NEW 4 LITRE CYLINDER HEAD PROJECT ON A SHOESTRING
BELOW IS A COPY OF THE ORIGINAL CROSS SECTION THROUGH THE PROPOSED 4 LITRE HEAD DRAWN BY ONE OF RICARDO`S DESIGNERS AND DATED 30th JANUARY 1930. BENTLEY CHIEF DESIGNER BARRINGTON MADE MINOR CHANGES TO THE VALVE GEAR BUT CLOSELY FOLLOWED RICARDO`S PROPOSALS WHEN DETAIL DESIGNING THE PRODUCTION HEADS.
THERE WERE IN TOTAL THREE CYLINDER HEADS PRODUCED FOR THE 4 LITRE ENGINE BEFORE PRODUCTION CEASED IN 1931.
ABOVE IS SHOWN THE ORIGINAL BENTLEY DRAWING BM 7583 WHICH IS THE HEAD THAT WENT INTO SERVICE WITH THE FIRST BATCH OF 4 LITRE ENGINES
ABOVE IS SHOWN THE LATER TYPE OF CYLINDER HEAD BM 7761. THE HEADS WERE NOT INTERCHANGEABLE BETWEEN ENGINES UNLESS THE COMPATIBLE BLOCK WAS USED. THE ONLY DIFFERENCE BETWEEN THE HEADS WAS THE CONFIGURATION OF THE COOLING WATER PASSAGES.BETWEEN BLOCK AND HEAD AND MORE HEAD HOLDING DOWN STUDS IN THE INLET TRACT THAT ADJOINED THE MANIFOLD.
SHOWN ABOVE IS HEAD BM 9270 WHICH WAS A VARIANT BASED ON BM 7761 THE ONLY DIFFERENCE BEING THAT BM 9270 HAD IMPROVED INLET GAS FLOW BUT THIS HEAD WAS PROBABLY JUST AN EXPERIMENTAL ONE AND WAS NEVER FITTED TO A PRODUCTION ENGINE.
UNFORTUNATELY THESE DRAWINGS HAVE NOT ADAPTED TO THE WEBSITE FORMAT COMPLETELY AND CANNOT BE ENLARGED. I WILL TRY TO FIND OUT WHAT CAN BE DONE ABOUT THIS. I`VE FOUND OUT THAT DOCUMENTS UPLOADED INTO WEEBLY WEBSITES ARE HOSTED BY SCRIBD.COM. IF YOU LOOK AT THE DRAWINGS ABOVE THEY CAN BE ENLARGED BY CLICKING ON THE PLUS AND MINUS IKONS OR BE EXPANDED TO FULL PAGE SIZE. UNFORTUNATELY THERE`S UNWANTED ADVERTISING THAT APPEARS ON SCREEN.
UNFORTUNATELY THESE DRAWINGS HAVE NOT ADAPTED TO THE WEBSITE FORMAT COMPLETELY AND CANNOT BE ENLARGED. I WILL TRY TO FIND OUT WHAT CAN BE DONE ABOUT THIS. I`VE FOUND OUT THAT DOCUMENTS UPLOADED INTO WEEBLY WEBSITES ARE HOSTED BY SCRIBD.COM. IF YOU LOOK AT THE DRAWINGS ABOVE THEY CAN BE ENLARGED BY CLICKING ON THE PLUS AND MINUS IKONS OR BE EXPANDED TO FULL PAGE SIZE. UNFORTUNATELY THERE`S UNWANTED ADVERTISING THAT APPEARS ON SCREEN.
IF YOU HAVE READ MY ARTICLES PUBLISHED IN THE BDC REVIEW YOU WILL BE AWARE THAT I MADE COMMENTS THAT THE 4 LITRE HEAD DESIGN BY RICARDO WAS LIMITED IN IT`S POSSIBILITIES FOR UPRATING THE PERFORMANCE OF THE ENGINE. AND THAT A NEW HEAD WOULD HAVE TO BE PRODUCED TO DO THIS.
