Thread: slotted rocker arm shims?

I came up with this sotted ship thing on both sides in 97-98 and it works flawless. Take the time to do it right and it is one of the most proven methods on keep the rockers on.

I have a question Andreas. I followed all your recommendations when I had my W11 head rebuilt except the VE oil pump. I had thought the W11 oil pump still moved a high volume of oil just at less pressure than the VE pump.

(my head mod thread here) http://www.sr20-forum.com/general-sr20/53864-overkill-my-head-modifications.html

So what RPM range do you think my head would be capable of? Does the W11 oil pump reduce the RPM range potential any?

When doing this mod the VVL pump is better because of the higher presure. The higher presure is what helps to stop the lifter from collapsing. This stops valve float and keeps the HP from droping off to quick.

Its mainly called a "dual guide" conversion. Since the DET engines were notorious for spitting shims out, people started doing the 2 guides instead of 1 shim and 1 guide. This will hold the rocker in place if one still decides to spit itself out.

We provide the service if anyone is interested.

The inventor is right here and also does the job if you are untreated but can be done at home

noone uses stoppers?

Rocker arm stoppers are crap

Yep. Dont need them, not worth the damage they can cause.

been usin em for years. had an issue when I haven't used em... guess ill look into it.. is there a write up on slotting the shims?

Valve float is what throws the rocker arms is what a lot of people fail to realize. Especially when on stock cams the stock valve springs will start to float at 7000-7200 so when your reving to 7500 or so your well into the floating stage.

A good set of aftermarket springs can solve this, a smoother ramping cam can solve it for the most part. I ran my jwt s4 cams to 8k all day long on stock springs and retainers and never tossed a rocker arm not even once. And just like on my C2 cams the motor saw 11-12k+ rpm a couple times when gears gave away at redline and shot past the factory limiter. Never threw a rocker.

Ultimate is a VE oil pump, twin groove shim mod and springs and retainers. 9k+ rpm capable head all day long.