^^^ Agree the stock cam is anemic... IIRC 360 magnum cam specs are .410 lift and 252 degrees duration on both intake and exhaust. If the motor is not in the car... 1st item to get swapped out with a new set of lifters. All the other bolt on power adders are fairly easy to swap with the engine in the car.
Usable power for the street?
- Thread starter ValleyRat
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Here is an idea of what basically a stock 360 Magnum will give you. 305/414. Awesome flat torque from down low for the street but watch what happens when they stroke it stock bore.
Couldn't find without commercials....
Stroked Stock Mopar Magnum
Couldn't find without commercials....
Stroked Stock Mopar Magnum
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My comparison on a lot of this stuff is the Chevy 300HP 350 engine. It had an iron low rise quadrajet intake, stock non HP exhaust manifolds tiny flat tappet cam and 9:1 "or so" compression. Tons of magazines and independents have done lots of dyno tests on those through the years and Chevy's advertised HP was right on the money. Drag strip times even back it up.
The 5.9 has better heads, a roller cam and more compression and longer stroke. I believe with a good intake, a 750 DP and headers, it might make 350 spinning it to 6K. It would certainly be well past the 300 mark.
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furrystump
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The level of power I want is as much as possible without it becoming NEEDY. I control what the car does. Drive a 390 hp car on a 6” tire on the street you need to pay ATTENTION. Painted lines, small crests in the road, sand. All things that can bite you, however the more I run the car at the track the less spirited driving I do on the street. Nothing to prove on the street, there is always someone quicker. So basically blip here, blip there, always going straight and putting around.
DionR
Well-Known Member
Here's the YT video -
And a screenshot:
Doubt it makes 350 at 6K unless it takes a really weird upturn after they stopped the test. And note it is with headers and a 750 carb.
Here are the specs off a Cam Doctor run off the 2002 5.9 cam I sent Bullet to get reground.
Duration @ 0.050: I/E 189*/194*
Lobe separation angle: 111*
Lift @ cam: I/E 0.273"/0.278"
Valve lift w/ 1.6 rockers: I/E 0.437”/0.445”
Pretty small.
Commando/Charger 273's are very nice all around engines. You have one. You should consider what you will need to get your 67 Barracuda in fun mode. If you have a /6 barracuda, what rear do you have, what brakes are you running, torsion bars, sway bar, transmission, radiator? My brother and I grew up with 273 Barracudas and put about 450,000 miles on them. He still has his and I'm on my second due to accidents. 300 hp is plenty for an every day street car, even less with a 4 speed and a high winder. Racers are different. You can get by with a 7 1/4 rear with a 273, but not a 360. Some 833's are built lighter for 273's and slant sixes, what do you have?
Well, I stand corrected. We all know the internet and youtube videos are the benchmark for any comparison.
DionR
Well-Known Member
Don't get me wrong, I'm not saying that it the end-all definitive answer. Just one data point. Nor do I pretend that there aren't factors that could throw this off.
It does jive with my limited experience, though. My current build is pretty close to to a 300hp crate motor and it did fall off after 4500 rpm. Add I've seen multiple builds that swapped a bunch of parts and were disappointed with the return. To paraphrase "feels like a caged lion down low but a kitty cat up high", like someone is pull timing as timing increased.
I wonder how the cams compare between the stock 5.9 and the 300hp SBC.
DionR
Well-Known Member
Looks like the 300hp 350 SBC cam was a 212/222 cam? GMPP 350/300 HP Cam
So probably 20+ degrees more duration and similar lift (just a guess)? I'd bet that removes the cylinder head and longer stroke advantage from the 5.9.
You wouldn't think the roller design brings some of that back?
DionR
Well-Known Member
Seems like it does since they are both rated at 300hp.
I'm just saying that with the dinky cam Mopar put in the 5.9, I would guess it wouldn't add more power to change anything out. Roller cam or not. I just doubt that it can make 350 hp without swapping the cam for something that actually has lobes on it.
The 350 on the other hand seems to have a decent sized cam and added 30 hp by swapping to the Vortec heads.
Note that in the test above that 5.9 made 350+ hp with a cam that was similar in size to the one in the 300hp 350 you mentioned.