OF COURSE I HAD THE ADVANTAGE OF HINDSIGHT IN MAKING THESE COMMENTS AS THE LATER MK6 ENGINES USING THE MODIFIED 4 LITRE RICARDO HEAD WERE ABLE TO PUSH OUT MUCH HIGHER OUTPUTS THAN THE 4 BENTLEY MOTORSLITRE EVER DID.
OF COURSE I HAD THE ADVANTAGE OF HINDSIGHT IN MAKING THESE COMMENTS AS THE LATER MK6 ENGINES USING THE MODIFIED 4 LITRE RICARDO HEAD WERE ABLE TO PUSH OUT MUCH HIGHER OUTPUTS THAN THE 4 BENTLEY MOTORSLITRE EVER DID.
FROM THE FIRST THERE HAS BEEN A CONTINUING NAGGING DOUBT IN MY MIND ABOUT THE ACTUAL POWER OUTPUT OF THE 4 LITRE ENGINE WHICH WAS OFFICIALLY STATED AS 120 HP @ 4000 RPM. THE PERFORMANCE FIGURES FOR THE 4 LITRE ENGINE THAT BENTLEY MOTORS SENT TO RICARDO FOR TESTING DID NOT STEP UP TO THIS MARK, AND RECENT FIGURES OBTAINED FOR BERT DEGENAAR`S 4 LITRE BLOWN ENGINE DID NOT EITHER!
FOR THOSE OF YOU THAT ARE WONDERING WHY I`M SUSPICIOUS ABOUT THE VERITY OF THE BENTLEY MOTORS STATED POWER OUTPUT OF THE 4 LITRE ENGINE, YOU MIGHT LIKE TO TAKE A LOOK AT MY ARTICLE "THE CONSPIRACY TO KILL OFF BENTLEY MOTORS" AT THE TIME OF THE PROPOSED SALE OF BENTLEY MOTORS TO ROLLS ROYCE, THE 4 LITRE ENGINE AND CHASSIS WERE BEING MADE READY FOR PRODUCTION. ROYCE WAS VERY INTERESTED IN BUYING BENTLEY MOTORS IN ORDER TO NEUTRALISE THE BENTLEY THREAT TO ROLLS ROYCE AND HAD RECEIVED INFORMATION FROM DIFFERENT SOURCES SUCH AS RICARDO AS TO THE PERFORMANCE OF THE 4 LITRE ENGINE. THIS WAS A VERY TENSE TIME FOR EVERYBODY AT BENTLEY MOTORS AND SOMEBODY SAW AN OPPORTUNITY TO CREATE MISINFORMATION ABOUT THE STATE OF PLAY OF THE 4 LITRE, THIS IS PROBABLY WHERE THE 120 HP FIGURE EMERGED.
i HAVE THE 4 LITRE ENGINE RECONDITIONED BY CHRIS WILLIAMS MOUNTED IN MY BITSA AT THE MOMENT BUT THIS ENGINE HAS NOT RUN YET AND WHEN THE CAR IS IMPORTED INTO NORWAY THAT WILL BE THE TIME TO GET PERFORMANCE FIGURES FOR IT, BUT THIS IS MONTHS AWAY!
GATHERING THE DESIGN INFORMATION
THOSE OF YOU THAT HAVE NOT BEEN INVOLVED IN DESIGN WORK WILL NOT BE AWARE OF HOW A PROJECT IS STARTED. LOGICALLY ALL VEHICLE MANUFACTURERS HAVE TO KEEP ABREAST OF ALL THE LATEST DEVELOPMENTS IN ENGINE DESIGN IF THEY ARE TO REMAIN COMPETITIVE. A SIMPLE WAY OF DOING THIS IS TO HIRE THE LATEST MODEL OF THE CARS THAT THEY ARE INTERESTED IN AND SIMPLY REMOVE THE CYLINDER HEADS, GET THEM SKETCHED UP AND MEASURED ON ONE OF THOSE MACHINES THAT ELECTRONICALLY SURVEYS COMPONENTS AND THE JOB IS DONE. THIS GOES FOR ANY PART OF THE CAR THAT IS OF INTEREST. THEN THE CAR IS RE ASSEMBLED AND NOBODY IS THE WISER!
