440 performance

[mavwreck]

Hey all!
I’m a younger guy looking to up the outage on my 440 without killing my wallet in the process (I’m in college)

As it sits here’s the combination:
Stock 1978 440 rotating assembly
“516” casting heads w 440 red stripe valve springs
Mopar 484 purple shaft
1972 4bbl motorhome intake with a 1” spacer
Holley 700cfm fully mechanical
7 quart deep sump oil pan.

I do have a pair of 452s that I plan on smoothing out the ports on (not porting, just getting the uneven flack and casting out of the ports. Maybe gasket matching?) If I did the same to the 516s would I see more performance? I do plan on learning to port on a few of my junk motorhome intakes so I can maybe get some hps out of the 72’ that’s on the car.

I’m wondering if putting higher compression height pistons and putting on the modified 452 heads if I would see a noticeable difference? I’m aware that the 516 heads are a crutch to the amount of air the 440 would move. They were on the motor when I got it.

If anyone has stock muscle car era 4.320 pistons and rods please lmk! And I hope to hear some neat tricks that you guys have tried!

 

[RemCharger]

I ran the same combo down to 12.20s. Heads were milled 60 with big exh valves, and a torker intake.
Gears help alot.
The low comp new heads don't help enough in this situation
IMO

 

[mavwreck]

I ran the same combo down to 12.20s. Heads were milled 60 with big exh valves, and a torker intake.
Gears help alot.
The low comp new heads don't help enough in this situation
IMO

452 or 516 heads? I have a 3.23 sure grip in the car. It’s a 67 coronet

 

[1967coronet]

If the bottom end is in decent shape myself I would leave it.
Run a compression test to verify.
The 516s give you a little bump in compression but from what I have heard the 452s flow a little better. So...
If the 516s are good run them.
Like Rem posted ,gears will help.
The thermoquad style intake with a adapter and sq.bore carb on top is a bottle neck. I would think a better match on intake and carb will help the low end.
A well set up distributor matched to your cam specs and a well tuned carb is good.
Try to get everything hitting in the same rpm range,
Those low compression 440s will surprise you once you get things matched up.
The bonus is you can fuel up at any C store.

 

[mavwreck]

If the bottom end is in decent shape myself I would leave it.

The thermoquad style intake with a adapter and sq.bore carb on top is a bottle neck. I would think a better match on intake and carb will help the low end.
.

the bottom end was balanced with all new rings and bearings. It’s as good as a motorhome rotating assembly gets XD

It’s an earlier square bore pancake style intake. I pulled it off of a 413 industrial. I’ve been on the hunt for a dual plane!

 

[1967coronet]

452 or 516 heads? I have a 3.23 sure grip in the car. It’s a 67 coronet

Pretty much the same as mine, I have 452s on , a fast curve on the distributor and a little smaller cam. Headers, Preformer intake and a thermoquad.
The old gal will smoke the tires and run 120 , I'm fine with that.

 

[Geoff 2]

Agree with most of the above comments. The 516 heads have the small 1.6" exh valves; the 452 heads have a better flowing intake port. For a low performance engine, it would be a toss up whether you would notice much difference.
I would lose the Holley/1" spacer & use a TQ carb.

 

[1967coronet]

If your holley is tuned good I would try to find a little better dual plane and get a good curve on the distributor.
A lazy distributor will really mess with you trying to tune.

 

[mavwreck]

It has a good tune but the car just feels only a little more torquey than the 318 that was in it. It’s a brand new stock distributor, the type you get at any major AP store. I’m running 13 initial with 38 full advance.

If your holley is tuned good I would try to find a little better dual plane and get a good curve on the distributor.
A lazy distributor will really mess with you trying to tune.

 

[mavwreck]

If your holley is tuned good I would try to find a little better dual plane and get a good curve on the distributor.
A lazy distributor will really mess with you trying to tune.

I should add that the 318 was a hodge podge of performance parts and was a real screamer for mostly stock parts

 

[DanielSlocum]

Sorry to say that your cam is too big for your compression ratio. It has quite a bit of overlap period [where both valves are open] which is causing very low cylinder pressure. Thats why it has barely more low rpm torque than the 318 had. The 516 heads are the way to go for you as you need every bit of compression you can get with those way down in the hole pistons.I think your heads and intake will flow all that a smaller camshaft is going to allow through the valves at this level anyway. Get a cam with something like 224/224 duration at .050 with 110-112 lobe seperation to create some low speed cylinder pressure and torque. Lift would then be about .460-.470. Some of the more modern grinds will have steeper lobes for more lift at the same [or less] duration for even better cylinder filling and torque. The down side is that they may be more prone to premature lobe/lifter failure which is a rampant and extremely frustrating problem now days. 1 3/4 dia. long tube headers will help your power and torque a lot also. More gear and/or a looser converter helps a lot also but too much is not good for a street driver. Good luck young man.

