On Tue, 22 Apr 2003, Alan & Debbie Lindner wrote:
> I believe my head was milled. Does anyone have a measurement
> of the the adjustment threads length with a narrow nut on for a
> standard or milled head.
Ummm... this is one reason that you need to shorten your pushrods if the
head is milled. What happens is that you arrive at the proper valve lash
by backing the adjusting screw nearly all the way out...
The Competition Prep Manual shows how to make a dummy pushrod to get the
proper pushrod length, and you then need to obtain a tubular pushrod set
to shorten (or you can buy them already shortened).
Note: the Euro Spec motors ran higher compression heads from the factory.
so there's a euro spec stock pushrod that some folks sell (I recall BPNW
having them sometime in the past). The stock pushrods are not tubular
type.
> Also, can I just measure the height of the head to get an idea of
> how much has been milled?
Well, you might be able to, but you have to know what you started with.
For example, I had over .110 milled of my stock 74 TR6 head and it got me
to about 9:1... all the late heads are 'real thick" whereas the '72 head
would only need less than .050 milled off to get over 9:1 (seeing that it
starts life as more than 8:1 and the '74 is a 7.75:1 stock compression
ratio.
As a generaly rule, if you measure from the deck to the surface that the
valve cover seal to, you come up with a "thickness", and you can
approximate the compression ratio. But the only true way to measure is to
get a burrette and pull the head and measure the volume of the combustion
chamber (and don't forget that that head gasket needs to be included in
your computations.
> Alan
regards,
rml
------------------------------------------------------------------------------
Bob Lang Room N42-140Q | This space for rent
Consultant MIT unix-vms-help |
Voice:617-253-7438 FAX: 617-258-9535 |
------------------------------------------------------------------------------
|