Has anyone Modified an Enzo with a bubble over the prop?

[PA_Mike 0]

I have a 2007 Enzo 230 and just got off the phone with ACME props. He said if you really want to make you Enzo your dream boat that you need to do two things.

 

1. Take the boat to a body shop and have them create a bubble over the prop like the new centurions have in order to have room to upgrade from a 13 inch prop to a 15 inch prop.

 

2. Change the gear ratio from 1:46 to a 1:75 (believe those were the numbers he used). This would allow the use of 15 inch prop with a 16 deg pitch.

 

He claims by doing these two mods that he can put me in a prop that will not only have the low end torque for the weights I am running while surfing, but also i will not loose any top end speed for wakeboarding/Cruising.

 

 

Looks like about $1500 to $2000 for the two....was hoping someone had done this and could let me know how it worked for them.

 

Thanks,

 

Mike

[duffymahoney 10]

I know acme says put a cavitation plate on the bottom of the hull helps. They are basically glued stainless right about the prop to stop gel coat burn. Why don't you try one of the new OJ 5 blades first? It would be a scary mod to do all that fiberglass work. But hey if you want then go for it.

[Dreamer 96]

I am going to try one of the OJ 5 blade props on my 07 Enzo but I will not have my boat in the water until April. I will keep you posted on whether it was worth it or not.

 

I currently have a modified Acme 1433 on my boat. It was trimmed down to a 13.5" diameter and 0.185 cup. Pulls great with 2200#'s of water ballast for surfing and the engine turns 3400 rpm at 11.5 mph. Top speed when empty is 37 mph.

 

My 537 could not hold speed surfing with this much weight but was fine when we ran 1400 #'s of water ballast. Top speed was a little over 40 mph.

[duffymahoney 10]

Are they making a 13.5 oj prop now? They weren't before.

[Spud 7]

Are they making a 13.5 oj prop now? They weren't before.

Thats the word on the streets.

[PA_Mike 0]

I don't know anything about the OJ props, which one are people running on the Enzo's?

[duffymahoney 10]

OJ just came out with 5 blade props. I guess they work way better for low end and actually cut out a ton of rpms.

[Sporty 4]

I have an 07 240 and have this exact problem.

the hull mod sounds like a good idea, but I was looking at it and thinking possibly an easier approache would be a longer propshaft.

I think I could have a 1.5" longer prop shaft built and that would move my prop substantially away from the hull.

It was just a idea on how to move the prop away from the hull.

Anyone have a pic of what a newer 240 looks like above the prop?

[Kevin Baugh 78]

I dont think there is enough room between the prop and the rudder to make the shaft longer

[Sporty 4]

Hi Kevin, from my measurements, especially with a very shallow prop I have a good 1.5" to make this shaft longer. I wish I understood the effect it would have without just trying it, however I think I might try it. It will ba a good time to put bushings in the strut anyway.

[duffymahoney 10]

So talking to acme, the distance from the strut to the prop shouldn't exceed 1.5". I guess that's the rule of thumb for props. Currently I am 1/4 from my prop to my strut and I have a bent shaft:) so I am going to get a 1" longer one. Right now I have 7/8ths of an inch clearance with a 13.5 inch prop. Acme claims 5/8 clearance is all you need. Now I just need to see if 1" longer shaft will give me enough clearance to run a 14" prop.

 

On a side note, acme claims the 5 blades are crap and they have tested everything and still they claim crap. Acme has a new idea though. Since we don't care about getting on plane or hole shot, they suggest I go with with a 1591 in a 14" prop. So 14x16. Which is the opposite of what they used to suggest. They are changing their minds with so many people only wakesurfing and not boarding at all. I told him I could care less about hole shot. Just enough power to push the boat at 11.5 mph with 3k in ballast in it:)

[Dreamer 96]

If we were to move the prop further back would it not create more prop wash, even a rooster tail?

[CenturionSkier 43]

I have always heard that more than 1/4 of gap between the prop and the strut risk shaft whip. And can cause the shaft to fail. Every inboard boat I have ever been around had about a 1/4" gap. So thier must be something to this.

 

The other comment about a bigger prop makes no sense to me either. If you are putting a big load on the engine, then the life of the engine will be reduced. If you a car with a standard transmission and you are trying to start up hill from a stop in 3rd gear it will just load put the engine and it will die. A higher pitch prop is just a higher gear. So it is just like starting up hill in 3rd gear, lots of load on the engine. Lower pitch prop = more power. More weight in a boat needs more power.

