so i got my timing belt and waterpump changed the other day (after mike reminded me how important it was to do it, thanks buddy). anyway, i’d had my timing belt changed i think twice before, but i’d never changed the waterpump, even though you’re supposed to do it when you change the timing belt.

so i got to thinking, since it’s only supposed to last about 60k miles or so, and my poor integra now is pushing 180k, about how many times that thing has spun. i’m gonna do some bigtime estimates, but here goes.

a timing belt is about 24″ long. the diameter of the gear on the waterpump is 1.5″ so the circumference of the gear is 1.5*π= 4.71″… so 24″/4.71″ = ~5… so 1 revolution at the crank = 5 revolutions of the waterpump.

now my car has an rpm range of 0-7k, normal driving is around 3.5k though, and with all the traffic i’m in, it’s often at or near idling of about 700rpm. so here’s a big estimate of 2k on average engine rpm.

ok, now for even bigger estimates… how many minutes i’ve driven my car… or moreover, how many minutes it’s been at an rpm of 2k. well, the max i drive on the freeway is about 80mph, and the slowest, fucked up traffic goes is around 10mph, so to be conservative, let’s say 30mph on average, over the 180k miles. 180,000/30 = 6000 hours = 36,000 minutes.

so… 2000rpm for 36,000 minutes, at 5 times the speed of the crank = 360,000,000 rotations

so that fucking waterpump spun about a third of a billion times. that’s fucking insane.