Wossner piston inspection

[1976RD400C]

I thought I better take a peek in there. I have 2 summers, maybe 1000 miles on these Wossner pistons running in my hot rod. The rings were shot with an end gap of +.030". Looks like they were starting some blow by. The pistons themselves measured about .001" smaller than new. That ain't bad compared to the Wisecos I had that would collapse a lot more than that. The cylinders are worn to the point of a bore job needed, .002" in some areas. The top part of the cylinder, where the rings ride is definitely worn even though the hone marks are still there. The area below the intake port shows how the piston skirt bangs away, especially when the bore clearance gets big (.005"). Overall, both pistons and cylinders look the same. I'm happy with how the Wossners held up. Crank looks great, it's not spreading apart on the ignition side, like has happened before. Ported, big reeds, 34mm vm carbs, hpi ignition, 25:1 Yamalube R, and loves going up to 9500 rpm.    

[m in sc]

nothing to complain about there.        underside looks great. rering, light pass w the dingleball hone and have at it. 

[automan]

Thanx to bean oil cooking off and doing it's job.

Damn you run that thing hard!

Lookin' good.