If your PA-12, PA-18, PA-20,
PA-22 or even old PA-28 has an oil cooler in the front/center
of the cowl (the "Cheesegrater up Front"), you have
some options when it comes to selecting/installing a Sky-Tec
starter in place of the old Prestolite/Delco starters.
Using
the 122-12PM Starter
First off, and by a wide margin,
most of our customers utilize the 122-12PM starter by modifying
the oil cooler diagonal brace.
Using
the NL Starter
Since the advent of the Sky-Tec
High-Torque Inline Lycoming starter, many of our customers
have chosen to avoid any modification to their oil cooler
entirely by simply installing a 122-NL starter.
However,
Bill Robek of Stoddard's
Aircraft Parts Center in Anchorage, AK suggests you
pay special close attention to the clearance between the
Sky-Tec NL starter and the vertical oil cooler brackets.
On some PA-12, PA-18, PA-20,
PA-22 or even old PA-28 has an oil cooler in the front/center
of the cowl (the "Cheesegrater up Front"), you may
have to trim the "ears" (noted as accessory mounting
tabs "C" and "D" on the NL
Installation Sheet) on the NL starter to clear the oil
cooler bracket. Those ears are sacrificial. So why
are they there? Well, they were put
there to emulate the location of the mid-body bolts on the
most popular Prestolite starters that are required by many
airframe manufacturers to hang various brackets, accessories,
and baffling. On some of the small Pipers, however,
those ears may simply just be in the way.
First
Generation NL Starter Installation on a PA22.
Note
mounting tab "D" has been properly trimmed by
installing
mechanic
to clear the Piper oil cooler diagonal
brace.
So while we know of dozens (if not
hundreds) of cloth Piper installations that required no
modification, to install the NL starter, that appears
to not necessarily be true for ALL installations.
If it becomes evident that your
Piper's oil cooler bracket interferes with the NL mounting
tabs or power bolt, you may have to make some modifications
during starter installation.
Missouri customer Alan B
Arrow has generously shared his solution for modifying
his oil cooler bracket on his 1957 PA22:
To begin, Alan writes, "I recently installed a Sky-Tec 122-NL High Torque light weight starter on my 1957 Piper PA22
(N7410D) Serial Number 22-5171 which is equipped with a Lycoming 0-320 narrow deck engine...I did find that modification of the Oil Cooler Mount is indeed necessary for
the 122-NL starter to fit my aircraft. I have enclosed photos
showing...both C and D mounting tabs on the starter did in fact need to be removed to clear the Oil Cooler
Mount...as well as modifications to the oil cooler diagonal
brace to clear the [B+ power] Terminal on the NL
starter...[I also had to
extend the power cable forward 6" since] the NL starter's
electrical terminal is located a full 6 inches forward of the old Delco-Remy
starter's electrical terminal." -
A B Arrow
Mounting
Tabs C & D Cut off to clear oil cooler mount
Battery
post was directly against oil cooler mount (tape is only to
highlight contact area)
Modified
Oil Cooler Brace
New
starter B+ power terminal location required 6"
extension
Finished
installation after modifications
Sky-Tec sincerely hopes no such
modifications are required for your NL installation. But
if they are, we hope you found this information from Alan and
Bill helpful. Thanks guys!
