Pro Street or No Street Nova - Part II

(PAT)>> WELCOME TO ENGINE POWER, AND WE'RE CONTINUING ON "PROJECT PRO STREET OR NO STREET". VIEWER RESPONSE ON THIS CLASSIC NOVA HAS BEEN HUGE. SEEMS EVERYONE LOVES IT AS MUCH AS WE DO. SO FAR WE'VE PLAYED WITH IT, PULLED THE ENGINE, ADDED A FRONT CLIP FROM TOTAL COST INVOLVED, AND PREFIT OUR 588 INCH BIG BLOCK CHEVY WE BUILT A WHILE BACK, AND TO MAKE IT MORE STREET FRIENDLY WE'RE CONVERTING IT TO EFI. WE'VE ALREADY INSTALLED A WILSON MANIFOLD, SPACER, AND THROTTLE BODY. ROBIN LAWRENCE, HOLLEY'S EFI GURU, HAS BROUGHT THEIR HOLLEY HP EFI SYSTEM TO LEND A HAND.

(ROBIN)>> FROM THE RACE SIDE, YOU KNOW, WE HAVE A LOT OF DIFFERENT NUANCES THAT WE CAN DO WITH YOU KNOW, INJECTOR PHASING, AND INDIVIDUAL CYLINDER CONTROL, THINGS LIKE THAT. ON THE STREET SIDE WE SEE A LOT MORE OF THESE REPLACEMENT TYPE CARBURETOR OPERATIONS THAT, YOU KNOW, BASICALLY UNBOLT YOUR CARBURETOR, BOLT THIS ON. THE ECU'S IN THE SIDE. IT IS ONE OF THE EASIER SYSTEMS TO LEARN AND USE ON THE MARKET AT THIS POINT. WELL WE NEED A VACUUM PORT. OTHERWISE WE CAN'T READ SPEED DENSITY.

(PAT)>> SO WITH LONGER STUDS INSTALLED, WE ADDED A ONE INCH SPACER TO THE MIX THAT WAS ALREADY TAPPED FOR MEASURING MANIFOLD VACUUM.

(ROBIN)>> THE RED AND WHITE WIRE IS YOUR IGNITION ON, HOT, AND SO ONCE WE GET THAT WE SHOULD BE ABLE TO MAKE SOME NOISE. I MEAN AFTER YOU PRIME IT, AND PUT FUEL IN IT, AND WE BUILD A PROGRAM FOR IT.

(PAT)>> BESIDES THAT WE'RE ALMOST READY TO GO.

(ROBIN)>> ALMOST YEAH!

(PAT)>> AS I AM FINISHING UP THE WIRING...

(ROBIN)>> DOUBLE CHECK OUR PIN MAPPING.

(PAT)>> ...ROBIN IS BUSY BUILDING A BASE PROGRAM FOR THE ENGINE.

(ROBIN)>> AND WE'LL RECONFIGURE OUR FIRING ORDER.

(PAT)>> WITH THE INITIAL TUNE LOADED UP, WE CHECK FOR CRANK SIGNAL AND TO SEE IF THE IGNITION IS FIRING.

(ROBIN)>> YEP, OKAY, I'VE GOT AN RPM SIGNAL. LET'S GO POINTS OUTPUT AND SEE WHAT THAT DOES.

(PAT)>> WE HAD TO CHANGE THE PROGRAM TO POINTS OUTPUT TO WORK WITH OUR DYNO'S MSD IGNITION BOX, AND PRESTO, THE IGNITION IS HOT.

(ROBIN)>> WE SHOULD BE GOOD TO FIRE.

(PAT)>> WITH OUR HIGH DOLLAR RACE FUEL IN THE CELL AND OUR FUEL PRESSURE SET, WE LIGHT HER UP. [ engine starts and idles ]

(PAT)>> LOOK AT THAT! WITH A LITTLE MECHANICAL AND ELECTRONICALLY TWEAKING, THE 588 IS RUNNING NICELY. ALL RIGHT, ONTO GLORY RIGHT HERE. OUR INITIAL RUN IS FROM 3,700 TO 5,500 RPM JUST TO MAKE SURE THINGS ARE BEHAVING THEMSELVES. [ engine revving ]

(ROBIN)>> WE NEED TO WORK ON THAT A LITTLE BIT. THIS IS OUR RPM TRACE RIGHT HERE.

(PAT)>> WITH ONLY A FEW MINOR CHANGES TO THE COMPUTER PROGRAM WE HAVE THE GREEN LIGHT TO MAKE A PULL FROM 4,500 TO 7,000 RPM. [ engine revving ]

(PAT)>> THAT PULL, NICE START, 912 HORSEPOWER, 738 POUND FEET OF TORQUE. PEAK HORSEPOWER WAS AT 7,000, PEAK TORQUE 6,100. THE DATA SHOWED WE NEEDED 10 PERCENT MORE FUEL ABOVE 6,000 RPM, AND THAT'S AN EASY CHANGE TO MAKE WITH THE HOLLEY HP SOFTWARE, THAT SMOOTHED OUT THE TRANSITION ON THE FUEL MAP TABLE. ALL RIGHT, SO WE PUT 10 PERCENT MORE FUEL ABOVE 6,000 TO WORK ON THE CORRECTION AND WE'VE ACTUALLY MATCHED THE TIMING TO THE CARBURETED PULLS. SO WE'RE UP AT 36 DEGREES OF TIMING NOW. SO THIS IS GONNA BE AN INTERESTING COMPARISON AND OBVIOUSLY WE'LL HAVE TO FUZZ ON IT SOME MORE, BUT I THINK WE'RE GONNA GET...

(ROBIN)>> ARE WE GOING TO 7,500?

(PAT)>> AND WE'RE GONNA BE AT 7,500 FOR TOP OF THE PULLS. WE AREN'T TRYING TO BEAT THE CARB FOR ALL OUT POWER JUST YET. THE IDEA IS TO MAKE OUR NOVA MORE DRIVABLE ON THE STREET. THE GRAPH IS VISIBLY SMOOTH. IT MADE 917 HORSE RIGHT AT 7,100. PEAK TORQUE IS NOW 743.9 BETWEEN 6,000 AND 6,100. IF YOU WANT TO LOOK AT SOME DATA OUT THERE AND SEE WHERE WE'RE AT. MAYBE FUZZ ON IT A LITTLE BIT MORE AND WE'LL GO FROM THERE.

(ROBIN)>> YOU BET YA!

(PAT)>> WITH THE TIMING TABLE UNTOUCHED AT 36 WE DECIDED TO TAKE OUT A LITTLE MORE FUEL.

(ROBIN)>> WE'RE GOING TO LEAN IT OUT A LITTLE BIT TO A TARGET OF 12.9. SO BASICALLY I HIGHLIGHTED THAT AREA, I PUNCH IN 12.9, HIT ENTER, AND 12.9.

(PAT)>> ALL RIGHT, MY FAVORITE PART. [ engine revving ]

(PAT)>> WELL, LET'S SEE WHAT THAT DID. THAT'S MORE LIKE IT, 925 HORSE, 748 POUND FEET OF TORQUE. I'M HAPPY WITH THAT!

(ROBIN)>> YEAH THAT LAST PULL WAS, IT WAS GOOD. IT WAS, THE CORRECTION WAS VERY GOOD. SO WE'VE GOT A GREAT BASELINE, WE GOT SOME NICE PULLS, THE ENGINE SOUNDS GREAT. THE NEXT THING TO DO IS GET THE THING IN THE CAR AND WE'LL SORT IT OUT GOING DOWN THAT TRACK.

(PAT)>> OUR THANKS TO ROBIN AND HOLLEY FOR PROVIDING ANOTHER POWERFUL YET TUNABLE SYSTEM.

(PAT)>> HEY WELCOME BACK. WE JUST FINISHED RUNNING OUR BIG BLOCK ON THE DYNO WITH EFI, AND WITH THE ENGINE ALL FINISHED UP WE HAVE A TON OF WORK TO DO. NOW ALL THE PARTS WE HAVE ARE LAID OUT ON THE FLOOR IN THEIR RESPECTIVE PLACES. FROM THE FRONT WE HAVE A BIG ALUMINUM RADIATOR THAT WILL SUPPORT OVER 1,000 HORSEPOWER. ALSO NEW LIGHT WEIGHT WHEELS FROM RC COMPONENTS, SOME NARROW MICKEY THOMPSON SPORTSMAN SR'S. NEXT IS A RACE BUILT TURBO 400 TRANS FROM BOWTIE OVERDRIVE. PLUS A COMPLETE LADDER BAR KIT FROM CHECKERED RACING, AND THIS AWESOME FAB NINE REAR AXLE HOUSING FROM CURRIE ENTERPRISES, AND HOOKING ALL OF THAT TO THE GROUND ARE THESE MASSIVE 31 BY 16.5 MICKEY THOMPSON ET STREET "R'S" AND MORE RC COMPONENT WHEELS. UNDER THE CAR NOW ARE SINGLE LEAF SPRINGS ON EACH SIDE AND LADDER BARS. THE REAR END IS A 12 BOLT WITH A SPOOL. IT WAS FINE FOR STREET CRUISING AND THE OCCASIONAL PASS DOWN THE STRIP, BUT FOR OUR INCREASED POWER LEVEL WE ARE STEPPING IT UP. THE FIRST ORDER OF BUSINESS IS TO TAKE OFF THE OLD TIRES. THEN LOWER THE CAR DOWN TO REST ON OUR AXLE STAND. AND STOP ABOUT RIGHT THERE, PERFECT. REMOVE THE MAIN BRAKE LINE.

NEXT FREE UP THE LOWER SHOCK MOUNTS. THEN REMOVE THE NUTS HOLDING THE FRONT OF THE OLD LADDER BARS. WE PUT A JACK STAND UNDER THE YOKE OF THE REAR END. REMOVE THE NUTS OF THE REAR BOLTS HOLDING THE LEAF SPRINGS, AND WITH A DELICATE BLEND OF PSYCHOLOGY AND EXTREME VIOLENCE, THE SPRINGS ARE FREE OF THEIR SHACKLES, BUT WE WEREN'T DONE QUITE YET.

THE FRONT SHACKLE MOUNTS NEEDED A BIT MORE GENTLE PERSUADING... OH MY GOD! ...TO FINALLY ACHIEVE VICTORY.

(MIKE)>> WHILE PAT RECUPERATES I'M JUMPING IN BY CUTTING OFF ALL THE OLD MOUNTING POINTS FROM THE OLD SUSPENSION WITH A CUTOFF WHEEL AND PLASMA CUTTER. NOW I'M USING THE CUTOFF WHEEL TO AVOID GOING TOO DEEP AND GETTING IN TO THE FRAME RAIL. IT DOES TAKE A LITTLE BIT OF TIME BUT REQUIRES LESS CLEAN UP WORK AT THE END. THE PLASMA CUTS WAY FASTER. I'LL USE IT FOR AREAS THAT I'M NOT WORRIED ABOUT CUTTING THROUGH. PAT'S BACK JUST IN TIME FOR A FEW SOLID BLOWS WITH THE HAMMER. HE GETS INTO IT, LIKE A WHACKAMOLE CHAMPIONSHIP AT THE ARCADE.

(PAT)>> WATCH YOUR FACE.

(MIKE)>> HE'S ALSO KNOCKING DOWN ALL THE ROUGH SPOTS FROM THE CUTS WITH A GRINDING WHEEL. THIS WILL GIVE US A SMOOTH, CLEAN SURFACE FOR ALL THE NEW STUFF GOING ON.

(PAT)>> WITH IT OUT OF THE CAR AND ON THE FLOOR WE CAN GET A GOOD LOOK AT SOME GOOD OLE FASHIONED BACK YARD ENGINEERING. THE FRONT OF THE LADDER BAR MOUNT IS MADE FROM COMMON ANGLE IRON AND IT'S WELDED TO SOME ONE BY TWO SQUARE TUBING. SOME STRAP, MORE ANGLE IRON MAKES UP OUR DRIVESHAFT LOOP, AND WE HAVE A CUTOUT HERE WHICH WAS PROBABLY AN AFTER THOUGHT FOR DRIVESHAFT MOVEMENT. NOW THERE'S NOTHING WRONG WITH A LITTLE BACK YARD ENGINEERING. THIS IS A GREAT EXAMPLE OF WHAT CAN BE DONE WITH A LITTLE BIT OF RESOURCE BUT A LOT OF CREATIVITY, AND OBVIOUSLY IT WORKED FINE, BUT FOR OUR PURPOSES WE NEED TO BUILD SOMETHING A LITTLE STURDIER. THERE'S MORE TO DO BUT THE DYNO CELL IS EMPTY. SO WE'RE JUMPING BACK ON A PROJECT WE NEED TO FINISH UP, STAY WITH US.

(MIKE)>> WELCOME BACK. WE HAVE SOME OLD COMPANY BACK IN THE SPOTLIGHT. THIS IS THE SMALL BLOCK STROKER THAT CAME OUT OF OUR NOVA PROJECT. WE NAMED IT "383 REREV". NOW WE'RE NOT TRYING TO SET THE WORLD ON FIRE WITH THIS ENGINE. WE'RE JUST TRYING TO SHOW YOU A LITTLE BIT OF TECH WITH SOME PARTS WE HAD LAYING AROUND THE SHOP. HERE'S A LOOK AT WHAT GOT US TO THIS POINT. THE ENGINE WAS DOCKED UP TO THE DYNO. WE RAN THE SAME HEADERS IT HAD IN THE CAR, AND OUR 750 CFM DYNO CARB. WE PULLED IT TO 6,500 RPM, AND THE DYNO REPORTED 443 HORSEPOWER. A QUICK PRESSURE WASH OF THE ENGINE WAS NECESSARY. IT HAD QUITE A FEW YEARS OF DIRT AND OIL BUILD UP ON THE OUTSIDE. ONCE DRY, THE TEARDOWN BEGAN, AND WE DISCOVERED WHAT PARTS THE ENGINE HAD THE SAME TIME YOU DID. THE CYLINDER HEADS WERE REMOVED, WHICH SHOWED US A SHORT BLOCK THAT WAS IN GOOD SHAPE. THE CAM SHAFT WAS THE LAST PART TO COME OUT. IT WAS REPLACED WITH A CAM WE USED IN A PREVIOUS SMALL BLOCK BUILD, AND A NEW TIME SET WAS INSTALLED.

(PAT)>> THE NEW SOLID ROLLER CAM SHAFT IS BIGGER IN ALL RESPECTS AND HAS A 900 BASE CIRCLE FOR STROKER APPLICATIONS. NOW SINCE IT'S BIGGER ON THE INTAKE AND EXHAUST, PISTON TO VALVE CLEARANCE HAS TO BE CHECKED. OUR NEW PUSH RODS MEASURE EIGHT-200 HAVE COME IN FROM TRENT PERFORMANCE, AND I'VE GONE AHEAD AND SETUP EVERYTHING UP TOP TO COMPLETE THE PROCESS. WE'RE NOT USING CLAY BECAUSE WE HAVE THE RIGHT MEASURING EQUIPMENT. WITH TRUE TDC SETUP, WE'LL TURN OUR DEGREE WHEEL UNTIL BOTH ROCKERS ARE MOVING, WHICH INDICATES SPLIT OVERLAP. THE INTAKE CLEARANCE IS CHECKED 10 DEGREES AFTER TOP DEAD CENTER AND ZERO LASH ON THE ROCKERS. THIS IS THE POINT WHERE THE VALVE IS PHYSICALLY CLOSEST TO THE TOP OF THE PISTON WITH THIS PARTICULAR CAM SHAFT SETUP. NOW ZERO THE DIAL INDICATOR ON THE INTAKE'S VALVE RETAINER, AND PRESS DOWN ON THE ROCKER UNTIL THE VALVE CONTACTS THE TOP OF THE PISTON. WE HAVE A GENEROUS 165 THOUSANDTHS CLEARANCE. THE MINIMUM WE NEED HERE IS ONLY 60 THOUSANDTHS. THE EXHAUST CLEARANCE IS MEASURED AT 10 DEGREES BEFORE TDC ON SPLIT OVERLAP. ON THE EXHAUST WE HAVE 156 THOUSANDTHS, WHICH OUR MINIMUM HERE IS 120 THOUSANDTHS. SO WE ARE WAY IN THE GOOD. NOW THE HEADS WILL BE FITTED WITH NEW VALVE SPRINGS, RETAINERS, AND LOCKS. THE SPRINGS ARE BRAND NEW AND SPEC'ED FOR THE CAM WE'VE INSTALLED, MORE ITEMS THAT WERE ON OUR PARTS SHELF.

(MIKE)>> ALSO OUT OF A USED ENGINE ARE THESE TIE BAR STYLE SOLID ROLLER LIFTERS. COMETIC MLS HEAD GASKETS WILL SEAL THE HEADS TO THE BLOCK'S DECK. THESE HAVE A 27 THOUSANDTHS COMPRESSED THICKNESS AND WILL INCREASE THE COMPRESSION RATIO FROM 10.10 TO ONE WITH THE OLD 41 THOUSANDTHS GASKET TO 10.46 WITH THESE. THESE ARP HEAD BOLTS HAVE A TENSILE STRENGTH OF 180,000 PSI, MAKING THEM WAY STRONGER THAN OEM TYPE BOLTS. NOW THE GUIDE PLATES CAN BE TORQUED IN PLACE WITH NEW ROCKER STUDS. THE NEW PUSH RODS CAN DROP IN, AND THEY GET TOPPED OFF WITH SUMMIT RACING GOLD ROCKER ARMS WITH A ONE POINT FIVE RATIO. COLD LASH IS 10 THOUSANDTHS ON THE INTAKE, 14 THOUSANDTHS ON THE EXHAUST. KEEPING VALVE STABILITY IN CHECK ARE SUMMIT RACING ROCKER GIRDLES. MAKE SURE YOU RECHECK YOUR LASH. THE GIRDLE CAN ALTER YOUR SETTING. NOW THE ORIGINAL VALVE COVERS GO BACK ON. THE RIGHT STUFF FROM PERMATEX IS A ONE MINUTE GASKET MAKER AND IS BLOW OUT RESISTANT. WITH THAT BEAD LAID, THE DART SINGLE PLANE INTAKE IS BACK AT HOME. WE IMPROVED ON THE OIL PAN WITH A WEIAND OIL PAN KIT. THIS ONE HAS A SEVEN QUART CAPACITY. WHEN WE COME BACK IT'LL BE ON THE DYNO READY TO FIRE UP.

(MIKE)>> WE'RE BACK AND IT'S TIME TO SEE HOW WELL PROJECT "383 REREV" RESPONDS.

(PAT)>> FIRES RIGHT UP.

(MIKE)>> IT'S RUNNING THE HEADERS FROM THE NOVA AGAIN, AND THE SAME CARB AS BEFORE. WE DID ADD A TWO INCH SPACER FOR A LITTLE MORE PLENUM VOLUME.

(PAT)>> ALL RIGHT, WE HAVE 33 DEGREES TOTAL TIMING IN IT, AND WE HAVE FRESH 93 OCTANE IN THE CELL. WE'RE GONNA MAKE OUR SWEEPS JUST LIKE WE DID BEFORE WE TORE IT APART FROM 3,000 TO 6,500. LET HER BUCK. [ engine revving ]

(PAT)>> OH YEAH!

(MIKE)>> WOW!

(PAT)>> THAT'S NOT A BAD IMPROVEMENT RIGHT THERE. 481 HORSE, 454 POUND FEET OF TORQUE.

(MIKE)>> AT 6,500. BEFORE IT WAS 420 HORSEPOWER, NOW WE'RE AT 481. THE SAME NUMBERS WITH TORQUE AT 6,500, 339 BEFORE, 388 NOW.

(PAT)>> THAT IS INCREDIBLE. THERE'S STILL A LITTLE LEFT IN IT. WE'VE GOT TO BUMP THE TIMING UP.

(MIKE)>> BY ADDING TWO DEGREES FOR A TOTAL OF 35. OIL PRESSURE STABILIZED, YOU READY?

(PAT)>> YOU BET! [ engine revving ]

(PAT)>> YEAH, IT SNUCK A LITTLE MORE IN IT, 484 HORSE, 462 POUND FEET OF TORQUE. WE STEPPED UP ONE MORE DEGREE TO 36 TOTAL AND THIS IS GONNA BE OUR GRAND FINALE. SO WHY DON'T YOU GO AHEAD AND STEP IT UP ANOTHER 300 RPM TO 6,800. LET'S SEE WHAT SHE DOES. [ engine revving ]

(PAT)>> WE FOUND THE LIMITS RIGHT THERE, WHICH IT DIDN'T DROP ANY, 484 HORSE, 461.7 POUND FEET OF TORQUE. SO INTERESTING THING IS IT DIDN'T FALL OFF A WHOLE BUNCH UP TOP. NICE ENGINE, AND WE DIDN'T HAVE TO DO IT. IT'S A TAKE OUT THAT WE JUST KINDA SWAPPED IN SOME PARTS ON.

(MIKE)>> IT ONLY DROPPED ONE POUND FOOT OF TORQUE WITH ONE DEGREE. BACK IT DOWN TO 35, IT'S IN THE HAPPY ZONE.

(PAT)>> WHATEVER THIS THING GETS PUT IN IT'S GONNA BE A ROCKER.

(MIKE)>> GOOD JOB.

(PAT)>> THIS PROJECT GOES TO SHOW THAT IDENTIFYING SOME SMALL PROBLEMS AND CHANGING OUT SOME EASY PARTS CAN YIELD BIG RESULTS. NOW NEXT TIME YOU HAVE A TAKE OUT ENGINE DON'T ASSUME IT'S USELESS. A LITTLE WORK GOES A LONG WAY.

(MIKE)>> HEY EVERYBODY, TODAY'S TECH TIP IS ALL ABOUT THE GAP. NOW THAT'S AN IMPORTANT WORD THAT HAS SEVERAL DIFFERENT MEANINGS IN THE AUTOMOTIVE INDUSTRY. ONE DEFINITION IS BECOMING EXTREMELY POPULAR BECAUSE OF THE DRAG RACING SHOWS THAT ARE ON TV. A GAP AT THE DRAG STRIP IS BEST DESCRIBED AS PUTTING A WHOOPING ON YOUR COMPETITOR AND BEING AHEAD IN A BIG WAY.

(PAT)>> ANOTHER DEFINITION OF GAP HAS TO DO WITH PISTON RINGS. IT IS THE AMOUNT OF SPACE IN BETWEEN THE ENDS OF THE RING WHEN IT IS IN THE BORE AND AT AMBIENT TEMPERATURE. THE AMOUNT OF GAP IS BASED ON WHAT THE ENGINE IS ACTUALLY GONNA BE USED FOR. NATURALLY ASPIRATED, NITROUS, AND SUPERCHARGED ENGINES ALL REQUIRE DIFFERENT AMOUNTS OF GAP.

(MIKE)>> MAHLE IS OUR OFFICIAL PISTON AND BEARING SUPPLIER, AND THIS IS THEIR RECOMMENDATIONS FOR PISTON RING GAP DEPENDENT ON THE ENGINE'S APPLICATION. THE BORE SIZE IS MULTIPLIED BY MAHLE'S RECOMMENDED GAP BASED ON EXPANSION. IT SPECIFIES THE RING GAP FOR THE TOP AND SECOND RING BASED ON THE ENGINE USE. FROM NATURALLY ASPIRATED STREET ENGINES, UP TO TURBO OR SUPERCHARGED ENGINES AND THEIR SPECIFIED BOOST LEVELS. NOTICE HOW THE GAP INCREASES AS THE POWER LEVEL RISES. THIS IS DUE TO THE AMOUNT OF HEAT GENERATED BY CYLINDER PRESSURE.

(PAT)>> WITH MORE CYLINDER PRESSURE MORE HEAT IS GENERATED, AND THAT CAUSES THERMAL EXPANSION OF THE RING. THE GAP IS INCREASED TO KEEP THE RING ENDS FROM BUTTING UP AGAINST THEMSELVES, WHICH WILL CAUSE DAMAGE TO THE RING LAND AND THE CYLINDER WALL, AND BOTH WILL LEAD TO CATASTROPHIC ENGINE DAMAGE. IF YOUR ENGINE IS GONNA BE SUPERCHARGED AND MAKE LESS THAN 15 POUNDS OF BOOST THIS IS THE COLUMN YOU'D USE. NOW SAY YOUR BORE WAS FOURO-30. YOU WOULD MULTIPLY THAT BY SIX THOUSANDTHS AND IT WOULD EQUAL 24 THOUSANDTHS FOR YOUR TOP RING GAP. FOURO-30 TIMES 5,000? FOR YOUR SECOND RING GAP WOULD EQUAL 20 THOUSANDTHS.

(MIKE)>> SPARK BOLTS, OR THE PROPER TERM SPARK PLUGS, ALSO REQUIRE GAP TO FUNCTION PROPERLY. NOW THAT GAP IS ALSO DETERMINED BY THE POWER LEVEL OF THE ENGINE, BUT THE THEORY IS TOTAL OPPOSITE OF RING GAP. THE HIGHER THE POWER LEVEL OF THE ENGINE THE TIGHTER THE GAP ON THE SPARK PLUG IS GOING TO BE. THE REASON BEING THE HIGHER AMOUNT OF CYLINDER PRESSURE, THE MORE ENERGY YOU NEED FOR THE SPARK TO JUMP THE GAP IN THE SPARK PLUG. NOW BY TIGHTENING THE GAP UP YOU INCREASE THE SPARK POTENTIAL, WHICH REQUIRES LESS ENERGY TO BRIDGE THE GAP WITH THAT SAME SPARK.

(PAT)>> DAILY DRIVERS WITH STOCK TYPE ENGINES USUALLY HAVE A SPARK PLUG GAP IN THE 50 TO 60 THOUSANDTHS RANGE. HIGH PERFORMANCE STREET AND STRIP CARS USUALLY HAVE A LITTLE BIT TIGHTER AT 40 TO 50 THOUSANDTHS. SUPERCHARGED ENGINES UNDER 15 PSI OF BOOST HAVE A GAP IN THE NEIGHBORHOOD OF 30 TO 35 THOUSANDTHS, AND VERY HIGH SPECIFIC OUTPUT ENGINES, LIKE AN NHRA PRO STOCKER, CAN RUN GAPS AS TIGHT AS 24. WE'LL WE HOPE THIS GIVES YOU AN IDEA OF GAPS, WHETHER THEY'RE BIG AND SMALL, AND JOIN US NEXT TIME FOR MORE ENGINE POWER TECH.

(MIKE)>> ROCK AUTO DOT COM IS AN EXCELLENT SOURCE FOR AUTO, TRUCK, MARINE, AND MOTORCYCLE PARTS. NOW THEY ARE STRICTLY AN ONLINE COMPANY. THEY DON'T HAVE ANY STORE LOCATIONS, WHICH ALLOWS THEM TO KEEP THE COSTS DOWN ON THE PARTS YOU WANT TO BUY. ROCK AUTO DOT COM IS A HUGE DATABASE, AND EASY TO USE. SIMPLY CHOOSE YOUR VEHICLE'S MAKE, YEAR, MODEL, AND ENGINE TYPE. THEN A LIST OF PART CATEGORIES ARE AT YOUR FINGER TIPS. ONCE A PART IS SELECTED, YOU'LL GET A LIST OF THE MANUFACTURERS WHO OFFER IT AS WELL AS PICTURES AND INSTALLATION TIPS. ROCK AUTO IS FAMILY OWNED AND SHIPS THOUSANDS OF PARTS FROM HUNDREDS OF MANUFACTURERS ALL OVER THE WORLD. WELL THAT'S IT FOR THIS EPISODE OF ENGINE POWER. WE'LL SEE YOU NEXT TIME.