nahasapeemapetalon

iTrader: (9)

Guys-

There are probably lots of variables (valve type etc etc) but on a typical BB chevy build without blowing budget on titatnium valves etc...What is the typical safe rpm range for a BB chevy?
Example: afr 305cc heads or trickflow oval ports(in carcraft march article)
I have heard different opionions, some say 6000 some say 6500.
Give me your input!

This is going to decide which head listed above is purchased probably. Oval port trickflows made sick numbers tq and hp throughout the curve in carcraft magazine.

ZONES89RS

iTrader: (25)

I am waondering the same thing, everyone sais how big piston speed is on a BBC at high RPM, i wanna push 7000RPM on a 496 with pump gas if possible.

nahasapeemapetalon

iTrader: (9)

Yea, i didnt mention what kind of cam. Hydraulic Flat Tappet.
7000 is prly going to get expensive....I am pretty sure youd need lightweight everything with a mech. roller.
Nice car.

Villain281H

iTrader: (5)

I know of a 496 with Edelbrock oval ports with off-the-shelf valves but a Jesel shaft rocker system, solid roller cam in a 3400 lb street car that turns 7 grand at the finish line on spray. It can be done.

Derek

prostock1455

Getting 7K out of a oval port headed big block isn't to hard, but they need to flow serious numbers.

I have a 510" (4.310x4.370) and I shift at 8200, through the traps at 8800 with no issues. Just have to buy the correct parts. One piece stainless valves, good roller springs, good roller lifters. Make sure you have the valve to pistion clearance at .080+, you have to remember the faster you spin the motor the more the rods stretch.

Rotating weight is also an issue, keep it as light as your budget will allow, remember is always good to pay a little more for a better part, then have a $200 diffence in price destory a $5K motor.

I have ran many lightly modified ovel port big blocks with stock rotating assys to 7500 with no failures. But that is about it's limit. The rotating weight of a heavy stock steel crank will only spin to about 7600 max then it fights back with resistance.

The main issue is valve springs!! make them tight, I recommend if your going to buzz a mechanical cam to 7500, the seat preasure of the springs should be 160 Lbs, this will keep the valves chasing the cam and not the pistions.

Run a pana-vac system, the biggest piston/rod failures occur during the exhaust stroke, To much preasure under the pistion that is just going for the ride will heighten your risk of popping the piston off the top of the rod.

ZONES89RS

iTrader: (25)

So, basically, a 7000 RPM 496 big block with any forged parts and a good valve train is no prolem then? Thats good.

cncbird

iTrader: (3)

hydraulic flat tappet is probably going to quit before 6000

ZONES89RS

iTrader: (25)

I will go ither Hyd roller or solid roller.

67pontiac

iTrader: (6)

U dont need to spin that kind of rpm with a big block thats why u go bbc u can take a stock 496 put a bigger roller cam in so u will have to put good springs an retainers but shift it at 6200-6500 and spray it with a 200 shot and u will have nothing but fun.

ZONES89RS

iTrader: (25)

So what formula would make the 700hp quest for the RPM needed to make it on a 496?