AFTER ALL THE DATA HAS BEEN GATHERED, THEN THE HEAD WILL BE DESIGNED AND TESTED.
IT`S THE SAME FOR THIS PROJECT, I SPENT SEVERAL YEARS TALKING TO PEOPLE AND TRYING TO FIND THE APPROPRIATE DRAWINGS AT THE ROLLS ROYCE OWNERS CLUB SITUATED IN A MANSION IN THE SMALL VILLAGE OF PAULERSPURY IN NORTHAMPTONSHIRE. THIS WAS NOT EASY AS ALL THE THOUSANDS OF DRAWINGS WERE STORED IN PLAN CHESTS CONTAINED IN SEVERAL LARGE ROOMS IN THE ATTIC. THE KEY TO FINDING THE DRAWING THAT ONE REQUIRED WAS TO FIND IT`S DEDICATED NUMBER. THIS COULD BE FOUND IN BOOKS CONTAINED IN THE LIBRARY. ARMED WITH THE DRAWING NUMBER, THE APPROPRIATE PLAN CHEST HAD TO BE LOCATED AND SEARCHED THROUGH. THERE`S A CORRECT WAY TO TAKE OUT AND REPLACE DRAWINGS BUT THE PEOPLE THAT HAD BEEN SEARCHING THROUGH THESE CHESTS HAD NOT BEEN AWARE OF THIS AND THE RESULT WAS THAT DRAWINGS HAD BEEN DAMAGED AND MISFILED. i SPENT SOME TIME TRYING TO FILE THE MISFILED DRAWINGS THAT I`D FOUND, BACK IN THE CORRECT ORDER, IT HELPS OTHERS!
THE FIRST TIME I WAS THERE I FOUND THE EARLY MK6 CYLINDER HEAD DRAWING AND WAS ABLE TO TAKE AN A4 COPY OF THE SECTION THROUGH THE COMBUSTION CHAMBER IN ORDER TO COMPARE IT WITH THE 4 LITRE COMBUSTION CHAMBER. I ALSO FOUND THE CAMSHAFT DRAWING, BUT ON MY SECOND VISIT I WAS UNABLE TO LOCATE THESE DRAWINGS.
ANOTHER TIME WHEN I PHONED PAULERSPURY TO ORDER THE DRAWINGS THAT I NEEDED THE LADY THAT ANSWERED THE PHONE TOLD ME THAT I WOULD HAVE TO JOIN THE CLUB IN ORDER TO DO THIS. WHEN I BUMPED INTO PHILLIP HALL AT THIS YEARS BEAULIEU SPRING AUTOJUMBLE, I TOLD HIM THIS AND HE REPLIED THAT THIS WAS NOT CORRECT AND THAT NON MEMBERS ARE ABLE TO PURCHASE COPIES OF DRAWINGS!
THIS IS JUST AN EXAMPLE OF THE KIND OF PROBLEM THAT ONE ENCOUNTERS WHEN SEARCHING FOR INFORMATION.
I WILL TRY TO OBTAIN THESE DRAWINGS AGAIN, AND WHEN I DO, I WILL THEN SQUEEZE OR EXPAND THE DRAWING TO FIT ON THE 4 LITRE BLOCK. IF i CAN BORROW A HEAD THEN IT IS MORE EASY TO VISUALISE THE SQUEEZING AND EXPANDING PROCESS AND ALSO BE ABLE TO MEASURE THE COMBUSTION CHAMBER EXACTLY AND FIND ITS VOLUME IF ANYBODY CAN HELP WITH THE DRAWINGS OR OTHER INFORMATION, THEN PLEASE CONTACT ME, YOU WILL BE HELPING THE PROJECT ALONG. AS I REALLY WANT TO FINISH IT BEFORE I FALL OFF MY PERCH!
