But a big difference in compression height (pin to crown). The pin on mine breaks into the oil control ring grove and that’s a 22mm pin, yours will be 24mm, and there is a support ring for the oil control ring to bridge the gap – I almost forgot to install them as they were packed separately with the pistons. Those AA pistons look good, including scuff pads on the skirts. Were the weights pretty close?
Weighing might be tonights job if I can sneak scales out of the kitchen.... Sent from my SM-G930F using Tapatalk
Mini bench grinder knocked up for mounting in a drill... mounted in a vice ...with a cable tie to pull trigger!. A bit Heath but seemed to work just fine on a test ring. Can get it squarer when using both hands but suppose as long as faces are parallel a gap is a gap. Sent from my SM-G930F using Tapatalk
I bought a set of AA barrels and pistons with rings supplied. Would I need to check the ring gap? It's not a job I was anticipating. I assumed they would be supplied ready to fit...
You'd hope they'd be bang on out of the box if it's a set... Worth a check though, just in case.. Doesn't take much to check... I did because I had cylinders rebored to match.. though I'm not sure if they're right now! Will be remeasuring tonight. Sent from my SM-G930F using Tapatalk
Never assume new parts are correct. You need to check ring gaps and side clearance and piston to barrel clearance.
But grinding both ends with the wheel in the middle means that when the ring closes up the gap will be tapered. Not a lot but a taper is a taper.
It is actually a lot in the gap world 0.1mm on a 3mm grinding wheel.on a 96mm dia ring.. but as opinions seems to be divided on what that gap should be I'm not overly concerned. As long as the gap at the top where it will touch first is right the gap at piston face say 0.1mm away when its in the cylinder the difference there is only 0.02mm so should be ok there. Now on to getting reliable repeatable cylinder diameter readings.... and van shooting discussions with locals... Sent from my SM-G930F using Tapatalk
Scuff pads took a beating on todays cylinder matching, don't think they'll last long in use.. Had to do a bit of "honing" to get minimum clearance only took an hour and a half per pot with all the 're cleaning measuring re honing cycles they were a tolerance fit at the bottom of stroke.. stayed pretty round and true though . All weighed... Bare ( no rings etc) 418.1 to 419.3g, with rings and pins 616.6g to 617.7g Sent from my SM-G930F using Tapatalk
