273 Commando with roller camshaft

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superstock64polara

superstock64polara

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Has anyone built a 273 Commando or other mild 273 mill, with either a hydraulic or solid roller stick?
Is there any real benefit to a roller stick in such a small V8?

Hypothetical A Body 273 build to base this discussion on:

273 block bored 0.030" with a zero-deck flat-top piston (9.5:1 SCR)
Mopar 920 heads with bowl work & port match
Roller stick to be discussed??
Edelbrock Performer intake
Holley 600 vac sec or Edelbrock 600 carb
Doug's headers 1-5/8" primaries

4-speed
8-3/4 sure-grip 3.23 rear
 
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I'd say yeah, as long as the heads and "everything else" gets matched to the flow potential of the camshaft, otherwise it's a waste of money. And I'd not mess around with anything hydraulic.
 
superstock64polara said:
Has anyone built a 273 Commando or other mild 273 mill, with either a hydraulic or solid roller stick?
Is there any real benefit to a roller stick in such a small V8?
Click to expand...
You don't need oil with extra zinc
 
usually have to sleeve right side lifter galley to use roller cams. from mopar race manual. can get very expensive . probably have piston to valve clearance probs
 
I used a hydraulic roller in my 273 for my 65 Barracuda. I got Bullet to grind me a cam to the specs in the link below, because Lunati had no blanks at the time. I used Morel Hydraulic roller lifters and roller rockers. I did sleeve the lifter bores, but ONLY because 2 of them were way big. The Morel lifters do not require sleeved bores and the oil band on the lifters is low enough to where it stays in the lifter bore. My motor is .030 over with Race Tech flat tops, 9.6 compression. Later model 302 heads worked like you described yours will be. I have a Weiand 8007 dual plane and ran a Quick Fuel 600 Brawler when we dyno'd the motor. It had headers on the dyno as well. It's a pretty mild motor, and made 265 HP and 280 lbs of torque. More than they had from the factory and all I need at 66 years old....lol. Hope this helped some.
www.lunatipower.com

High Efficiency Retro-Fit Hydraulic Roller Cam - Chrysler 273-360 272/272

Retro-Fit Hydraulic Roller. Great stock replacement cam with good economy and excellent torque and HP. Good idle.; Advertised Duration (Int/Exh): 272/272; Duration @ .050 (Int/Exh): 206/206; Gross Valve Lift (Int/Exh): .447/.447; LSA/ICL: 114/108; Valve
www.lunatipower.com www.lunatipower.com
 
i mean, sure it could be done. but with such a mild build i'd just run a standard solid flat tappet.

for all the theoretical benefits a roller cam gives, they'd kind of be not used to full potential on something this mellow and i don't think that would justify the cost. but that's just me.

it'd be cool as hell tho.
 
JDMopar said:
I used a hydraulic roller in my 273 for my 65 Barracuda. I got Bullet to grind me a cam to the specs in the link below, because Lunati had no blanks at the time. I used Morel Hydraulic roller lifters and roller rockers. I did sleeve the lifter bores, but ONLY because 2 of them were way big. The Morel lifters do not require sleeved bores and the oil band on the lifters is low enough to where it stays in the lifter bore. My motor is .030 over with Race Tech flat tops, 9.6 compression. Later model 302 heads worked like you described yours will be. I have a Weiand 8007 dual plane and ran a Quick Fuel 600 Brawler when we dyno'd the motor. It had headers on the dyno as well. It's a pretty mild motor, and made 265 HP and 280 lbs of torque. More than they had from the factory and all I need at 66 years old....lol. Hope this helped some.
www.lunatipower.com

High Efficiency Retro-Fit Hydraulic Roller Cam - Chrysler 273-360 272/272

Retro-Fit Hydraulic Roller. Great stock replacement cam with good economy and excellent torque and HP. Good idle.; Advertised Duration (Int/Exh): 272/272; Duration @ .050 (Int/Exh): 206/206; Gross Valve Lift (Int/Exh): .447/.447; LSA/ICL: 114/108; Valve
www.lunatipower.com www.lunatipower.com
Click to expand...
i *love* this combo. thank you for the specific details down to the part numbers.
 
JDMopar said:
I used a hydraulic roller in my 273 for my 65 Barracuda. I got Bullet to grind me a cam to the specs in the link below, because Lunati had no blanks at the time. I used Morel Hydraulic roller lifters and roller rockers. I did sleeve the lifter bores, but ONLY because 2 of them were way big. The Morel lifters do not require sleeved bores and the oil band on the lifters is low enough to where it stays in the lifter bore. My motor is .030 over with Race Tech flat tops, 9.6 compression. Later model 302 heads worked like you described yours will be. I have a Weiand 8007 dual plane and ran a Quick Fuel 600 Brawler when we dyno'd the motor. It had headers on the dyno as well. It's a pretty mild motor, and made 265 HP and 280 lbs of torque. More than they had from the factory and all I need at 66 years old....lol. Hope this helped some.
www.lunatipower.com

High Efficiency Retro-Fit Hydraulic Roller Cam - Chrysler 273-360 272/272

Retro-Fit Hydraulic Roller. Great stock replacement cam with good economy and excellent torque and HP. Good idle.; Advertised Duration (Int/Exh): 272/272; Duration @ .050 (Int/Exh): 206/206; Gross Valve Lift (Int/Exh): .447/.447; LSA/ICL: 114/108; Valve
www.lunatipower.com www.lunatipower.com
Click to expand...