IT`S NOT AS EASY AS IT SOUNDS AND ANOTHER PROBLEM IS THAT THIS PROJECT IS NOT COMMERCIALLY VIABLE SO THAT THE INITIAL COSTS OF MANUFACTURE WILL NOT BE RECOUPED! ALSO THE NEW HEAD MAY NOT GIVE THE IMPROVEMENTS IN PERFORMANCE AS EXPECTED.
AFTER ALL THE DATA HAS BEEN GATHERED, THEN THE HEAD WILL BE DESIGNED AND TESTED.
IT`S THE SAME FOR THIS PROJECT, I SPENT SEVERAL YEARS TALKING TO PEOPLE AND TRYING TO FIND THE APPROPRIATE DRAWINGS AT THE ROLLS ROYCE OWNERS CLUB SITUATED IN A MANSION IN THE SMALL VILLAGE OF PAULERSPURY IN NORTHAMPTONSHIRE. THIS WAS NOT EASY AS ALL THE THOUSANDS OF DRAWINGS WERE STORED IN PLAN CHESTS CONTAINED IN SEVERAL LARGE ROOMS IN THE ATTIC. THE KEY TO FINDING THE DRAWING THAT ONE REQUIRED WAS TO FIND IT`S DEDICATED NUMBER. THIS COULD BE FOUND IN BOOKS CONTAINED IN THE LIBRARY. ARMED WITH THE DRAWING NUMBER, THE APPROPRIATE PLAN CHEST HAD TO BE LOCATED AND SEARCHED THROUGH. THERE`S A CORRECT WAY TO TAKE OUT AND REPLACE DRAWINGS BUT THE PEOPLE THAT HAD BEEN SEARCHING THROUGH THESE CHESTS HAD NOT BEEN AWARE OF THIS AND THE RESULT WAS THAT DRAWINGS HAD BEEN DAMAGED AND MISFILED. i SPENT SOME TIME TRYING TO FILE THE MISFILED DRAWINGS THAT I`D FOUND, BACK IN THE CORRECT ORDER, IT HELPS OTHERS!
THE FIRST TIME I WAS THERE I FOUND THE EARLY MK6 CYLINDER HEAD DRAWING AND WAS ABLE TO TAKE AN A4 COPY OF THE SECTION THROUGH THE COMBUSTION CHAMBER IN ORDER TO COMPARE IT WITH THE 4 LITRE COMBUSTION CHAMBER. I ALSO FOUND THE CAMSHAFT DRAWING, BUT ON MY SECOND VISIT I WAS UNABLE TO LOCATE THESE DRAWINGS.
ANOTHER TIME WHEN I PHONED PAULERSPURY TO ORDER THE DRAWINGS THAT I NEEDED THE LADY THAT ANSWERED THE PHONE TOLD ME THAT I WOULD HAVE TO JOIN THE CLUB IN ORDER TO DO THIS. WHEN I BUMPED INTO PHILLIP HALL AT THIS YEARS BEAULIEU SPRING AUTOJUMBLE, I TOLD HIM THIS AND HE REPLIED THAT THIS WAS NOT CORRECT AND THAT NON MEMBERS ARE ABLE TO PURCHASE COPIES OF DRAWINGS!
THIS IS JUST AN EXAMPLE OF THE KIND OF PROBLEM THAT ONE ENCOUNTERS WHEN SEARCHING FOR INFORMATION.
I WILL TRY TO OBTAIN THESE DRAWINGS AGAIN, AND WHEN I DO, I WILL THEN SQUEEZE OR EXPAND THE DRAWING TO FIT ON THE 4 LITRE BLOCK. IF i CAN BORROW A HEAD THEN IT IS MORE EASY TO VISUALISE THE SQUEEZING AND EXPANDING PROCESS AND ALSO BE ABLE TO MEASURE THE COMBUSTION CHAMBER EXACTLY AND FIND ITS VOLUME IF ANYBODY CAN HELP WITH THE DRAWINGS OR OTHER INFORMATION, THEN PLEASE CONTACT ME, YOU WILL BE HELPING THE PROJECT ALONG. AS I REALLY WANT TO FINISH IT BEFORE I FALL OFF MY PERCH!
