After
some checking about experiences with electronic ignition, plan was use
of an Petronix unit. This way its easy to change back for regular
points when units malfunction.The Petronix did make the engine run
smoother, and said to give better performance/ milage. And, seems to be
stable without malfinction, expecially with original Petronix coil unit.
When a friend visited US last time, he did buy a
complete new
HEI -assy for an 250 six, the bigcap w/external coil for an resonable
price.( same price as Petronix unit Bought in Norway ) Then, it was no
return,
install it!
Bigcaps doesn´t give a nice clean spaced enginebay, but is
said to be better functional when even higher voltage, without
inteference between capconnections.
The external coil, is easy changed to another, higher current coil,
without mounting trouble.
Coil mounted as earlyer on the engine side, 12v cable from
ignition key, to the coil -connection near the orange(+) cable from
distrubitor, and distrubitor mounted as the original, plug cables
mounted at cap, some adjustment, and SPEED UP!
YEAH! it did gave changes! The engine spins more even,without
misfires, at idle & the hole accelerationband, to top rpm.
 Use of
original 4.3ltr V6 TBI distrubitor in the inline.
The distrubitor
needed an major change to be put inside the 250 inline six. ( original
250 cid
point distrubitor to left, reworked 4.3 V6 to right.
Underhousing on the 4,3 needed to be cutted approx.
4.25 inch (10.8cm)Alligned against the original distrubitor. The
bushing
at the lower part, needs relocation to the new lower underhousing.
Housing
on the 4.3 needed some grinding at mounting flange to get similar with
the 250 distrubitor.( 4.3 has double flange in different sizes, only
the
upper is kept.)
4.3
axle is put in the reworked housing, and measured
for lower cutting to exactly same length, and tip is grinded at same
spot
at rotation as original 4.3 distrubitor. Slipped the 250´drive
gear
on the reworked 4.3 axle, and posisioned this at angle as original 4.3
drive gear, and drilled hole trough the axle for the mounting pin.
Maked a bushing for the gear, because 4.3 axle shaft is slightly
smaller,
of some 1/2" copper tubing drilled & roamed to fit.
Nearly the same as to rework the 2.8/ 4.3 GM V6 distrubitor
to fit into the 235 Blue Flame.
www.stovebolt.com
HEI
Conversion
Believe
it or not, its easier than you might think.
First off,
you need to find a donor. Of early
1980's
vintage Chevy's, many of which were powered by the ever-abundant 250
six cylinder. A distributor from one of these can be had quite cheaply,
and is easily modified to fit your truck's 216 or 235 power plant. The
GM "HEI" distributors have a coil integrated into the cap, making the
wiring simple enough for the average five year old to accomplish
successfully.
Be sure to
take the "hold down clamp" from the donor along with your "new"
distributor. You will need it as well.
It
is important to note that
the oil pump in a Chevrolet six cylinder
engine is driven by a
tang at the base of the distributor gear. This tang must engage the oil
pump in order for the pump to deliver lubrication to the engine. Upon
first inspection of the donor distributor, it may appear to be a "drop
in" replacement, and the gear will engage enough to turn the rotor.
However, the tang at the base will not engage the oil pump…
Modifications are necessary!
The
shoulder on the distributor housing
needs to be removed in order to allow the distributor to enter far
enough into the block to engage the oil pump. Although this may seem
slightly intimidating, it can be easily accomplished with a coarse file
in just a few minutes.
Now
that the shoulder has been removed, you need to make a new one for the
distributor to seat against in the proper position. A simple split
collar clamped around the distributor housing will suffice. It should
be clamped in order to let the distributor go about 3/16" further into
the block than the original shoulder would allow. The "hold down clamp"
that you got with the distributor can now be used to clamp on top of
the split collar. Once you
have your "new" HEI installed, you should double check to make sure
that you do, in fact, have oil pressure.
Now
get out that timing light and set it up right. Oh yeah, be sure
to hook the vacuum line up to the advance.
Paul
Yacabitis"Inky05"
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