I need help with finding a redline on a 70 chevelle

[slacker69]

What all is involved on finding a redline for a 70 chevelle with a 350 in it.
Is it the cam if so here are the specs:
I:230/E:236 with a 110 lobe seperation
106 Intake center line

please help it is me and my dads project car and we want to know what it will rev to.

[Magnus]

Try the chevelle ubb

http://www.chevelles.com/cgi-bin/forum/Ultimate.cgi

[WickEdSix9838]

if its a hydraulic cam it doesnt need to go over 6500 because the valves will float, if its a flat tappet dont go over 7000

[Shadly]

A 32 year old 350? I wouldn't take it up much past 5000. That's some old iron you're playing with. What you're really going to have to look at is the age and type of bearings, springs, pushrods, lifters... It's not so much whether the engine can take high RPMs, it's what will happen to the engine if it fails at high RPMs. The odds of a new engine failing are a LOT less that an old engine.

[John_D.]

Well, it's not exactly a v6, but some of the topic is still general enough to go here...

First off, do you want to know redline as in how high will it go without self-destructing? Or as in how high before the power starts falling off?

Power/torque/whatever will be dependent on the cam, yes. But also on the intake and exhaust, compression, and some other factors. Intake and exhaust are biggies. Longer intake runners are better at high rpms. The old cross ram and tunnel ram intakes were good up to 7000. Shorter intakes would drop power quickly on the top end. Header diameter and length make a big difference too.

As far as surviveability, you need oil pressure, minimal weight, and strength. Oil pressure to make sure there is always a layer of oil keeping the bearings from touching the crank as that piston and rod whip back and forth 117 times a second at 7000 rpms. Rule of thumb is about 10psi per 1000 rpms. The pistons, as they jerk back and forth in their cylinders, will be trying to come off the end of the piston rod. They need to be light and durable. Do you have forged pistons or cast? Rods - shot peened? Hardened rod bolts? And the comment was already made about valve float. Spring pressure is a factor too. Also are they hydraulic or solid. High spring pressures will give you a few more rpms, but is harder on the valvetrain.

(valve float is where the valve doesn't close all the way - not enough time - so you are losing compression, but more importantly, the lifter can come up off the cam lobe, and when the lobe comes back around it will catch the corner of the lifter - it's really rough on both parts...)

[2001 Green machine]

I agree with the above posts, My rule of thumb with a mild 350 is 5500 rpms max. Throw an Edelbrock cam , intake and carb on it and you will see good power from 1500-5500 rpm's. Pretty cheap bolt on horsepower. It will wake your motor right up, especially if you put dual 2 1/2"
exhaust on it.You can do all of this for under $1000.

[Tiago]

its a new 350, I would find the redline by knowing how far up the cam makes power and how strong the rods are.

[slacker69]

Yeah new engine new tranny its all fairly new less than 3500 miles on the engine and tranny. It has a nice comp cam and a holly 750 cfm carb. Stage 2 heads or at least thats what the shop called them when my dad bought them we just want to make sure trhe car is shifting efficently.

[IFlyLow]

I have a 69 chevelle with a 350 with a 280 comp cam and double hump heads(1.94/1.60 valves). It has about 5k street miles and 30 1/8miles passes and i turn it regularly to 7500 to 8000 with no float along with 150 shot of act-right-juice [img]graemlins/rofl.gif[/img] for a little wheel toting fun....

[KillerBeeCamaro]

Its as easy as running second gear all the way out and let of when is stops pulling, somewhere aroud 6100-6200.