IT`S NOT AS EASY AS IT SOUNDS AND ANOTHER PROBLEM IS THAT THIS PROJECT IS NOT COMMERCIALLY VIABLE SO THAT THE INITIAL COSTS OF MANUFACTURE WILL NOT BE RECOUPED! ALSO THE NEW HEAD MAY NOT GIVE THE IMPROVEMENTS IN PERFORMANCE AS EXPECTED.
THE RISK FACTOR SHOULD NOT BE IGNORED SO IT`S IMPORTANT TO GET THE BEST INFORMATION THAT CAN BE HAD SO AS TO MINIMISE THE RISK OF FAILURE. ALSO THE HEAD WILL NEED TO BE EXTENSIVELY TESTED ON A 4 LITRE ENGINE TO DETERMINE THE RELIABILITY OF ANY REDESIGNED COMPONENTS THAT HAVE BEEN CREATED. ALSO PERFORMANCE FIGURES WILL HAVE TO BE TAKEN.
LIABILITY IS ANOTHER HEADACHE! IF ONE SELLS A HEAD TO A THIRD PARTY AND THERE IS A CATASTROPHIC FAILURE OF ANY OF THE NEW COMPONENTS WHICH CAUSE DAMAGE TO THE ENGINE. THEN THERE IS THE QUESTION OF REPARATION OR THE MAKING GOOD OF THE DAMAGE WHICH MAY LEAD TO FINANCIAL COMPENSATION BEING MADE! THIS VERY UNWELCOME SITUATION COULD CAUSE YOU TROUBLE AT THE BANK.
THERE YOU ARE, A SHOESTRING PROJECT CAN CAUSE SERIOUS FINANCIAL LOSS, ON THE OTHER HAND AN EXTRA 50 HP AT THE CRANKSHAFT CAN GIVE THAT WARM FEELING THAT WE ALL LIKE TO HAVE.
LIABILITY IS ANOTHER HEADACHE! IF ONE SELLS A HEAD TO A THIRD PARTY AND THERE IS A CATASTROPHIC FAILURE OF ANY OF THE NEW COMPONENTS WHICH CAUSE DAMAGE TO THE ENGINE. THEN THERE IS THE QUESTION OF REPARATION OR THE MAKING GOOD OF THE DAMAGE WHICH MAY LEAD TO FINANCIAL COMPENSATION BEING MADE! THIS VERY UNWELCOME SITUATION COULD CAUSE YOU TROUBLE AT THE BANK.
THERE YOU ARE, A SHOESTRING PROJECT CAN CAUSE SERIOUS FINANCIAL LOSS, ON THE OTHER HAND AN EXTRA 50 HP AT THE CRANKSHAFT CAN GIVE THAT WARM FEELING THAT WE ALL LIKE TO HAVE.
THE DESIGN PHASE AND UNRAVELING THAT SHOESTRING
FOR ME THE DESIGN PHASE IS THE MOST INTERESTING AND THE MOST CHALLENGING. THIS IS WHERE COST SAVING HAS TO BE SERIOUSLY CONSIDERED AS THE DETAIL DESIGN OF THE HEAD WILL INEVITABLY SHAPE THE AMOUNT TO BE SPENT ON THE MANUFACTURING COSTS.
THE CYLINDER HEAD IS ONE OF THE MOST COMPLICATED COMPONENTS ON THE ENGINE. IT HAS ODDLY SHAPED COOLING WATER PASSAGES THAT RUN AROUND THE HOLES THROUGH THE HEAD AND REQUIRE MINIMUM LANDS TO SEAT THE HEAD GASKET TO AVOID LEAKAGE OF THE COOLING FLUID
APART FROM ADAPTING THE DESIGN OF THE MK6 CYLINDER HEAD TO THE 4 LITRE BLOCK I WILL BE LOOKING TO REMANUFACTURE THE ROCKERS FROM HIGH TENSILE ALUMINIUM TOGETHER WITH LIGHTWEIGHT PUSHRODS AS THE HEAVY VALVE GEAR IS ONE OF THE PROBLEMS WITH THE 4 LITRE. THEN THE HEAD CASTING HAS TO BE DESIGNED SO THAT IT CAN BE MACHINED TO FIT BOTH THE THE EARLY AND LATE TYPE BLOCKS.