JDMopar said:
I used a hydraulic roller in my 273 for my 65 Barracuda. I got Bullet to grind me a cam to the specs in the link below, because Lunati had no blanks at the time. I used Morel Hydraulic roller lifters and roller rockers. I did sleeve the lifter bores, but ONLY because 2 of them were way big. The Morel lifters do not require sleeved bores and the oil band on the lifters is low enough to where it stays in the lifter bore. My motor is .030 over with Race Tech flat tops, 9.6 compression. Later model 302 heads worked like you described yours will be. I have a Weiand 8007 dual plane and ran a Quick Fuel 600 Brawler when we dyno'd the motor. It had headers on the dyno as well. It's a pretty mild motor, and made 265 HP and 280 lbs of torque. More than they had from the factory and all I need at 66 years old....lol. Hope this helped some.
www.lunatipower.com

High Efficiency Retro-Fit Hydraulic Roller Cam - Chrysler 273-360 272/272

Retro-Fit Hydraulic Roller. Great stock replacement cam with good economy and excellent torque and HP. Good idle.; Advertised Duration (Int/Exh): 272/272; Duration @ .050 (Int/Exh): 206/206; Gross Valve Lift (Int/Exh): .447/.447; LSA/ICL: 114/108; Valve
www.lunatipower.com www.lunatipower.com
Click to expand...
Those are some decent numbers for such a mild cam. It's good to see someone build one with a roller.
 
JDMopar said:
I used a hydraulic roller in my 273 for my 65 Barracuda. I got Bullet to grind me a cam to the specs in the link below, because Lunati had no blanks at the time. I used Morel Hydraulic roller lifters and roller rockers. I did sleeve the lifter bores, but ONLY because 2 of them were way big. The Morel lifters do not require sleeved bores and the oil band on the lifters is low enough to where it stays in the lifter bore. My motor is .030 over with Race Tech flat tops, 9.6 compression. Later model 302 heads worked like you described yours will be. I have a Weiand 8007 dual plane and ran a Quick Fuel 600 Brawler when we dyno'd the motor. It had headers on the dyno as well. It's a pretty mild motor, and made 265 HP and 280 lbs of torque. More than they had from the factory and all I need at 66 years old....lol. Hope this helped some.
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Click to expand...

Thanks JD, interesting build.
Food for thought.
 
junkyardhero said:
i mean, sure it could be done. but with such a mild build i'd just run a standard solid flat tappet.

for all the theoretical benefits a roller cam gives, they'd kind of be not used to full potential on something this mellow and i don't think that would justify the cost. but that's just me.

it'd be cool as hell tho.
Click to expand...
I used it because I'm an old fart that's too lazy to adjust valves anymore!
:rofl:
 
JDMopar said:
I used a hydraulic roller in my 273 for my 65 Barracuda. I got Bullet to grind me a cam to the specs in the link below, because Lunati had no blanks at the time. I used Morel Hydraulic roller lifters and roller rockers. I did sleeve the lifter bores, but ONLY because 2 of them were way big. The Morel lifters do not require sleeved bores and the oil band on the lifters is low enough to where it stays in the lifter bore. My motor is .030 over with Race Tech flat tops, 9.6 compression. Later model 302 heads worked like you described yours will be. I have a Weiand 8007 dual plane and ran a Quick Fuel 600 Brawler when we dyno'd the motor. It had headers on the dyno as well. It's a pretty mild motor, and made 265 HP and 280 lbs of torque. More than they had from the factory and all I need at 66 years old....lol. Hope this helped some.
www.lunatipower.com

High Efficiency Retro-Fit Hydraulic Roller Cam - Chrysler 273-360 272/272

Retro-Fit Hydraulic Roller. Great stock replacement cam with good economy and excellent torque and HP. Good idle.; Advertised Duration (Int/Exh): 272/272; Duration @ .050 (Int/Exh): 206/206; Gross Valve Lift (Int/Exh): .447/.447; LSA/ICL: 114/108; Valve
www.lunatipower.com www.lunatipower.com
Click to expand...
I bet that's really snappy, too!
 
superstock64polara said:
Has anyone built a 273 Commando or other mild 273 mill, with either a hydraulic or solid roller stick?
Is there any real benefit to a roller stick in such a small V8?

Hypothetical A Body 273 build to base this discussion on:

273 block bored 0.030" with a zero-deck flat-top piston (9.5:1 SCR)
Mopar 920 heads with bowl work & port match
Roller stick to be discussed??
Edelbrock Performer intake
Holley 600 vac sec or Edelbrock 600 carb
Doug's headers 1-5/8" primaries

4-speed
8-3/4 sure-grip 3.23 rear
Click to expand...

I'd look at a custom Racer Brown solid flat tappet cam. That kind of power can be made with stock 2 barrel pistons, factory Commando intake and carb, and an Isky E-4 cam. Nothing to go wrong with a solid flat tappet cam, adjust the valves every 100,000 miles once broke in.
 
66fs said:
I'd look at a custom Racer Brown solid flat tappet cam. That kind of power can be made with stock 2 barrel pistons, factory Commando intake and carb, and an Isky E-4 cam. Nothing to go wrong with a solid flat tappet cam, adjust the valves every 100,000 miles once broke in.
Click to expand...
Thanks 66fs, l’d prefer a flat tappet solid stick but there’s been a spate of cam & lifter failures in the past few years. I’ve never wiped a cam before, and would prefer it to stay that way.

Ideally l’d like to build a mild 300 hp 273 that runs nice on the street with a 4-speed and 3.23 gears.
 
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"Ideally l’d like to build a mild 300 hp 273 that’s run nice on the street with a 4-speed and 3.23 gears."

That's do-able, but you'd be better off to use 915 J heads with 1.88 valves and port work, a solid roller bigger than the specs I posted for mine and a good dual plane intake, like an LD340 or an RPM Air Gap. Maybe consider custom flat top pistons that will get you to 10 or 10.5-1 compression with whatever CC's and gasket thickness you have if you use J heads. The 1.88 valves are all that will fit without notching the cylinder bores....and they barely fit. I had 1.88 intake valves put in my 302 heads, but if I had it to do over again I'd dig a pair of J heads out of my stash and work them....then build under them.

:thumbsup:
 
superstock64polara said:
Has anyone built a 273 Commando or other mild 273 mill, with either a hydraulic or solid roller stick?
Is there any real benefit to a roller stick in such a small V8?

Hypothetical A Body 273 build to base this discussion on:

273 block bored 0.030" with a zero-deck flat-top piston (9.5:1 SCR)
Mopar 920 heads with bowl work & port match
Roller stick to be discussed??
Edelbrock Performer intake
Holley 600 vac sec or Edelbrock 600 carb
Doug's headers 1-5/8" primaries

4-speed
8-3/4 sure-grip 3.23 rear
Click to expand...
I have posted my build before and sorry to bore anybody.
I bought a 62 Polara 500 off ebay sight unseen. It appears the owner, a Coors Exec in Spokane in the second gas crisis (1980?) yanked the OEM 361 4bbl/727 and installed a rebuilt warmed over 273/4sp. On Ebay that likely killed some of the car's desirability. I wanted the car, not the engine, since I expected to very quickly drop in a very warmed over 440. What I didn't expect was how peppy the combo turned out to be, made a great cruiser, so I bought another Polara 500 to hot rod.
So I did a few tweaks on the 273 car to help it out and I am very satisfied with the package. It has a mild Hyd Comp Cam when it arrived. I have a very slightly hotter Hyd Roller sitting on the shelf, but not sure it needs it.
The car's current tweaks included:
Fiberglass hood w/under scoop & trunk
MSD all in One Electronic Distributor
TTI Headers w/2.5 Duals
Passon Alum 4 Speed
Alum DS
Alum 8.75" w/3.55 SG
QA1 adj alum shocks
1.03 TB's
FG Leafs
SFC
600 Holley Street Avenger
Dp4? Intake
Valley shield
Windage screen
Wilwood Front Discs
Dual MC
Electric FP
Alum Rad

A lot of focus above was in reducing weight to help out the little motor.
And I also added a lot of non-performance oriented stuff, and have a short list of future upgrades, first being slightly upgraded front discs and add rear discs, alum FW, and LED headlights.
I would not suggest anybody seek out a 273 for a build for any reason, if you have a good motor, it's a fun cute motor, otherwise I suggest first a dime a dozen in the US 318 build, or 360 brute and lastly a 340 race motor for SB strokers(?), and they all look nearly the same.
It also puts me in a weird position because It doesn't feel right to ever sell mine, because it makes so little sense for anyone to buy, you might one day be in the same position.
Good Luck.
 
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J-c-c said:
.... a short list of future upgrades, alum FW...
Click to expand...
having had and driven that setup (albeit 318) in a lighter car (64/65 dart) i'd probably forego the alum wheel in a heavier car.

neat little set up though. sounds like a fun b body.
 
junkyardhero said:
having had and driven that setup (albeit 318) in a lighter car (64/65 dart) i'd probably forego the alum wheel in a heavier car.

neat little set up though. sounds like a fun b body.
Click to expand...
Don't to want to hijack this thread, good eye btw, I am very hesitant on the Alum FW, but car has a cast steel? bellhousing that weighs a ton, I really want to ditch it, I have a Quick Time BH sitting on the shelf and with a Richmond new 6sp with a deep 1st gear, and OD, it's not a high torque tranny, and thought the combo might work with the Alum FW, I have a good home (62 Lancer) for the Passon 4 sd.
And yes, I consider myself very lucky, in many ways.
 
yeah, all i can say is think long and hard about how much you like rowing the gears. with a light wheel and low 1st on something that doesn't make a bunch of torque it's gonna be all the time.

fun at the track and when bombing a twisty two lane. torture in traffic of any kind.
 
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