I found Gates kevlar racing timing belt for my P 944.. going to order one.. wonder anyone use kevlar tb for ferrari. any good? thanks for sharing..
Kevlar ( brand name for arimid fibers ) is an interesting fiber, it has a high modulus (low stretch), low weight and high strength... all desirable characteristics for a timing belt. If there is an area of caution, it would be in long term use. Kevlar fibers do NOT like to be flexed. Flexing causes the fibers to weaken and break ( much like the way a paper clip can be flexed until it breaks ). Gates lists it as a "racing" timing belt. Long term service is not implied when the term "racing" is used. Need to look at the specs with respect to long term service and length of estimated service vs a standard construction timing belt. Also need to compare costs vs length of recommended service life.
having worked with the Gates engineers when I designed the timing pulley redux for the 3x8's the bulk of their belts are an arimid fiber blend. And yes there is a 'service life' on these, and shelf life too. a belt sitting on the shelf for 3-4yrs is just as liable to fail as one that's been in service. interestingly the line of 'industrial' belts is of better construction and will outlast the automotive belts by a wide margin, however they will never make the automotive belts the same way. industrial timing runs more critical tolerances then an engine, and down time is HUGE $$$$ lost. I tried but could not get a cross reference to an industrial belt for the automotive sizes, it's intentional to avoid the use of an industrial belt in an engine. the only go around is to re-design the pulley system, not cheap. Gates racing belts are tad better then the std ones but still not where they could be. all the above aside, the biggest reason why the life is short on the ferrari belts is due to the tiny drive pulley, it's dia is right at the critical bend radius for the belts construction. NEVER BEND the belt smaller than 2" in dia, it starts to break and shear the cords. folding the belt will cause even more damage, they should be in a loop form when they ship.
"valve"...now theres a bit of electronics nomenclature not heard in practical application in over 40 years....it was an engineer and prototype designer from an old stereo guy in cambridge, M A he was with "AR"{acoustic research} the original latent holder for "acouistic suspension" speakers and encloseures... despite the impending total shift from "tubes" to "chips"...the old guys called them "valves" and not tiubes(tubes are what the tissue in the loo comes wrapped abbout"... it is really odd.......especially since this engineer succumbed to Luekemia yesterday evenin g...how weird.....