ANOTHER CONSIDERATION IS THE CYLINDER HEAD GASKET, THIS WILL HAVE TO BE MADE, BUT THERE IS ONLY ONE PERSON IN THE UK THAT MAKES THESE COPPER ASBESTOS, OR THEIR MODERN EQUIVALENT, AND HE ONLY WORKS FROM AN ORIGINAL GASKET NOT FROM DRAWINGS. IDEALLY, I NEED TO HAVE THE STEEL GASKETS THAT THE LATER MK6 ENGINE USED AND WILL HAVE TO LOOK INTO FINDING A POSSIBLE SUPPLIER THAT WILL PRODUCE THEM AT A REASONABLE PRICE.
ANOTHER CONSIDERATION IS THE CYLINDER HEAD GASKET, THIS WILL HAVE TO BE MADE, BUT THERE IS ONLY ONE PERSON IN THE UK THAT MAKES THESE COPPER ASBESTOS, OR THEIR MODERN EQUIVALENT, AND HE ONLY WORKS FROM AN ORIGINAL GASKET NOT FROM DRAWINGS. IDEALLY, I NEED TO HAVE THE STEEL GASKETS THAT THE LATER MK6 ENGINE USED AND WILL HAVE TO LOOK INTO FINDING A POSSIBLE SUPPLIER THAT WILL PRODUCE THEM AT A REASONABLE PRICE.
COMPARISON OF THE 4 LITRE AND EARLY MK6 COMBUSTION CHAMBERS
ABOVE IS A CROSS SECTION OF THE RICARDO DESIGNED 4 LITRE COMBUSTION CHAMBER.
NOTE HOW CLOSE TO THE TOP OF THE PISTON THE INLET VALVE IS.
NOTE HOW CLOSE TO THE TOP OF THE PISTON THE INLET VALVE IS.
ABOVE IS A CROSS SECTION OF THE EARLY MK6 COMBUSTION CHAMBER. ROLLS ROYCE MODIFIED THE RICARDO HIGH POWER HEAD TO GIVE CLEARANCE BETWEEN THE VALVE AND THE PISTON AND ALTERED THE THROAT AREA WHICH GAVE THE TURBULENT FLOW TO THE EXHAUST VALVE PORTION OF THE CHAMBER.
DESPITE THESE MODIFICATIONS, THE EARLY MK6 ENGINES ONLY GAVE A SLIGHT INCREASE IN POWER OVER THE 4 LITRE ENGINE FROM 1931!
DESPITE THESE MODIFICATIONS, THE EARLY MK6 ENGINES ONLY GAVE A SLIGHT INCREASE IN POWER OVER THE 4 LITRE ENGINE FROM 1931!
ALSO TO BE CONSIDERED IS THE DESIGN OF THE CAMSHAFT, ALTHOUGH NOT CYLINDER HEAD, THE 4 LITRE CAMSHAFT DID NOT COME UP TO EXPECTATIONS AND A REDESIGN OF THIS WOULD PROBABLY RESULT IN RELEASING MORE OF THOSE DESIRABLE HORSES FROM THE ENGINE.
I`VE HAD FILL OF CAMSHAFT DESIGNERS IN THE PAST! I COMMISSIONED ONE OF THEM TO REDESIGN THE 4 LITRE CAMSHAFT. AFTER GIVING HIM ALL THE INFORMATION HE NEEDED AND A £250 CASH UPFRONT PAYMENT AND WAITING TWO YEARS, THE RESULT WAS THAT HE HAD DONE NOTHING AT ALL! WHEN I REMONSTRATED WITH HIM ON THE PHONE, HIS ANSWER WAS THAT HE HAD MORE IMPORTANT CUSTOMERS TO WORK FOR THAT HAD PRIORITY! I HAVE A BIT OF A SHORT FUSE AND THE NEXT TIME THAT I WAS IN THE UK, DROVE TO LINCOLNSHIRE TO RETRIEVE THE STANDARD 4 LITRE CAMSHAFT THAT I`D LENT HIM. HE TURNED OUT TO BE SUFFERING FROM DEPRESSION AND DENIED SAYING WHAT HE DID TO ME.
