440 rpms?

[gahi]

how high can i safely rev a 440 mostly stock. has a street strip cam and double timing chain. I want to take it to the strip soon but i don't want to blow it up. thanks

[Mopar_Maniac]

Safely?

3000 rpm.......just kidding.

It really depends on alot of factors. Typical stock 440's run out of breath at about 5000 rpm. What you are looking for is where the engine makes its power. There is no sense in running the rpm up high if the car won't make power up there.

Big Block engines make most of there power low in the rpm range. I would take it to the strip and practice "leaving" on a good light and let the transmission shift itself (automatic?). If you want to manually shift it, or you have a 4 speed start out shifting at about 4500 rpm. Then gradually climb the rpm ladder 100 rpm at a time. You will find a point where the car will stabilize its ET or slow down...you just went too far for your engine combo.

Don't run the rpm higher than you need for getting the job done.

Good luck,
Mopar_Maniac

[Doug Wilson]

What he said.

[Stoga]

On a stocker, valve springs seem to be the limiting factor, then the ability to breathe. I'd experiment shifting at 4000 or so, then increase your shift point rpm by 100 rpm until the car starts to slow down. There's nothing to gain by over revving them, I've drove a few of my friend's cars and have gained speed and trimmed et, just by shifting them earlier. Unless the engine or heads are modified for it, too much rpm will just slow you down.
Most of the old stock Mopars I used to bracket race, as long as tuning and fuel system was in good shape, almost always seemed to like to be shifted at 4200 to 4400 rpm. Each car/engine is different, so hit the test and tune night and see what your car likes.

[451Mopar]

What everyone else said. I think 5,000 may be about the redline with all stock parts, mainly limited by your valve springs. With good valve springs the engine will rev higher, but the stock rod bolts and heavy pistons could cause a rod to break. With lightweight pistons, re-conditioned rods and good rod bolts, 6,000+ RPM is fairly common.

When this question comes up about what is the safe RPM for an engine, Hot Rod Magazines answer was Zero RPM! There is alaways a chance something will fail at any RPM.

[gsmopar]

Man you guys need to live a little! Rev it until the valves float then shift! Next gear try shifting a little sooner. j/k However, I wouldn't worry about hurting the engine. Like everyone above me just said, the valves float before you really do any damage. If you're still running a stock distributor (points) they'll float before the valves ha ha!!!

Good luck,


Greg

[451Mopar]

The bad thing about floating the valves is if you bounce one off the piston and bend/break the valve.

The 451 stroker has been getting a good workout lately making many chassis dyno passes up to the 7,000 RPM limiter chip in the MSD 6AL.
The light weight pistons in the stroked 400 block, while still using stock 440 rods (resized with ARP rod bolts.)

[gahi]

thanks for all the info. it seems about 4500 is where my car likes to shift. but with 3.76 gears it kind of limits my top end. I haven't tried the 1/4 mile yet but hopefully I wont go much past 4500.