Chrysler Big Block redline??

[Toolmanmike]

Just a quick image from Nicks Garage's Dyno Pulls, granted most of what I watch are 440 builds and I've been always waiting for him to do a full 6.5k rpm pull as argumentatively can't be done on a BB Mopar but has been disproved with the 6.5k 440-6bbl/pack & Hemi rallye tach. Most I've seen Nick pull a 440 is to 6.2k, even the Hemi's he has been restricted by the customer(s) to 5.5k on the 'vintage' blocks as if he blows it up on the dyno he owns it.

View attachment 671640


1971 Plymouth HEMI Cuda 6.5k Tach

View attachment 671651


(edit) better picture quality


.

This one went to almost 7500. Obviously a purpose built race engine but things are moving around inside pretty darned fast.

 

[68PK21 440.6bbl]

Appreciate the pictures and the information, feels like I have the front row seats at Nick's!

6.2K... yup, I don't think I'm brave enough to go that high!
(Even if the engine is capable of getting there)

Yeah if you got a old engine with unknown internals... luckily I had my 440's when they were only a several years old but even at 100k plus miles with my second 1968 PK21 440 I wasn't shy to put it to the floor and hold it there. Heck as I said before with the Maryland State Police unmarked 440HP PK21 in 1972 driving around town with the small Holly on it I couldn't hear the secondary's ever opening up, it wasn't till I got it out on the Interstate and at 120mph that's when the secondary's opened up, I guess that was the pursuit mode. heh

.

 

[Sir Dodge alot]

Neat video. Hope you get an air cleaner on it soon as the DFW atmosphere can get gritty.

Be careful with over-tightening the secondary air valve spring. On the 9801 TQuad, seeking to do the same things you seek to, I managed to tighten it enough that it broke. Not good.

Take care,
CBODY67

Thanks.
This was an old video, this is the current air cleaner setup.

A bit "butchered" but I didn't like the thought of cutting a hole through the hood, so the core support was cut instead.

And the idea of the engine sucking in hot engine compartment air was a no bueno.

 

[Sir Dodge alot]

Yeah if you got a old engine with unknown internals... luckily I had my 440's when they were only a several years old but even at 100k plus miles with my second 1968 PK21 440 I wasn't shy to put it to the floor and hold it there. Heck as I said before with the Maryland State Police unmarked 440HP PK21 in 1972 driving around town with the small Holly on it I couldn't hear the secondary's ever opening up, it wasn't till I got it out on the Interstate and at 120mph that's when the secondary's opened up, I guess that was the pursuit mode. heh

.

Old iron cop cars are hella cool, "
It's got cop tires, cop brakes"

Interesting, a Holley carb? Not a Thermoquad?

 

[Sir Dodge alot]

This one went to almost 7500. Obviously a purpose built race engine but things are moving around inside pretty darned fast.

Yikes, that's one hell of a buzzsaw! Getting me nervous!

 

[Just Carbs]

Thanks.
This was an old video, this is the current air cleaner setup.

A bit "butchered" but I didn't like the thought of cutting a hole through the hood, so the core support was cut instead.

And the idea of the engine sucking in hot engine compartment air was a no bueno.

View attachment 671742

I don't think that cap on the carb will feed the carb very well. It DOES reduce air flow. And can mess with the carb fuel draw. And cause lean conditions.
Air cleaners are designed with a curve in the bottom plate, and it sits lower than the carb throat so that the air feeds into them as a smooth flow all the way around the carb and promotes good even fuel draw.
If you put the original air cleaned back on the car and feed it with your temp reducing fresh air duct you will be in the pink.
Your carb cap is for forced induction.

 

[Sir Dodge alot]

I don't think that cap on the carb will feed the carb very well. It DOES reduce air flow. And can mess with the carb fuel draw. And cause lean conditions.
Air cleaners are designed with a curve in the bottom plate, and it sits lower than the carb throat so that the air feeds into them as a smooth flow all the way around the carb and promotes good even fuel draw.
If you put the original air cleaned back on the car and feed it with your temp reducing fresh air duct you will be in the pink.
Your carb cap is for forced induction.

A bit of a long post, bear with me.

At first I couldn't find an air cleaner to fit the Carter AVS carburetor neck, since I moved from a 2 barrel carb to a 4 barrel.

But all of your points are valid for sure, I'm not discounting that thought.
From my limited knowledge, wouldn't the ducting enrichen the A/F mix?
Due to the engine taking in air "through a straw" so to speak.
The smooth ducting should reduce turbulence and add some sort of "ram air supercharger effect" albeit a negligible amount.

one other thing I thought was the ducting creating some sort of a tuned runner length sort of like the cross ram manifolds on 1962 Chrysler 300's/imperials.
This was mostly an experiment to see how it would work, a proof of concept perhaps?

