low_psi

Say What??

ealesh33

iTrader: (1)

Long block that was bought was originally an HP500 carb motor. He had the motor refreshed, and elected to have the fuel injection setup from the 502mpi that came in the boat considering he had everything he needed, instead of buying a carb set up. With going fuel injection the HP500 cam wouldn't work, so the builder put his stock 502 mpi cam in that long block. Really what needs to be figured out is what else is in the motor as far as valve train? Rockers, lifters, etc...I personally would get a cam equivalent to an HP500 to work with fuel injection, and put in it if there is a roller set up in it. But I am not sure that would be the case since a 502 mpi isn't roller right?

pwrboatn

Heres some numbers finally guys. The boat will turn the prop now that i finally found the issue i was having with my motor. I was having a fuel pressure issue but now that its all figured out the boat is spinning the 24p 4 blade but not like it should. The boat is taking alot to come on plain and top end is only spinning 4800 rpms. when i think it should be spinning 51-5100. Now what prop size do you guys reccommend for my boat?

bbladesprops

Labbing that propeller is a definite option.
What speed do you see at 4800 rpm now?

Brett

pwrboatn

I wasnt sure of speed with the 24 because of no gps at the time. But just ran a mirage plus 23p 3 blade this weekend and only saw 52mph around 4800rpms

bbladesprops

You efficiency is poor. The slip % is 25.39%. Of course we don't know where the propeller has been.

Brett

pwrboatn

Not sure what u mean by that?

bbladesprops

The slip % is the % of forward travel you are loosing. So the 23 Mirage+ is loosing over 25% of it forward movement. It is not efficient.
Not knowing where it has been refers to whether it has been repaired poorly or if it is in bad shape currently.

Brett

pwrboatn

I gotcha im gonna get you some solid numbers off my 24-4 b1 soon mph and rpms anything else u would need?

CAPTAIN JACK

Hey any numbers yet with the 24P bravo. I'm in the same "Boat" literally.