Need Help Finding The Right Prop 29' Envision, 454, Bravo 1
 

I currently have a 1996 29' Envision Combo Cabin. When I received it the engine had been pulled and was just the hull and drive. I dropped in a 454 bbc, 781 heads with enlarged valves, Edlebrock RPM intake, IMCO PowerFlow exhaust and Comp cams 262 XTREME MARINE cam. The machine shop that built the engine said that I should be running it at 5500rpm's but the cam specs say 1-5k rpms. Any suggestions? My current max RPM's at WOT are about 4500 at roughly 40-45mph. My current prop is a 23p Mirage Quicksilver 48 13704 A41. One last thing is the prop seems to cavitate or loose traction if I try to trim it up to quickly. My thoughts where adding a Hydrofoil for the cavitation and switching to either a 19 or 21p prop for the RPM gains. Any advice? Sorry kinda a newbie.

Welcome to OSO.

I would try a Mirage+ in the pitches you suggested. The M+ has better bite and bow lift than the old Mirage, so should ventilate and cavitate less. The Revolution 4 could be a good choice for a 4 blade.

Do you think I would be ok running at 5500 even though the cam specs are 1k-5k rpms? I don't really have any props to test out so was gonna buy a 19p unless advised otherwise. Also would the hydrofoil help with the cavitating or would it just be a bandaid for my problem?

Forgot to ask. Should I stick with a 3 blade or jump up to a 4 blade? Also how would the pitch difer if I went from 3 to 4? And should I stick with the same diameter? Wanting a new prop by the weekend but will have to order one. Don't wanna make a expensive mistake.

What gear ratio is your drive? Your prop slip is very high. If your drive is a 1.65 slip is between 24-33% and if your drive is a 1.5, your slip is 31-40%. How is the condition of the bottom of the boat, and the old prop? You should be around 10-12%.

In your case, I would call Brett Anderson at Bblades. There are too many variables and other things to figure out, and he's one of the best when it comes to props.

When all that is said and done, a 19" M+ would put you around 5300-5400, and a 19" Rev4 prolly around 5100-5200, if your current prop is in good condition.