PWC Jet drive units

[DYI]

Hi YALL ! I'm the nu-bee on the block ( throw stones now ) And My question is How much over power Or (over rpm) can you throw at a PWC jet drive unit Before it fails, or cavitates , or simply discentergrates . Would inturnal cavitation be the most likely failure reaching the threshhold before self destruction? How much above rated HP can it take and will their be a increse in boat speed ? Just some fun stuff I'm working on and cant find any answeres . Did you know a Old VW trans axle will take the HP from 454 block kind if the premmis For this post on a jet drive ..

[Jets]

Lets look at your note backwards. The VW transaxle was probably designed to handle more than four times the power of the original 36 hp engine. In fact the Porshe car that James Dean died in back in the early fifties could handle 220 HP in race trim using a very similar transmission except that the motor was ahead of the tranny. (one of my friends had a 220 HP reproduction from California) Now a transmission gear tooth only "sees" the impulse of a single firing cylinder at a time so that a 4 cylinder engine producing 220 HP could be replaced with an 8 cylinder engine producing 440 HP without too much trouble because the number of impulses has doubled. However an 80 HP single cylinder would probably kill the tranny. The jet drive: you need a boat big enough to float the engine; you need a drive big enough to pass enough water mass to to exceed the drag that occurs when the boat tries to plane. If the drive cannot move the water mass through fast enough to overcome the drag, you don't plane. Adding horsepower will probably result in a cavitating pump rather than disintegration as the PWC pumps are quite robust. Don't despair, Bombardier is getting close to that 454 power with a 215 HP PWC that does 0-60 in 6.5 sec.