Classic Racer — September — October 2017

ClassicRacer 47

Moto Guzzi’s

defendingWorld

championsingles in the 1953 and 54 seasons,

so Carcanohadalreadyhad agood measure

of the qualityofits work.TheHirth crank for

theV8employedthe sameformatas theNSU

twins, timesfour,with his patentedcouplings

employingradially serratedfacescut into one

end of eachhollow30mmdiametercrankpin

and its corresponding flywheel(still full circle),

thenthe pinfitted withtwo roller bigends

eachemploying aunitarycage,and apairof

one-piece steel conrods, sharingacommon

crankpin.Theresultingassembly wasthen

clamped togethervia differentially-threaded

internal coupling bolts to create an extremely

strong,stiffstructure thatresolvedGuzzi’s

problems of flexand vibration.

In the V8 engine therewere no separate

cylinderblocksassuch, with what would

have beenthe lowerhalves of eachcast

integrally into the one-piece crankcase,

and theupperhalvesformingpartofeach

of the twocylinderhead castingsthat were

attached to the crankcasevia tenlongstuds.

Four cast-iron wetliners comprising the

cylinder boreswere screwedinto each

cylinder head,with ataperedinterference

fit water seal wherethe bore met the head.

In spiteof originally experimentingwith

fuelinjection backin1940 on his abortive

supercharged 500triple,and morerecently

on the short-lived longitudinalin-line four that

precededthe V8, Carcano optedforeight

rubber-mountedmagnesium-bodiedDell’Orto

SS1carbs –first20mm,then 21mmunits

forfastercircuitsand18mmfortighter tracks

–with alinkage systemofrods and levers

controlled by asingle throttlecable.

TheV8 50 0wasproneto

mechanicalissuesduringitsshort

racinglifebutnothingdetracts

fromthefactthatthismotorcycle

wasattheverycuttingedgeof

Guzzi’sout-of-the-boxthinking.

044 MotoGuzzi500 V8_SEP.indd 47 26/07/201715:23:13