Can someone explain thrust side to me? I am assembling my 4.6 and the ring gaps should be farthest from thrust side. I thought I understood it but I am now thoroughly confused.

 

Thrust side= the side of cylinder wall that endures the most stroke pressure, from piston, during rotation of assembly
I have a diagram ..... Looking

 

Notice angle or con rod as pressure is placed thrust side

 

I'm allowing myself to get really confused. Is thrust side the same for all cylinders in a bank or is it determined on a per cylinder basis? I can see how, if I note the rotation of the crank and then check the angle of the rods I can figure it out, but wow, from what I have read it is super critical that I get this right. I wish there was a chart.

 

Well maybe I need to just stick with the instructions. If the front of the piston is viewed from the arrow then this should work.

4. Position oil control expander ring joint and ring rail gaps all at one side, between gudgeon pin and away from left hand (thrust) side of piston -viewed from front of piston. Space gaps in ring rails approximately 25 mm (1.0 in) each side of expander ring joint.
5. Position compression rings with ring gaps on opposite sides of piston between gudgeon pin and right hand side of piston - viewed from front of piston.

 

Ah, to heck with it. I just made sure that the gaps didn't overlap.

 

As Dusty says, here's another diagram

Résultats Google Recherche d'images correspondant à http://speed.academy/wp-content/uploads/2015/01/JE-Pistons-Asymmetrical-18.jpg

It is also related to crank direction, whereas most are clockwise as viewed from the front some are anti clockwise (rare) in which case the thrust side reverses. In the case of the V8 the thrust is always the same side, clockwise rotation it would be the left side of the piston/bore on both banks. It's a function of the crank direction and power stroke.

PS. Piston ring gap positioning is more important than thrust side positioning as piston rings can and do rotate on worn engines. Piston ring gaps at 1/3, 1/3, 1/3 radially is the accepted norm.

 

What a relief. After spending days finding correct conrod bore for the engine shop, days more getting dowty washers, then more days finding stretch bolts for the conrods, I finally guessed something right. Thanks for that, Dusty and OR France!

 

de rien. Glad you've got it sorted.

By the way, I didn't nickname Dusty 'the Oracle' for nothing