Hi listereens.
The questions: (1)
Any good reference material available on 948 Heralds, especially
under-bonnet stuff? I couldn't find shop manuals at the usual
sources. Best info on carbs I have so far is from catalog pics,
(Moss, VB, Rimmer) and the instruction sheet that came with a carb
rebuild kit from SpitBits.
What did the intake and exhaust pipes arrangement look like on a 948cc
Herald? I searched the archives and the web but hits on Herald 948,
and SU H2 were pretty sparse. And it looks like H1s were original on
this motor.
How were the choke links connected? None of the pictures I have show
linkage like I have -- the brass arms for lowering the jets are
identical on the front and rear carbs. I arranged them to point
toward each other, but I have no idea how they should be actuated and
coordinated. (I'm tempted to connect a loop of cable, one end to each
arm, and just pull in the middle of that.)
How was the accelerator pedal attached to the throttle on this
vehicle? (I'm assuming that this really came from an Herald.) The
Spit linkage won't fit through the exhaust pipes. I'm considering
fitting a cable linkage. Sound reasonable?
Should I try to fit the HS2 carbs instead? I would have to fabricate
an intake extension to get more clearance between the carbs and the
exhaust pipes, but the rest looks simple enough.
The background:
Here's what I have. 1969 Spitfire MkIII, 948cc motor (1296cc motor
currently in cryo storage, awaiting resurrection,) choice of SU H2 or
HS2 carbs. The 948 manifolds appears to be cast steel; intake and
exhaust are all one piece. (Looks like a mold was made from a
fabricated-from-tube assembly and cast; surface is clearly sandcast,
but weld marks are clear enough wherever pieces meet.) Intake has
normal front and rear carb mounting positions which fork on the way to
the head. Exhaust looks just like a header, but cast. And they are
all cast together.
I started installing the HS2s, but the clearance between #4 exhaust
pipe and jet feed pipe left a lot to be desired. Not even enough room
for a heat shield. Front carb (not complete yet) will have the same
problem. I could perhaps turn the jet around (it's one of those
universal F/R ones with sufficient pipe length and choke lever screw
boss that runs all the way across) but the fuel bowl is still closer
to the exhaust than I would be comfortable with. Perhaps an inch.
But that is enough room for heat shielding.
Thinking that the H2s might be a better choice, I dug them out and did
a test fit. With the internal jet feed there is no external pipe to
worry about, and the distance from the jet to the throttle shaft is
longer, giving more clearance from fuel bowl to exhaust runner. But I
have no idea what the installation should look like.
Thanking all in advance,
Donald.
-- under-the-bonnet on the Frankenspit, waiting for the right storm to
reach the correct intensity. "Soon, Igor, soon!"
(1) Wow. I didn't realise I had so many questions. Well, I guess I
knew I had a lot of questions, but I didn't think it would take so
many words to ask them.
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