Thread: Rocker Arms & Shafts parts differences

I had noticed some upgraded parts in the past but today I made a more thorough research.

Rocker Arms
SR16VE 13257M (including N1)
stock:13257-1N510 replaced with 13257-1N515,13257-1N516 latest 13257-1N517 QTY:8
Models after December 2000 use 13257-8H600

P11 SR20VE 13257M
stock:13257-1N516 replaced with 13257-1N517 QTY:8
Models after February 2001 use 13257-8H600 QTY:8

P12 SR20VE 20V 13257M
13257-8H600 QTY:8

T30 SR20VET Intake 13257M
13257-8H600 QTY:4
T30 SR20VET Exhaust 13257MA
13257-8H610 QTY:4


Rocker ARM SHAFTS
Intake 13252
Stock:13252-1N510 replaced with 13252-1N520

Exhaust 13253
Stock:13245-1N500 replaced with 13245-1N510

Used on all VVL engines. Newer engines use from stock latest parts.
SR20VE September 1997- July 1999 & SR16VE September 1997 - October 1999 have the old parts.


Factory replaces parts for a reason. If everything is fine there is no need to change the part number. What's wrong with the above?
Anyone got some experience with them?

There is an interchangeability code 7 (can be used under certain conditions) on N15 and P11 which use old rocker arms (latest 13257-1N517) and want to change to 13257-8H600 but I can't read the part note. My guess is that it requires the newer arm shafts.

so if i want to upgrade to the n1's? i would do the first ones?

I have updated my post. These are used on all vvl engines. There not N1 specific parts. The only specific is the T30 SR20VET exhaust rocket arms due to the camshaft pattern.

I looked at this also as it was just brought to my attention. Only the rocker arms have the date break you mention. All other parts under them, shafts, springs, shims etc. are all the same. I'm going to order the 13257-8H600 and see what it looks like. The only thing that makes it dubious, is it is such a difference in part# from the other. And it follows the changes made to the VE with the P12 and the VE-T.

We'll see...

Rocker arms are quite expensive and you certainly know that.
My thought was if somebody doing a full rebuild really worth the trouble in spending on the upgraded parts?

There is a great picture thread from the New Zealand guys which shows the SR20VET internals. People with experience could make some assumptions.

Am I missing something? How is the middle lobe activated? What rides on it to move the valves?

The first pic is the SR20VET exhaust rocker which only rides on the small lobe. It never switches over.

actually, I didn;'t.

Lets take a look at this pic one more time. I would like to if someone could make this out of Titanium. Should be no problem. Also if you look closly the swipe pads are glue ons so this should be no problem to be done and should allow for some super high and super fast RPMs.