the stud threaded bores in the head, then
> installing a larger stud that fits snugly inside the pedestal hole.
> That also allows larger nuts, and considerably more applied tension to
> hold the pedestals in place. I think that milling the feet of the
> pedestals perfectly flat and 90 deg. to the stud holes will help a bit,
> since they seem to come from the factory without precise finishing and
> over time may deform a bit and allow the pedestal to rock back and forth
> under load.
>
>
> Cheers.
>
> --
>
>
> Michael Porter
> Roswell, NM
>
>
> Never let anyone drive you crazy when you know it's within walking
> distance....
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