I have been doing a lot of studying lately and have found many diffrent rockers.... I Found some roller rockers that are 1.7 ratio and require the 7/16's studs and I am wondering can you just swap the studs (since they are screw in's in my trick flows) to the 7/16's and install the 1.7 ratio's? I am planning a cam swap and correct valve springs for the adventure but just wanted to know if anyone has used the 1.7 ratio before?

 

would the 1:7s be for a LS1 by any chance? i doubt you find 1:7s for a SBC, except the LS1

 

You will probably need to upgrade to better push rods with 1.7 rockers. That may lead to a clearence problem for the pushrods going through the head (depends on the heads...) I wouldn't go that much on a street car. Instead, get a bigger cam (roller).

 

Well these were for SBC not for LS1 and this isn't a street car so im not to concerned about thar....... The pushrod problem did come to mind but I guess I will have to contact some of the manufacturers about it.

 

Superstock engines have used 1.7 rockers. I cant add much other than they use shaft assemblies.

 

Swapping the studs is no problem. Just make sure the dimensions are correct on the thread length at both ends. I would think that a 1.7 rocker ratio might cause problems as mentioned above. You would need to make sure that there is clearance in the heads. Also that the pushrod does not contact the rocker arm at full lift.

You will also have to make sure there is enough spring clearance to stay out of coil bind and the recommended .050-.060" spring coil clearance at max lift. With the high lift cams available maybe the 1.6 rocker ratio might be enough. There are also 1.65 ratios out there. And last but not least the decrease in the life of your valve train componets. Make sure to use the best if you decide to go that route.

 

Well the problem I have is that I ran a forged I-beam rod instead of a H-beam capscrew style and when I clearance it I did it for the cam I am running now which is a .501 so I can't run much more then that. I guess I might just pull it back apart and put in some H-beams instead so I can go to a much more aggresive ramp. If I did do the rocker swap I would of course change to the proper springs so that coil bind would not happen as well.

 

On my race motor in the dragster we run 1.85 on the intake and 1.80 on the exhaust. Of coarse you have to check for proper clearance and stay out of coil bind.

I would say that "the recommended .050-.060" spring coil clearance at max lift" that 1989GTATransAm listed is way too close. I would say that you need to have .100 minimum clearance. Of coarse if it is an all out race motor you can run it a bit tighter.

I run .075 but we run huge valve spring pressue and a rev kit. I turn the dragster motor over 9600 through the lights.

 

9600 RPM on a pushrod motor?!?! geez, is that even possible???

 

Hey comp, so did you clearance the heads for the extended rockers or do they just fit? The only thing I am wondering is pushrod geometry and wether or not they will not go at to much on an angle.