Cam match to intake

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Brian Donahue

Brian Donahue

Exhaust system
Joined
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Guys I recently acquired an A body Duster with 440. Previous owner just gave me the cam #'s. The engine ha a very recent rebuild, with compression ratio around 9:1. There is an Edelbrock, Performer manifold and #1411, 750cfm carburetor. Cam numbers he gave me are 284/.484 lift. It is running stock, cast iron exhaust manifolds. I am estimating this set up to be about 375 hp. The exhaust, (Dura Max) is not suggesting a very lobe sound at idle. Is this the optimum cam for this set up. It is a street driver, not a strip car, but I also don't want a pussy street car if you know what I mean. The engine was built down from the early Trouper, Highway Patrol issue engines. It ran higher compression and a 1500cfm carb putting out about 390 hp. and drinking as much 93 octane as the state could buy. Thanks for any suggestions, including Intake manifold as well as cam.
 
I'm not a fan of that cam. I ran the next size smaller, a 280/474 in a 9.0 to 1 440 in my 70 Charger. It was a decent idling cam and tire smoker. I ran 14 seconds flat at 101 with a terrible 2.6 60 foot time. More practice or a better driver could have clipped a 13.6 with the car.
I built another 440, a 9.2 CR mill with the 284/484 cam. Idle was rougher than the first cam but there wasn't much if any increase in power. It threw a rod at 846 miles due to a crack in the middle of #4 rod that was undetected at the time of the build.
For my stroked 440/493, I went with the 292/509 cam. This idled a bit rough but with almost 500 inches, it would have been worse in a smaller engine. This engine was a real killer. Fast, quick, fair idle and fun to drive.
If you want honesty, here we go:
The cam isn't what I would pick for a strong street build. It needs more compression to run to ts potential but if you are not willing to swap in something else, you can still make it work with a few changes to the combination. The intake is barely better than the stock iron intake. Small ports, small plenum and mediocre flow. The 484 cam needs a bigger intake to feed it. A Holley Street Dominator or the Edelbrock Performer RPM are really tough to beat for a street Big Block. The Edelbrock carburetors are okay for stock or nearly stock engines but beyond that, they often are hard to tune. A Holley 750 with vacuum secondaries is another proven performer and has HUGE support in terms of tuning parts and advice. Next up.... exhaust! Many people choose to retain the stock exhaust manifolds but the truth is, even a stock engine benefits from headers. The further you deviate from stock, the greater the benefits you will see with headers. I laugh and shake my head at the old timers that swear they make just as much power with their "Magnum" manifolds as others with full length headers. The HP gain between log manifolds to Magnum manifolds is less than 10 in a stock engine. The gain of headers on a stock 440 Magnum is 19-23 HP depending on a few other factors.
Finally, the 484 cam needs a bit more transmission torque converter stall speed than a stock 440 cam. A converter vendor will have better advice for that than I can give.
Oh yeah....GEARS! I hope for your sake you are running a 3.55 gear or thereabouts.
 
This cam numbers he gave you don't tell the whole story. What's the duration at .050 and what is the LSA? The lift tells me it's a wimpy cam for that engine. with factory manifolds I'd like to see a little more duration on that lobe too.

Lunati #30230740 would be my pick if it were mine.
 
