Rockers vs Aftermarket Camshaft

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#11

08-25-2009, 01:08 PM

Frosty LS1

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Ahh, so it's just another intake mod to help give the engine more air. Thanks for explaining it, that really helps.

#12

08-25-2009, 01:14 PM

nemesis

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Quote:

Originally Posted by chibiblacksheep

They are only one set, but it refers to the side of the engine that they are on. ER Rockers (which are best for NA applications) are called ER because they stand for Extended Range Rockers. You will get 12 rockers, 6 for each side of the engine. Only they have a different ratio depending on the engine side, because through research ZZP found that splitting the ratio for NA applications is more beneficial.

Stock rockers are considered 1.6 Ratio. That means that the stock rocker opens the valves 1.6 times the amount of the Cam lobe. The higher the ratio, the longer the valve stays open, the more air flow rates go up, and more air means more power (to an extent). They researched with different ratios and found that 1.8 for the exhaust side, and 1.85 for the intake side gave the most results (on NA while keeping the stock springs)

Of course since you are altering your air flow, after you do rockers you should get that car tuned. Also since you are doing the work of taking off the upper intake manifold and valve covers, it's a good time to put the HV3 in at the same time so your upper RPM band gets to use more power.

blacksheep, you're the mcf encycolpedia, you're da man with da plan!!

#13

08-25-2009, 01:23 PM

ChibiBlackSheep

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lol

I've just done a lot of research on them because I'm putting them in Saturday...

I'm doing the mild NA build (and staying mild NA) so it's easy to help someone with a mild NA build

#14

08-25-2009, 02:36 PM

bumpin96monte

Join Date: Feb 2008

Posts: 6,064

Quote:

yo bum, with your intense stage 3 cam and 1.7 rockers setup how much hp you think you gain? from what i read alot of guys saying you will not see any gain at all by going little higher on the rockers ratio, unless you have heads done.

Its impossible for me to tell. I did both of them when I did my L67 swap, along with headers, ZZP S4 iron heads, p&p blower, p&p tb, etc etc etc- the only mod I didn't do with the swap was the whipple.

The main reason I did it is because I really wanted to run the IS4 blower cam, but it was back when it first came out- and everyone said it was "completely unstreetable", and that there was no way you could drive a car on the road with one (obviously thats false because a lot of people do)- so I got an IS3 blower cam and did the higher ratio rockers to make it a little more beefy.

I'm sure the power difference is pretty small from stock rockers, but the main reason I wanted them was for the roller tips- to help reduce friction.

Quote:

So a 10HP gain is about all I'll get by going with rockers? Is there anything else I need to upgrade, replace, or worry about when doing rockers?

I'm not an NA power gain expert, but from the couple I've done- that sounds about right, 10whp.

I'd also reccomend doing new valvecover gaskets while you're in there. HV3 is another good mod, as mentioned by others.

Quote:

ER Rockers are actually 1.85 in the Intake and 1.8 in the exhaust.

Thanks for the correction!

Quote:

Ahh, so it's just another intake mod to help give the engine more air. Thanks for explaining it, that really helps.

Its an intake and exhaust mod- you change the rockers for both valves.

#15

08-25-2009, 03:01 PM

ChibiBlackSheep

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Quote:

Originally Posted by bumpin96monte

I'd also reccomend doing new valvecover gaskets while you're in there.

If you buy ZZP's Rocker Install kit, you'll get new valve cover gaskets, as well as the bolts you need (Rockers have torque to yield bolts, so they are only one time use)