Long runners increasing torque while short ram would be increasing top end performance, yay or nay?

The ducting is on a cruiser type of a lead sled, so it doesn't see much high RPM, which definitely the ducting would choke the engine, it's
More "optimized" for low end torque.

But that's all I got, just some theory I had while putting the ducting together.

Thanks for voicing your thoughts, it's good to hear some feedback on a pseudo project.

 

[Just Carbs]

I like the duct.
The problem is the cap and the cap alone, it's a choke.
It will be easy for you to research air cleaner bases and their effect on none pressurized air flow.

 

[Sir Dodge alot]

I like the duct.
The problem is the cap and the cap alone, it's a choke.
It will be easy for you to research air cleaner bases and their effect on none pressurized air flow.

Thanks, & Gotcha, will look around for another Carburetor Cap/Hat, the one I used fits the bill as I needed hood clearance more than anything.

 

[Just Carbs]

Air cleaner bases are designed so as not to kill low mph-low rpm full throttle torque. And still not restrict high rpm flow.

Look at the factory curved designs from the side, the point of view level with the plane of the carb. The curve in the air cleaner base serves as a long-tuned intake runner. That's why they have big diameter air filters in the cleaner canister. So that the filter doesn't interfere with the base plate air feed curve inside the actual filter.

The old Toronado dual snorkel air cleaner base is commonly used on top of high-rise manifolds that cause hood clearance issues. Thats a stock 425 ci- 385 hp-475 torque motor. The motor is elevated in that car because of the front wheel drive setup.

 

[68PK21 440.6bbl]

Old iron cop cars are hella cool, "
It's got cop tires, cop brakes"

Interesting, a Holley carb? Not a Thermoquad?

Yes in 1968 I guess the 440 HP motor had a small Holly 650cfm on it like some(?) Imperial 440's.
I drove my 2nd PK21 for quite awhile with the all stock motor, it even had the big non-snorkel air cleaner on it from like a 426 wedge motor (later to be used as a parts cleaning pan). About 6/7 months later I put the 440 6bbl motor in it from my first PK21, the original motor wasn't burning much oil if I remember, just wanted to get the 6bbl motor in it as it was sitting in the back yard under a tarp.

But by then premium grade gas had gone up and the 6bbl motor was a wallet drainer so I put the 2nd PK21's 440 Holley on the 6bbl motor, got good results and in a mileage check during a long high speed run of 200 miles with a average cruising speed of 95mph it got 15mpg. Not to shabby, way better than 4/6mpg and average light pedal of 9/12mpg.

I'm glad I was driving the car way before all the Blues Brother crap. Never really got pulled over in the 1968 PK21 car's much. I remember one late night run where I was running up around 100 and had headlights come up on me and rolled it back to see who it was and sure 'nuff a State Trooper went flying by me and kept on going. 1st one was rolled after a police chase where the cop crashed out before me and he got desk duty after that 'cause he had already wreaked one cruiser chasing a buddy of mine that had a 1967 GTO. I got stopped more times in my 1977 PK41 both by State Police & local and that was in the early 80's so maybe cause of some affect from the movie... IDK.

.

 

[Sir Dodge alot]

Yes in 1968 I guess the 440 HP motor had a small Holly 650cfm on it like some(?) Imperial 440's.
I drove my 2nd PK21 for quite awhile with the all stock motor, it even had the big non-snorkel air cleaner on it from like a 426 wedge motor (later to be used as a parts cleaning pan). About 6/7 months later I put the 440 6bbl motor in it from my first PK21, the original motor wasn't burning much oil if I remember, just wanted to get the 6bbl motor in it as it was sitting in the back yard under a tarp.

But by then premium grade gas had gone up and the 6bbl motor was a wallet drainer so I put the 2nd PK21's 440 Holley on the 6bbl motor, got good results and in a mileage check during a long high speed run of 200 miles with a average cruising speed of 95mph it got 15mpg. Not to shabby, way better than 4/6mpg and average light pedal of 9/12mpg.

I'm glad I was driving the car way before all the Blues Brother crap. Never really got pulled over in the 1968 PK21 car's much. I remember one late night run where I was running up around 100 and had headlights come up on me and rolled it back to see who it was and sure 'nuff a State Trooper went flying by me and kept on going. 1st one was rolled after a police chase where the cop crashed out before me and he got desk duty after that 'cause he had already wreaked one cruiser chasing a buddy of mine that had a 1967 GTO. I got stopped more times in my 1977 PK41 both by State Police & local and that was in the early 80's so maybe cause of some affect from the movie... IDK.

.

Man must have been cool to see every (mostly) car that had a 440 motoring around.

Come up to a stop at an intersection and you hear the other car's with their "V-8" sounds emanating from every car that's stopped.

