replacing SR20DET rocker arms - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

[email protected] · 10-10-2011, 07:35 PM

I have a rebuild going on and I'm thinking of replacing just my rocker arms since the ones on there are showing a bit of wear. I got all my shims numbered etc but I'm wondering if I have to re-shim cause I'm getting new rockers. Thanks for any input and yes I have searched but nothing specific comes up

Luvs2slide · 10-10-2011, 07:54 PM

Dont have to re-shim since all the rockers are the same size.

[email protected] · 10-10-2011, 10:47 PM

anyone else have any input on this?

brickerj · 10-11-2011, 06:41 AM

If you're talking about the shims that sit on top of the valve stems, no. Their purpose is to make sure that both valve stems are the same height so that the rocker arm is level which isn't affected by the rocker arms at all. The height of the rocker arm is controlled by the lash adjusters. If you're running solid lash adjusters, yes you should re-shim these while you are in there (really just a 'might-as-well' thing; you should be checking the lash periodically regardless). If you're running the stock hydraulic lash adjusters you don't have to do anything because the height is controlled automatically. That is, as long as you kept them upright the entire time. If they were ever in a position that wasn't standing upright you will have to bleed them before installation.

All of that being said, what exactly did this rebuild include? If you had your valves replaced/relapped/anything that involved removing them from the head, I would certainly re-shim because it is highly unlikely they are at the same height as they were before the rebuild.

s14unimog · 10-11-2011, 07:24 AM

define, "showing some wear"

Leetfade · 10-11-2011, 07:37 AM

This is very, very simple. I did this as well as I had grooves in my strike plates on my old head. Made a ton of noise (sounded like rod knock almost). I replaced these and it made a world of difference.

If you have the factory HLAs (as mentioned), you do not need to reshim. DO NOT TAKE THE SHIMS OUT. You don't want to mismatch the shims that are currently in there or you could have an issue. I do, however, recommend you take the extra 10 - 20 minutes and bleed the HLAs with clean oil. It will get the old gunk out and help prevent any sticking.

I have a BNIB set of rocker arms for sale if you're interested. Just let me know.

Boost_Fiend · 10-11-2011, 07:53 AM

Yeah like the people about above have said do not take them out. If you absolutely have to you are going to have to remember exactly where they go. I made the mistake of dropping my head during my rebuild and all my shims and guides went everywhere. If it makes you feel any better I said f**k it and just threw them back in there and am about 6000 miles on my motor and no issues at all. My valve train makes as much noise as any other sr.

Another person on here has mentioned that since the sr uses HLA's that it would automatically adjust the height and that is what I thought but I have been told otherwise and you need to reshim. Idk I say just make sure you bleed them correctly and you will be ok

[email protected] · 10-11-2011, 09:12 AM

The shims will be going to they're original spots..no mixing up or anything..just getting new rockers. Thanks guys

s14unimog · 10-11-2011, 09:23 AM

I bleed my lifters every time I have the cams out it's just too easy to do while you're there. Do it.

Matman03 · 10-22-2012, 08:39 PM

What size are the stock shims? I cannot find that statistic.

AsleepAltima · 10-22-2012, 08:52 PM

i think i measured them at .096" average... thats totally off the top of my head though. when i rebuilt my sr, i used a set of calipers to make sure that each rocker arm had the exact same size shims on each side. there is a difference in size between them. some were as much as .003-.005 thicker.

steve shadows · 10-26-2012, 01:46 PM

If you do re-shim make sure to get a re-shim tool. Bleed the lifters while you're in there, don't mix up the shims or the ninja angels of nissan gods will literally haunt you forever and your car will not right also. But everything else has pretty much been covered in this thread. Swapping lifters is super easy, just pop the cams out of the way and you're in business. Just make sure to tie off the timing chain tight so you don't have to go fishing for it at he bottom of the timing cover. This will make a simple lifter swap a job from hell.

10-10-2011, 07:35 PM	#1
[email protected] Nissanaholic! Join Date: Jul 2008 Location: Zacatecas, Mx; Paramount, Ca Age: 31 Posts: 1,626 Trader Rating: (32) Feedback Score: 32 reviews	replacing SR20DET rocker arms I have a rebuild going on and I'm thinking of replacing just my rocker arms since the ones on there are showing a bit of wear. I got all my shims numbered etc but I'm wondering if I have to re-shim cause I'm getting new rockers. Thanks for any input and yes I have searched but nothing specific comes up

10-10-2011, 07:54 PM	#2
Luvs2slide Zilvia FREAK! Join Date: Oct 2006 Location: NW Florida Age: 39 Posts: 1,490 Trader Rating: (81) Feedback Score: 81 reviews	Dont have to re-shim since all the rockers are the same size. __________________

10-11-2011, 07:24 AM	#5
s14unimog Nissanaholic! Join Date: Dec 2003 Location: In a place, near a river, over a lake Age: 34 Posts: 2,415 Trader Rating: (22) Rides Gallery: s14unimog Feedback Score: 22 reviews	define, "showing some wear" __________________ Fuking ginger bread man stole my wallet... SHIFT*lock_slide to side d3m3rs0n: if i have a baby im naming it Brandons Fault Emerson