Brian Donahue said:
Guys I recently acquired an A body Duster with 440. Previous owner just gave me the cam #'s. The engine ha a very recent rebuild, with compression ratio around 9:1. There is an Edelbrock, Performer manifold and #1411, 750cfm carburetor. Cam numbers he gave me are 284/.484 lift. It is running stock, cast iron exhaust manifolds. I am estimating this set up to be about 375 hp. The exhaust, (Dura Max) is not suggesting a very lobe sound at idle. Is this the optimum cam for this set up. It is a street driver, not a strip car, but I also don't want a pussy street car if you know what I mean. The engine was built down from the early Trouper, Highway Patrol issue engines. It ran higher compression and a 1500cfm carb putting out about 390 hp. and drinking as much 93 octane as the state could buy. Thanks for any suggestions, including Intake manifold as well as cam.
Click to expand...
Kern Dog said:
I'm not a fan of that cam. I ran the next size smaller, a 280/474 in a 9.0 to 1 440 in my 70 Charger. It was a decent idling cam and tire smoker. I ran 14 seconds flat at 101 with a terrible 2.6 60 foot time. More practice or a better driver could have clipped a 13.6 with the car.
I built another 440, a 9.2 CR mill with the 284/484 cam. Idle was rougher than the first cam but there wasn't much if any increase in power. It threw a rod at 846 miles due to a crack in the middle of #4 rod that was undetected at the time of the build.
For my stroked 440/493, I went with the 292/509 cam. This idled a bit rough but with almost 500 inches, it would have been worse in a smaller engine. This engine was a real killer. Fast, quick, fair idle and fun to drive.
If you want honesty, here we go:
The cam isn't what I would pick for a strong street build. It needs more compression to run to ts potential but if you are not willing to swap in something else, you can still make it work with a few changes to the combination. The intake is barely better than the stock iron intake. Small ports, small plenum and mediocre flow. The 484 cam needs a bigger intake to feed it. A Holley Street Dominator or the Edelbrock Performer RPM are really tough to beat for a street Big Block. The Edelbrock carburetors are okay for stock or nearly stock engines but beyond that, they often are hard to tune. A Holley 750 with vacuum secondaries is another proven performer and has HUGE support in terms of tuning parts and advice. Next up.... exhaust! Many people choose to retain the stock exhaust manifolds but the truth is, even a stock engine benefits from headers. The further you deviate from stock, the greater the benefits you will see with headers. I laugh and shake my head at the old timers that swear they make just as much power with their "Magnum" manifolds as others with full length headers. The HP gain between log manifolds to Magnum manifolds is less than 10 in a stock engine. The gain of headers on a stock 440 Magnum is 19-23 HP depending on a few other factors.
Finally, the 484 cam needs a bit more transmission torque converter stall speed than a stock 440 cam. A converter vendor will have better advice for that than I can give.
Oh yeah....GEARS! I hope for your sake you are running a 3.55 gear or thereabouts.
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Thanks Kern Dog. The truth only hurts if you're not looking for it. Right now we are running about a 3.55 gear. I agree fully regarding headers, and I am suspicious of this intake just by looking at the profile. The car runs good and seems to take off well, but it doesn't have the feel of a big block when I punch it hard. Carb is burning fat and very hard to lean out except for the jet changes. I think the previous owner was looking for a comfortable ride more than maximizing performance. They built the engine down from 12:1 compression. I'm OK with a more civil engine, it just needs to pop more. I don't know fully what they did with the heads, but they used the set that had been on the Trouper block. I imagine they cleaned them up a bit and put them back on. I can still talk to the owner and get some more background info. His car was sold by a family member due to his age etc. It seems I could gain what I want with intake and headers. I don't know specific cam make or duration which would give me more to go on.
 
If that's the Mopar 284/484-

There are two cams with those specs- different center lines.

Must be the tame center line version if there's no lope.

The one I had loped like hell in a 9.5:1 383.

Sounded like two Harleys!
 
I had the .284/484 MP cam in a mild 360 in a Duster with 3.91's hit 12.90's at almost 105 mph in a 100% street driver, full exhaust and street tires. I would think a 440 with the same cam would stomp what I had. I will say, you really should have headers. That would be huge for you...
 
Changing the cam becomes a slippery slope. You'll likely need to change valve springs, higher lifts require the guides to be trimmed, custom length push rods, some will need adjustable rockers and I highly recommend degreeing the cam or your wasting your time and money on all the above.

The Performer and manifolds are holding you back if that cam is what they say it is.
 
dano said:
Changing the cam becomes a slippery slope. You'll likely need to change valve springs, higher lifts require the guides to be trimmed, custom length push rods, some will need adjustable rockers and I highly recommend degreeing the cam or your wasting your time and money on all the above.

