I have a head that used to belong to Jack Wheeler. It is milled
0.175". It is "pinned". The way Jack described it to me, to "pin" the
head, you drill and tap a number of small holes around the circumference of
the combustion chamber directly over where the head would mate to the
liner, opposite the combustion chamber. You use long, hardened set screws,
coat them with epoxy, thread them through until they hit the other side of
the water jacket and then mill the head.
In my head, you can see round shiny patches on the surface of the head that
are the "pins". I'll try to describe the locations of the pins: there are
2 or 3 of them inboard of the water jacket hole closest to the exhaust
valve. There is one on the opposite side of the combustion chamber of both
of the valves. Total of 4 or 5 per combustion chamber. I've posted a
description and a crude drawing of the pin locations on my website.
Description and thumbnail picture is at the bottom of the following page:
http://www.tonydrews.com/Tony_Car.htm
The full size drawing is at: http://www.tonydrews.com/Tr-4_head_pins.jpg
My knowledge of this is based on one head and the description that Jack
verbally told me. If others have better descriptions, or alternate
(better) locations for the pins, or other descriptions on what you do to
glue the pins into the head, or other ways of reinforcing the head, I'm
extremely interested them.
- Tony Drews
At 01:35 PM 2/16/2002, Brad Eells wrote:
>Greg,
>
>Interesting comments. I have a head for my TR4 that was raced very seriously
>that is cut .210. The second head that came with the car is cut .117.
>
>What sort of reinforcement would I look for to see if this modification was
>done to this head??
>
>I just about choked when I got that measurement thinking about what kind
>compression ratio the PO was trying to run. Looking at his logbook, he had a
>number of engine related DNF's. I think he was pushing the envelope a bit.
>
>Brad
>62 TR4
>
>PS. For you PHA Hillclimb fans...I just confirmed via a printed program
>purchased on Ebay that my car was an entrant in the Oct. 10, 1971 Weatherly
>Hillclimb event. This pushes back by two years the car's known competition
>history! Amazing what you can find on Ebay!
>
>
><<With a reinforced head we have run
>comjpression ratios of over 12.7: 1 with over .220" milled off. BUT this is
>not s goal that I recomend.>>
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