Quote:
Originally Posted by i82much
i thought pontiacs needed beehives and titanium retainers to pull 6500.
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Possibly. Lightweight parts are always a good idea, and the valvetrain on a Pontiac is a bit on the heavy side to start with anyway.
6500 wouldn't be that hard to pull off though with a hydraulic roller as long as the engine is making power up there.
We don't have any of the beehive stuff on dad's 571 Pontiac. Those heads were converted to a 2.19 intake valve which is a bit heavier, then had Paul spec the dual springs for the Hydraulic roller, I set them up at the install height he recommended. 160 lbs. seat pressure and 420 open. I think the retainers are titanium though. Dad repeatedly puts that thing on the chip, the engine revs up quicker than he can shift the darn thing. Has a 6300 chip in it and he's all over it all the time. It runs right up there no problem. On the dyno it was done making power however at 5800 rpm but still carried nicely just past that.
My chevelle has slightly heavier valve train (BBC) with a similar dual spring setup. 2.25 1.88 valves that aren't fancy lightweight stuff. Again it does have titanium retainers. BBC's are horrible about valvetrain weight and can sometimes have valvetrain issues as well. Hydraulic roller and it zings right up to 6500. Made peak power at 6300 but runs best times when I shift at 6500. Rev limiter at 6800. That engine has been together 25 years doing that LOL
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