The Performer and manifolds are holding you back if that cam is what they say it is.
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Thanks to all, keep the info coming. YY1, I think you hit it. Former owner wanted this to be more tame, ,no burn outs etc. Almost a trailer queen. That status is soon to be changed. I also get what dang is saying, as all these pieces have to match. Sometimes, don't fix what ain't broken. It is a lot faster than my '51 Chevy that is running a modified 235 inline and probably pushes 125 hp downhill on a good day. It does sound bad *** though through split dual headers with Flow masters.
 
You said it doesn't feel like a big block when you stomp it. Is it tuned right and is your gearing and chassis dialed in? You have to figure that the late model cars we drive everyday approach or exceed the hp that 440 is putting out so it may just take a little more engine to impress you.
 
roccodart440 said:
You said it doesn't feel like a big block when you stomp it. Is it tuned right and is your gearing and chassis dialed in? You have to figure that the late model cars we drive everyday approach or exceed the hp that 440 is putting out so it may just take a little more engine to impress you.
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Life's a ***** when an old iron block 440 doesn't impress as much as the new aluminum plants do. God I am not looking forward to driverless battery cars!
 
That cam has traded away off-idle torque for high rpm power. If it's running the factory TC,of course it won't pop. It may now have less pop than it did in factory trim. There are only two alternatives to this situation, A) a higher stall TC, or B) a torquier cam, or C) More compression, or D)I guess, put the car on a diet to loose 200+pounds, or E) skinnier tires,lol

I like that cam, but it's not for everyone. I think the 050 on it is about 240ish. That would be big for a SBM, but sweet in a sharp 440.
So the first thing to do in my mind is a compression test. Let's see how much cylinder pressure is in this ex-race engine.
I wouldn't make any purchases or decisions until this is known.
Except headers. If you want pop, you are gonna need them.
If you just want a cruiser, I would pull that cam in a heartbeat. But before I did, I would verify what it is, otherwise you might be replacing it with another same or similar cam,lol.And that would suck! That 284 needs headers and wants a TC over 3000. And then the whole pkg will not be real hiway friendly.
And If I was doing it and had the cash,behind those headers would be full-length,dual 3inchers,with an H pipe. But that would be overkill for a cruiser....
 
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Kern Dog said:
I'm not a fan of that cam. I ran the next size smaller, a 280/474 in a 9.0 to 1 440 in my 70 Charger. It was a decent idling cam and tire smoker. I ran 14 seconds flat at 101 with a terrible 2.6 60 foot time. More practice or a better driver could have clipped a 13.6 with the car.
I built another 440, a 9.2 CR mill with the 284/484 cam. Idle was rougher than the first cam but there wasn't much if any increase in power.
Click to expand...

There wasn't much difference in the cam grind, so that makes sense.
 
Sorry, I forgot to add that in my second engine, I had six pack pistons and Edelbrock aluminum heads. The new pistons should have raised the compression to 9.3-9.4. instead of the 9.2 I previously wrote.
The heads should have helped out too.
My point was also that while the engine idled a bit rougher, it didn't perform much better.
 
Kern Dog said:
Sorry, I forgot to add that in my second engine, I had six pack pistons and Edelbrock aluminum heads. The new pistons should have raised the compression to 9.3-9.4. instead of the 9.2 I previously wrote.
The heads should have helped out too.
My point was also that while the engine idled a bit rougher, it didn't perform much better.
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I think the summary on this is that the 484/284 cam is not a low RPM power cam, especially with the E-brock Performer intake and 750 carb. Since it is a street only car, no strip racing a stall converter doesn't seem worthwhile. Also, lots of you will hate this, ,but I want to put a 2.96 gear in over the current 3.55. I like to take distance cruises and I like the mellow sound of 2500 over 4000 RPM on the road. I realize some of you are going to wonder why I am talking about slow take off when I have a 2.96 gear in mind. Crazy, right? What I am referring to is that I don't get the feel of big block torque when I step into the accelerator say from a slow rolling start like in traffic. The car does seem to get going once it gets going it just doesn't have that sudden response till the tach moves up. Seems the cam needs to either be less aggressive, or the top end of the engine needs to breath better. I am going to try and fit Schumacher headers around this engine without drastically altering the fender wells. I will also look at fitting a Performer RPM manifold under the hood. The hood currently has original equipment hood scoop/ram air set up. I think I can make the higher manifold work, possibly ditching the iconic "Super Commando 440" intake and replacing it with a much tighter Ram air that really forces outside air into the carb. No reason to ditch the original hood scoop, the hood is already cut up anyway. I may have to change out the Edelbrock 1411, 750cfm but I will check with Edelbrock's tech wizards first. End result should be a more breathable engine that should be a monster going into passing gear. Wheels and tires are already at 27" so I don't think there is much I could do with those that would be of much significance. The previous owner did change out the Flow Master mufflers in favor of lower decibel Dura Max. I have the Flow Masters, and I will likely put them back on. The rear end gear will probably solve, for me anyway, the highway "decibel" issue. If it doesn't, open the windows. I only drive on clear warm days and I like Mopar music.

