Estimated HP output - Build Sheet attached
#33
Platinum Member

Joined: May 2003
Posts: 240
Likes: 1
From: Arnold,Md
A 33 Powerplay with 500hp will need 28 pitch prop with 1.50 gear. Will run 78-82 mph gps. The short deck version like that will run those speeds with 465hp. Check the engine carefully or dyno to check actual power.
#35
Thread Starter
Registered
Joined: May 2014
Posts: 206
Likes: 3
From: Buffalo NY
I'll put some time in and get to know the boat. I have a set of labbed 28P bravo 1's ready to go in boxes - which I bought before I even paid for the boat and just as I started this thread. Coming to the relative conclusion this build package can make 500+HP, I figured it could've swung the 28s - like most Powerplays with 500s. After sea trial, it makes me second guess that, but I'll run the 24s or Mirage Plus 25s the boat has and work from there.
The engines were built by Precision Automotive in CT if that helps.
The engines were built by Precision Automotive in CT if that helps.
#37
Registered

Joined: Jul 2004
Posts: 11,332
Likes: 73
From: chicago
What ignition system are you running? Any chance its hitting the rev limiter? What total timing are you running?
what carb is on it? Was it dyno tuned, or how was it tuned? The engine should make over 500hp, but only if tuned properly. If its short on timing, carbs not tuned right, it will be down on power
what carb is on it? Was it dyno tuned, or how was it tuned? The engine should make over 500hp, but only if tuned properly. If its short on timing, carbs not tuned right, it will be down on power
#38
Thread Starter
Registered
Joined: May 2014
Posts: 206
Likes: 3
From: Buffalo NY
What ignition system are you running? Any chance its hitting the rev limiter? What total timing are you running?
what carb is on it? Was it dyno tuned, or how was it tuned? The engine should make over 500hp, but only if tuned properly. If its short on timing, carbs not tuned right, it will be down on power
what carb is on it? Was it dyno tuned, or how was it tuned? The engine should make over 500hp, but only if tuned properly. If its short on timing, carbs not tuned right, it will be down on power
As far as carb, build sheets indicate a rebuild - not replacement, so I'd have to look into it but its a Holley. Maybe pros know what it is based on sight:
#39
Registered

Joined: Oct 2013
Posts: 2,888
Likes: 148
From: SF Bay Area
I’m still quite new to the bbc power boat thing so I’ve had quite the learning curve, but I’ve found most of my gains in the rigging and tuning. Stupid stuff like finding a neglible kink in my fuel line, the wire to my ignition was too small, the fuel pump was too small for my upgrades on so on. I put a wideband on what I thought was a great running engine and found wot to be low 10s. Jetted it for mid 12s and found 600rpm. It’s all in the details.


