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496 big block chevy what to expect

 
Bwash44
I love my Chevy Chevette!
Posts: 3
Joined: 11/12
Posted: 11/01/12 08:41 AM

Hey guys I just built a 1972 chevy nova back half pro street car with 4link set up has 33/18.50/15 tires bolted to Dana 60 with 456 gears  I'm running a turbo 400 with OTC 4200 stall takin it to the track this wknd trying to get a idea of the horsepower / time slip I should expect  my engine is a 496 4 bolt with forged scat crank 4.250 stroke 6.385 h beam rods .38cc dome pistons isky solid roller cam 714/714 lift  dart aluminum 345 heads cnc machined 1000cfm davinci carb  hoping to run high 9s low 10s what would it take to get there?  

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Bwash44
I love my Chevy Chevette!
Posts: 3
Joined: 11/12
Posted: 11/01/12 08:42 AM

Ptc converter sorry  

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pepsi1
Big Block power for the win
Posts: 940
Joined: 03/11
Posted: 11/02/12 03:11 PM

I had a similar set-up in my 1968 Camaro I ran 11:20's 122 MPH.

You have a lot more head and carburetor. Maybe mid 10's. Surprise me.It will take about 650HP to run the 9's. Heay but what do I know. Do it to it.
Does it have juice?

Bob  

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Bwash44
I love my Chevy Chevette!
Posts: 3
Joined: 11/12
Posted: 11/19/12 10:12 AM

Ok here it is tool it to the track last week ran a 10.60 at 125 with 1.72 sixty foot also put on a dyno put down 582 hp and 558tq at the wheels however  on the dyno it never made a peak hp at 5600 it was at 582 and stayed flatlined until 7200 rpm what would cause the week springs bad cam I'm at a lost bc it should have made more power in the upper rpm  

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pepsi1
Big Block power for the win
Posts: 940
Joined: 03/11
Posted: 11/19/12 01:09 PM

Bwash44
How close was I when I guesstimated what it would run?

When you went to the track what was your shift point?
You deffinetly ran out of something!
I've got your specs. I'll see what I come up with.Hang in there a day or so...

Bob  

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pepsi1
Big Block power for the win
Posts: 940
Joined: 03/11
Posted: 11/19/12 01:12 PM

Bwash44
One question on your heads are they OVAL or RECTANGULAR port?...
It will make a difference.

Bob  

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pepsi1
Big Block power for the win
Posts: 940
Joined: 03/11
Posted: 11/19/12 02:22 PM

Bwash44
I'll tell you Isky has one of the worst catalogs I have ever seen.

  I went to Dart and pulled up their Pro-1 heads. The valve spring they put on the head is supossed to be good for .660 lift.They recommend Vasco Jets for .790.If you didn't upgrade the valve spring thats your problem?
  You may have just run out of fuel. 1000 CFM carb you will need atleast 6PSI fuel pressure at the big end, maybe more with the Big Cubes.

  I ran a Small Block 331ci with 1200 CFM and that needed 7PSI min. at the Big End. Less then that and it just didn't pull had. I had a 14" tire that was 28" tall on a 12" wide rim 15" wheel. I ran a 5:67 rear gear on a Ford 9" I went through the big end at 9,000+ on a good run.
  You don't want to spin that BB that high. Unless you have all the good pieces in the Bottom.

So not knowing the fuel pressure and the tire is so tall. Isky listed 7 cams with .714/714 not knowing all the specs.

Here's a list of what I would check.

A.Do you have the correct Valve Spring for the Cam? Dart standard V/S is good for .660 lift. They rec. Vasco Jet upgrade .790 lift. Confused

1.I would check that fuel pressure.

2.Check the timing. 16* base and 34* or more total all in at 2500RPM.

3.Put more gear in it for the track. I would go with atleast a 5:30 rear gear.The 33" tall tire you last some MPH. I had a Dream Wheel that was 37 years old. It broke. Moroso still makes it. I could come so close to your ET&MPH. It was almost dead on. Your ET you should have been a little over 130MPH.

4.Make sure your valve lash didn't change.

5.Maybe the heads won't flow up at 7,200.

Good Luck.... Grin  Cool

Bob  

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daddyb
I love my Chevy Chevette!
Posts: 1
Joined: 11/12
Posted: 11/19/12 06:09 PM

HEY BRO! HAVE SOME INFO FOR YA. IM RUNNIN DART PRO 1 345 HEADS ON MY 540 WITH A CAMSHAFT OF .730 LIFT WITH 1050 DOMINATOR. HERES WHAT I KNOW. ACCORDING TO DARTS FLOW SHEET THOSE HEADS WILL FLOW OVER 400 ON INTAKE SIDE AT 7500 AND FELLA TALKIN BOUT SPRINGS IS RIGHT. I CHANGED MY SPRINGS AND WENT FROM A 1.59 TO A 1.625 SPRING WHICH ALLOWED FOR HIGHER RPM. PROBLEM WITH THAT IS YOUR TIMING NEEDS TO BE APPROXIMATELY 36 DEGREES AND I WONDER IF YOUR NOT RUNNING OUT OF FUEL ON THE BIG END.ADEQUATE AIR AND FUEL ON THE BIG END WILL MAKE A DIFFERENCE ON TOP ENDS WITH THOSE HEADS. DEFINITELY NEED WORK ON GETTING THAT 60FT. DOWN LITTLE BIT. ARE YOU HOOKIN OUT THE HOLE? MAYBE HIGHER STALL 4500 TO 4800 OR EVEN A TRANNY BRAKE WOULD HELP WONDERS IF YOU COULD. 496 IS A GOOD ENGINE ALL THE WAY AROUND AND PEOPLE WITH THE RIGHT COMBINATION HAVE MADE OVER 700 HORSE AND OVER 600FT. PD. TQ. YOU SHOULD ATLEAST GET LOW TENS TO HIGH NINES AND THATS PUMP GAS!!!!  

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pepsi1
Big Block power for the win
Posts: 940
Joined: 03/11
Posted: 11/20/12 05:26 PM

THERE are NO BROS on  our SUPER CHEVY Forum are you in the wrong Forum or  place?

Please address people by their posted names or don't post anything! Even if it's has good information! Confused

Bob  

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