I am looking at purchasing a set of scorpion LS1 roller rocker arms and was wondering whether to go with the stock 1.7 ratio or 1.8?(both are the same price, around 400 shipped)? My new cam specs are,
2001 LS6 cam
207/217 int/exh @ 0.05" duration
0.525" / 0.525" int/exh lift
116 LSA
If I decide to go with 1.8, this would change my lift to a .555, but I am worried about valve to piston clearance. I am running stock pistons and heads have not been milled. I spoke with a few GM guys who told me there would be more than enough clearance. I know we are talking about a few hundredths of an inch, what are your thoughts?? The stock 5.3 cam specs are
5.3 LM7
190/191 int/exh @ 0.05" duration
0.466" / 0.457" int/exh lift
114 LSA

 

 

I would stick with stock ratio rocks, but thats me..

John

 

That's what I am thinking about doing, stick with the stock 1.7 ratio. I imagine I will pick up some Hp with the roller rockers compared to the stamped ones and get the benefits of running a roller rocker arm.

 

I think the rollers would be a mod I would do later on. Everything in the lsx valvetrain is beefy, works fine on cam swaps. I would put that extra money into a better mod. You might pick up some hp, but unless your spinning hit to 6500 I don't think you would be able to tell. But hey its up to you..
John

 

I have it set up so shift at 6000rpm from a dead stop or 6500rpm if I turn on the tow hall feature, kinda of like a performance button. I am spinning 370rwhp and 400rwtq, I was hoping for a bit more top end by swapping to the 1.8 rollers.

 

You'll gain enough to not tell the difference.
I can't see justifying spending that kind of money for such a small gain. Concensus is you can gain HP on the old GenI engines. but on an LSX your just throwing your money away.

 

If you really want to buy em. I say Dyno it with the cam and stock rockers. then install the rollers and dyno it again. Just for sake of argument.

 

just get a bigger cam..if you see any difference it with be less than 5 hp. you can see that kinda of difference between a warm and heat soaked engine..

 

If I decide to swap out the cam, it won't be till next year. For now, I am going to buy either the scorpion rockers or cranes quick lift rockers. More than likely I am going to stay with the stock 1.7 ratio. A friend of mine referred me to Wayne Landon who lives in Michigan. He is a scorpion dealer and has been racing for 60yrs. He said that I would gain Hp with the 1.7 roller rockers over stock stamped and should consider using the 1.8 ratio. I have done a lot of research on roller rockers compared to stamped and whether to stay with stock ratio or next step up. Most agree on going with a roller rocker over stock stamped. Whether to go with a higher ratio is another highly debated matter.