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Old 10-05-2005, 09:31 PM   #1
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Default How 1.9 rocker work?

Hi,
sorry if my question look "newb" but i have interrest in what i put in my car

I want to know what are the characteristic that made a 1.9 ratio rocker better than stock?


i know it open the valve higher... (sorry if i look stupid) but if you make the valve open higher, it will not close?? (my friend told me that )

i have a friend that really doubt it work and want to show him mathematicaly that it work, i know that the rocker will give me a nice gain , but i just want to know why
(that way i can shut his mouth )

Any info will be greatly appreciated.

Thx

Mike
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Old 10-05-2005, 09:50 PM   #2
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Michel...c'est le temps que tu change d'ami

Rockers are referred to by their ratio;

Stock rockers are 1.6 to 1
High ratio rockers 1.9 to 1 (others ratios are available)

What this means is that for every inch of camshaft lift, the stock rocker will open the valve 1.6 inches. The high ratio (1.9 to 1) rocker will open the valve 1.9 inches for every inch of camshaft lift.

The rockers will work great, the valves will have more lift and they will close properly and your friend is still an idiot that thinks he knows something.

Cheers,
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Old 10-05-2005, 09:57 PM   #3
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Quote:
Originally Posted by Foghorn
Michel...c'est le temps que tu change d'ami

Rockers are referred to by their ratio;

Stock rockers are 1.6 to 1
High ratio rockers 1.9 to 1 (others ratios are available)

What this means is that for every inch of camshaft lift, the stock rocker will open the valve 1.6 inches. The high ratio (1.9 to 1) rocker will open the valve 1.9 inches for every inch of camshaft lift.

The rockers will work great, the valves will have more lift and they will close properly and your friend is still an idiot that thinks he knows something.

Cheers,
Clean fast and well explained Paul, i understand how it work now!
Just remain to know if my friend will undertstand...

If hes not a believer after that... je vais changer d'ami

Thx Paul
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Old 10-05-2005, 10:11 PM   #4
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Ok here it is in a nut shell. First lets grab some "what if" numbers and keep it simple.
You have a cam with a 1" intake and 1" exhaust, what this means is when the lobe of the cam is at its highest point it is 1" above its neutral line. (of course this is much bigger than an actual cam but makes for easy math )
Now the cam has a hydraulic lifter that rides on the cam, this lifter then pushes a Rod. This Rod is seated (ie mounted) into one end of the "Rocker". The rocker is mounted to a pedestal and works like a Teeter Toter or See Saw (playground toy). The valve is held closed by a very strong spring and retainer, the valve is seated (ie mounted) to the other end of the Rocker (there are two ends to the rocker, one end has the valve the other end has the push rod).
So when the cam rotates it pushes up the Hydraulic lifter and the push rod, This causes the Rocker to push down on the spring making the valve open.
Which takes us to Ratio'*.
When the cam lifts 1" and the rocker ratio 1.6 to 1 (stock size) the valve opens 1.6"
When the cam lifts 1" and the rocker ratio 1.9 to 1 (high ratio size) the valve opens 1.9"

The bigger the opening the more the flow. But dont look at the hole size as being the only opening?
Think of it this way, take a beer can a poke a hole in the side, now put your finger over the hole but not against the can, get it really close within a few thousands of an inch.
Beer will still flow out but not as fast as when it was 'wide open'.
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Old 10-05-2005, 10:15 PM   #5
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For those linguistically challanged:

Quote:
Originally Posted by Foghorn
Michel...c'est le temps que tu change d'ami
Michel, It'* time to change your friends.

Quote:
Originally Posted by mike_peperni
If hes not a believer after that... je vais changer d'ami
If he doesnt believe me after that...I will change friends.



I think...
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Old 10-05-2005, 10:18 PM   #6
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Quote:
Originally Posted by Rogue
I think...
You got it...Pontiac

Cheers,
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Old 10-05-2005, 11:15 PM   #7
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Quote:
Originally Posted by Rogue
For those linguistically challanged:

Quote:
Originally Posted by Foghorn
Michel...c'est le temps que tu change d'ami
Michel, It'* time to change your friends.

Quote:
Originally Posted by mike_peperni
If hes not a believer after that... je vais changer d'ami
If he doesnt believe me after that...I will change friends.



I think...
you got it!

also PontiacDad for that great info.
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Old 10-06-2005, 08:28 PM   #8
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Well...

my friend still doesnt believe it can work, it seem impossible to him that with a higher ratio the valve will close.

he tell that because the pushrod is connected to the rocker and the rocker with the valve, it cannot close, ( im sure you understand his thinking)

i make a drawing of what he is thinking:
http://putfile.com/pic.php?pic=10/27818124965.jpg&*=x7

sorry for bad quality, but thats the same thing he draw this morning to me trying to explain that it is impossible.

(what i think its that the rocker is different only where the valve is , this is why it can close.may be im wrong, i just want to shut his mouth )

so if you guys can tell what is different on the rocker from stock that make it still close.
any link of a pic or something welcome.

"The shutting mouth project."


Mike
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Old 10-06-2005, 08:35 PM   #9
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Quote:
Originally Posted by Foghorn
and your friend is still an idiot that thinks he knows something.

Cheers,
LMFAO
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Old 10-06-2005, 08:48 PM   #10
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The rocker is actually different where the pushrod meets with it. The fulcrum of the rocker and the tip where it connects to the valve never changes. The seat where the pushrod sits in the rocker arm is moved away from teh valve and the angle of the pushrod changes slightly.
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