[duffymahoney 10]

I'm just quoting what acme told me.

[Sporty 4]

So talking to acme, the distance from the strut to the prop shouldn't exceed 1.5". I guess that's the rule of thumb for props. Currently I am 1/4 from my prop to my strut and I have a bent shaft:) so I am going to get a 1" longer one. Right now I have 7/8ths of an inch clearance with a 13.5 inch prop. Acme claims 5/8 clearance is all you need. Now I just need to see if 1" longer shaft will give me enough clearance to run a 14" prop.

 

On a side note, acme claims the 5 blades are crap and they have tested everything and still they claim crap. Acme has a new idea though. Since we don't care about getting on plane or hole shot, they suggest I go with with a 1591 in a 14" prop. So 14x16. Which is the opposite of what they used to suggest. They are changing their minds with so many people only wakesurfing and not boarding at all. I told him I could care less about hole shot. Just enough power to push the boat at 11.5 mph with 3k in ballast in it:)

I just did a swack of measuring in the garage as I had to remove my propshaft anyway. I have 5\8 of an inch clearance and have hull erosion.

So I would not trust that to be enough clearance. I unhooked my coupler and moved the shaft back from factory about 1\2" between prop and strut to 2" just to see what clearance that would give me. I went from 5\8 to 1 1\16. This is with a 13.5 prop on an Enzo. I am going to call the shaft\strut manufacturer to see how far away you can actually go. I would love to go 14" and have 3\4 inch clearance.

I have always heard that more than 1/4 of gap between the prop and the strut risk shaft whip. And can cause the shaft to fail. Every inboard boat I have ever been around had about a 1/4" gap. So thier must be something to this.

 

The other comment about a bigger prop makes no sense to me either. If you are putting a big load on the engine, then the life of the engine will be reduced. If you a car with a standard transmission and you are trying to start up hill from a stop in 3rd gear it will just load put the engine and it will die. A higher pitch prop is just a higher gear. So it is just like starting up hill in 3rd gear, lots of load on the engine. Lower pitch prop = more power. More weight in a boat needs more power.

I think part of the cavitation or hull erosion comes from the speed the water is leaving the prop tips. It makes a ton of sense to me now to have a lower gear in the v-drive and a bigger pitch prop. That would certainly slow down the shaft and prop tip speed. This would also help with any shaft whip. I think. I also think some problems come from high shaft speeds and low angle on the prop.

 

I am almost convinced to try a 1" longer shaft, change the ratio in the V-drive, I also think I can shim down the strut 1\8" and still be flush with the hull (will need to reset engine alignment so coupler is aligned properly)

 

I am going to call the shaft strut guys Monday and see if any of this might work.

Sporty.

[CenturionSkier 43]

I do not think you can shim it down. That would change the angle the shaft takes to go thru the hull. So the hole cut in your bottom would no longer be at the correct angle or location. Also the shaft log is at the same angle as your strut, so that would not longer be true and you would more than likely hit the top of the shaft log.

[Sporty 4]

I do not think you can shim it down. That would change the angle the shaft takes to go thru the hull. So the hole cut in your bottom would no longer be at the correct angle or location. Also the shaft log is at the same angle as your strut, so that would not longer be true and you would more than likely hit the top of the shaft log.

Yea, I may be on crack. But... If I built a 1 degree wedge to change the strut angle from 16 to 17 there is enough room in the log for the shaft to deflect 1 degree. Seeing as this would completely change the engine position, I would need to understand that as well.

The shaft is 1 1\8" diameter and the ID of the log is 1 3\8". True the log is 16 degree, but i just measured with a good angle finder and the shaft could go thru the log anywhere from 10 to 22 degrees. At these extremes the shaft would contact, but a degree or two I think it would work.

As for the hull, its pretty much the same, lots of room, and if there is not, get the grinder out. After last years ballast install I am so over cutting holes in this thing!

If you think about it 1 degree at the vdrive would translate to quite a bit of clearance out at the shaft end?

But I am pretty much guessing at this point.

Gotta check this out with a drive line engineer or someone who could validate or crush my theory.

I just hate fiberglass work, although it may end up to be the easier of the two.

Sporty.

[Kevin Baugh 78]

Yep you are on crack

_{If you change the strut angle you have to change the engine alignment significantly then your prop would get close to the rudder}

[duffymahoney 10]

Yeah I don't think you should change the strut angle!

[duffymahoney 10]

Ok talked to acme me again. Maxium safe distance is less then the shaft diameter. So if 1-1/8th then less then that.