Prop recommendations

**85vking** · 07-22-2020, 08:20 PM

Hi everyone,

I have a Mirage Jaguar that runs a 2.4L 200 Merc. Given that, what style prop works best? I want to believe a cleaver is the choice since I don't want additional bow lift. If I'm right, what pitch? I know its a small shaft 14.5 I have been running a 28P cleaver and wondered if that was a good size and style (vs chopper) or I should go bigger? Incidentally, my 28p and shaft went to the bottom of my lake when the shaft snapped!

**Merc 2.5** · 07-22-2020, 09:46 PM

Dont have experience with ur hull but the chopper will give alot bowlift

**nitro_rat** · 07-22-2020, 09:54 PM

What speed and RPM were you turning the 28 cleaver?

**85vking** · 07-23-2020, 07:09 AM

Originally Posted by nitro_rat

What speed and RPM were you turning the 28 cleaver?

Good question....I can't be accurate on that because of minimal time on the water. I haven't been able to wind it up with the winds lately. I guess at this point, I can only ask for a "general recommendation". The motor has done 7K but since I didn't build it or know anything about it, I get anxious hearing that motor scream that fast. Then again, maybe it's totally fine for this motor. I'm relatively new on this end of the spectrum and my first tunnel. I'm normally a Stream guy and v-bottom. I run a 28P chopper on my Stream with this same engine. I moved the engine onto the Mirage and am trying to dial in a decent prop. I am not going to be racing; just playing. Also, I see cleavers like the one I used to have (as of last weekend) that was what I would call a conventional over the hub style exhaust and others that are thru hub. Is there some advantage either way on these two types?

Mike

**nitro_rat** · 07-23-2020, 10:28 AM

I don't have any experience setting up that type of boat, I'm a V-bottom guy myself. With some good hard numbers it's much easier to know which way to go. A stock 2.4 200 usually is real happy at 6500 RPMs. If your oil injection is deleted you may be safe a little over 7k. For 7k+ regularly I would be thinking about forged pistons, if your block is still all chrome Wisecos are a slam dunk.

From what I've seen, cleaver type props are the go to on those hulls. You need to lay down some GPS runs with RPM to know how your current prop is working. If the handling is good you're in the ballpark.

Difference between through hub and over hub props is takeoff and handling. The exhaust blows over the blades and ventilates the prop on an over hub. This can act kinda like a stall converter on a drag car. Lets the revs come up on takeoff. A through hub has bite all the time, this can give more punch in situations where you're making tight turns like turning around in the river. When you slow down to turn around, the over hub prop might ventilate when you go to accelerate again and make you fall off plane. The through hub will have bite all the time. Both types can be tuned. Ventilating the exhaust above the prop will give an overhub more bite, drilling holes or changing PVS plugs in a through hub will decrease bite.

**85vking** · 07-23-2020, 12:15 PM

[QUOTE=nitro_rat;3221537]I don't have any experience setting up that type of boat, I'm a V-bottom guy myself. With some good hard numbers it's much easier to know which way to go. A stock 2.4 200 usually is real happy at 6500 RPMs. If your oil injection is deleted you may be safe a little over 7k. For 7k+ regularly I would be thinking about forged pistons, if your block is still all chrome Wisecos are a slam dunk.

From what I've seen, cleaver type props are the go to on those hulls. You need to lay down some GPS runs with RPM to know how your current prop is working. If the handling is good you're in the ballpark.

Difference between through hub and over hub props is takeoff and handling. The exhaust blows over the blades and ventilates the prop on an over hub. This can act kinda like a stall converter on a drag car. Lets the revs come up on takeoff. A through hub has bite all the time, this can give more punch in situations where you're making tight turns like turning around in the river. When you slow down to turn around, the over hub prop might ventilate when you go to accelerate again and make you fall off plane. The through hub will have bite all the time. Both types can be tuned. Ventilating the exhaust above the prop will give an overhub more bite, drilling holes or changing PVS plugs in a through hub will decrease bite.[/QUOT

It seems everything I've been told about prop info regarding the differences of the what I should/shouldn't use on a tunnel like mine is consistant. I do in fact have the offshore exhaust snout above the cavitation plate (Bob's) and the cleaver I did have, pulled a lot of R's out of the hole but once it caught...it grabbed and launched. I did notice that slowing down and turns did cause the boat to want to rev high again to get traction, so maybe that thru hub cleaver would be my best all around prop. I'm not drag racing. Thanks for your help and knowledge Nitro!