camd01silv

I'm toying with the idea of rebuilding the 5.3 in my ride... Prolly gonna Whipplecharge it or Magnacharge it. I'd like to bore it over to the 3.9" bore of the Camaro/Corvette engines, as well as put something like a 3.75" stroke crank in it. Prolly gonna be running 9:1 compression or so. As for the GM hot cam thats in the engine now, I've heard it's not that good of a blower cam. Which cam would be a good one to go with? Judging by what I've seen other people use, about the only real difference I can see is the lobe separation is farther apart. Is this correct? Well, better go, thanks for any help guys.

1Bad454

9:1 compression is pretty high for a blower motor. It's always best to call which ever cam company you choose to help assist you is selecting the right cam.

TurboBerserker

iTrader: (1)

9:1 compression isn't high at all for these motors. Depending on what boost you can squeeze out of the whipple, I might not drop the CR at all. The rule of thumb there should be "keep it as high as you can for your boost level". I'm running 8.6:1 for 18psi.

General advice on the cam: 220/224 115lsa-ish

Vinci Performance has a ton of blower cams -- give Joe a call when your ready and tell 'em what you got and want -- they'll help you out.

1Bad454

Lets say your pushing it at 9:1.... If your building an engine for a boosted application compression plays a key role especially if your not running an intercooler. The Whipple does not have an intercooler.

TurboBerserker

iTrader: (1)

Thes genIII motors can run up to 12 psi on 10.1:1 with meth only (as with the stock SS 6.0L block). With either the radix (which is intercooled) or a whipple (which will be intercooled with the next version I believe), you're going to have a big fight to get to 12psi, let alone beyond it.

9:1 is probably low for a radix and is not pushing it at all IMO (assuming proper fueling and tune). I know plenty of guys running 10.1:1 and 10psi with no issues with a radix on a completely stock low end.

Detonation is a function of CR, heat, octane and timing, not just CR.

1Bad454

Right on the money with detonation. If you want to run on meth or race gas go right ahead thats a given.

ranwalk

iTrader: (1)

For the record, i'm running 10psi of boost on my 6.0 with a Whipple and 9.1 compression, no intercooler and no meth, on 93 octane. There is more to consider than just CR. The cam, exhaust, headwork, and the very important tune. 9.1 or even a little higher would be good for a whipple or radix. If you get into turbos or something like a procharger that can really make alot of boost then a lower CR would be better IMO.