Piston placement

[Andrew McNeice]

I have just fitted two new rings +.40 to the piston on my 380 Griffon and whilst I understand the piston is fitted with the ring pegs to the rear of the engine, do the three vertical holes in the piston wall also face the rear? Thanks for your help. Andrew.

[John-Boy]

I have just looked at a 380 piston which has the ring pegs to the rear and the three holes at the front. I guess the holes are to provide some lubrication to the bridge between the exhaust ports.

[Andy Z]

I have just looked at a 380 piston which has the ring pegs to the rear and the three holes at the front. I guess the holes are to provide some lubrication to the bridge between the exhaust ports.

I've just fitted a new piston to my 360 (actually a 380), and concur with John, the 3 holes are for extra lubrication of the exhaust port bridge.

Cheers,
Andrew
#190

[dave higgins]

The front of the piston is also the thrust side, so it would make good sense to allow extra lubrication to that area. dave

[Andrew McNeice]

Piston placement

WOW great stuff - so it's the three holes in the piston to face the front, and set the ring pegs to the rear. Thanks so very much to you all. Andrew