Glenn:
I don't think there is anything wrong here. The pushrods are
closer to the head
because the ratio of 1.75:1 requires that the pushrod be moved closer to
the
rocker fulcrum, which means they are closer to the head. You will need
to remove the
head and grind the head to clearance the pushrods.
As I recall (never very reliable) the stock ratio for US is
~1.45:1 and for the
PI versions is ~1.55:1. So a 1.75:1 ratio is a big pop, and it is not
surprising
that you have run into clearance problems. This is racing hardware, and
you must expect
this sort of thing when going to such aggressive ratios. You will of
course need to
check for coil bind and can expect reduced cam life with such extreme
components.
Any chance you would consider 1.65:1 rockers instead?
Vance
------------------------------
1974 Mimosa Yellow Triumph TR6
Cogito Ergo Zoom
(I think, therefore I go fast)
-----Original Message-----
From: owner-6pack@autox.team.net [mailto:owner-6pack@autox.team.net] On
Behalf Of Glenn Rierson
Sent: Monday, February 16, 2004 7:13 AM
To: 6pack
Subject: Cylinder head identification - '70 TR6
I am attempting a roller rocker upgrade on my '70 TR6, but have run into
a
problem with the standard (solid) pushrods either slightly touching or
coming
too close to the head at the pushrod journals. The spec for the rockers
indicates the distance from the pushrods to the journal walls should be
.030".
As far as I know the engine is stock and the 1:1.75 ratio roller rockers
should work. The engine number is CC52689E, which according to the TRF
catalog and my British Motor Industry Heritage Trust Certificate is
correct
for my car. I know the engine has been rebuilt. The head has multiple
stampings and casting identifications and I don't know what they mean,
and is
the head "correct" for the engine.
<snip>
I know this question is asking a lot, but I don't want to give up on the
roller rockers.
Thanks,
Glenn Rierson
'70 TR6
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