On Mon, 22 Nov 2004, John & Allison Cyganowski wrote:
> Say, I have 2 questions about a couple of recent posts:
>
> 1.) What is "soda strip"? I am assuming this is a chemical strip of the
> paint. Why would you want to do this instead of say a wire brush approach?
Soda stripping is a media blasting process using bicarbonate of soda
instead of courser media (such as sand). It's a very good method to remove
paint because it doesn't make as much heat in the panels and therefore no
panel distortion.
I've done a couple of restorations. Trust me that you don't want to
wirebrush an entire car body unless you have a lot of time and a lot of
patience. And an extremely dry garage... because once you remove the paint
on your car it'll rust faster than you can possibly imagine. I've seen
rust form overnight on recently stripped steel (a TR6 "bonnet").
> 2.) Why does one want to lower the block deck height? I assume that this is
> part of increasing compression? Is shaving the head not enough? I have
> heard that decking the head removes the block s/n. Can it be re-stamped?
You deck the block to insure that the combustion chamber size is exactly
what you want. IMHO, nobody needs to do this unless they are shooting for
really big numbers (like more than 12:1). I say this because at lower
compression, the variance likely between cylinders is marginal.
As a point of reference, the Kastern TR6 Comp. Prep. manual lists a total
gain of about .5 of a compression step by decking the block. For example,
a head milled to 10:1 placed on a block that is decked gets you 10.5:1
compression.
Of course all this really means nothing because what really matters is the
actual size of the combustion chamber. Period. Whether the block is decked
or not. I suppose there is a certain cachet in saying that you've had your
block decked - but unless you are building a race motor, I'd consider the
action more along the lines of an interesting exercise more than anything
that will produce gobs of HP.
Make sure the block is FLAT, that's all you really need to do.
If you don't know what you are doing when you get into decking the block,
you will wind up with unforseen problems (like pistons hitting the head)
and if you run into these probs, it'll cost big $$$ to fix it. IF you can
fix it.
> John Cyg.
regards,
rml
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