I failed to mention that I acquired this car from an older gentleman who was the son of the original owner. The car spent its entire life in Florida under the ownership of the same family. The body is near perfect original. An extensive bare metal paint/body restoration was recently done to the car, including re-welding inner fender panels back in place. They had been cut out for header fit. I can't bring myself to undo all that nice resto work to fit a cheaper set of pipes to the car. Let's hope that Schumacher's claim to fit a-body 440's without fender modification is true. The other thing I have going for me in that area is this is not a power steering car.

I am still hoping to hear feedback on these plans. Shoot straight, I'm asking for feedback to everything I have laid out. Also, if anyone has experience sliding headers into this package, or with the Schumacher, $800 headers, I'm all ears.

Thanks
 
The Schumaker headers are reported to fit well and outperform even the Magnum manifolds.
Regarding the taller axle gearing: Fine by me! These cars can be many things. Drag racing got all the glory but higher speed cruising is fun too. I'll bet with a milder cam and an optimized setup, the car will still pull strong even with those gears.
Flow master mufflers....I liked the sound for many years but did grow tired after awhile.
 
Degree the cam and figure out if it's the 108lsa or 114lsa. The 114 cam is absolute GARBAGE!

If it's the 108lsa, change the installed centerline to 100-102. Advance it 6-8 degrees. It will run like a whole different engine.

If it's the 114LSA, pull it and use it as a door stop.

Headers would provide a good increase in power everywhere.
 
crackedback said:
Degree the cam and figure out if it's the 108lsa or 114lsa. The 114 cam is absolute GARBAGE!

If it's the 108lsa, change the installed centerline to 100-102. Advance it 6-8 degrees. It will run like a whole different engine.

If it's the 114LSA, pull it and use it as a door stop.

Headers would provide a good increase in power everywhere.
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Thanks, will do
 
Lets see a pic of this 1500 CFM carburetor. I love it when people come up with crappola like this. Somebody's drinkin the kool aid again.
 
If it's as soft on the bottom as you describe with 3.55s, then the cylinder pressure has almost got to be in the basement,cuz if it was were it was supposed to be and the stall was at all near 3000 it should annihilate those 27s

So compression test is job #1. OOps, I said that already
 
a 284 MPP cam IS very much a low RPM power cam. Granted I run the mechanical version but it's still 242@.050. It makes gobs of off idle torque and does not make high RPM HP. I don't know which LSA you have. Mine is the 112 or 114 cam. 242@.050 is nothing crazy in a 440.
 
RustyRatRod said:
Lets see a pic of this 1500 CFM carburetor. I love it when people come up with crappola like this. Somebody's drinkin the kool aid again.
Click to expand...
I wanted to see it as well. Remember, the past owner is 75 years old and is going on memory back 20 yrs. My guess is dual 4 barrel, or ..... he can't remember.
 
Kern Dog said:
Wasn't the 440 6 barrel setup close to 1350 cfm?
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We need to remember that 2-bbl carburetors were rated at 3" of vacuum and 4-bbl carburetors are rated at 1-1/2" of vacuum. A 1,350 cfm 3 x 2bbl is about 950 cfm as a 4-bbl.
 
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