5.0L Valvetrain Questions

rowekmr · Feb 20, 2011

Forgive me for some simple questions but I couldn't find the information that I need. I have a stock block 5.0L in a 95 GT and wanted to know the stock stamped rocker arm length is it 1.5 or 1.6? I see many with 1.7 roller rockers but are those recommended for aftermarket cams on stock pistons? I have read that at some point the pistons need to be notched but is that with a mild or wiild cam? I was considering a mild Comp Cam or TFS Stage 1 cam when I get heads and intake.

stykthyn · Feb 20, 2011

I believe stock is 1.6. You can put roller rockers on a stock set up but you will see more bang for your buck elsewhere.

HiFlow5 0 · Feb 20, 2011

rowekmr said:
Forgive me for some simple questions but I couldn't find the information that I need. I have a stock block 5.0L in a 95 GT and wanted to know the stock stamped rocker arm length is it 1.5 or 1.6? I see many with 1.7 roller rockers but are those recommended for aftermarket cams on stock pistons? I have read that at some point the pistons need to be notched but is that with a mild or wiild cam? I was considering a mild Comp Cam or TFS Stage 1 cam when I get heads and intake.

Stock ratio is 1.6:1 but because of the stamped steel they flex a lot.

A lot of guys run 1.7 rockers with a stock cam to help get a little more lift. I never understood why guys would buy 1.7 rockers and use them on an aftermarket cam? That's the point in replacing your cam with aftermarket, to get the desired lift you want with the duration designed into that cams specific lift.

RacEoHolic330 · Feb 20, 2011

HiFlow5 0 said:
I never understood why guys would buy 1.7 rockers and use them on an aftermarket cam?

Because, in addition to the lift, the duration and overlap characteristics of the cam change with the 1.7 rockers compared to the 1.6's. The 1.7's will allow the specs of the cam to be optimized for a specific engine combination.

squekster · Feb 20, 2011

I have an 87 with an E303 cam and I run 1.7 rollers with that and have no problems. The 1.7 rollers with a hotter cam like the E303 can benefit from the 1.7's. If you notice , the 1.7 cobra rollers are cheaper than 1.6's. I don't know why .but they are.

f8tlfiveo · Feb 20, 2011

I have 1.7's with stock cam and gt40p heads.. Seems to breathe a little better.

HiFlow5 0 · Feb 20, 2011

RacEoHolic330 said:
Because, in addition to the lift, the duration and overlap characteristics of the cam change with the 1.7 rockers compared to the 1.6's. The 1.7's will allow the specs of the cam to be optimized for a specific engine combination.

Why not just buy a specific cam that meets the needs or your engines power band?

RacEoHolic330 · Feb 20, 2011

The cam creates the desired performance and powerband of the engine, but the rockers can tweak those characteristics. If you lift the valve with a 1.7 rocker, the valve will come off it's seat before it would with a 1.6 rocker. This will make the valve duration longer. Since the duration is longer the the overlap will increase too. The bigger advantage of using higher ratio rockers is that you can run a milder cam lobe and still have good valve action. Also, since the lifter has more mass than the rockers and valves, the higher ratio can help with high rpm stability and prevent valve float.

The rockers change cartain characteristics of the engine that cannot be ground into the cam.

HiFlow5 0 · Feb 20, 2011

RacEoHolic330 said:
The rockers change cartain characteristics of the engine that cannot be ground into the cam.

I don't know if I completely agree with that, but I agree with everything else you said. I still don't see the gains on any street driven car.

5.0L Valvetrain Questions

rowekmr

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stykthyn

I want to measure mine. It doesn't look that tall.

HiFlow5 0

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RacEoHolic330

I like to dress like a pretty girl

squekster

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f8tlfiveo

My wife likes my spool and blow-off valve.

HiFlow5 0

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RacEoHolic330

I like to dress like a pretty girl

HiFlow5 0

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