 

[493 Mike]

Agree with most of the above comments. The 516 heads have the small 1.6" exh valves; the 452 heads have a better flowing intake port. For a low performance engine, it would be a toss up whether you would notice much difference.
I would lose the Holley/1" spacer & use a TQ carb.

And hook up the vacuum advance.
Mike

 

[mavwreck]

Sorry to say that your cam is too big for your compression ratio. It has quite a bit of overlap period [where both valves are open] which is causing very low cylinder pressure. Thats why it has barely more low rpm torque than the 318 had. The 516 heads are the way to go for you as you need every bit of compression you can get with those way down in the hole pistons.I think your heads and intake will flow all that a smaller camshaft is going to allow through the valves at this level anyway. Get a cam with something like 224/224 duration at .050 with 110-112 lobe seperation to create some low speed cylinder pressure and torque. Lift would then be about .460-.470. Some of the more modern grinds will have steeper lobes for more lift at the same [or less] duration for even better cylinder filling and torque. The down side is that they may be more prone to premature lobe/lifter failure which is a rampant and extremely frustrating problem now days. 1 3/4 dia. long tube headers will help your power and torque a lot also. More gear and/or a looser converter helps a lot also but too much is not good for a street driver. Good luck young man.

Darn! I do have a factory camshaft that I pulled from a 68 440. Would I see any low rpm gains by switching to that? I should note that it came out of a running car and I do have all the lifters in order. I should also add that I do have headers on the car, I’m almost certain that they are 1” 3/4 but I’d have to double check. I also have a B&M hole shot converter rated 2400-2600 though with my combo in reality I see that it stalls between 2300-2400. I would rather like to keep the 3.23 because I have to drive on the freeway to get to most places with the car.

If I was to get a new cam, what brands are best recommended? I’ve used melling and comp in the past and I’ve yet to have a lifter failure. Thank you!

 

[4speed68rt]

What kind of car is it? Not relevant, but I am curious. Maybe show us some pictures of it.
Sounds like it has potential. Maybe that stock cam would be a big improvement on the low end torque.

 

[Don Frelier]

Shorten the mechanical advance slot to allow you to start at 20 deg initial advance or more, hook up the vacuum advance and put lighter springs in the distributor.
Another tuning aid would be a wide band O2 sensor so you can see what your mixture is (might need more or less fuel)

You might want to check the installed position of the .484 cam (a degree wheel etc) and then possibly advance the cam 4 - 8 degrees as that will close the intake valve sooner.
You'll need a timing set with multiple keyways for setting the advance.
This will give better low end performance.

Changing the cam is certainly an option but you might be able to get big improvement with what's in there.

I agree on getting a better dual plane intake.

But one thing at a time.

 

[mavwreck]

What kind of car is it? Not relevant, but I am curious. Maybe show us some pictures of it.
Sounds like it has potential. Maybe that stock cam would be a big improvement on the low end torque.

I did just post something in the photo gallery about the car and its story but the short is that is a 67 coronet 440 2 door hardtop. 440 engine 727 with 3.23 suregrip action

 

[mavwreck]

Shorten the mechanical advance slot to allow you to start at 20 deg initial advance or more, hook up the vacuum advance and put lighter springs in the distributor.
Another tuning aid would be a wide band O2 sensor so you can see what your mixture is (might need more or less fuel)

You might want to check the installed position of the .484 cam (a degree wheel etc) and then possibly advance the cam 4 - 8 degrees as that will close the intake valve sooner.
You'll need a timing set with multiple keyways for setting the advance.
This will give better low end performance.

Changing the cam is certainly an option but you might be able to get big improvement with what's in there.

I agree on getting a better dual plane intake.

But one thing at a time.

Degreasing the cam is something that I would like to do as I do have a multi keyway gear in it already. I installed it straight up because I didn’t have a wheel at the time

 

[4speed68rt]

I did just post something in the photo gallery about the car and its story but the short is that is a 67 coronet 440 2 door hardtop. 440 engine 727 with 3.23 suregrip action

Cool looking beater!! One of those "street sleeper" looking cars. Get that 440 tuned up right and it should surprise some people.

 

[RemCharger]

452 or 516 heads? I have a 3.23 sure grip in the car. It’s a 67 coronet

That was with 516s.
Also 456 gear and a 3500 stall.

 

[mavwreck]

That was with 516s.
Also 456 gear and a 3500 stall.

I don’t know if I could go all the way to 456s but I’ve considered just having 4.11s with a spool if I ever took it to the track