GreggymacZ28

Lately I've been reading up on rocker arm ratio's, and people staggering them. I have read about them putting 1.6 rocker arms on the intake side and 1.5 on the exhaust. But i know this has many variables.

So basically taking into account my variables. Being that i have 1.5 rr, my camshaft numbers are 236/242 duration @.050 and .520/.540 lift, that vortec heads usually are stronger on the intake side than the exhaust side, and that my retainer to guide clearance and spring pressures are only good to .550" lift. My question is, if i went to a 1.55 rr for just the intake, which would increase my lift to .537" compared to the .520" previous. Would this be a gain in the right direction?

Main reason why i wouldn't run anything on the exhaust side is because i am already at .540" and wouldnt want to push that any further. Another reason for not going to 1.6 on the intake is that that would take me to .555" lift which would leave too little clearance for my liking.

Any info. or suggestions would help me here, if the question is stupid at least it's something for me to learn,lol.

91_B4C_RS

Is. 017" lift worth the extra 200-300$ I say no. Save for a better set of heads

AlkyIROC

Rocker ratio is a poor mans cam swap. If all things are equal and you change from a 1.5 to a 1.6 ratio, your gain will only be about 5hp.

Increasing the ratio moves the pushrod closer to the pedestal, Not all heads have clearance through the head for this relocation and may need the slot modified.

Increased cam lift doesn't make the lobes any higher. The base circle is cut down to increase the lift. When you start getting into very high lobe lifts especially with a SBC, you don't want too small of a base circle since it changes things like pushrod length etc. A normal base circle cam with an increased rocker ratio can give the same amount of valve lift. Duration increases very slightly but not enough to notice.

Other than bragging rights to say you have 1.6 ratio rockers, there's no benefit to using a higher ratio rocker other than you don't have to replace the camshaft to get the same results. Changing the camshaft to get the lift you want will have a bigger gain because of duration, LSA etc that can also be changed.

GreggymacZ28

Okay that makes sense. I am using stamped steel rocker arms right now and to get 8 more at 1.55 would be 8 dollars a piece. I wouldnt need to spend $300, otherwise i would never have mentioned this,lol. I just figured if it would increase a little horsepower for around $70 it wasnt a bad deal.

mw66nova

iTrader: (13)

you said you have stamped steel rockers? and roller rockers? which is it? are you using the comp magnum's or something?

i'd think a full roller rocker would benefit you more now than a rocker ratio change. just for stability's sake.

GreggymacZ28

I have stamped steel rocker arms but a hydraulic roller camshaft. Not sure if i ever said i had roller rockers? If i did then sorry about that! And yeah i figured i would see more of a gain there but not sure if the $300 price tag on that would be worth it.

Basically this was just an idea that i figured with an extra $70 dollars i could add a few horsepower.

mw66nova

iTrader: (13)

AlkyIROC

Going from stamped steel to a roller rocker will be a better gain just with the reduction in friction plus the better tolerance in the ratio. Stamped steel are rarely close to 1.5 ratio except for the good aftermarket ones for classes that are not allowed to run roller rockers such as Stock Eliminator.

When I said all things being equal, I was referring to going from 1.5 roller rockers to 1.6 roller rockers will only get you around 5 more hp.

If you have stamped steel on the car and want to buy roller rockers then 1.5 ratio is a safe bet. With an already higher than stock lift in the cam, as long as there are no clearance issues with the extra ratio then buying 1.6 rockers instead of 1.5 wouldn't be bad. Your cam grind is already .520/.540. You really need to check all the clearances before buying 1.6 rockers. With that much lift on stock stamped steel rockers, you probably already have issues unless the rockers are long slot.

GreggymacZ28

Alky - Okay thanks that helps alot. I will probably save up till i can afford new heads or a new camshaft at this point.

Mw66nova - That was a lack of understanding of abbreviations on my part,lol. I thought that "rr" stood for rocker ratio,lol. Thanks for the heads up on my misunderstanding.

86iroc2try

Everything alkyiroc said above.

Save your money for better parts.