i have the ms4 cam and am lookin into getting prc227 heads, wondering what would be the best ratio for rockers to make power and what brand for strength, what does eveyone like? feed back will be apreceated, thank you!

 

Stock rockers are fine.

 

whats the stock rocker ratio?

 

1.7:1

 

I'm liking the Yella Terra 6646. 1.8, lightened nose, full needle bearings, joined shaft and it is supposed to fit under stock covers.

transmarobird91, what car do you have? Fourth gen? 91? No sig....

 

ya i got a 98 ws6

 

I'm not a fan of running larger ratio rocker arms. there really isn't any point in them with a cam like the MS4 (on stock heads). I'm not sure what the new heads are going to flow, but I would stick with stock ratio if it were me.

 

You should check out Texas Speeds upgraded stock rockers. Definetly some nice pieces, and the price is nice as well.

 

The 1.7 Yella Terra rocker arms would be YT6645. Better than stock with the bearing & trunion kit.

 

whats the difference in ratio between 1.7.1 and just 1.7 i understand 171 is stock ratio and id rather run different roller rockers rather than stock..

 

1.7 = 1.7:1 meaning the ratio of valve lift to lobe lift on the cam is 1.7":1". multiply lobe lift by rocker ratio to yield valve lift.

 

i failed math multiple times lol

 

look on your cam specs for your lift. for instance, the torquer v2 is .598/.595. That is on a stock 1.7:1 rocker arm ratio. If you wanted to jump to a 1.8:1 ratio, your lift would change by the difference. To calculate it take the lift/1.7*1.8

.595/1.7=.35
.35*1.8 = .630

The MS4 already has such a high lift that I don't think there would be any benefit from a larger rocker ratio.

 

okie dokie ill go with some aftermarket 1.7 rollers then. thanks for the help guy