I have heard and read a little on the evolution drive, never saw one but stumbled on a Duffy on Yachtworld tonight with one installed.

Any comments for or against? Theory sounds good.

Here's the drive:

http://www.evolutionmarine.com/detail.html?id=3001&cart=132019343445994#info

Here's the boat, nice rig!!!

2011 Duffy SPORTFISH CUSTOM Power Boat For Sale - www.yachtworld.com (http://www.yachtworld.com/boats/2011/Duffy-SPORTFISH-CUSTOM-2409068/MA/United-States)

Pics of the evolution drive:

When i snapped a 2.5 inch shaft on my MDI a few years back i was goin to look into buying that system...but it was alittle to pricey....but its gotta be SMOOOOTH

I have spoken with one prominent DE builder and he "won't put one in a boat" unless the customer absolutely demands it. He claims the system "runs too hot" !!

Then again Ellis Boats promotes the system in their boat lineup!

Go figure!

I don't anymore about the Evolution than what I read in the ads.

Personally using the KISS rule and the almighty dollar rule, I would not go this route. If you struck something hard it would be expensive to repair if damaged and I would also be afraid of a swinging shaft if a u-joint let go however unlikely. It has its place in certain instances, but I think a well installed engine with coupling faced for zero zero run out, shaft checked, Barry controls mount, lap fitted prop, and maintained cutlass bearing will be as good. There are many reasons for vibrations not all related just to the running gear though all components need to be checked especially if new since shafts and couplings are almost never to spec. Look into aerating the prop wash also if you are looking for a super quiet cruise The oil bath syst and u joints just seems too complicated and would need to be serviced at some point seal wise as everything wears out at some point under use with many things wearing from no use. Looking forward to your build on this site what engine HP are you going with and I assume Cummins of course.

I agree with the KISS principle too, but love engineering. :D

Look into aerating the prop wash also if you are looking for a super quiet cruise



I have heard about aerating the prop but also don't know much about it, care to elaborate??

I have heard you use a series of thru hull that allow air to vent the area of the hull where the prop will throw water against it, port or stbd depending on the rotation of the prop, correct??

The new Cummins QSB 6.7 will be the power of choice

Prop wash aeration design on a 36NB

The airation thing definatly works but the evelution system won't help that anyway. What it does is basically seperates the engine from the drive train so you can have the softests mounts on the engine that money can buy. The engine kind of floats in the engine bed and all the force is put on where the shaft is bulkheaded to the hull. If you look at the rear bulkhead where the shaft comes in all the pressure is there. The airation block puts a layer of air between the hull and the water so the water coming off the top of the wheel does not slap the bottom of the hull.

With that said, I had an evelution shaft in my last 36NB. I would never put one in again. Not because I ever had a problem but because there are so many problems that can happen with it. There are a ton of moving parts on that thing and a ton of possible failure. You have to change the shaft oil every season, lube universals, and god forbid the thing goes under water. Imagine how fast the boat would sink if that rear universal let go at 2000rpms.

Interesting, something to be said about tried and true methods.


On aeration, where do the thru hulls "exhaust" actually "intake" to?? Under the gunwale??

Also, on the evo drive you would think they would have a driveshaft loop on that thing, kind of like a muscle car.

Keep you from punching a hole through the bottom in case of u-joint failure.

http://home.fuse.net/fastmonte/FastMonte_driveshaft_loop_installed.JPG

Hey Mike,i didn't know you had that in the FISHWISH did it really stop alot of vibration??????

Yes, that boat had a big engine, 122p volvo 3500lbs with gear. You could put a cup of coffee on the dash at 23 knots and there would hardly be a ripple in it. It was a pain in the ass to set up though, you have to have the proper amount of roll to the universals or they say they will fail. I miss the speed of that boat!

The thru hulls above the prop are "open to the atmosphere" under the deck above the water line with intake hose. A real simple design
Allows cavitation bubbles etc. to be vented.

Aquadrive is the KISS solution. No oil incased bath. Just a short shaft that goes to a thrust bearing and then CV joints on the other side of the thrust bearing and engine with a tubular shaft in between. NO U-joints..these can pulse...CV's do not and allow dissimilar angles on either side of the tubular shaft.

Full disclosure....I sell these

What is the max HP the Aquadrive can be bolted up to, swinging a 2.25 shaft with a 26 x 24 wheel.

thanks

The easy answer is about 1500hp. This depends on gear reduction.

I have the Evoution drive in my rig. I won't argue there is potential for failure but i don't believe anymore so than other setups. My system includes a loop to catch the drive shaft in case of failure. The ride is very smooth and anyone who has fished with me claims it is one of the quietest DE around. I bought my boat used so I did not have to make the choice, but after running it for a while I would say I like it.

Cool, would love to see more pics of your rig Blacktide.

Ill see what i can find