DionR
Well-Known Member
For what it's worth (last comment on this) the test where the guy compared a JY 5.9 with the BB intake and EFI to the 300hp crate motor with a dual plane and 4 bbl is partly why I think the real bottle neck is the cam. I always thought the 300hp crate motor gained 55hp (rated values) because of the intake. It was the big difference between a 5.9 in a Ram and the crate motor. After he ran them both and got darn near the exact same numbers, I started to think the intake had little to do with the HP they made. I think it is all in the really small cam.
Note too that it was 300hp with no water pump, PS pump, AC, air cleaner or full exhaust. So in the car, they both probably made closer to 250 hp.
Note too that it was 300hp with no water pump, PS pump, AC, air cleaner or full exhaust. So in the car, they both probably made closer to 250 hp.
Lots of good discussion here but I’ll add one more opinion-
Streetable power is mostly about your threshold of traction. 85% of these cars are rolling on stock-ish diameter wheels which means that we’re either driving around on DOT legal drag radials…or we ain’t getting much power to the ground at all.
If you have a set of 15” Cooper Cobra tires, you’re about maxed out at 300rwhp and even that will mostly go up in smoke.
Streetable power is mostly about your threshold of traction. 85% of these cars are rolling on stock-ish diameter wheels which means that we’re either driving around on DOT legal drag radials…or we ain’t getting much power to the ground at all.
If you have a set of 15” Cooper Cobra tires, you’re about maxed out at 300rwhp and even that will mostly go up in smoke.
mygasser
Well-Known Member
sounds like you need traction before more hp. if it spins 1st and into 2nd that's why you feel no 'kick', it's lost in tyre spin. if your power got to the street it'd feel (and be) a lot quicker.Also, I agree with what was said above. Torque converter and gears are huge! I was cheap and haven't invested in a converter yet but will. I have 3.23 gears and sure grip. I spin all the way through 1st and into 2nd, but I still dont have enough kick you in throat power... soon
neil.
mygasser
Well-Known Member
well you were right about the 350hp (0.2 under for the nit pickers
), it just didn't need to go as far as 6000rpm's 
neil.
DionR
Well-Known Member
well you were right about the 350hp (0.2 under for the nit pickers
neil.
I think you are confused. The stock cam dyno wasn't anywhere near 350. Better than 350 only after the cam swap.
I say give it a little more duration (10*’s) and be good with it. The MP crate 360/300 is 55hp better than stock. That’s with the 5.9 broom stick cam, M1 dual plane, 750 & 1-3/4 headers.
Why new lifters?
Richard also had the dyno set up with no accessories.
DionR
Well-Known Member
I think that 55hp increase is a smokescreen because it's without accessories, an air cleaner and with headers. That's the only way he got a 300hp crate motor to make 300 hp. And don't forget that a JY 5.9 with the same setup but with the beer barrel intake and EFI made within 1 hp of the crate motor.
So the 55 hp "increase" is because one is engine dyno numbers and the other is as installed in a truck.
Something else of interest, that same motor made 291 hp with the small outlet Magnum exhaust manifolds, 294 with the large outlet manifolds and 301 with headers. Only 10 hp for headers compared to stock, and only 7 hp compared to the early manifolds? Pretty small return for what it would cost to put good headers in an A-Body.
Just seems to me that while a stock 5.9 with a carb and headers is a decent option, don't expect much beyond 300 hp unless you put a cam in it first.
I have to agree, but you don't need 390 hp to get in trouble. I rebuilt a 72 340 for a Cuda 4 speed, pretty much stock, kinda but with good machining. He had to race some one and hit a little sand/gravel in an intersection, lost it and totaled a beautiful car. Drag racers have a guard rail, ambulance and a straight level track. Not the same on the street.
pishta
I know I'm right....
as much power as the rear wheels can transmit to the pavement without breaking traction.
@mygasser I know I need to get more traction, the only way to do that is with bigger tires (requires spring relocation and is on the to do list) , then a better torque converter and taller gears... all in due time and I will have all those done.. I only do little by little. Trying to purchase a practice right now, so can't be dumping 5k into the dart.
Rat Bastid
Dunamis Metron
There are many ways to increase bite, with bigger tires being pretty low on the list.
@Rat Bastid care to share some more ways to increase traction.
Lighter weight, better rear springs and shocks, fore and aft, weight transfer is the key. A wider tire is good but you really don’t have to mini tub the car. A taller tire is also good.
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