Help seal combustion pressure and control oil on the cylinder walls with this Sealed Power piston ring set, part number E-251K. It is a premium, standard-size set sized for eight cylinders with a 4.0000-inch bore. It fits many vehicles, among them the 1975-1995 Ford F-150 and 1986-1995 Ford Mustang with the V8-5.0L, and the 1977-1996 Ford F-150 with the V8-5.8L.
- Plasma-moly top ring face: The steel-with-moly top rings have a face coated with the latest generation of plasma-moly. The coating decreases friction and is very resistant to scuffing.
- Reverse torsional second ring: The second rings are grey iron with a phosphate coating.
- 3-piece flex vent oil ring: The oil ring is 0.1875 inch wide.
- Exacting tolerances: Built to tolerances that meet or beat OEM specifications, using ISO- and QS-certified manufacturing.
Specifications: Bore diameter 4.0000 in. Ring groove widths 5/64 x 5/64 x 3/16 in. Standard size (not oversized). Not a file-fit set. One set per engine on the listed applications. Country of origin: United States.
Piston rings are commonly replaced as part of an engine rebuild. Signs that worn rings may need replacing include rising oil consumption, blue-gray exhaust smoke, low compression readings and excessive crankcase blow-by. Diagnose the cause before replacing, because other engine faults can produce similar symptoms.
Fitment covers many applications from American Motors, Buick, Cadillac, Chevrolet, Dodge, Ford and more. Covered engines are the V8-4.7L, V8-4.9L, V8-5.0L, V8-5.3L, V8-5.4L, V8-5.7L, V8-5.8L, V8-5.9L, V8-6.0L, V8-6.4L and V8-6.6L. See the "Vehicles it fits" section for the full list.
Interchange: M40058-STD
M40058STD · 3205941 · 6474170 · 3549588 · 3579044 · 3780016 · 251K · 40564CP · 2106114 · 40564 · E3ZZ6148A · E6TZ6148A · 1389176 · 3799438 · 3839510 · 3892364 · 3893202 · 8271 · 2M139 · MG4012 · N4012 · 474170 · T8325MX
This part cross-references / interchanges with the following part numbers:
3205941, 6474170, 3549588, 3579044, 3780016, 251K, 40564CP, 2106114, 40564, M40058-STD, E3ZZ6148A, E6TZ6148A, 1389176, 3799438, 3839510, 3892364, 3893202, 8271, 2M139, MG4012, N4012, 474170, T8325MX
Frequently Asked Questions
What comes in this Sealed Power engine piston ring set?
It is one set sized for eight cylinders. It includes steel-with-moly top rings with a plasma-moly-coated face, reverse torsional grey iron second rings with a phosphate coating, and 3-piece flex vent oil rings.
What bore size and groove widths does the E-251K fit?
It is a standard-size set (not oversized) for a 4.0000-inch bore. The ring groove widths are 5/64 x 5/64 x 3/16 inch, and the oil ring is 0.1875 inch wide.
Which vehicles does the E-251K fit?
Listed applications include the 1975-1995 Ford F-150 V8-5.0L and 1986-1995 Ford Mustang V8-5.0L, among many others. See the "Vehicles it fits" section for the full list.
What are signs that piston rings may need replacing?
Common signs include rising oil consumption, blue-gray exhaust smoke, low compression and heavy crankcase blow-by. Diagnose the cause first, because other engine faults can cause similar symptoms.
Is the E-251K a file-fit ring set?
No. The E-251K is listed as a non-file-fit set. Check the ring end gaps against your engine's service specifications during installation.