10-11-2011, 09:23 AM	#9
s14unimog Nissanaholic! Join Date: Dec 2003 Location: In a place, near a river, over a lake Age: 34 Posts: 2,415 Trader Rating: (22) Rides Gallery: s14unimog Feedback Score: 22 reviews	I bleed my lifters every time I have the cams out it's just too easy to do while you're there. Do it. __________________ Fuking ginger bread man stole my wallet... SHIFT*lock_slide to side d3m3rs0n: if i have a baby im naming it Brandons Fault Emerson

10-22-2012, 08:39 PM	#10
Matman03 Leaky Injector Join Date: Sep 2008 Location: ATL, GA Age: 36 Posts: 129 Trader Rating: (1) Feedback Score: 1 reviews	Shim Size What size are the stock shims? I cannot find that statistic.

10-10-2011, 10:47 PM	#3
[email protected] Nissanaholic! Join Date: Jul 2008 Location: Zacatecas, Mx; Paramount, Ca Age: 31 Posts: 1,626 Trader Rating: (32) Feedback Score: 32 reviews	anyone else have any input on this?

10-11-2011, 06:41 AM	#4
brickerj Leaky Injector Join Date: Oct 2011 Location: Delaware Posts: 58 Trader Rating: (4) Feedback Score: 4 reviews	If you're talking about the shims that sit on top of the valve stems, no. Their purpose is to make sure that both valve stems are the same height so that the rocker arm is level which isn't affected by the rocker arms at all. The height of the rocker arm is controlled by the lash adjusters. If you're running solid lash adjusters, yes you should re-shim these while you are in there (really just a 'might-as-well' thing; you should be checking the lash periodically regardless). If you're running the stock hydraulic lash adjusters you don't have to do anything because the height is controlled automatically. That is, as long as you kept them upright the entire time. If they were ever in a position that wasn't standing upright you will have to bleed them before installation. All of that being said, what exactly did this rebuild include? If you had your valves replaced/relapped/anything that involved removing them from the head, I would certainly re-shim because it is highly unlikely they are at the same height as they were before the rebuild.

10-11-2011, 07:37 AM	#6
Leetfade Zilvia Member Join Date: Jun 2010 Location: Northern Kentucky Posts: 174 Trader Rating: (2) Feedback Score: 2 reviews	This is very, very simple. I did this as well as I had grooves in my strike plates on my old head. Made a ton of noise (sounded like rod knock almost). I replaced these and it made a world of difference. If you have the factory HLAs (as mentioned), you do not need to reshim. DO NOT TAKE THE SHIMS OUT. You don't want to mismatch the shims that are currently in there or you could have an issue. I do, however, recommend you take the extra 10 - 20 minutes and bleed the HLAs with clean oil. It will get the old gunk out and help prevent any sticking. I have a BNIB set of rocker arms for sale if you're interested. Just let me know.

10-11-2011, 07:53 AM	#7
Boost_Fiend Zilvia Member Join Date: Jan 2009 Location: Ft. Lauderdale, FL Posts: 199 Trader Rating: (0) Feedback Score: 0 reviews	Yeah like the people about above have said do not take them out. If you absolutely have to you are going to have to remember exactly where they go. I made the mistake of dropping my head during my rebuild and all my shims and guides went everywhere. If it makes you feel any better I said f**k it and just threw them back in there and am about 6000 miles on my motor and no issues at all. My valve train makes as much noise as any other sr. Another person on here has mentioned that since the sr uses HLA's that it would automatically adjust the height and that is what I thought but I have been told otherwise and you need to reshim. Idk I say just make sure you bleed them correctly and you will be ok

10-11-2011, 09:12 AM	#8
[email protected] Nissanaholic! Join Date: Jul 2008 Location: Zacatecas, Mx; Paramount, Ca Age: 31 Posts: 1,626 Trader Rating: (32) Feedback Score: 32 reviews	The shims will be going to they're original spots..no mixing up or anything..just getting new rockers. Thanks guys

10-22-2012, 08:52 PM	#11
AsleepAltima Zilvia Addict Join Date: Aug 2006 Location: Ontario, Ca Age: 48 Posts: 667 Trader Rating: (8) Feedback Score: 8 reviews	i think i measured them at .096" average... thats totally off the top of my head though. when i rebuilt my sr, i used a set of calipers to make sure that each rocker arm had the exact same size shims on each side. there is a difference in size between them. some were as much as .003-.005 thicker.

10-26-2012, 01:46 PM	#12
steve shadows Post Whore! Join Date: Aug 2003 Location: LA and OC Posts: 8,202 Trader Rating: (5) Feedback Score: 5 reviews	If you do re-shim make sure to get a re-shim tool. Bleed the lifters while you're in there, don't mix up the shims or the ninja angels of nissan gods will literally haunt you forever and your car will not right also. But everything else has pretty much been covered in this thread. Swapping lifters is super easy, just pop the cams out of the way and you're in business. Just make sure to tie off the timing chain tight so you don't have to go fishing for it at he bottom of the timing cover. This will make a simple lifter swap a job from hell. __________________ Like Me on FaceBook !

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