Available Pistons FAQ
Posted: February 21st, 2008, 3:10 pm
Updated list; see last post-- SilverXJ
Pistons
Edited 6/03/08 to reflect changes to the H825/H802 and 677p/cp information as furnished by Sealed power tech dept. Thanks gradon for passing the info along.
Pistons
Piston Stock - '87-06 4.0L, 1.601 pin ht, 13.5cc
Piston 2229c - Silvolite, 1.581 pin ht, 11.5cc
Piston 3241HC - Silvolite, 1.592 pin ht, 14.1cc **
Piston H802CP - Sealed Power, 1.592 pin ht, 15.5cc
Piston H825CP - Sealed Power, 1.592 pin ht, 15.5cc
piston 677p/CP - Sealed Power, 1.585 pin ht, 14.0cc
All the above pistons are dish top, with Press fit Wrist pins of .931"dia.
Pistons are available 3.875 std,.020,.030,.040,.060 oversize.
H802/H825 have a D shaped cup, recessed head .116 inch deep.
677p/cp dish depth .116
H802 rings 1.5 1.5 4mm
H825 rings, 5/64 5/64 3/16"
3241HC has a D shaped dish that has been machined to a full round dish of 18cc
without depth change.Rings 1.5 1.5 4mm
STL-677 has a D shaped cup, recessed head .116 inch deep.
Rings, 5/64 5/64 3/16" one of the largest stock dish cc Can be enlarged
Silvolite 2229 has a thick top and is a favorite for machining larger dishes.
24cc is possible with this one..
2229's ok to .19" dish minimum thickness at KB technical Department. <---(updated 6/12/08)
**Same as Engine Tech p3071
Manufactures will tell you to avoid reducing crown thickness below 0.300" thickness.
If you decide to use the long 4.0 rods casting no. 53020126, custom forged
pistons with a pin height of 1.380" are needed to produce zero deck clearance.
More to come
John
Pistons
Edited 6/03/08 to reflect changes to the H825/H802 and 677p/cp information as furnished by Sealed power tech dept. Thanks gradon for passing the info along.
Pistons
Piston Stock - '87-06 4.0L, 1.601 pin ht, 13.5cc
Piston 2229c - Silvolite, 1.581 pin ht, 11.5cc
Piston 3241HC - Silvolite, 1.592 pin ht, 14.1cc **
Piston H802CP - Sealed Power, 1.592 pin ht, 15.5cc
Piston H825CP - Sealed Power, 1.592 pin ht, 15.5cc
piston 677p/CP - Sealed Power, 1.585 pin ht, 14.0cc
All the above pistons are dish top, with Press fit Wrist pins of .931"dia.
Pistons are available 3.875 std,.020,.030,.040,.060 oversize.
H802/H825 have a D shaped cup, recessed head .116 inch deep.
677p/cp dish depth .116
H802 rings 1.5 1.5 4mm
H825 rings, 5/64 5/64 3/16"
3241HC has a D shaped dish that has been machined to a full round dish of 18cc
without depth change.Rings 1.5 1.5 4mm
STL-677 has a D shaped cup, recessed head .116 inch deep.
Rings, 5/64 5/64 3/16" one of the largest stock dish cc Can be enlarged
Silvolite 2229 has a thick top and is a favorite for machining larger dishes.
24cc is possible with this one..
2229's ok to .19" dish minimum thickness at KB technical Department. <---(updated 6/12/08)
**Same as Engine Tech p3071
Manufactures will tell you to avoid reducing crown thickness below 0.300" thickness.
If you decide to use the long 4.0 rods casting no. 53020126, custom forged
pistons with a pin height of 1.380" are needed to produce zero deck clearance.
More to come
John