This stage is for
the budget-minded performance enthusiast who wants an increase
in horsepower and torque without spending a lot of cash. The first
step is to thoroughly inspect and clean the heads to ensure that
there are no cracks or flaws. If the heads have been previously
run, all valve spring pressures are
checked through the full range of motion and are replaced if necessary.
All valves are then inspected for straightness and then re-faced
and back-cut to optimize flow around the valve head area. The
intake and exhaust ports are then reshaped to optimize torque
producing airspeed and horsepower, producing airflow, removing
only the absolutely necessary amount of material. During the porting
process, the heads are generally on and off the flow bench five
to seven times. All porting is done utilizing the state-of-the-art
Superflow technology in the form of a Superflow bench, Flocom
microprocessor, intake and exhaust airspeed diagnostic probes,
and Winflow graphics software. The valve job consists of three
angles with a hand-blended, 60-degree angle which is backed up
with additional flow bench testing. The combustion chambers are
treated to a blending process that promotes both laminar transition
around the valve seat and maximum turbulence, and swirl characteristics
within the combustion chamber area. The swirl characteristics
of each combustion chamber is measured utilizing the Flocom computer.
The head surface area is then flat-milled to ensure an absolutely
flat gasket surface and to correct for the small amount of material
removed during the blending process. The heads are then re-cleaned
and assembled with all valve spring installed heights within .005
in. of one another to reduce valve train harmonics to a minimum.
Finally, the heads go back on the flow bench one last time to
ensure that the front and rear-head flow numbers are within 1.5%-2%
of each other to ensure proper cylinder balance and ease of tuning.
Stage 2 - $800.00
Stage 2 cylinder
heads are subjected to much of the same treatment as Stage 1
heads, except that these get the big valve treatment. Stage
2 heads are machined for larger valve diameters, such as 1.810
in. intake and 1.580 in. exhaust valves for Lightning heads
and 1.840 in. intake and 1.615 in. exhaust valves for Thunderstorms.
These valve diameters have shown to be a great balance between
maximum flow and maximum street/strip durability. All of the
Stage 2 heads receive NRHS "Black Magic" valves and high quality
springs with
titanium retainers and 10-degree locks and will accept cam lifts
up to .575 in. lift (larger lift capacity springs available
upon request). The porting procedures differ somewhat from the
Stage 1 in that all the stops are pulled out and airspeed and
airflow are absolutely maximized through a process that is unique
to Nallin Racing & Head Service, Inc., and is proven both
on the track and on the dyno. These heads are by far the most
popular choice because of their versatility to be utilized in
both mild and wild combinations. This feature allows the customer
to install the heads, observe gains, and then build upon them
without having to re-port the heads, which equates to more cost.
All of the careful documentation that goes into a Stage 1 head
in regards to assembly, and overall airflow balance also pertains
to a Stage 2 head.
Stage 3 - $1000. Call
for details.
Hours of Operation:
Monday - Friday: 8:00 a.m. to 5:00 p.m. CST
Nallin
Racing Head Service Inc.
(318) 631-NRHS (6747)•
E-mail: nascar@shreve.net
4313 Emory Street
Shreveport, LA 71109
fax (318) 631-9798
checked through the full range of motion and are replaced if necessary.
All valves are then inspected for straightness and then re-faced
and back-cut to optimize flow around the valve head area. The
intake and exhaust ports are then reshaped to optimize torque
producing airspeed and horsepower, producing airflow, removing
only the absolutely necessary amount of material. During the porting
process, the heads are generally on and off the flow bench five
to seven times. All porting is done utilizing the state-of-the-art
Superflow technology in the form of a Superflow bench, Flocom
microprocessor, intake and exhaust airspeed diagnostic probes,
and Winflow graphics software. The valve job consists of three
angles with a hand-blended, 60-degree angle which is backed up
with additional flow bench testing. The combustion chambers are
treated to a blending process that promotes both laminar transition
around the valve seat and maximum turbulence, and swirl characteristics
within the combustion chamber area. The swirl characteristics
of each combustion chamber is measured utilizing the Flocom computer.
The head surface area is then flat-milled to ensure an absolutely
flat gasket surface and to correct for the small amount of material
removed during the blending process. The heads are then re-cleaned
and assembled with all valve spring installed heights within .005
in. of one another to reduce valve train harmonics to a minimum.
Finally, the heads go back on the flow bench one last time to
ensure that the front and rear-head flow numbers are within 1.5%-2%
of each other to ensure proper cylinder balance and ease of tuning.
with
titanium retainers and 10-degree locks and will accept cam lifts
up to .575 in. lift (larger lift capacity springs available
upon request). The porting procedures differ somewhat from the
Stage 1 in that all the stops are pulled out and airspeed and
airflow are absolutely maximized through a process that is unique
to Nallin Racing & Head Service, Inc., and is proven both
on the track and on the dyno. These heads are by far the most
popular choice because of their versatility to be utilized in
both mild and wild combinations. This feature allows the customer
to install the heads, observe gains, and then build upon them
without having to re-port the heads, which equates to more cost.
All of the careful documentation that goes into a Stage 1 head
in regards to assembly, and overall airflow balance also pertains
to a Stage 2 head.