New Piston Rings Leaving Oil Streak

[James_03]

Hey guys,

Putting together a rb30dett tonight with CP pistons. So far I have 3 pistons in and installed.

I am following the CP guide for ring orientation etc. I have put a bit of oil in the bores before dropping them in, basically when I turn it over 2 of the pistons are leaving a small oil streak as they go down the bore probably 2-3mm thick, whilst the one other left does not do this. Just wondering if this is normal?

Or could there be something wrong with the ring orientation? I will proceed with the rest tomorrow to see what they do, just got me worried. The one that does not do it leaves a bit of oil around the top, but as it goes down the bore wipes it completely clean leaving no streak.

Thoughts?

Cheers.

[JonnoHR31]

checked the bores for round? what orientation does the cp guide say to use?

[James_03]

Yeah checked the bores they came up fine. Was honed at Mendham a few months back for 86.5 with a torque plate.

Basically I think the CP ring orientation is wrong. They recommend having the 1st and 2nd ring gaps on either end of the thrust surface, and I have read this to be wrong in multiple other places.

I have attached CP and Nissan way, CP is a little hard to read but basically the 1st and 2nd gaps are on either end of the thrust surfaces, and nissan has them offset.

Big thanks to Greg at Pro Engines too for his advice last night at like midnight lol.

[r33_racer]

Virtually all piston & ring manufacturers state that ring clocking setup these days. I think it has something to do with keeping the top ring gaps near the inlet valves to keep ring growth under control or so im lead to believe, but the rings rotate around anyway, so it doesnt really matter all that much.

My old man said the samething to me too when i was doing my engine as I was going off the total seal clocking chart which looks identical to the CP one you have there. He was taught to assemble like the nissan guide is showing. But everyone has a different idea in regards to their orientation. They all work fine!

[James_03]

Ok cool thanks for that guys. Maybe just getting a bit overboard with things, just like making sure it's right but.

[mid life crisis]

ive always done the nissan way for the last 25 yrs without any probs