Piston ring orientation .. - GT-R Register - Official Nissan Skyline and GTR Owners Club forum

SR BEAST · 14th June 2007, 09:24 AM

Hey guys ..

Was wondering what piston ring orientation do people tend to place their new rings when rebuilding with forged pistons

Different orientations effect blowby, compression etc ..

The JE/CP orientation :

The OEM orientation :

T.F.S. · 14th June 2007, 12:27 PM

i always go with the recommendations supplied with aftermarket pistons..

Chris Wilson · 14th June 2007, 07:25 PM

I never fit the open ends of rings on the thrust side of pistons.

Cord · 14th June 2007, 08:04 PM

The second diagram is how it should be done, end of story.

I've never seen recommendations to do it as shown in the top diagram, and even if I did I would throw it in the bin, it is all wrong.

SR BEAST · 15th June 2007, 01:00 PM

It seems that If i follow the JE/CP orientation, after some miles ...the engine starts to have some crankcase pressure that goes higher with time ...

I'm installing the JEs the oem way this time

NISFAN · 22nd June 2007, 10:31 AM

Yep, I installed my JE rings as per the second diagram.

hytech · 22nd June 2007, 09:47 PM

I use gapless rings.

M SKinner · 23rd June 2007, 11:20 AM

I do em like the OEM diagram personally but less of a 90 degree X more like a 110-120 degree one with the compression rings 180 degrees apart.

Ive always been told never to have a ring gap in line with the gudgeon pins, and as chris wilson says, never on the thrust side (another reason for more like a 110-120 degree angle between them rather than just 90)

SR BEAST · 23rd June 2007, 12:08 PM

Quote:

Originally Posted by M SKinner

I do em like the OEM diagram personally but less of a 90 degree X more like a 110-120 degree one with the compression rings 180 degrees apart.

Ive always been told never to have a ring gap in line with the gudgeon pins, and as chris wilson says, never on the thrust side (another reason for more like a 110-120 degree angle between them rather than just 90)

can u draw a diagram showing me exactly ? I really gotta know how it looks ? thrust side ?

M SKinner · 23rd June 2007, 02:40 PM

thats what i mean by a 120ish degree angle rather than 90

The thrust side is the side that gets pushed towards the block on the power stroke. because the con rod is at an angle the downwards push of combustion is tranlated into a thrust force as well as the downward force.

You will see this if you take an engine apart and look at any scuffing/polishing to the piston skirts. It will be more severe on one side

SR BEAST · 23rd June 2007, 06:48 PM

Alright thanx, I got what you mean ...

RB26zcar · 24th June 2007, 03:41 AM

Just curious, but do the rings not spin around on the piston when in use? Seems like I remember seeing my ring gaps at funky angles after a tear down long ago...

Just asking, to be sure... thanks

SR BEAST · 24th June 2007, 01:44 PM

That's what is happening to my engine after a teardown too ..

a guy at cp pistons told me that they do move later on ...

14th June 2007, 09:24 AM	#1 (permalink)
SR BEAST SR BEAST is unaware they can edit their status GTR Register Member Join Date: Mar 2005 Posts: 275	Piston ring orientation .. Hey guys .. Was wondering what piston ring orientation do people tend to place their new rings when rebuilding with forged pistons Different orientations effect blowby, compression etc .. The JE/CP orientation : The OEM orientation : __________________

14th June 2007, 12:27 PM	#2 (permalink)
T.F.S. T.F.S. is fully aware that they can edit their status GTR Register User Join Date: Feb 2004 Location: londonish Cars owned: 32 GTR Posts: 1,902	i always go with the recommendations supplied with aftermarket pistons.. __________________

14th June 2007, 07:25 PM	#3 (permalink)
Chris Wilson Chris Wilson is unaware they can edit their status GTR Register User Join Date: Aug 2001 Location: Shropshire Cars owned: R33 GTS-t with RB26 engine and Tractive dog box. And too many race cars according to `er indoors... Posts: 3,116	I never fit the open ends of rings on the thrust side of pistons. __________________

14th June 2007, 08:04 PM	#4 (permalink)
Cord Cord is unaware they can edit their status GTR Register Member Join Date: Aug 2002 Location: RB Motorsport Cars owned: dirty poo Posts: 1,568	The second diagram is how it should be done, end of story. I've never seen recommendations to do it as shown in the top diagram, and even if I did I would throw it in the bin, it is all wrong. __________________

15th June 2007, 01:00 PM	#5 (permalink)
SR BEAST SR BEAST is unaware they can edit their status GTR Register Member Join Date: Mar 2005 Posts: 275	It seems that If i follow the JE/CP orientation, after some miles ...the engine starts to have some crankcase pressure that goes higher with time ... I'm installing the JEs the oem way this time __________________

22nd June 2007, 10:31 AM	#6 (permalink)
NISFAN NISFAN is on a dyno............. a human dyno :) GTR Register User Join Date: Oct 2003 Location: Herts Cars owned: A Skyline version of the DB9R Posts: 1,956	Yep, I installed my JE rings as per the second diagram. __________________

22nd June 2007, 09:47 PM	#7 (permalink)
hytech hytech is 2009 Night Speed Drag Wars Champion GTR Register User Join Date: Feb 2003 Location: www.hytechengines.co.nz Cars owned: 2 x R32 GTRs & 1 x R33 GTR V-Spec, 1 x Evo Drag Car Posts: 223	I use gapless rings. __________________

23rd June 2007, 11:20 AM	#8 (permalink)
M SKinner M SKinner is unaware they can edit their status New Users Join Date: Feb 2007 Location: Croydon, Surrey Cars owned: BNR32, HNR32 Posts: 834	I do em like the OEM diagram personally but less of a 90 degree X more like a 110-120 degree one with the compression rings 180 degrees apart. Ive always been told never to have a ring gap in line with the gudgeon pins, and as chris wilson says, never on the thrust side (another reason for more like a 110-120 degree angle between them rather than just 90) __________________

23rd June 2007, 02:40 PM	#10 (permalink)
M SKinner M SKinner is unaware they can edit their status New Users Join Date: Feb 2007 Location: Croydon, Surrey Cars owned: BNR32, HNR32 Posts: 834	thats what i mean by a 120ish degree angle rather than 90 The thrust side is the side that gets pushed towards the block on the power stroke. because the con rod is at an angle the downwards push of combustion is tranlated into a thrust force as well as the downward force. You will see this if you take an engine apart and look at any scuffing/polishing to the piston skirts. It will be more severe on one side __________________ Last edited by M SKinner; 23rd June 2007 at 02:44 PM..

23rd June 2007, 06:48 PM	#11 (permalink)
SR BEAST SR BEAST is unaware they can edit their status GTR Register Member Join Date: Mar 2005 Posts: 275	Alright thanx, I got what you mean ... __________________

24th June 2007, 03:41 AM	#12 (permalink)
RB26zcar RB26zcar is unaware they can edit their status GTR Register User Join Date: Mar 2004 Cars owned: rb26powered74zcar Posts: 67	Just curious, but do the rings not spin around on the piston when in use? Seems like I remember seeing my ring gaps at funky angles after a tear down long ago... Just asking, to be sure... thanks __________________

24th June 2007, 01:44 PM	#13 (permalink)
SR BEAST SR BEAST is unaware they can edit their status GTR Register Member Join Date: Mar 2005 Posts: 275	That's what is happening to my engine after a teardown too .. a guy at cp pistons told me that they do move later on ... __________________

Thread Tools
Show Printable Version Email this Page
Display Modes	Rate This Thread
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode	Rate This Thread: