273 / 318 Exhaust Manifold Question
Considering all things on your 273 Commando Build are set up properly and are good choices. Let's talk about your camshaft selection for a bit.
Here are the Stock Specs for the 273 4 bbl camshaft:
Lift: 415 / 425
Duration: 248 / 248
You probably had some pretty good low end torque with this stock cam,
With the power band around Idle to 4,500 rpm.
_______
Now the likes of the specs of a mopar performance 340 camshaft:
Lift: 429 / 444
Duration: 268 / 276
Lobe Center 114
RPM Range: Idle - 5800 rpm
_______
Now the likes of your Comp Cams XE262H
Lift: 462 / 469
duration: 262 / 270
Lobe Center 110
RPM Range: 1300 - 5600 rpm
As you can see this camshaft does not start making power until you get to 1300 rpms, whereas the other camshafts start making power right away at Idle on up to 5000 rpms.
_________
With your small displacement 273 engine and a 4 speed would think you would want to set it up for lots of low end torque on the bottom end to get everything rolling without hesitation, instead of having to wait to build rpm to 1300 rpm and then go from there.
Quote:
Okay, now you've really peaked my interest. I love the 273 Commando in my Barracuda, however it's a little soft on torque.
____________
The Comp Cam XE262H cam is probably fine for a decent compression 318 or 360, but think it is a little much to go after the low end torque you want out of your small displacement 273 Commando.
Want to get things perfectly dialed in for how you want to use your car and how you plan on driving it.
I have always loved low end torque engines when you put your foot into it at low rpm it is ready to go.
____________
Camshaft Comparisons / RPM Ranges:
Considering all things on your 273 Commando Build are set up properly and are good choices. Let's talk about your camshaft selection for a bit.
Here are the Stock Specs for the 273 4 bbl camshaft:
Lift: 415 / 425
Duration: 248 / 248
You probably had some pretty good low end torque with this stock cam,
With the power band around Idle to 4,500 rpm.
_______
Now the likes of the specs of a mopar performance 340 camshaft:
Lift: 429 / 444
Duration: 268 / 276
Lobe Center 114
RPM Range: Idle - 5800 rpm
_______
Now the likes of your Comp Cams XE262H
Lift: 462 / 469
duration: 262 / 270
Lobe Center 110
RPM Range: 1300 - 5600 rpm
As you can see this camshaft does not start making power until you get to 1300 rpms, whereas the other camshafts start making power right away at Idle on up to 5000 rpms.
_________
With your small displacement 273 engine and a 4 speed would think you would want to set it up for lots of low end torque on the bottom end to get everything rolling without hesitation, instead of having to wait to build rpm to 1300 rpm and then go from there.
Quote:
Okay, now you've really peaked my interest. I love the 273 Commando in my Barracuda, however it's a little soft on torque.
____________
The Comp Cam XE262H cam is probably fine for a decent compression 318 or 360, but think it is a little much to go after the low end torque you want out of your small displacement 273 Commando.
Want to get things perfectly dialed in for how you want to use your car and how you plan on driving it.
I have always loved low end torque engines when you put your foot into it at low rpm it is ready to go.
____________
Camshaft Comparisons / RPM Ranges:
