VALVE TIMING AND ITS EFFECT ON ENGINE PERFORMANCE:
BASIC RULE FOR CAM TIMING ARE:
"ADVANCING" THE CAM IMPROVES LOW END TORQUE AND RESPONSE AT THE EXPENSE OF HIGH RPMs.
"RETARDING" THE CAM IMPROVES TOP-END AT THE EXPENSE OF LOW SPEED RESPONSE.
THE HIGHER THE COMPRESSION RATIO THE WIDER THE LOBE CENTERLINE ANGLES. THE LOWER THE COMPRESSION RATIO THE MORE OVERLAP OR A NARROWER LOBE CENTERLINE.
*******************************************************
THE CAM TIMING WHEN CHECKED AND SET AT THE DESIRED POSITION SHOULD" ALWAYS" TAKE INTO CONSIDERATION "CHAIN STRETCH OR TIMING BELT DEFLECTION" THUS, ALTERING OR RETARDING THE CAMSHAFT AT HIGH RPMs!
MANY OVERLOOK THIS !
(this scenario has me advancing my cam timing 2* advance to anticipate belt/chain stretch retarding the cam phasing, the more evident when heavy spring pressures are used for high lifts!)
*******************************************************
WHEN WE ARE DEGREEING A CAMSHAFT AT "ZERO" WHAT ARE WE ACCOMPLISHING AS IT RELATES TO THE ENGINES PERFORMANCE? BE IT WITH A STOCK CAMSHAFT OR AN ALL OUT GRIND WITH A SPLIT DURATION! SO HERE WE START AND TRY TO SIMPLIFY AND EXPLAIN THE NET EFFECT....
FACTORY CAMSHAFTS FOR MOST ENGINES ARE WHAT THEY CALL "SPLIT OVERLAP DESIGN". THIS MEANS BOTH VALVES INTAKE AND EXHAUST, ARE OPEN AN EQUAL DISTANCE AT TDC "OVERLAP".
THIS IS ALSO CALLED A SINGLE PATTERN CAMSHAFT. THIS IS MOST LIKELY THE STOCK TYPE AND WE START WITH THIS TO KEEP OUR PERSPECTIVE IN CHECK SO AS TO HAVE CONTINUITY FOR THE NOVICE ENGINE AFFICIONADOS.
DEGREEING A CAM SPECIALLY WHEN YOU COMPETE IN CLASSES THAT REQUIRE A "FACTORY STOCK" ENGINE WILL YIELD DIVIDENDS! THE FACTORY CAMSHAFT WAS OPTIMIZED AT THE ZERO TIMING POSITION, THIS ALLOWS THE ENGINE TO RUN AT ITS DESIGNED CONFIGURATION...HOWEVER ANY KIND OF MODIFICATIONS ON THE INTAKE AND EXHAUST USUALLY MAY RENDER THIS LESS THAN OPTIMUM.
FOR EXAMPLE: IF YOUR FACTORY CAR/MOTORCYCLE IS INVOLVE IN A TOP END/TOP SPEED ONLY CONTEST?
THE CAM TIMING SHOULD BE RETARDED AT LEAST 2-4* FROM FACTORY. THIS IN EFFECT WILL PLACE YOUR RPMs A LITTLE HIGHER FROM PEAKING OR RUNNING OUT OF STEAM!
THE REASON BEING A RETARDED CAMSHAFT WILL LET THE INTAKE VALVE STAY OPEN LONGER, TO GIVE THE COLUMN OF "INERTIA RAM" OF AIR/ FUEL TO CONTINUE FILLING THE CYLINDERS PAST BDC PISTON POSITION. IN SHORT THE LATER CLOSING OF THE INTAKE VALVE BENEFITS THE HIGHER THE RPMs! ALL THIS GAINS WILL BE AT THE PENALTY OF LOW SPEED RESPONSE FROM THE REDUCTION OF DYNAMIC CYLINDER PRESSURES!
----------------------------------------------------------------------------------
DYNAMIC COMPRESSION" IS THE ACTUAL COMPRESSION RATIO THE ENGINE SEES AFTER THE INTAKE VALVE CLOSES ON THE INTAKE STROKE! THE INTAKE VALVE USUALLY CLOSES PAST BDC PISTON POSITION AND WHEN IT FINALLY CLOSES THE COMPRESSION IS ACTUALLY LOWER THAN THE COMPUTED MECHANICAL COMPRESSION RATIO!
----------------------------------------------------------------------------------
SO WHAT SITUATIONS DO YOU" ADVANCE" THE STOCK CAMSHAFT?
WHEN YOU HAVE A RACE AT A HIGH ELEVATIONS LIKE" PIKES PEAK" IN COLORADO OR A SLALOM EVENT AT " BAGUIO" IN THE PHILIPPINES! THIS HIGH ELEVATIONS HAVE A LESS DENSER ATMOSPHERE OR WEIGHT. THIS SITUATION RENDERS THE CAR WITH A LOT LESS AIR TO INGEST IN THE CYLINDERS. THAT IS WHY WHEN YOU ARE AT THIS PLACES, THE ENGINE JUST DOES NOT HAVE THE SAME POWER AS IT HAS ON SEA LEVEL OR LOWER ELEVATION RACETRACKS....IT JUST PLAIN HAVE LESS POWER HERE!
ADVANCING YOUR CAMSHAFT AGAIN 2-4* OR MORE WILL HELP YOU REGAIN SOME OF THIS DYNAMIC PRESSURES LOST DUE TO ELEVATION. YOU ARE FOOLING THIS ENGINE INTO THINKING, WITH CAM TIMING, THAT IT GAINED SOME COMPRESSION AT THIS ALTITUDE. AS THE EARLIER CLOSING OF THE INTAKE VALVES RESULTS IN A HIGHER DYNAMIC COMPRESSION RATIO!
SUCCESSFUL PIKES PEAK RACERS USUALLY HAVE A HIGHER THAN NORMAL COMPRESSION RATIOS AND OR ADVANCED CAM TIMING IN ANTICIPATING THE EVER INCREASING ALTITUDE THAT THEY HAVE TO CLIMB TO THE FINISH LINE....
SO WORD ON ADVICE TO THE BAGUIO RACERS.....ADVANCE YOUR CAMSHAFTS!!!
----------------------------------------------------------------------------------
SO NOW WE ARE AT THE HIGH PERFORMANCE CAMSHAFTS.....
MOST PEOPLE INCLUDING MYSELF, HAS "OVER CAMMED" AT ONE TIME OR ANOTHER!
SOME JUST DO IT ALL THE TIME!
SO I WILL SHED SOME LIGHT INTO SOME TIPS ON HOW TO KNOW IF YOU ARE OVER THE TOP...
WHEN BUYING YOUR FIRST CAMSHAFT AND GETTING IT INSTALLED AND DEGREED. MAKE SURE YOU DID NOT MISS TO CHECK THE CRANKING COMPRESSION PRESSURES ON YOUR ENGINE WITH THE STOCK CAMSHAFT!
THE REASON I STRESS THIS IS BECAUSE WHEN YOU HAVE THE STOCK CAM IN PLACE, DON'T FORGET TO DO A COMPRESSION CHECK.
EXAMPLE= 185# PSIG OF PRESSURE
TAKE NOTE OF THIS AND AVERAGE ALL YOUR READINGS....
NEXT AFTER INSTALLING YOUR NEW CAM AND DEGREED OR JUST LINED UP TO FACTORY MARKS.
DO ANOTHER COMPRESSION CHECK AND TAKE NOTE OF THE NEW READINGS......
DID THE COMPRESSION NUMBERS DROP FROM 185# TO NOW 130-145# ???
THIS DROP IN COMPRESSION PRESSURES IS "NORMAL" AND INDICATES TO ME THAT YOUR ENGINE WILL LOSE SIGNIFICANT LOW-MID RANGE RESPONSE OR TORQUE!
THIS IS DUE TO THE DURATION OF THIS CAMSHAFT THAT EXTENDS THE VALVE EVENTS.
THE INTAKE VALVE CLOSING LATE, THIS DROPS YOUR DYNAMIC COMPRESSION.
THAT IS LIKE GETTING A LOWER COMPRESSION ENGINE IN THE PROCESS! THIS IS THE REASON "BIG" CAMS HAVE SOFTER RESPONSE AT LOWER RPMs!
IF THE CAM IS MILDER? THE COMPRESSION TEST WILL NORMALLY SEE A LOT LESS DROP IN COMPRESSION PRESSURES, IF IT IS 10-20# LESS? IT PROBABLY WILL NOT LOOSE LOW-MID RANGE PULLING POWER....
SO WHAT DO YOU DO WHEN THE PRESSURES ARE LIKE THE FIRST EXAMPLE OF ONLY 130-145# ???
RUN THE CAR AT THE TRACK AND DO "CONSISTENT" BACK TO BACK PASSES TO HAVE CONSISTENT DATA AND RESULTS.....
NOW ADVANCED THE CAMSHAFT 2-4* AND DO A COMPRESSION PRESSURE CHECK.....ADVANCING INCREASED PRESS. TO 175???
THIS INCREASED IN COMPRESSION PRESSURES WILL INCREASE RESPONSE AND IF RUN AT THE TRACK WILL PROBABLY GO FASTER DUE TO A MORE RESPONSIVE AND TORQUEY ENGINE!!!
AND IF IT DID RUN FASTER??? THE CAM IS PROVING TO BE TOO BIG!!! "ADVANCING THE CAM" WILL MAKE IT ACT LIKE A MILDER/SMALLER CAMSHAFT....
BUT WHAT IF YOU HAVE A LOT OF CRANKING PRESSURES EVEN AFTER A CAM CHANGE?
ADVANCING THE CAM PROBABLY WILL BOOST THE LOW-MID RESPONSE AT THE COST OF HIGH RPMs!
THIS SIGNIFIES THAT THE ENGINE ALSO HAS AMPLE COMPRESSION RATIO AND THE CAM IS PROBABLY JUST RIGHT FOR THE COMBINATION HERE....
AND IF THIS IS CAM IS" RETARDED" AND GAINS SPEED AT THE TRACK? THIS TELLS YOU IT IS PROBABLY OR LIKELY TO BE ON THE SMALL SIDE!!!
THE PERFECT SCENARIO IS WHEN YOU HAVE THE CAM INSTALLED AS PER CAMSHAFT MANUFACTURERS SPECS @ STRAIGHT UP OR AT "ZERO".
ADVANCING AND OR RETARDING THIS CAMSHAFT YIELDED LESS OR NO CHANGE IN SPEED OR LAP TIMES ???
YOU PROBABLY HIT THE MARK VERY WELL!
THIS TELLS YOU YOUR RIGHT ON THE MONEY ON YOUR CAM PROFILE AT THIS POINT....NEITHER TOO BIG OR SMALL!
SO TO WRAP THIS UP!
DO NOT BE AFRAID TO EXPERIMENT OR TEST BEYOND THE FACTORY SETTING AS LONG AS YOU CHECKED VALVE TO PISTON CLEARANCE FROM +8* TO -8* DEGREES EITHER WAY.....
SO IF YOUR ADVANCED BEYOND 4* DEGREES ? car got faster...
GET A SMALLER CAM!
RETARDED BEYOND -4* DEGREES ? car got faster...
STEP UP! YOUR CAMSHAFT SPECIFICATIONS.
ADVANCED OR RETARDED 6-8* DEGREES AND RAN FASTER?
YOU OR YOUR ENGINE BUILDER ARE REALLY- "RETARDED" !
YOU GUYS ARE BARKING AT THE WRONG TREE!
GO BACK AND RE-LEARN THE BASICS.....lol good luck!
TRACK TIPS:
EVEN WHEN MY RACECAR IS OPTIMIZED ON EVERY ASPECT,
YOU SHOULD KEEP TRYING DIFFERENT THINGS ALWAYS!
THIS GIVES YOU THE EDGE, SPECIALLY WHEN THEY DO NOT TEST.....
BUT TEST ONLY "ONE THING" AT A TIME TO EVALUATE THE CHANGES INDIVIDUALLY ON ITS OWN MERITS!
AS FOR "CAM TIMING" CHANGES AT THE TRACK?
MANY TIMES WHEN THE TRACK HAS "EXCELLENT" TRACTION OR HOOK-UP. WE WILL TRY TO ADVANCE THE CAMSHAFT TO GAIN "TORQUE" OFF THE LINE! (faster lap times)
THE REVERSE IS TRUE WHEN THE TRACK IS MARGINAL OR SLIPPERY WE WILL RETARD TO KILL THE BOTTOM END TORQUE TO ENHANCE TRACTION!
WHEN YOUR CAM SELECTION IS OPTIMUM OR OPTIMIZED TO YOUR COMBINATION, TRY TO ALWAYS CHANGE YOUR CAM TIMING. THIS TO ADVANCE OR RETARD AS FOR THE REASONS
DESCRIBE ABOVE.
=========================================
MANY RACERS THAT GO TO THE TRACK ALSO "NOTICED" THAT THE BEST CAMSHAFTS WILL USUALLY PERFORM OR RUN BETTER @ 2* ADVANCED!
THIS IS BECAUSE OF "CHAIN/BELT DEFLECTION" OR "STRETCH" THAT WILL RESULT IN THE CAM RETARDING AT HIGH RPMs!
=========================================
BEN ALAMEDA @ PARA, FB, BENALAMEDARACING.COM
(in memory of Chuck Stevens: Mentor & Friend )
BASIC RULE FOR CAM TIMING ARE:
"ADVANCING" THE CAM IMPROVES LOW END TORQUE AND RESPONSE AT THE EXPENSE OF HIGH RPMs.
"RETARDING" THE CAM IMPROVES TOP-END AT THE EXPENSE OF LOW SPEED RESPONSE.
THE HIGHER THE COMPRESSION RATIO THE WIDER THE LOBE CENTERLINE ANGLES. THE LOWER THE COMPRESSION RATIO THE MORE OVERLAP OR A NARROWER LOBE CENTERLINE.
*******************************************************
THE CAM TIMING WHEN CHECKED AND SET AT THE DESIRED POSITION SHOULD" ALWAYS" TAKE INTO CONSIDERATION "CHAIN STRETCH OR TIMING BELT DEFLECTION" THUS, ALTERING OR RETARDING THE CAMSHAFT AT HIGH RPMs!
MANY OVERLOOK THIS !
(this scenario has me advancing my cam timing 2* advance to anticipate belt/chain stretch retarding the cam phasing, the more evident when heavy spring pressures are used for high lifts!)
*******************************************************
WHEN WE ARE DEGREEING A CAMSHAFT AT "ZERO" WHAT ARE WE ACCOMPLISHING AS IT RELATES TO THE ENGINES PERFORMANCE? BE IT WITH A STOCK CAMSHAFT OR AN ALL OUT GRIND WITH A SPLIT DURATION! SO HERE WE START AND TRY TO SIMPLIFY AND EXPLAIN THE NET EFFECT....
FACTORY CAMSHAFTS FOR MOST ENGINES ARE WHAT THEY CALL "SPLIT OVERLAP DESIGN". THIS MEANS BOTH VALVES INTAKE AND EXHAUST, ARE OPEN AN EQUAL DISTANCE AT TDC "OVERLAP".
THIS IS ALSO CALLED A SINGLE PATTERN CAMSHAFT. THIS IS MOST LIKELY THE STOCK TYPE AND WE START WITH THIS TO KEEP OUR PERSPECTIVE IN CHECK SO AS TO HAVE CONTINUITY FOR THE NOVICE ENGINE AFFICIONADOS.
DEGREEING A CAM SPECIALLY WHEN YOU COMPETE IN CLASSES THAT REQUIRE A "FACTORY STOCK" ENGINE WILL YIELD DIVIDENDS! THE FACTORY CAMSHAFT WAS OPTIMIZED AT THE ZERO TIMING POSITION, THIS ALLOWS THE ENGINE TO RUN AT ITS DESIGNED CONFIGURATION...HOWEVER ANY KIND OF MODIFICATIONS ON THE INTAKE AND EXHAUST USUALLY MAY RENDER THIS LESS THAN OPTIMUM.
FOR EXAMPLE: IF YOUR FACTORY CAR/MOTORCYCLE IS INVOLVE IN A TOP END/TOP SPEED ONLY CONTEST?
THE CAM TIMING SHOULD BE RETARDED AT LEAST 2-4* FROM FACTORY. THIS IN EFFECT WILL PLACE YOUR RPMs A LITTLE HIGHER FROM PEAKING OR RUNNING OUT OF STEAM!
THE REASON BEING A RETARDED CAMSHAFT WILL LET THE INTAKE VALVE STAY OPEN LONGER, TO GIVE THE COLUMN OF "INERTIA RAM" OF AIR/ FUEL TO CONTINUE FILLING THE CYLINDERS PAST BDC PISTON POSITION. IN SHORT THE LATER CLOSING OF THE INTAKE VALVE BENEFITS THE HIGHER THE RPMs! ALL THIS GAINS WILL BE AT THE PENALTY OF LOW SPEED RESPONSE FROM THE REDUCTION OF DYNAMIC CYLINDER PRESSURES!
----------------------------------------------------------------------------------
DYNAMIC COMPRESSION" IS THE ACTUAL COMPRESSION RATIO THE ENGINE SEES AFTER THE INTAKE VALVE CLOSES ON THE INTAKE STROKE! THE INTAKE VALVE USUALLY CLOSES PAST BDC PISTON POSITION AND WHEN IT FINALLY CLOSES THE COMPRESSION IS ACTUALLY LOWER THAN THE COMPUTED MECHANICAL COMPRESSION RATIO!
----------------------------------------------------------------------------------
SO WHAT SITUATIONS DO YOU" ADVANCE" THE STOCK CAMSHAFT?
WHEN YOU HAVE A RACE AT A HIGH ELEVATIONS LIKE" PIKES PEAK" IN COLORADO OR A SLALOM EVENT AT " BAGUIO" IN THE PHILIPPINES! THIS HIGH ELEVATIONS HAVE A LESS DENSER ATMOSPHERE OR WEIGHT. THIS SITUATION RENDERS THE CAR WITH A LOT LESS AIR TO INGEST IN THE CYLINDERS. THAT IS WHY WHEN YOU ARE AT THIS PLACES, THE ENGINE JUST DOES NOT HAVE THE SAME POWER AS IT HAS ON SEA LEVEL OR LOWER ELEVATION RACETRACKS....IT JUST PLAIN HAVE LESS POWER HERE!
ADVANCING YOUR CAMSHAFT AGAIN 2-4* OR MORE WILL HELP YOU REGAIN SOME OF THIS DYNAMIC PRESSURES LOST DUE TO ELEVATION. YOU ARE FOOLING THIS ENGINE INTO THINKING, WITH CAM TIMING, THAT IT GAINED SOME COMPRESSION AT THIS ALTITUDE. AS THE EARLIER CLOSING OF THE INTAKE VALVES RESULTS IN A HIGHER DYNAMIC COMPRESSION RATIO!
SUCCESSFUL PIKES PEAK RACERS USUALLY HAVE A HIGHER THAN NORMAL COMPRESSION RATIOS AND OR ADVANCED CAM TIMING IN ANTICIPATING THE EVER INCREASING ALTITUDE THAT THEY HAVE TO CLIMB TO THE FINISH LINE....
SO WORD ON ADVICE TO THE BAGUIO RACERS.....ADVANCE YOUR CAMSHAFTS!!!
----------------------------------------------------------------------------------
SO NOW WE ARE AT THE HIGH PERFORMANCE CAMSHAFTS.....
MOST PEOPLE INCLUDING MYSELF, HAS "OVER CAMMED" AT ONE TIME OR ANOTHER!
SOME JUST DO IT ALL THE TIME!
SO I WILL SHED SOME LIGHT INTO SOME TIPS ON HOW TO KNOW IF YOU ARE OVER THE TOP...
WHEN BUYING YOUR FIRST CAMSHAFT AND GETTING IT INSTALLED AND DEGREED. MAKE SURE YOU DID NOT MISS TO CHECK THE CRANKING COMPRESSION PRESSURES ON YOUR ENGINE WITH THE STOCK CAMSHAFT!
THE REASON I STRESS THIS IS BECAUSE WHEN YOU HAVE THE STOCK CAM IN PLACE, DON'T FORGET TO DO A COMPRESSION CHECK.
EXAMPLE= 185# PSIG OF PRESSURE
TAKE NOTE OF THIS AND AVERAGE ALL YOUR READINGS....
NEXT AFTER INSTALLING YOUR NEW CAM AND DEGREED OR JUST LINED UP TO FACTORY MARKS.
DO ANOTHER COMPRESSION CHECK AND TAKE NOTE OF THE NEW READINGS......
DID THE COMPRESSION NUMBERS DROP FROM 185# TO NOW 130-145# ???
THIS DROP IN COMPRESSION PRESSURES IS "NORMAL" AND INDICATES TO ME THAT YOUR ENGINE WILL LOSE SIGNIFICANT LOW-MID RANGE RESPONSE OR TORQUE!
THIS IS DUE TO THE DURATION OF THIS CAMSHAFT THAT EXTENDS THE VALVE EVENTS.
THE INTAKE VALVE CLOSING LATE, THIS DROPS YOUR DYNAMIC COMPRESSION.
THAT IS LIKE GETTING A LOWER COMPRESSION ENGINE IN THE PROCESS! THIS IS THE REASON "BIG" CAMS HAVE SOFTER RESPONSE AT LOWER RPMs!
IF THE CAM IS MILDER? THE COMPRESSION TEST WILL NORMALLY SEE A LOT LESS DROP IN COMPRESSION PRESSURES, IF IT IS 10-20# LESS? IT PROBABLY WILL NOT LOOSE LOW-MID RANGE PULLING POWER....
SO WHAT DO YOU DO WHEN THE PRESSURES ARE LIKE THE FIRST EXAMPLE OF ONLY 130-145# ???
RUN THE CAR AT THE TRACK AND DO "CONSISTENT" BACK TO BACK PASSES TO HAVE CONSISTENT DATA AND RESULTS.....
NOW ADVANCED THE CAMSHAFT 2-4* AND DO A COMPRESSION PRESSURE CHECK.....ADVANCING INCREASED PRESS. TO 175???
THIS INCREASED IN COMPRESSION PRESSURES WILL INCREASE RESPONSE AND IF RUN AT THE TRACK WILL PROBABLY GO FASTER DUE TO A MORE RESPONSIVE AND TORQUEY ENGINE!!!
AND IF IT DID RUN FASTER??? THE CAM IS PROVING TO BE TOO BIG!!! "ADVANCING THE CAM" WILL MAKE IT ACT LIKE A MILDER/SMALLER CAMSHAFT....
BUT WHAT IF YOU HAVE A LOT OF CRANKING PRESSURES EVEN AFTER A CAM CHANGE?
ADVANCING THE CAM PROBABLY WILL BOOST THE LOW-MID RESPONSE AT THE COST OF HIGH RPMs!
THIS SIGNIFIES THAT THE ENGINE ALSO HAS AMPLE COMPRESSION RATIO AND THE CAM IS PROBABLY JUST RIGHT FOR THE COMBINATION HERE....
AND IF THIS IS CAM IS" RETARDED" AND GAINS SPEED AT THE TRACK? THIS TELLS YOU IT IS PROBABLY OR LIKELY TO BE ON THE SMALL SIDE!!!
THE PERFECT SCENARIO IS WHEN YOU HAVE THE CAM INSTALLED AS PER CAMSHAFT MANUFACTURERS SPECS @ STRAIGHT UP OR AT "ZERO".
ADVANCING AND OR RETARDING THIS CAMSHAFT YIELDED LESS OR NO CHANGE IN SPEED OR LAP TIMES ???
YOU PROBABLY HIT THE MARK VERY WELL!
THIS TELLS YOU YOUR RIGHT ON THE MONEY ON YOUR CAM PROFILE AT THIS POINT....NEITHER TOO BIG OR SMALL!
SO TO WRAP THIS UP!
DO NOT BE AFRAID TO EXPERIMENT OR TEST BEYOND THE FACTORY SETTING AS LONG AS YOU CHECKED VALVE TO PISTON CLEARANCE FROM +8* TO -8* DEGREES EITHER WAY.....
SO IF YOUR ADVANCED BEYOND 4* DEGREES ? car got faster...
GET A SMALLER CAM!
RETARDED BEYOND -4* DEGREES ? car got faster...
STEP UP! YOUR CAMSHAFT SPECIFICATIONS.
ADVANCED OR RETARDED 6-8* DEGREES AND RAN FASTER?
YOU OR YOUR ENGINE BUILDER ARE REALLY- "RETARDED" !
YOU GUYS ARE BARKING AT THE WRONG TREE!
GO BACK AND RE-LEARN THE BASICS.....lol good luck!
TRACK TIPS:
EVEN WHEN MY RACECAR IS OPTIMIZED ON EVERY ASPECT,
YOU SHOULD KEEP TRYING DIFFERENT THINGS ALWAYS!
THIS GIVES YOU THE EDGE, SPECIALLY WHEN THEY DO NOT TEST.....
BUT TEST ONLY "ONE THING" AT A TIME TO EVALUATE THE CHANGES INDIVIDUALLY ON ITS OWN MERITS!
AS FOR "CAM TIMING" CHANGES AT THE TRACK?
MANY TIMES WHEN THE TRACK HAS "EXCELLENT" TRACTION OR HOOK-UP. WE WILL TRY TO ADVANCE THE CAMSHAFT TO GAIN "TORQUE" OFF THE LINE! (faster lap times)
THE REVERSE IS TRUE WHEN THE TRACK IS MARGINAL OR SLIPPERY WE WILL RETARD TO KILL THE BOTTOM END TORQUE TO ENHANCE TRACTION!
WHEN YOUR CAM SELECTION IS OPTIMUM OR OPTIMIZED TO YOUR COMBINATION, TRY TO ALWAYS CHANGE YOUR CAM TIMING. THIS TO ADVANCE OR RETARD AS FOR THE REASONS
DESCRIBE ABOVE.
=========================================
MANY RACERS THAT GO TO THE TRACK ALSO "NOTICED" THAT THE BEST CAMSHAFTS WILL USUALLY PERFORM OR RUN BETTER @ 2* ADVANCED!
THIS IS BECAUSE OF "CHAIN/BELT DEFLECTION" OR "STRETCH" THAT WILL RESULT IN THE CAM RETARDING AT HIGH RPMs!
=========================================
BEN ALAMEDA @ PARA, FB, BENALAMEDARACING.COM
(in memory of Chuck Stevens: Mentor & Friend )
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