Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/125498
TECHNICAL GUIDE: THE BLACK KNIGHT • By Bob Ebeling surfaces. Since tbe alloys are ditferent in tbeir metallergical structure. tbey would not fuse or grab and tbus balf tbe problem was solved but slippage was still prevalent. Recently Micheals bas cbanged back to Barnett plates of special competition ne~cork facings and the elapsed times are growing sborter as tbe speeds go up. -Black KnigbtO is a name cbosen from an age long past. ,And to a new generation, tbe model year 1948 of Bob Micbeals' Harley-Davidson is ancien this tory. Despite repeated urging by friends and family to trade up for a newer model. Micbeals bas pursued the task of improving and perfecting wbat was once a 74 incb HarleyDavidson. Today tbe big macbine bas grown larger. into a displacement-- of 80 incbes. Its performance bas cbanged, too. It does elapsed times of 10.54 seconds witb a best speed of 134.00 mph in a quarter mile. Weight and Traction Custom Barrels Micbeals cast a wide searcb for someone capable of producing tbe cylinder be had in mind and finally found macbinest Tom Denton of Upland. Calif. Denton patiently listened to Bob's description and then picked up a piece of Cbrome Moly Billet, stock and turned to the lathe. Tbe end product is beautiful indeed and tbe results are tbose that Micbeals fotsaw. Originally tbe Harley stroker was accommodated by the addition of spacer plates under tbe 74° stock barrels. but the new 80 incbers were macbines to a longer overall size. eliminating the spacer plates. ,A small and also necessary change was the pusb rod lengtb. Tbis was easily done by building up the stock ones by welding and tben grinding back to original sbape. From the Bottom Up Obtaining optimum performance does not stop with those beautiful cylinders and yet none of tbis fantastic Harley seems radical. Tbe lower end is untouched except for a little polisbing and tbe unique oil system. Tbe transmission is a standard box with 1st and 4th gear removed. That empty space is used as an oil tank or reservoir. Tbis use has been thougbt of by many drag racers but cast aside as a bad idea due to the metal particles ground off tbe gears. Bob felt tbat tbe Harley box did not have the bearing or insert problems of others and seems to have proven his faith by applying bis idea and suffering none tbe worse for the effort. - Thl cylinders arl by DII ilon and carbs by Llnk.ts" Noll shift IIVII by Sial down posl. from tw~incb Pontiac automotive val ves. Tbe auto valve is flat so tulips were made by cutting tbe centers out of tbe Pontiacs and adding another stem and valve portion by welding. Machine and beat treat fol· lowed the weld and voila! .A perfect' valve. Tbe springs are standard HarleyDavidson products. but the collars were machined from tungsten. to achieve a little lightening for a few more R.P.M. Transmission & Clutch Power transmission is tbrough tbe second and tbird gear of tb e Harley box and bere is a place that verifies wbat some people call a, °lot of bairn on the part of tbe rider. Just as tbe rear tire grabs traction, Bob must shift from second to third by band! He release's the bandIe bars with one band while tbe otber engages tbe clutcb and reaches down to a lever for the change of gears! A bike tbat bas its torque pr~ duced by large Nitro menthane percentage is notorious for cl utcb slippage and inverse °grabbingO pr~ blems. In an effort to solve tbis Bob cut some aluminum plates to replace tbe neoprene and cork discs. The otber plates are steel and thus tbe °Black KnigbtO was running metal to metal Compression -More! More'o cried Micbeals, as though the 11.5 to 1 M.C. pistons did not produce enough. Head gaskets were removed and on tbe first time out a strange swoosbing noise came fro m tbe bead-t~cylinder joints. There was no secret as to the source and a step was made to keep the expanding air and gasses wbere tbey belonged. A Vee grove was cut into the cylinder surface and copper wire has been inserted to form ·0· rings that flatten and seal the joint for a complete compression seal. Traction is elusive witb all drag racers. Tbe narrow 4 incb ,Avon slicks are tbe only motorcycle tire available. Bob again brought ingenuity to play and built up a rear wheel to accommodate an automotive 6.00 xI6 inch Cassler racing slick. Tbat buge rubber carcass still breaks loose and billows smoke as it attempts to bite tbe drag strip aspbalt and hurtle tbe Harley to a quick run. No matter wbat steps you take with a 74 incb Harley-Davidson its going to weigh a buncb! Micbeals' major weight saving tool has been tbe electric drill. Comparison to swiss cheese would. if anytbing. be understatement. ,Fenders. guards. fins and mounting brackets look as tbougb tbe motbs bad been at work from tbe date of tbe machine's birtb in 1948 and since Bob Micbeals only weighs 117 Ibs. tbey may bave ni bbled a little at him. Tbe Black Knight's total weight is 396 Ibs•• and a few remaining facts of tbis quick Harley are: ,Front forks from a 165 Harley, wbeel base 59 inches, beads stock. carburetion by 172° Linkerts and ignition is magneto by Joe Hunt. ,Add tbis all togetber and we bave an ultimate example of craftsmansbip tbat produces speed, tempered witb a nostalgia of an era tbat is not really gone. SPECIFICATIONS -BLACK KNiGHr engine: Harley-Daviason 1946-74" displacement: 80 inches horsepower: Approx.-100 ~ mile perfroamnce: 10.54 E. T.-134.00mph pisrons: M.C. 11:5-1 cylinders: Custom by Tom Denton valves: 2 in. Pontiac cams: Sitton lower end: Stock igni tion: Magneto transmission: H·D 2nd & 3rd c1 utch: Barnett final gear ratio: 3:42 frame: Harley carbs: Linkerts size 1~" front suspension: 165 Harley rear: Rigid rotal weight: 396 I bs. tires: 6.00x16 Casler rear-front 21" valve springs: Har·Dav with Tungsten wh eel base: 59" coll ars heads: Stock lubrication: Wet sump (Castrol • RO) Cams and Val yes Several different grinds bave been tried and the best run of 10.54 seconds was obtained on a set of Schallers. Today tbe quest for something better is still on and a new grind by Sifton is now trying to pulse the en· gine into a faster elapsed time. The valves and passages are large enougb to confuse tbe pistons as to wbich path tbey should follow. Actually tbe valves are constructed LAUGH WITH US NEXT WEEK (,\pril Fool) r~~#knJda C-z 1';" Husqvarna ~. • Complete Service, Parts, Me: .., ' ..,.. , :'::;:fl/ff:g:. t;) ';,:' ,• :'.:-: In M 0 Itt) R 5 Bob MldI.. ls poSIS nlll to his MlcHV1l1948 Black Knlpt HD. Bob had had a varl.d racln, c• •r. HI won 1II1 Daytona 100 Mil. National In 1951, rod. a Harley 74 to 123 mph lor Skip Fordyc. al Rosamond Dry Lakl and races und. #12 at Carrell Speedway. MOTOICYCU SALES-SIRVICI 0.. Sepulveda Blvd., south of NordhoH St. "In the heart of the Valley" PARTS • ACCESSORIES URGE SELECTION OF USED MOTOICYCUS U22 E. HI':HIN(;TO:,/ DRIVE HL'AIlTt:. C\UFOK:-iIA rolophono 359-4548 894-9218 PpMt~ 2707 - W. lst Street Sanla Ana, CallI.