Ok, simple enough...Ive seen many people say they have 1.6 rockers on say, the intake side (could be exhaust side, this is a hypothetical situation) and 1.5s on the other.

How can this be? someone draw me a little picture or something. Excuse my ignorance

Thanks

 

Each valve has its own rocker arm. The way they increase the ratio (stock is 1.5, more or less) is by shortening the distance between the push rod seat in the end of the rocker and the pivot ball. So, you can just select the ratio you want for specific valves, and put arms of that ratio on just those valves, and get any mix you want. On a SBC with typical heads, the intake side of the whole system outflows the exhaust side considerably; so under some circumstances you can get better results if you increase exhaust side flow more than intake side, compared to what you get by increasing them equally. That's why most of the better modern cams have unequal intake and exhaust lobes, always with more duration and usually with more lift too on the exhaust.

Don't feel ignorant, until you've actally done it, it is a bit hard to visualize.

------------------
"So many Mustangs, so little time..."

 

Here's a prime example of when you would need staggered rocker ratios:
I have the ZZ9 cam in my 355 motor.
.490 int lift (with 1.52 rockers)
.527 exhaust lift (with 1.52 rockers)
The intake lift is on kind of low, but the exh lift is rather high.
So I can put 1.6's on the intake valves.
That would change it to
.520 int lift (1.6 rockers)
.527 exh lift (1.52)

I am actually planning on doing this in the near future.


------------------
AKA Pony Punisher II on all other boards.

89' Iroc-Z
ZZ3 short block-355 TPI ZZ9 cam
NOS 150 shot.
blah...blah...blah..
95' T-56, 6-speed
99' Z' rearend w/ 4.10's
------------------
1997 black Trans AM
A4, bone stock except for the Flowmaster.

 

I've heard of racers staggering the rocker arm ratio on every other cylinder to smoothen the torque curve. Cylinders 1, 4, 6, 7 are fitted with 1.5:1 rockers, and cylinders 8, 3, 5, 2 are fitted with 1.6:1 rockers. It's like having half an engine with a small cam and half an engine with a large cam. Pretty trick.