A while back I rebuilt an 1800 for my '67, with rimflo valves, hardened
seats, mild head porting, an Elgin street cam with a little bit of overlap,
a shaved head, and new HS4s with "5" needles, stock manifold. My machinist
talked me into iron/steel valve guides--a mistake, as they coked up and one
stuck after 8,000 mi. I used David Vizard's "A" book as a general guide--a
"B" is just an oversized "A" engine, right?
I learned a few things:
--Don't overdo it on raising compression. I had a moderate detonation
problem under load, at what I figured to be 9.5:1. This was made worse by
an oil control problem with one set of rings that didn't properly break in,
contaminating the mixture in one cylinder.
--Use the best quality "bronze" guides you can get. The soft ones wear too
quickly, and plated rimflo valve stems need the "lubrication" of a bronze
guide.
--Even a mild street non-stock cam, with other changes, can mess up a smog
test. I had to have my car tested under CA SMOG II, and despite timing,
carb needle, valve clearance, and fuel pressure tweeks, I ended up removing
the Elgin cam in favor of a stock regrind. It barely passed. (That the
first regrind cam, from Victoria, was rusted and pitted is another story.)
Before the smog test mods, I had an engine with a bit more high end power,
at the expense of some low end torque. Better breathing may have helped a
little bit, but I would bet you wouldn't find more than 4-7 HP difference
on the dyno
--If you're reboring a block, find a machinist with a boring plate to do
it, or buy one. Stressing the block does improve the trueness of the
cylinders.
Chris Attias
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