Ford heads have been made for many years with a straight section between
the head and the sealing surface. This can be 1.9, 3.8, 4.6, 5.4, 6.8 liter
engines and Triton models. The spark plug: starting from the taper seat is
approximately 8.5mm has NO threads down to 8.5mm of threads at the
bottom of the plug illustrated below. The overall length of approximately
17mm from the taper to the “Last Thread”.
Z-tec insert p/n 66151460
included in 6605553 kit
Click here for larger view
Newer model Fords 2000 and up, can have sparkplug's
fully threaded in heads with straight sections. We still
want to repair the spark plug hole back to the factory OEM style of the
head. This way the head will accept any half threaded or fully threaded
spark plug manufactured by Autolite or motorcraft.
KIT NUMBER 6605553
Solutions for the blown out
sparkplug problems: PROS AND CONS
PROS: The insert duplicates the
threads in the factory head, which means that any spark plug specified for
this head type would fit.
CONS: This kit will remove a bit
more material and is more expensive.
KIT NUMBER 6604412E
This is also considered an "over the fender repair".
Repair the hole by putting a “Fully Threaded” thin walled taper seat insert in the head with kit p/n 6604412E with insert
p/n 66144186. Sealer
p/n 6626020 is also required. This M14x1.25 Extended tooling will repair 3/4 reach taper seat spark plugs.
: If repairing a and up head the insert will stick up too high and not be in the correct location due to a step found in these problem heads.
PROS: This repair removes less material.
CONS: Sparkplugs going into the newly repaired TIME-SERT hole must be fully threaded!
If anyone doing a future spark plug change were to use
spark plugs with
a straight section the spark plug would bottom out to early on the straight
section and would not be in the proper location. This would cause miss
firing of the engine, and possible engine damage. There would be no way
of knowing one hole may be different. Certain OEM spark plugs would not fit.
If the head being repaired were a romeo style head 1L2E the seat cutter
would also not be in the correct location because of the problem
countersink in these romeo style heads. We add a special tool in the Triton
repair kit p/n 6605553 listed above to prepare the hole so that the insert
will be in the correct location.
One solution would be to repair all holes at
the same time. This way all the
holes will be consistent using a fully threaded spark plug. The head should
not be a Romeo 2001 or similar head.
CHAMBER SIDE REPAIR:
THIRD OPTION: (Engine rebuilders method) Undocumented
The head must be removed and there must be at least 1 or 2 good threads
to guide the piloted step tap.
Repair the hole by putting a short thin walled insert in the head from the
chamber side. The installation would go as follows: Using kit number
6604412 and insert 66144123 this is an 8mm length insert.
NOTE: Do not tap all the way through!
Tap the hole from the chamber side CAREFULLY as to not wipe out the
original aluminum taper seat. You would have to inspect the tapping from
the chamber side to insure that you just tap deep enough to accept the
insert approximately 12mm. Normally you would use the seat cutter next
in the instructions but in this case you do not use the seat cutter because
the tap will not be deep enough below the surface. After tapping the hole
you will install the insert from the chamber side using the driver tool.
is a very fast repair if the head has been removed, and its the
Time wise you have to remove the head first, and the head must
have 1 or 2 good threads to guide the piloted step tap to insure the
threads are tapped straight so the spark plug will seat correctly.
In conclusion we
recommend the first repair p/n 6605553
as a solution to
blown ford sparkplugs for "over the fender repairs".
Ford has a longer version of the "Triton" style head we call the longer plug
style insert a "" style. The insert is just a longer version of
the "Triton". The Z-Tech is 24mm over all length. P/N ..
Yes, the 6605553 kit will work to repair the longer length spark plugs all you
need is the insert.