clutchdust
Millionaire Playboy
I have almost made up my mind. On my new-to-me AFR190 heads, I am planning on running 1.6 rockers which will put the lift right at the advertised limit for the valves in these heads. I've been going back and forth on upgrading the springs or just adding a "rev kit". Some of you have said to do the springs, but that will involve cutting new pockets in addition to new springs and retainers, quickly pushing this budget build close to new head territory.
So I'm thinking of verifying I do not have coil bind at the maximum lift, and if that's true, just using the rev kit to provide that ever so slight additional pressure to prevent valve float. My reasoning is simple, the valve spring has to dampen and reverse the momentum of the valve, rocker arm, push rod and lifter. If the original springs are close to that limit, eliminating or at least reducing the lifter mass the valve spring sees by the installation of a rev kit should noticeably reduce the overall mass/inertia that valve spring has to counteract.
I do plan on dynoing the engine once it is assembled to see where I make peak power so I know the RPM range of the engine. Plus that will tell me if I'm getting valve float also. But with my cam, I would expect peak power somewhere between 5500-5800 and it to drop like a rock at anything greater than 6200.
So what say you (again)?
So I'm thinking of verifying I do not have coil bind at the maximum lift, and if that's true, just using the rev kit to provide that ever so slight additional pressure to prevent valve float. My reasoning is simple, the valve spring has to dampen and reverse the momentum of the valve, rocker arm, push rod and lifter. If the original springs are close to that limit, eliminating or at least reducing the lifter mass the valve spring sees by the installation of a rev kit should noticeably reduce the overall mass/inertia that valve spring has to counteract.
I do plan on dynoing the engine once it is assembled to see where I make peak power so I know the RPM range of the engine. Plus that will tell me if I'm getting valve float also. But with my cam, I would expect peak power somewhere between 5500-5800 and it to drop like a rock at anything greater than 6200.
So what say you (again)?