 
In
our last edition, I outlined the Colorado Red project and our basic
plan of attack. I will continue to update you on the project every
month since I hate to loose track of a project once it has begun as
much as anyone. This month, we received the 4.7 stroker kit from
HESCO Manufacturing in Birmingham, AL ((205) 251-1472) and
performed machine shop work on the engine. In addition, we had
Sam's Off-Road in Tulsa, OK ((918) 446-5535) build a custom Dana 44
rear axle. Colorado Red is currently with out engine, transmission,
and transfer case as it awaits its new performance parts. Here are
some specifics about the engine and rear axle.The 4.7 Stroker Kit
HESCO
Manufacturing in Birmingham, AL is best known for its work in the
Jeep racing circuit. They build race motors for the big boys and
have adapted some of the technology into a kit you can buy to make
your 4.0 engine come alive. The idea here is simple; but it is the
math that will get you. HESCO's kit increases the cubic
displacement by increasing the stroke of the motor via the crank,
rods and .060 over pistons. HESCO's unofficial slogan is "Speed
Costs Money, How fast Do You Want To Go?" and so far part of that
slogan is true. The kit is not cheap at $2000.00 retail. It
includes the crank, cam, pistons, rings, and rods all balanced and
ready to install. As for the "speed", HESCO claims 260+ hp and
350+-ft lbs. of torque can be expected from this motor when you
install the recommended peripheral equipment (better keep that
wallet out awhile). HESCO advised us to use 20% larger fuel
injectors and an adjustable fuel pressure regulator to feed the
beast. In addition, they recommended adding a bored throttle body
to increase airflow. All these peripherals added up to roughly
another $1000.00. Knowing it will be able to breath-in better,
Steve (the Owner) also directed an upgrade to the exhaust so it
will breath-out better. For this, we ordered a Borla header from
Four Wheel Parts Wholesalers here in Oklahoma City ($333.00) and
plan on using a free flow catalytic converter and Flowmaster
muffler. I asked HESCO what they recommended for machining the
head. They advised we retain the pre-1991 head design since it is
not cost effective to convert to the H.O. motor head. The head
should be machined and put back to factory "new" condition to
retain low-end toque. "Nothing fancy" was the advice HESCO experts
provided.Folks Machine Shop in Norman, Oklahoma is considered the one of the best in the Oklahoma City area where the build-up is taking place. So, we took Colorado Red's tired (135K miles) 4.0 motor there for the machine work. Leaving nothing to chance, Folks double-checked all the HESCO parts for proper balance and all were found to be within .5 grams. They line honed the block which should allow the crank to rest easy and reworked the head before installing all new valves. The bill for the machine work was roughly $645.00. Currently, the motor parts reside with an expert mechanic who has built hundreds of Jeep 4.0 motors. The Custom Dana 44 Rear Axle
There were many
debates over which rear axle to use for Colorado Red. We discussed
using a Ford 9 inch, but it would not support the ARB locker Steve
wanted installed. Then we discussed a Dana 60 reverse rotation; but
everyone we talked to said a reverse rotation 60's pinion/ring was
about the same strength as a regular rotation Dana 44. This being
the case, why carry the extra 60-75 pounds around and give up 3/4
inch in ground clearance to a Dana 44? Then we talked to the folks
at Sam's off-Road in Tulsa, Oklahoma. They said a Dana 44 with high
quality axles would take care of business just fine. In their
showroom, they have a custom axle on display. Here, they explained
many of the upgrades available. The rear disc brake set-up, which
is adapted from a Ford Explorer, is particularly interesting. It is
a drum and a disc all in one. 
The disc is used for main braking and the drum is for the emergency
brake. Sam's technicians said this set-up works very well on and
off-road. The decision was made and we ordered the Dana 44 with
disc brake set-up, ARB air locker, and 4.56 gears. All total, the
rear axle came to roughly $2300.00. Sam's built the custom axle
using a housing from a Ford truck as the foundation. It was cut
down to fit the XJ, leaving off the spring pads until we install
the axle. This will allow proper pinion adjustment with out the use
of shims. They used high alloy axle shafts from Currie Enterprises
to handle the increased torque.  We
will have to wait to install the axle until we have the Atlas II
transfer case installed to determine proper pinion angle.
Similarly, we cannot order driveshafts until we have both
components installed and measure for the appropriate length.
By - David
Jones Follow us on Twitter at www.twitter.com/OffRoadDotCom
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