I LATER ASKED A WELL KNOWN CAMSHAFT MANUFACTURER TO REDESIGN AND MANUFACTURE A NEW CAMSHAFT FOR ME. AFTER TWO YEARS, AND MANY PROMPTINGS, I AT LAST PICKED UP THE NEW CAMSHAFT AND IT`S STILL SITTING IN MY WORKSHOP AWAITING IT`S INSERTION INTO AN ENGINE.
CAMSHAFT DESIGN SEEMS TO BE ANOTHER OF THOSE "BLACK ARTS" THAT MYSTIFY MOST PEOPLE AND THE GURUS THAT DO THIS WORK SEEM TO TREAT THEIR CLIENTS AS MUSHROOMS. THAT IS, KEEP THEM IN THE DARK AND FEED THEM LOTS OF MANURE.
I`VE HAD FILL OF CAMSHAFT DESIGNERS IN THE PAST! I COMMISSIONED ONE OF THEM TO REDESIGN THE 4 LITRE CAMSHAFT. AFTER GIVING HIM ALL THE INFORMATION HE NEEDED AND A £250 CASH UPFRONT PAYMENT AND WAITING TWO YEARS, THE RESULT WAS THAT HE HAD DONE NOTHING AT ALL! WHEN I REMONSTRATED WITH HIM ON THE PHONE, HIS ANSWER WAS THAT HE HAD MORE IMPORTANT CUSTOMERS TO WORK FOR THAT HAD PRIORITY! I HAVE A BIT OF A SHORT FUSE AND THE NEXT TIME THAT I WAS IN THE UK, DROVE TO LINCOLNSHIRE TO RETRIEVE THE STANDARD 4 LITRE CAMSHAFT THAT I`D LENT HIM. HE TURNED OUT TO BE SUFFERING FROM DEPRESSION AND DENIED SAYING WHAT HE DID TO ME.
I LATER ASKED A WELL KNOWN CAMSHAFT MANUFACTURER TO REDESIGN AND MANUFACTURE A NEW CAMSHAFT FOR ME. AFTER TWO YEARS, AND MANY PROMPTINGS, I AT LAST PICKED UP THE NEW CAMSHAFT AND IT`S STILL SITTING IN MY WORKSHOP AWAITING IT`S INSERTION INTO AN ENGINE.
CAMSHAFT DESIGN SEEMS TO BE ANOTHER OF THOSE "BLACK ARTS" THAT MYSTIFY MOST PEOPLE AND THE GURUS THAT DO THIS WORK SEEM TO TREAT THEIR CLIENTS AS MUSHROOMS. THAT IS, KEEP THEM IN THE DARK AND FEED THEM LOTS OF MANURE.
THE PATTERN FOR THE HEAD CASTING
FOR THOSE UNFAMILIAR WITH THE PROCESS OF MAKING CASTINGS, THESE ARE PRODUCED BY POURING MOLTEN METAL INTO IMPRESSIONS MADE IN SAND. IT`S A SIMPLE CONCEPT THAT HAS BEEN USED FOR THOUSANDS OF YEARS TO PRODUCE BRONZE, IRON WEAPONS AND SILVER JEWELRY FOR EXAMPLE.
HOWEVER, FOR OUR HEAD, NOT ONLY IS THE OUTSIDE SHAPE TO BE CAST IN ALUMINIUM BUT ALSO THE WATER AND INLET PASSAGES WITHIN THE HEAD CASTING ITSELF! THAT`S THE REALLY TRICKY PART.
PATTERNS ARE NORMALLY MADE OF WOOD AND FOR THE HEAD IT`S A VERY COMPLEX PATTERN AS PROVISION FOR LOCATING THE "CORES" FOR THE INTERNAL PASSAGES HAVE TO BE MADE AS WELL AS PATTERNS FOR THE CORES THEMSELVES. IT SOUNDS COMPLICATED AND BY GUM IT IS!
