Lunati High Efficiency Cam

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MagicMan

MagicMan

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Anybody running one of these ? Thought about one for my daily driver for better low end power and fuel mileage. Its a 69 dart with a 273 auto,2.76 gears currently running a 66 commando 4bbl intake and a 500 holley carb.

Here is a link http://www.lunatipower.com/Product.aspx?id=2459&gid=294

Cam Specs:
Hydraulic, smooth idle. Good cam for daily usage with good low-end torque and horsepower.
Advertised Duration (Int/Exh): 260/260
Duration @ .050 (Int/Exh): 210/210
Gross Valve Lift (Int/Exh): .441/.441
LSA/ICL: 110/106
Valve Lash (Int/Exh): Hyd/Hyd
RPM Range: 1000-4500
 
thats identical specs to a comp 260 h.i ran one in a mild 318.it would not be my first choice if an rv/mileage cam is what you are after in a stock 273.id honestly go smaller like an isky 256 super cam 256/202@ .50 .425 lift.
 
Budget is the name of the game with this old mill, what valve springs would you recommend ? Or is the summit cam low enough lift to get away with the factory ones ?
 
I'm kinda thinking such a modest increase in lift wouldn't be a problem even for stock springs. Not to mention unless you're using aftermarket rockers, you likely won't see advertised lift anyway.

...I would probably check the springs for good seat pressure...JMO though...
 
Just need to make sure the springs will work with stock installed height...saw in another post that the Edelbrock springs are taller than stock mopar springs
 
They are for stock heads. They are supposed to be run at 1.65" at 90 psi and are good upto .470 lift.
 
ive also run the summit cam thats listed in a low comp 318 4bbl.its not a bad grind,but still would not be my first choice for a stock 273.rather than save a few bucks on something that works ok,spend a few bucks more on a custom grind that will give you exactly what you want and be happier in the long run.id contact rod at isky cams or jerry cantrell at schneider racing cams. they can grind you a custom hyd. for about 150 bucks.
 
For what it's worth, the 273 Commando camshaft lifted 0.415 at the intake valve an .425 on the exhaust, intake opens at 18° BTDC.

Here are factory specs of some other cams for your consideration:

'68 340 manual .445 .455 26° BTDC
'68 340 auto .430 .445 22° BTDC
69+ 340/360-4 .429 .444 22° BTDC

I'll invite other 273-4 drivers chime in here. IMO, the 273-4 is not a low-end torque monster. It likes to be wound up before it makes power.

http://www.summitracing.com/parts/sum-k6900/overview/make/dodge

http://www.summitracing.com/parts/sum-k6901/overview/make/dodge

I bought a 6901 about seven years ago. It was a Crane Fireball that had been repackaged in generic packaging. I use this cam in a 318 with 302 heads, stock valves, Performer, and a 625 AFB. The car is a full-bodied 72 Demon, 904, and presently a 2.93:1. I'm in the process of collecting parts for a 3.55:1 8.75" axle. With 15" wheels, I have a little too much cam in the car for my purposes.
 
I have a 273 in my Dodge D50, I use it as a daily driver, off-road toy, and work truck.

.060 Over, Forged Domed Pistons, 340 J 1.88 Heads, 10.1:1 Compression, .500 Mechanical/Solid Lift Cam (unknown make), 340 Intake, 850cfm Thermoquad.

I get about 17mpg out of it, and it is a torque monster for being such a small engine. IF I ever upgrade the engine, it'll be a 318/340 built to similar specs. If I ever have to replace/upgrade the cam in the 273, I'll probably go with a Lunati 494/513 lift cam (don't know the #, they've changed their numbers since the last time I last bought one)


Here she is : 4.10 Gear Ratio (2.92 ratio after figuring in the tire size), 40x17-15" Tires. I can burn the tires through 1st, and chirp them going into 2nd.





It's a bit aggressive in stop & go traffic over extended periods of time, but it is a blast to drive.
 
Thanks guys, I think I will talk to lunati more about their grind and also isky about a custom grind or the mentioned super 256. My fear is that I will get a cam that moves the peak torque too far up in the rpm range. Here is a chart I found comparing the 273's , the 2bbl 273 is only 20 ftlbs shy of the commando, but its at 1600 rpm vs 4000 rpm.


Intake Exhaust
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Std. 273 2 Brl (8.8:1):
Valve Lift: 0.395" 0.395"
Duration: 240ø 240ø
Opens: 14ø BTDC 58ø BBDC
Closes: 46ø ABDC 2ø ATDC

273 Commando (10.5:1):
Valve Lift: 0.425" 0.425"
Duration: 248ø 248ø
Opens: 14ø BTDC 56ø BBDC
Closes: 54ø ABDC 12ø ATDC

D/Stock 273 (10.5:1, Actually a Camcraft part):
Valve Lift: 0.495" 0.505"
Duration: 284ø 284ø

SAE Gross Horsepower & Torque:
Std 273
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180 @ 4200 RPM & 260 Ft/lbs @ 1600 RPM

273 Commando
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235 @ 5200 RPM & 280 Ft/Lbs @ 4000 RPM

D/Stock 273
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275 @ 6000 RPM & 295 Ft/Lbs @ 4400 RPM
 
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