Also neat is the fact you just had "a spare motor lying around"

The MPG's were not bad for a 6bbl, it's mostly in economy mode, if you don't mash the pedal. XD

 

[RemCharger]

Just a quick image from Nicks Garage's Dyno Pulls, granted most of what I watch are 440 builds and I've been always waiting for him to do a full 6.5k rpm pull as argumentatively can't be done on a BB Mopar
.

huh? Who argues that??

 

[Dads300]

If your stock nylon timing gear was missing teeth when you swapped in the new timing set, I would pull the oil pan and clean the screen in the oil pickup tube. I lost an excellent running 383 to that. P.O. Put new timing set in with new heads when the nylon gear jumped and it bent all of the valves. They never pulled the pan and the screen was plugged. About a year after I got it, I was getting on the freeway with some vigor and it spun a rod bearing. Lesson learned.
Travis..

 

[Dads300]

I don't think that cap on the carb will feed the carb very well. It DOES reduce air flow. And can mess with the carb fuel draw. And cause lean conditions.
Air cleaners are designed with a curve in the bottom plate, and it sits lower than the carb throat so that the air feeds into them as a smooth flow all the way around the carb and promotes good even fuel draw.
If you put the original air cleaned back on the car and feed it with your temp reducing fresh air duct you will be in the pink.
Your carb cap is for forced induction.

If you haven’t seen the engine masters show where they dyno test air cleaners, you owe it to yourself, it’s a good watch. They found a flat base makes more power than a drop base. Also, any set up that feeds air downward is better yet, think velocity stack.

I’ve seen other tests where that hat that you’re running can cause fuel distribution problems depending on which way it is positioned on the carb.
Travis..

 

[68PK21 440.6bbl]

huh? Who argues that??

Oh I got a lot of pushback way back in the day even with the sparse Mopar owners that I met, my first PK21 with the 440 6bbl one of the first accessories I install was a brand new Stewart Warner electronic tach, mounted on the A-pillar right by the spotlight and I didn't just stuff it in there, I made a aluminum bracket so it wouldn't go flying. First tire roasting session was left foot hard on the brake, trans in low and foot to the floor, speedometer needle straight up at 60mph and tach at 6,500 rpm... and held it there for a massive cloud of smoke (dumb kid) LOL Then when I was swapping out the 6bbl setup for a small 440 Holley setup I needed a 4bbl cold air oval cleaner like the 6bbl had. Go to want AD's and find one, slep on down to this guy's garage after work grab the air cleaner then he had a large box of dash gauges and wiring harness and asked if I was interested in it, saw it was a Cuda Rallye dash setup 150 mph gauge, wood trim panel, wiring and all switches, 50 bucks and I hauled it away only to just recently realize that the 6.5k redline tach in the cluster is a 440 6bbl & Hemi only item (and maybe AAR). I used the 6.5k redline tach as confirmation that 440's can do 6.5k and got back talk "that's a small block tach" Come to view a live Mecum Auction with the French 1971 Hemi Cuda and it has a 6.5k redline tach. (see below)

And (I think) same auction a 1971 Plymouth AAR Cuda Tach appears to be 6.5k (not best picture)

Standard 5.5k Tach with 7k limit.

.

 

[Ben Herman]

I have a stock 1966 383 with just under 250k on it, a stock 7727, and 2.76 gears. I'm running a 225/75r15 tire. Its been a little while since I've done this but you can stay in 1st till 65 and 2nd till 115 before valves start making bad noises. If I remember correctly that's around 6,500rpm.

Is that good for my engine? Probably not. Its certainly a lot of fun though.

 

[Nadir Point]

I have a stock 1966 383 with just under 250k on it, a stock 7727, and 2.76 gears. I'm running a 225/75r15 tire. Its been a little while since I've done this but you can stay in 1st till 65 and 2nd till 115 before valves start making bad noises. If I remember correctly that's around 6,500rpm.

Is that good for my engine? Probably not. Its certainly a lot of fun though.

Similar setup in my '71 is the same way, still chirping 2nd at 65-70mph with a little over 90k on the clock. 2.76 gears, HP440, 727 w/TransGo kit. But it's a freakin' gas hog.

 

[Jeremiah]

All 67-70 single 4 barrel 375 horse 440's used carter 4 barrels. AFB in 67, AVS 68-71. 72-up was Thermoquad right into the Diplomat era.

Personally I wouldn't worry about 5k rpm with a 727. If it was a stick I'd be cautious because if you missed a shift at 5k with no limiter it *might* float the valves enough to smack a piston. With the shorter connecting rod a low deck (361-383-400) has more dwell time at TDC, making them more prone to the scenario above. Just one guy's opinion so don't get to Freudian on that statement.

 

[Jeremiah]

I would check the accuracy of the tach on the 6500rpm stock 440. There wasn't an OEM 440 that would spin that high. In my experience by 6k rpm a stock 440hp is getting into serious valve float.