Text and Photography by Chirag
Asaravala
We left off in Part
1 without fully having our arms around the entire
project. We had mocked up the Vortech blower in the '67
Mustang engine bay and were left with several uncertainties.
We did not know how exactly the accessory belt routing
would be configured. Other challenges included plumbing
the radiator, setting up the fuel delivery, and fabricating
the supercharger ducting. The good news is since then
we've figured it all out, as is explained in detail in
this article. We've even fired up the motor with the blower
and attempted to drive the car under boost. We say attempted
because at 3lbs of boost on the gauge we felt detonation
and backed out. However this was expected as we are still
lacking timing advance control at the time of this article.
In Part III however we will deal solely with tuning issues.
Accessory Belt Routing
By far the biggest challenge of adapting the 5.0L kit
to our early Mustang was in setting up the belt routing.
The Vortech kit is designed to be used with a 5.0L serpentine
belt system. Such a system assumes a reverse
rotation waterpump, a 5.0L belt tensioner, and accessories
on both sides of the crank pulley (e.g. power steering,
AC compressor, alternator and smog pump.) Our '67 was
not only equipped with
a V-belt system, but a standard rotation waterpump and
only one accessory, the alternator. To make things more
complicated early Mustang waterpumps discharge on the
passenger side. While
we accepted that we had to convert to a serpentine belt
(necessitated by the Vortech crank pulley), for some reason
we were convinced it would be easier to use the stock
'67 pump. In the end we were wrong, but we'll outline
our failed attempt as there is always something to be
learned from mistakes.
The first sign that we were headed down the wrong patch
was with respect to pulley alignment. The distance from
the dampner face to the center grooves on the Vortech
crank pulley is stock 5.0L dimensions. However the hub
on the stock 1967 waterpump is closer towards the engine
block than would be on a late model 5.0L water pump. Furthermore
the early pumps being standard rotation requires that
you use a grooved waterpump pulley. We could not use a
late-model Mustang smooth waterpump pulley. Smooth pulleys
are driven with the backside of the serpentine belt which
means the accessory is turning counterclockwise.
Still trying to make the stock '67 waterpump work, we
ordered up a grooved waterpump pulley designed for an
early Lincoln.
Initial attempts to stick with the stock '67 waterpump
led to belt interference and no way to tension the
belt. |
Final belt routing worked best with a reverse rotation
5.0L waterpump. |
Use a grooved tensioner pulley, sourced from a 4
cylinder Ford. |
The 5.0L tensioner is adjusted manually in this
belt routing. |
We had a radiator shop move the lower outlet to
the opposite side - cost $80. |
We used spacers behind the pulley
to align it with the crank pulley. We thought we could
run a short belt around the crank, alternator and waterpump,
all turning clockwise. Unfortunately we hit a couple snags.
First off, there was no easy way to tension the belt.
Serpentine belts require proper tension to perform correctly.
Usually a spring loaded tensioner maintains proper tension
at all times, compensating for belt stretch and wear.
In our system we could not use a tensioner as there was
no place to mount it with the short length of our belt.
The second problem was that the belt rubbed on the lower
radiator hose. In fact it was rubbing, and this would
eventually lead to a hole in the hose (see image 1).
After racking our brains for several days the solution
began to appear (see image 2.) We suspected that all of
our headaches could be resolved by simply using a late-model
5.0L waterpump. This pump would be reverse rotation, allowing
us to use a smooth waterpump pulley off a late model Mustang.
The pump hub offset would be correct and require no pulley
spacing. The pump has it's outlet on the drivers side
which would alleviate our belt rub issue. This solution
however would require the lower port on our radiator to
be moved over to the drivers side (see image 5.)
We installed the 5.0L
waterpump and used a smooth, stock 1993 Cobra waterpump
pulley. Anytime you run a smooth pulley in a serpentine
system you must have a grooved pulley mounted higher in
the pulley chain on which the belt wraps around to change
direction. On a stock 5.0L engine the grooved power steering
and AC pulleys are mounted higher and to the right of
the waterpump, enabling proper belt routing. On our motor
we have no accessories on the driver side of the block.
Doing some research we came up with a solution. We took
the stock 5.0L tensioner (obtained from a wrecking yard)
and ground the locating pin off its back side. We then
swapped its' smooth pulley with a grooved pulley from
a belt tensioner off a Ford 4-cylinder engine, also from
the wrecking yard (see image 3). We mounted our modified
tensioner in the intended location on the Vortech bracket
(see figure 4). In this configuration, however, the tensioner
does not provide spring loaded belt tension. The tensioner
arm is meant to tension clockwise, however in our belt
routing we require tensioning upwards, or counter clockwise.
To achieve this we use simply use a large wrench and pull
the tensioner up until desired belt tension is achieved,
then tighten the large mounting nut down. Rather than
an automated tensioner it is a manual one, however it
works just fine. We had this setup on the dyno at 6500
rpm and it did not slip. A new belt will stretch and thus
the tension will need to be reset after first few miles.
With the belt routing finally resolved we felt as if we
were over a major hurdle. Now the entire front dress could
be bolted into place and the radiator and hoses dealt
with. The lesson learned here - what appears to be the
hardest solution may in fact be the easiest.
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(Radiator mouting)
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In
This Article:
We finish up installing a 5.0L centrifigual supercharger
kit on to our 331 stroker equipped 1967 Mustang.
The engine is fired up and test driven under boost.
Also See:
High
on Carbs
Part 1: Mock Up |
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