Theoretical top end of a second generation Charger

[Kern Dog]

Spinning a 4.250 stroke engine to over 7000 rpms sounds risky!

[c00nhunterjoe]

Spinning a 4.250 stroke engine to over 7000 rpms sounds risky!

Mine is 4.5 for the record. Been doing it for years.
7400 here
https://youtu.be/2ciFpx9QaxQ

[Challenger340]

Spinning a 4.250 stroke engine to over 7000 rpms sounds risky!

As long as the Engine can still make power and is still pulling against the "load" things typically don't fly apart ?

It's when people spin them that high when they are well past their powerband and peak power that things begin to 'freewheel'.... just rev'ing higher and higher with little pull remaining against the "load".... wherein stuff can exit stage BOTTOM !
Just say'in....
if your peak power occurs at 5,500 rpm and you keep spinning it to shift at 7,000rpm ? The engine is so far down the backside of it's power curve the parts are basically 'freewheeling' = scatter risk !
That said....
if you are running 280+ degree's at .050 Camshaft with Heads that can breath/still deliver Flow up there... then typically NOT a problem !

I have street pump gas 572 Hemi's using KB Blocks and Stage V Heads out there making 950 hp that see 7,000+ rpm shift points regularly.... year after year after year

[INTMD8]

At the front straight at Thunderhill, I just get into GV overdrive for maybe 2 seconds and am at 155 Via GPS before braking.  Don't have time to look at RPM's.  I could see myself 165-170 if longer.  Hotchkis suspension 512 ci A-833 Gv overdrive 4.10 Dana 295/50/18.

Awesome 

[cp-chargr/6]

As Challenger340 mentions, a modified engine surely can rev faster than a factory one made. Why: diff cam, larger carb, higher displacement (overboring) and compression, lighter pistons, rotating assembly balancing, no emission stuff, etc. can provide you with torque at higher RPM than the nominal limit of the engine as per factory specs... Also, as mentioned before tire diameter matter as much as differential gear ratio.

The theoretical limits are taken at factory production conditions. After that, of course there are ways to get higher top speed! (including driver's ... abilities, let's keep this civilized...).

[v21hemicharger]

At the front straight at Thunderhill, I just get into GV overdrive for maybe 2 seconds and am at 155 Via GPS before braking.  Don't have time to look at RPM's.  I could see myself 165-170 if longer.  Hotchkis suspension 512 ci A-833 Gv overdrive 4.10 Dana 295/50/18.

Do you have any videos of you racing your car?  

Here's an old one with the 440 engine before the 512 and gv was added

https://www.youtube.com/watch?v=2MHwDbGwSkQ

[Kern Dog]

I remember seeing you and the car at the 2011 Spring Fling.

[GT]

At the front straight at Thunderhill, I just get into GV overdrive for maybe 2 seconds and am at 155 Via GPS before braking.  Don't have time to look at RPM's.  I could see myself 165-170 if longer.  Hotchkis suspension 512 ci A-833 Gv overdrive 4.10 Dana 295/50/18.

Oh man your charger is tough looking - very nice pic in front of the chevy

[BSB67]

No offense but I'm not buying that. 4.10 gears into a Gear Vendors is a 3.20 final drive, You're not going to make 170 mph without spinning 2 stroke like rpms.

I trap 7200 in my 440. Aint a big deal.

No. But seems pretty far from the spirit of the original post, don't ya think?

[c00nhunterjoe]

No offense but I'm not buying that. 4.10 gears into a Gear Vendors is a 3.20 final drive, You're not going to make 170 mph without spinning 2 stroke like rpms.

I trap 7200 in my 440. Aint a big deal.

No. But seems pretty far from the spirit of the original post, don't ya think?

Not really. "Theoretical top speed of a charger". I am running a 727 behind a 440 in a charger. How is that off the path when the question was asked about high rpm?

[cp-chargr/6]

Well, you might be right. OP talked about Top Speed with "theoretical gearing", not anything else. He said also that thought that street cars (with "theoretical gearings") were designed more to start quickly than for high speeds (i.e. the Daytona...). I think that the essence of the discussion is that besides "theoretical gears", if you change tire size and get sure your engine can spin faster than factory recommended (in your case 7000 RPM, when factory tic-toc-tach was red lined at 5000 RPM, with factory max torque around 4300-4600) you will go faster, even with "theoretical gear". In fact I found some discussion about 5000 RPM being pretty conservative even for stock conditions (but I guess safer for MOPAR from the warranty side).

I also don't know how modified is your engine c00nhunterjoe, what have you done to your 440?

[RiverRaider]

Not theoretical but actual, one of the Car Life magazine tests for a Hemi 69 500 with 4 spd. on F70 15 tires had top speed at 134 @6100 also ran 13.68 in the quarter.  No information in rear end ratio.
I recall reading articles for 142 mph and 147 mph runs the latter was a salt flats run in a Hemi Daytona but I could not find hard copy to back up my memory.

[hemigeno]

No information in rear end ratio.

The ratio would have been 3.54:1 (Dana 60), as 4.10's would not have produced top-end speed #s.

[c00nhunterjoe]

Well, you might be right. OP talked about Top Speed with "theoretical gearing", not anything else. He said also that thought that street cars (with "theoretical gearings") were designed more to start quickly than for high speeds (i.e. the Daytona...). I think that the essence of the discussion is that besides "theoretical gears", if you change tire size and get sure your engine can spin faster than factory recommended (in your case 7000 RPM, when factory tic-toc-tach was red lined at 5000 RPM, with factory max torque around 4300-4600) you will go faster, even with "theoretical gear". In fact I found some discussion about 5000 RPM being pretty conservative even for stock conditions (but I guess safer for MOPAR from the warranty side).

I also don't know how modified is your engine c00nhunterjoe, what have you done to your 440?

The daytona in 1969 broke 200 mph so take that for what its worth. In my case, not as modified as you may think. My 440 is a stock hemi crank, pump gas pistons, indy 440-1 heads and a big solid roller cam. It wants rpm. Its pulling hard still when it traps. I choose to not spin it higher. No dyno sheets so no clue where it will peak.

[c00nhunterjoe]

Double post

[HPP]

I went with a set of P225 70R 14's..... mounted them... inflated them to 60 psi and set them out in the sun for 3 days turning occasionally, wherein by my Calcs I was able to "stretch" them, albeit only slightly to just a hair under 27" diameter if even that ?

At first, I thought the same thing but look at his tire size...almost 30" in diameter not counting growth at speed.

Bias ply tires could be stretched by using the trick in the first post. However, I've found that street radials do not respond similarly to this trick, nor do they grow in height at speed either. 

[sccachallenger]

OK, not a Charger, but thought this might be useful.
1972 340 Challenger, 4 speed, 3.23, g6015 bias belted T/As.
I was young and dumb then, wanted to know what top speed was.
Engine was stock, with headers, wouldn't go past 5500 rpms with stock fuel pump in high gear.
Memory a little fuzzy, but think speedo showed 128.
Added a Holley red pump, easily hit 6000 RPMs when I lifted, speedo showed 135mph.
On at least two occasions in my own cars, the stock mechanical pump was the limiting factor.
Unless I added one of the "race" mechanical, or an electrical pump no way could the car pull strongly in top gear.
Of course your results may vary.