Hello, 6 months ago I installed a newman phase 1 cam with their new hydraulic lifters. The problem is that the lifters are noisy and it seems my engine don`t like to rev.

Currently I have twin 40 DCOE with facet silver top 200hp pump, slightly worked head, and the engine will go up to 4000-4500rpm without much problem, but getting it to 5000 or even 5500 is very difficult. Something curious is that the engine fails sometimes and at 5000rpm it will lose quite power, even the sound of the engine changes.

Can this be the lifters? I think for the CVH the best now is mechanical lifters. I have checked all the engine and everything is fine. I have ngk iridium spark plugs.

This problem is drviving me crazy , as I suppose with that spec , my engine will go to 6000rpm without problem.