[Fot] Deck clearance

[Richard Good]

Charly,

I went .012" above once.  Made good power till a piston kissed the head 
and disintegrated.  It happened at 7000+ rpm.  I have stayed within a 
couple thousandths above since.

Richard Good

Charly Mitchel wrote:

>		 Friends,
>I'm building a race motor for my TR6 and have a few questions
>about the deck clearance.  On the last motor I built, I made the block zero
>deck clearance on all the pistons.  To do this I had to shave the top of
>several pistons and mill the block .020".  The motor I'm using now is a later
>TR6 motor with the recesses for the head gasket seal.  This recess is about
>.030".
>While measuring the piston travel for each cylinder I find the
>distance from the top of the block varies from .004" to .013".  I tried
>swapping pistons around to see if there was variance in rod centers and this
>seemed to make no difference.  I'm guessing this is from maching of the crank.
>While I was pick up my block from the machine shop I was speaking to a fellow
>that was building Ford 4 cylinder racing motors and he was saying he likes to
>have the piston .008" above the deck.  This is supposed to help with
>combustion swirl (I think that is what he called it).
>The thoughts I'm having
>is has anyone tried this with the TR 6 cylinder motor and if so what were the
>improvements if any?
>This would be fairly easy for me to do at this point and
>would do it if it made sense.
>I'm also concerned with partially milling off
>the recess around the bore and what consequences that may have.  I have no
>problem completely removing the recess since that is the style of the earlier
>6 motors.
>
>Thanks for any input.
>Charly Mitchel
>TR6 #44