ANOTHER TRICKY THING IS THAT THE PATTERN MAKER HAS TO MAKE THE PATTERN OVERSIZE USING SPECIAL MEASURING RULERS TO ALLOW FOR THE SHRINKAGE OF THE CASTING WHEN IT COOLS DOWN.
HOWEVER, FOR OUR HEAD, NOT ONLY IS THE OUTSIDE SHAPE TO BE CAST IN ALUMINIUM BUT ALSO THE WATER AND INLET PASSAGES WITHIN THE HEAD CASTING ITSELF! THAT`S THE REALLY TRICKY PART.
PATTERNS ARE NORMALLY MADE OF WOOD AND FOR THE HEAD IT`S A VERY COMPLEX PATTERN AS PROVISION FOR LOCATING THE "CORES" FOR THE INTERNAL PASSAGES HAVE TO BE MADE AS WELL AS PATTERNS FOR THE CORES THEMSELVES. IT SOUNDS COMPLICATED AND BY GUM IT IS!
ANOTHER TRICKY THING IS THAT THE PATTERN MAKER HAS TO MAKE THE PATTERN OVERSIZE USING SPECIAL MEASURING RULERS TO ALLOW FOR THE SHRINKAGE OF THE CASTING WHEN IT COOLS DOWN.
THERE HAVE BEEN MANY RECENT IMPROVEMENTS IN CASTING TECHNOLOGY, AND TO TAKE ADVANTAGE OF THESE, THE HEAD DRAWING WILL NEED TO BE CREATED USING A 3D COMPUTER PROGRAM AND THE PATTERN MADE ON A LARGE 3D PRINTER. THE PROBLEM HERE IS THAT THE PEOPLE WHO CREATE THE 3D DRAWINGS ARE VERY WELL PAID, SO THAT THE 3D DRAWING ITSELF IS VERY EXPENSIVE! ONCE CREATED THE DRAWING HAS TO BE CHECKED BY SOMEBODY EARNING EVEN MORE MONEY, IN ORDER TO AVOID MISTAKES.
THIS IS DEFINITELY NOT THE WAY TO GO FOR OUR SHOESTRING PROJECT, NOT ONLY THAT, THE OLDER PATTERNMAKERS THAT ARE SUITABLE FOR OUR PROJECT DON`T WORK THIS WAY AND CAN ONLY WORK TO 2D HARD COPY DRAWINGS.
SOME YEARS AGO I REMEMBER READING ABOUT A CAR COMPANY THAT USED TO MAKE PROTOTYPE CYLINDER HEADS BY MEANS OF TWO SEPARATE HORIZONTAL CASTINGS AND BONDING THEM TOGETHER.
THIS MEANS THAT CORES FOR THE INTERNAL PASSAGES WITHIN THE HEAD WILL NOT BE REQUIRED BUT MORE THOUGHT WILL BE REQUIRED TO FIND THE IDEAL "SPLIT POINT" FOR THE TWO HALVES IN THE DESIGN PHASE. THIS IS THE WAY THAT I WILL PROCEED WITH THE DESIGN AND NOW I WILL HAVE TO CONCENTRATE ON GETTING THE INFORMATION THAT I REQUIRE BEFORE THE PROJECT CAN GO ANY FURTHER.
THIS MEANS THAT CORES FOR THE INTERNAL PASSAGES WITHIN THE HEAD WILL NOT BE REQUIRED BUT MORE THOUGHT WILL BE REQUIRED TO FIND THE IDEAL "SPLIT POINT" FOR THE TWO HALVES IN THE DESIGN PHASE. THIS IS THE WAY THAT I WILL PROCEED WITH THE DESIGN AND NOW I WILL HAVE TO CONCENTRATE ON GETTING THE INFORMATION THAT I REQUIRE BEFORE THE PROJECT CAN GO ANY FURTHER.
TO BE CONTINUED