ZT240 prop question
 

I have a '97 ZT240 with a 310hp 454 carb, no mods to the motor. I'm debating getting the 23p mirage labbed or looking into a 4 blade. Anyone out there play this game already? I currently turn 4600-4800 rpm and run around 61 mph with alot of bow lift out of the hole. Also, anyone with experience trying to get another 100hp out of this motor, i.e., heads, exhaust, manifolds, etc.... Thanks for any help you can provide:confused: :confused:

Hello Mcorcora,

I would suggest you to change the engine to a 502 EFI (415hp) or to a 500 EFI (500hp), since I have a 500 EFI (500hp) in my 97 251 convincor which turns 5200 rpm with a 27'' three blade mirage. You can try to increase the hp with a wipple charger, but you will have problems with your engine to run it solid as time passes. That's why I recommend a stock engine.

Good luck

Liquidator

I had a Checkmate 229 which started life as a 454/330. Changed to rectangular port GM heads, GM forged rods and pistons,cam, rollers, intake, Holley carb and Mallory/MSD ignition. The engine dyno'd at 465hp and pushed the 229 to 74.6mph on GPS with a labed 24 Hydromotive. That boat was very reliable, idled with a little cam rumble and was pretty economical to run. I would not recommend Procharging or Wipple on your engine due to a weak stock bottom end.
If you're going to keep the boat for a while find a low hour 502 mag and drop it in, from there you can add a supercharger and get over 600hp pretty easy.

Prop
 

Hello mcorcora,
I have a 2002 240ZT with a 496mag. I ran a 25 mirage until I damaged it. I then went with a new 24" Bravo 1 four blade. I loved the prop. Handling, ride , planning time were all greatly improved. The little top end I lost was well worth it. I now have a 26 bravo I will be running on the boat due to performace mods. If you are interested in the 24" Bravo let me know I might sell it. It was only in the water a few times.
Here is my email if interested [email protected]

Brent,

Thanks for the info. I don't think I could pull the 24p with my 330hp. Before mods, what did the 496 mag get you for top end with the 25p. I'm thinking my best options are to either find a 502 mag crate engine or do heads, intake, exhaust on my current block. Any experience in that area? What are your plans for the 496?

Prop
 

You should have no trouble with a 24" Bravo. It is like a 23" Mirage as far as RPM. They rate the pitch of a Bravo at the end of the blades. 69 gps is the best I have gotten out of the boat stock. I am adding a 120' thermostat and PCM reprogram and possibly EMI headers. Should give me 37 more HP.