1.Idle: A cam with more than 260 deg duration can cause a stock SU to
"hunt" and requires airflow mods unsuitable to street use, is the cam he
used documented? I once put a Spreen cam he had stored under his desk (good
old Bob, God lov'em) in an MGB and it would'nt do anything right. Anyway
just a thought. Most likely a vacuum leak, put a rubber hose in your ear
and probe around.
2. Oil Pressure: rockers/shaft makes a difference, not a lot, sounds like
what you have is normal for the big-end being normal which is the
important part- 948 cranks are no more for less than very large $$, all
the HProd guys broke them years ago. I'd do the rocker
shaft/bushings just because it's time. The valve lash cannot be set right
if the shaft is worn and the rocker faces will wear unevenly.
3.Torque: if you undo all the bolts you will have to replace the
headgasket, I don't care what anybody else says, not to is a bodge of the
third degree (i.e., you'll get what you deserve) On a B I have replaced
the rocker/arms without taking out the towers just by loosening the
rocker adjustments & so on. I have removed a head bolt one at a time &
replaced one at a time without any problems. Torquing is the act of
pre-loading the bolt to just over the highest expected stress, doing it
in a certain order is the act of deforming the head evenly so when you're
done the head is flat and not distorted, therefore one at a time is not
detrimental. Re-torquing (ONE bolt at a time, only!) requires you to back
off each bolt 1/2 turn then slowly bring it up to the clicker point (You
are using a click style torque wrench?). No need to drain the coolant
if you are only doing one at a time. Any newly installed head (iron)
should be retorqued after one good heat cycle, THEN set the valve lash to
the final values.
All the above after years of bodging the B's. One learns by ones
mistakes which makes me VERY learned indeed!
Doug the bodger.
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