Justin Gibbons

I was wondering if a set of COMP 1.85 RR will have any Piston to Valve issues with my small cam.

Spec on the cam; 212/218 @.50 and .522/520 lift.

what would the lift be with these rockers?

405HP_Z06

iTrader: (11)

To figure cam lobe lift, divide the net lift by the rocker ratio. .522 / 1.7 = .307, .520 / 1.7 = .305

then multiply lobe lift by the new rocker ratio. .307 x 1.85 = .568, .305 x 1.85 = .564.

New cam specs 212/218, .568/.564.


Concerning PTV issues, this will depend on your combination and there isn't enough information to say either way.

Justin Gibbons

This is what you may need to know,
Push rods are comp 7.4, lifters are comp high energy hydraulic rollers, 918 springs.

If there is anything else someone needs to know just let know whats misssing.

I'm really out to lunch when it comes to these rockers.

Plese help!!

Justin Gibbons

Bump^

98RedZone

iTrader: (1)

If you have stock heads you will have no issues with ptv clearance.

405HP_Z06

iTrader: (11)

^^^^^^agree.

Justin Gibbons

Still have the stock heads, so I guess they will work.

thanks guys,

Any idea how many hp I could pick up?...Any cons to running 1.85 RR's?

eallanboggs

iTrader: (1)

I've been using Comp 1.85s with a set of heads that Richard of WCCH CNCed and milled off 0.030" for me nearly 10 years ago. I also install a set of Comp Rs at the same time and stuck with the stock length 7.4" pushrods, but upgraded to Comp Hi Tech hardened pushrods because as you know the Pro Mags use guide plates. The only thing I did to the internals in all that time was to put in a set of manley springs w/titanium retainers. They replaced a set of Comp 918s which have been in another LS for over a year now. I don't belive you're going to have clearance issues. As you might imagine I'm a big fan of Comp Pro Mags. If you use Comp Rs with them as I did be sure to stop at zero lash. You must have a very sensitive index finger to get this adjustment right. Nothing like experience with this one.