Big BLock Chevy Mechanic Needed

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letsdrag
Posts: 11
Joined: Mon Feb 16, 2009 8:58 am

Big BLock Chevy Mechanic Needed

Postby letsdrag » Mon Apr 27, 2009 5:49 pm

disreguard
Last edited by letsdrag on Mon Aug 15, 2011 4:28 pm, edited 1 time in total.
sbmrx7

Re: Big BLock Chevy Mechanic Needed

Postby sbmrx7 » Mon Apr 27, 2009 6:16 pm

Ask for greg !!! Quantee you he can help
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Larry Jr.
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Re: Big BLock Chevy Mechanic Needed

Postby Larry Jr. » Sun May 03, 2009 9:51 pm

if the engine has a spark knock the last thing you want to do is advance the timing..that will make it worse, and make it hard to start, and run hot...back your timing back down to 32-36 degrees total, i would run around 32-34 since its on the street and max performance is not an issue.....dont listen to your buddy unless you want a hole in the top of your pistons :thumbsup:
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78 malibu
540 bb cchevy
2008 no-e track champ
letsdrag
Posts: 11
Joined: Mon Feb 16, 2009 8:58 am

Re: Big BLock Chevy Mechanic Needed

Postby letsdrag » Thu May 07, 2009 1:10 pm

Timing is back to 32 but Im back to my orginal problem. I can ease it into the gas and go pretty good but if I give it to much gas get that spark knock. It has a solid timing distributer in it. Would changing it out help that. Also did a compression check and it is pushing about 200
Larry Jr.
Posts: 941
Joined: Fri Feb 13, 2009 6:10 pm

Re: Big BLock Chevy Mechanic Needed

Postby Larry Jr. » Thu May 07, 2009 6:22 pm

you can unlock the the distributor and put the springs and bushings back in it....thats will help some..but depending on camshaft grind the, the valve overlap and design of the cam, and the compression ratio of the engine, it may be too much for pump gas regardless of what you do with your timing. racing gas may be your only option to keep it from running lean and detonating....also what size is your carb? and what brand?
Image540


78 malibu
540 bb cchevy
2008 no-e track champ
letsdrag
Posts: 11
Joined: Mon Feb 16, 2009 8:58 am

Re: Big BLock Chevy Mechanic Needed

Postby letsdrag » Sat May 09, 2009 9:06 pm

It is a Holley 750 4 barrel. Ran the part number on it they call it a race carb. Here is the specks on it.

750 CFM Four Barrel Race Carburetor

Designed for use on race engines
Includes notched float and jet extensions
Vacuum Secondaries with quick change spring cover
3 vacuum ports (1 timed, 2 full)
30cc accelerator pump
Calibrated for gasoline
Dual fuel inlets
4 corner idle
Screw in air bleeds
Double step, down leg boosters
Venturii Size 1.376
Throttle bore 1.687
Stainless steel throttle plates
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CHEVETTEMAN
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Joined: Mon Feb 16, 2009 2:36 am
Location: REPUBLIC MO.

Re: Big BLock Chevy Mechanic Needed

Postby CHEVETTEMAN » Thu May 21, 2009 4:37 am

THERE ARE TWO THINGS THAT I SEE COULD BE THE PROBLEM WITH THE PINGING. 1ST POSS TO MUCH TIMING STILL. BIG ENGINES DO NOT NEED ALOT OF TIMING. TRY AROUND 26-29. ALSO YOU ARE RUNNING ON STREET SO YOU ARE LOW TO MID RPM SO YOU DONT NEED ALOT ANYWAY. 2ND RUNNING LEAN ON HIGH COMPRESSION CAN MAKE IT PING TOO. AS YOU MADE TIMING HIGHER IT GOT HOTTER TEMP RIGHT? RUNNING LEAN. EVEN WITH DOMES YOU CAN RUN PUMP GAS BUT JET UP ALOT MORE(OK TO DRIVE AROUND BUT NOT THE BEST FOR RACING/ USE RACE FUEL) AND BRING TIMING BACK. LIQUID FUEL IS NON-FLAMIBLE ONLY THE FUMES ARE. THE HEAT IN THE INTAKE TURNS IT INTO VAPOR THAT IS FLAMIBLE. IF THERE IS NOT ENOUGH IT WILL PRE-FIRE,PING, AND SOUND LIKE A DIESEL. THIS CAN DISTROY YOUR VALVE TRAIN. (DROP VALVE/BREAK ROCKER ARM) OR PUT HOLE IN PISTON VERY FAST.
BACK UP TIMING AND JET UP.

YOUR COMPRESSION CHECK AT 200PSI IS JUST STATIC CHECK. DID YOU DO IT WITH ALL CARB BORES ALL THE WAY OPEN AND ALL PLUGS OUT? ARE THEY ALL CLOSE 5-12PSI +/-? AS ENGINE RPM GOES UP SO DOES YOUR COMPRESSION. THAT IS WHY SOME IDEL GOODAND RUN LOW SPEED BUT RUN BAD AS RPM GOES UP, FUEL GOES DOWN. LEAN OUT EFFECT. WHAT DO YOUR PLUGS LOOK LIKE? WHITE LEAN. NEEDS TO BE A MED TO LIGHT BROWN, DRY NOT WET OR POWDERD BLACK. PUT IN AN RICH LEAN TOOL AND SEE WHEN IT PINGS IF IT IS RICH OR LEAN.
Last edited by CHEVETTEMAN on Tue May 26, 2009 3:50 am, edited 1 time in total.
SOMEBODY HAS TO WIN
MID AMERICA WHOLESALE SYSTEMS LLC.
Bob

Re: Big BLock Chevy Mechanic Needed

Postby Bob » Thu May 21, 2009 8:27 pm

My timing is locked at 40*, 10.5-1 though.
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CHEVETTEMAN
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Location: REPUBLIC MO.

Re: Big BLock Chevy Mechanic Needed

Postby CHEVETTEMAN » Fri May 22, 2009 2:35 am

40 seems high but i have seen your car run and it goes. but you have really good heads and all matches what you are doing, that i understand.
SOMEBODY HAS TO WIN
MID AMERICA WHOLESALE SYSTEMS LLC.
NOVAHOE
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Re: Big BLock Chevy Mechanic Needed

Postby NOVAHOE » Tue Jun 02, 2009 7:42 pm

i run 49* on my 468 lol with 13,5.1 and it loves it



kid with pingin mota buy a barrel of 110 and have funn

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