67' Barracuda 273 (Camshaft Results at the Track)

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sorry, didn't mean to step on your post with all your great info.
my apologes !
 

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Stroker 402.

All additions to this thread are welcome,,,,,,

Excellent photo,,,,,,

You said it correctly,,,,,,, some 273's are literally 'Freaks'....
 
I like the effort in this thread. Thanks a bunch!
Another thing I like a lot is the fact the heads are not ported, run the stock valve sizes. This saves the average Joe a good deal of money. You should certainly gather all the results up for a crazy good post in the racers forum sticky titled "Unported head quickness."

That thread lacks a 273 build I think.
 
69 cuda 440 those JE pistons your using would you know the weight on those as the stock commando pistons were 569 grams according to the work shop manual.I'm not sure if thats including the pin in that weight.
 
67 GT

The JE Pistons,,,,,,3.63 +.040" = 465 Grams

Piston Rings (Childs and Albert)......5/64" - 5/64" - 3/16"

These are 1969 Pistons.......10.5-1 Compression Ratio w/.140" Step-Dome

The Piston Pins have been machine-lightened and weigh...................130 Grams

The stock' Connecting Rods a have been machine-lighted and polished...625 Grams
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* Stock 273 Pistons......................569 Grams
* Stock Piston Pins.......................154 Grams
* Stock Connecting Rods...............726 Grams
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We are also using a 1967 Forged '273' Crankshaft {#2268119}

And a Professional Products #90012 PowerForce Plus 'Harmonic Damper Balancer' {9 lbs.}

 
Thanks for the info,much appreciated.man they are light! mine are 583grams at 40+,pins are 179 grams steel crank ,with the rods they are the scat i beam forged 4340 rods dont know of the weight as yet as im waiting on those to arrive with the comp cams pro mag rollers and the same power force harmonic balancer you have.
 
67 GT,

The JE pistons have been 'notched'. with .025" cuts removed for the Intake amd
Exhaust relief area.

Also some lightening around the inner area 'piston pin boss', and underside of the
piston top.

We probably removed about 25+ Grams.
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By the way,

The Racer Brown Camshaft should be in by later today (Saturday), and the Barrcauda shoud hit
the Test Area on Sunday......

This Camshaft has a 'red-Line at 6700 RPM's.

We should be leaving the 'line' at 5700 RPM's........

The Crower Valve Springs {#268 lbs} Load-Rate are supposed to hold up to....... 6000 RPM's.
 
Racer Brown #ST-12 Camshaft is in,,,,,,,

But 'poor weather', has ruined the 'Accelerated Timing Tests'.

One thing,,,,,,this Camshaft is 'Super Wild'..........

A)....the Valve Springs (#268 lb. Load-Rate) will surely be 'tested' at 6000+ RPM's.

B)....the 'stock gasket-matched port only' Cylinder Heads may restrict optimal performance.
 
Were did you install the racer brown at? What is the cranking commpression? I cant wait for the tuned results. Thanks again Joe
 
My cranking compression in my 1965 dartcharger 273 freak is 180# ... all cylinders checked with plugs out . engine Hot and with carb wide open.
now that seems high for a stock commando engine doesn't it ?,
unless it has a more aggressive cam ., pulls strong right up 7500rpm with NO valve float .
 
Yeah 180 does seem high but that is great to hear. I have never ran a 273 was just currious what kind of cranking compression one would have with 10.5-1.

My son and I are going to build a 288 ci in a differnt direction. It will be a .030 318 with a 2.96 stroke and diamond pistons. Hoping to get 11-1 out of it with a 360 head.

Sorry to post a 318 combo but I think you could see why this intrest's me.
 
1970 LA,

The Racer Brown #ST-12 has a 4* Advance built into the profille grind.

The 'cranking compression' is at 185 to 190 PSI.
 
The Racer Brown #ST-12 Camshaft,,,,,,{#7} with a .480 Lift / 294* Duration

On the 'Chassis Dyno' got 'adjusted' Horsepower up to 322 HP.

A 'gain' of +12 Horsepower over Camshaft #6 (Crower .477 Lift / 280* Duration)
which put out 310 Horsepower.

Weather is good, but a bit 'crisp'. Will test this afternoon, as the 'timing equipment' has been
set and calibrated.
 
Looks like your about to get the goody out of the cylinder heads.

Will be waiting to see what more duration does with these heads. Thanks again
 
I was just thinking about hp/ci and wow! This 273 is right at 1.5 hp/ci. You take a 340 at 1.5 and that is over 500 hp with a pretty good cylinder head. I'll bet you do have a pretty high tech valve job. :cheers:
 
69 Cuda 440 said:
69 Cuda 440 said:
* Camshaft Upgrade #7 ~ Racer Brown = .480 / .480 Lift ~ 294* / 294* Duration = {322 HP} = 12.51 @ 107.77 MPH

* Camshaft Upgrade #6 ~ Crower Camshaft = .477 / .477 Lift ~ 280* / 280* Duration = {310 HP} = 12.62 @ 106.99 MPH

* Camshaft Upgrade #5 ~ Norris Camshaft = .466 / .466 Lift ~ 270* / 270* Duration = {304 HP} = 12.77 @ 106.52 MPH

* Camshaft Upgrade #4 ~ Crane Camshaft = .446 / .467 Lift ~ 288* / 298 * Duration = {303 HP} = 12.72 @ 105.72 MPH

* Camshaft Upgrade #3 ~ Crower Camshaft = .447 / .447 Lift ~ 268* / 272* Duration = {299 HP} = 12.80 @ 106.86 MPH

* Camshaft Upgrade #2 ~ General Kinetics = .435 /. 441 Lift ~ 282* / 282* Duration = {294 HP} = 12.87 @ 106.45 MPH

* Camshaft Upgrade #1 ~ Camcraft Camshaft = .440 / .440 Lift ~ 260* / 260* Duartion = (280 HP) = 13.04 @ 104.97 MPH
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Click to expand...

The Racer Brown ST-12 was 'super impressive'. Launched at 5700 RPM's, and it pulled like a 'monster' out of the hole.

The 273 'screamed' right up to the 6800 RPM 'Red Line'.

Great pull thru Bottom-End and Mid-Range.

Valve-Springs {268 lb.. Load-Rate} were a touch 'shaky above the 6500 RPM range.

The Valve-Train 'peaked' about 100 feet from the Traps.
Click to expand...
 
Thank you for a top shelf thread I have been following it and so would like to thank you!! I love the old grinds and factory iron. my Xheaded 340 runs a cam very close to the racer brown in your last test and was waiting to see how it stacked up.
 
Been hanging out all week for an update.

Nice work. Mid-12s is nothing to sneeze at, but I get the feeling there's going to be a lot more in this as the cams get bigger.

I'm amazed at how well it goes with stock heads and intake.

So the hp figures are all rear wheel?
 
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