Chrysler Big Block Redline??

[Sir Dodge alot]

This is a copy & paste post I made from FCBO.
Thank you for your time and input.
But here's the question:

As the title says I'd like to know what the redline is for Chrysler BB's in particular the 361, I suppose a 383 is close enough candidate as reference.
Recently I have completed my Pushbutton A727 rebuild & installed a Transgo TF-2 kit with a 2000 stall converter from Hughes performance converters.
Rear gear is 2.76

The motor is stock with potentially a 256/256 cam.
It does have a forged crank which I hope the crank being forged raises the max RPM threshold.

The WOT at 2nd gear will shift just past 4800?/5000? RPM, but I tend to let off at around 4800.
I'm afraid of potentially blowing the motor if it does hit 5000 RPM.

Is 5000 RPM a "safe" WOT shift? Are Chrysler big blocks even capable of hitting 5000 with no unseen unfortunate events to occur?

Thanks for your input.

 

[Kern Dog]

5000 rpms?

I shift my fairly stock 383 at 6200 and it is STILL climbing.
The 440/495 in my red car has a longer stroke, 4.15 compared to the 361 crank of what.....3.38? I shift it right at 6000 rpms.
You are fine.

 

[Sir Dodge alot]

5000 rpms?

View attachment 1694045

I shift my fairly stock 383 at 6200 and it is STILL climbing.
The 440/495 in my red car has a longer stroke, 4.15 compared to the 361 crank of what.....3.38? I shift it right at 6000 rpms.
You are fine.

Thank you for your wisdom, excuse me as I go and hammer the throttle past 5K next time.
Knock on wood, ends up blowing up the engine.
That will be quite the laugh actually.

That is actually pleasing to hear, I've only heard the tires chirp from a WOT 2nd gear shift a limited number of times, I'm hungering for more!

 

[Kern Dog]

They were built with small carburetors, log exhaust manifolds and heads that didn't flow much past 5500 rpms but when those issues are addressed, 6000+ rpms are fine. The crank can take it. The rods can take it. The valves may start to float if the springs aren't matched to the camshaft operating range but when built right, you can take these engines well past 6000 rpms.
These were built with a power peak under 5000 rpms in most cases, especially the 2 barrel carbureted engines. They can rev higher but the engine won't pull as hard after 5000 rpms as it does from say 3500-5000.

 

[33 IMP]

You will float the valves with that tiny stock hydraulic cam, way, WAY before you endanger the internal pieces.
I'm betting there is no reason to take it past 4500, no horsepower to be found, but you won't hurt it at 5000.

 

[DanielSlocum]

The main limitation is hydraulic lifter pump-up,followed by the strength of the stock stamped rocker arms and stock 5/16 pushrods. Bottom end is mainly limited by oil pan capacity and whether a windage tray is present. Next is the strength of the stock rod bolts. I would avoid 6000 with stock parts mentioned.

 

[BeepBeepRR]

Nick is running this 383 up to 6000 rpm.

 

[AR67GTX]

With stock, early heads on an otherwise stock motor you won’t need to worry about it. It will probably reach 5,000 easy enough in first but you will probably get bored waiting for it to get all the way to 5,000 in second and go ahead and shift. Now with more gear and Magnum components you would probably gain a couple hundred more revs in the gears without problem.

 

[sam dupont]

You will float the valves with that tiny stock hydraulic cam, way, WAY before you endanger the internal pieces.
I'm betting there is no reason to take it past 4500, no horsepower to be found, but you won't hurt it at 5000.

Floating valves: Factory Rev Limiter

 

[sam dupont]

to be truly fast, you have to find a place at 7000 rpms (poking fun at the movie)

there;s a place at 7000 rpms - Google Search

 

[toolmanmike]

5000 rpms?

View attachment 1694045

I shift my fairly stock 383 at 6200 and it is STILL climbing.
The 440/495 in my red car has a longer stroke, 4.15 compared to the 361 crank of what.....3.38? I shift it right at 6000 rpms.
You are fine.

Don't laugh, a 383 has a shorter stroke than a 350 Chevy! A stock 440 doesn't need to rev to 5000 to get the power. The stock valve train can't support 5000+.

 

[Black_Sheep]

I have the rev limiter set at 6K, I’ve bumped it a few times with no adverse effects…

 

[toolmanmike]

Nick is running this 383 up to 6000 rpm.

Tom runs his big wedge to 7500. Purposely built of course.

 

[j-c-c-62]

They were built with small carburetors, log exhaust manifolds and heads that didn't flow much past 5500 rpms but when those issues are addressed, 6000+ rpms are fine. The crank can take it. The rods can take it. The valves may start to float if the springs aren't matched to the camshaft operating range but when built right, you can take these engines well past 6000 rpms.
These were built with a power peak under 5000 rpms in most cases, especially the 2 barrel carbureted engines. They can rev higher but the engine won't pull as hard after 5000 rpms as it does from say 3500-5000.

To be brief to the OP, with your combo, going past 5K may not make you any faster in the 1/4, even if your motor will actually do it.

 

[#41]

You are good to go for rpm, but I have to ask.... a stock 361, 2.76 gears, and a 2000 converter? That is not the right converter for this combo. I assume that you are planning further changes and upgrades?

 

[Jerry Hall]

My first new car with a 383 4-speed 3.23 sure grip in stock trim would float the valves at 5200 rpms. The same car with headers, ported 915 HP heads, and a highly upgraded cam & lifters, and stock bottom end was consistently shifted at 7000 rpms. Just saying you have no problems with the stock bottom end of your engine, if it's in good condition.

 

[RemCharger]

The stock valve train can't support 5000+.

This is 100% incorrect.
The springs themselves may be too weak , but are designed to run with the weak cam.
7 grand is about the limit for stock rockers and pushrods.

 

[6PKRTSE]

One of my 440's has a mild hyd f.t. camshaft, bored +.030 with all other stock components. I spin it and shift at 6300, with hundreds of passes and now has over 60,000 miles on it with never any issues.

 

[moparedtn]

Another joining the chorus here....
A stock 361 won't much care about anything above 4800RPM - and it'll let you know it doesn't
by the way it fights to go any higher, valves a-floatin' and all.
If you want more RPM, build an engine - hell, with those gears, build a dang driveline - suitable
for it. What you have now....isn't.

 

[F4R/T]

The one thing I’ve notice is Mopar lower ends are honestly pretty robust.. you’ll be floating your valves before anything else or it just won’t pull it due to restrictions from intake/ exhaust flow.. Mopars are bitched about for being heavily built especially the lower end and that’s why everyone ditches them for lighter stuff. I personally don’t, ie six pack rods for example. But quality of a rebuild is key and always replace the rod bolts every time with arp. This is my opinion take how you wish.