School me on Pistons....
Grand HDF Member
Joined: Jun 2013
Posts: 4,998
Likes: 875
From: Iowa
As far as I know skirts on narrow skirted pistons are the same length as full skirted ones unless the build is different (bore, stroke, rod length). You want resistance for the pivoting on the pin. It should float. I don't see how it would make any difference between the 2 piston types. Piston skirt, narrow or wide wears mainly on the thrust sides (front and back) where the skirts are located on a narrow skirt piston. The piston pin / rod keep the pistons from rocking where there isn't any skirt.
I have a 02 RKC (about 80K) with about 60K on a set of 95 ci 10.8 to 1 slipper skirt early wisecos. It's easily had 100 dyno pulls at various times, made as much as 110 hp, had ccps as high as 220 psi (depending on the cams) and been run hard at times even with temps over 100F. It hasn't blown up yet. Burns maybe 1/2 qt in 3000 miles.
I'm not worried.
I have a 02 RKC (about 80K) with about 60K on a set of 95 ci 10.8 to 1 slipper skirt early wisecos. It's easily had 100 dyno pulls at various times, made as much as 110 hp, had ccps as high as 220 psi (depending on the cams) and been run hard at times even with temps over 100F. It hasn't blown up yet. Burns maybe 1/2 qt in 3000 miles.
I'm not worried.
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,922
Likes: 8,027
From: poway
The full skirt reinforces the the area that the narrow skirt contacts the cylinder wall. I have partial skirts on mine as well, but I also run around 100 HP and lower RPMs. Racing pistons are full skirted for a reason, but I agree, are unnecessary in most street builds.
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,922
Likes: 8,027
From: poway
The full skirt reinforces the the area that the narrow skirt contacts the cylinder wall. I have partial skirts on mine as well, but I also run around 100 HP and lower RPMs. Racing pistons are full skirted for a reason, but I agree, are unnecessary in most street builds.
Grand HDF Member
Joined: Jun 2013
Posts: 4,998
Likes: 875
From: Iowa
Looks like a slipper skirt. My info above is from Randy Torgeson (aka: King of Cubes) who has 40 years building motorcycle engines and apprenticed under the owners of Zippers and Axtell in the 80s. Other than that I don't know what to tell you.
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,922
Likes: 8,027
From: poway
Heck Revolution performance once claimed that CP pistons collapsed skirts but I suspect that it was cylinder finish causing the issue..
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