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tcosta.2
04-23-2006, 06:01 PM
I have a 2004 x-30 what is the thought on changing prop rotation can it be done is it a bad idea

tommcat
04-23-2006, 06:04 PM
huh?? :confused:

roddydog
04-23-2006, 07:02 PM
I believe the rudder is slightly offset to accomodate the way the prop rotates now so, yeah probably a bad idea.

One question though....................Why???

Tom023
04-23-2006, 07:36 PM
I am wondering why myself. I seem to recall, maybe incorrectly, that a few years ago in one or some of the v-drive models, MC tried right hand rotation for a while, but then changed back to lefthand. I'm sure Eastie will let us know if I am dreaming or not.

I think reverse rotation in the v-drive can be handled through the shift linkage.

Edit:

Found a thread (http://www.tmcowners.com/teamtalk/showthread.php?t=2085&highlight=hand+rotation) where MYMC references the RH rotation in an X30

east tx skier
04-23-2006, 08:42 PM
Something you can do with the tranny fluid flow that will change rotation (or so I remember reading on here). No idea if the rudder offset would mess things up.

6ballsisall
04-23-2006, 09:11 PM
Don't think even by changing the trans around you can make it a right hand rotation setup. For enough money you could change it.........New Cam, new crank, new waterpump, new distributor........and probably alot of other parts I haven't thought of!

Cloaked
04-23-2006, 10:15 PM
I have a 2004 x-30 what is the thought on changing prop rotation can it be done is it a bad ideaNo on changing and yes on the bad idea. :twocents:

I said no for all practical purposes but to clarify, to do this, you'd need to change out the engine (rotation) to obtain the right hand rotation. This would be relevant to a direct drive machine.

I'd suggest learning to dock the boat with left hand rotation. It's not hard... :eek3: :uglyhamme

Tom023
04-23-2006, 10:16 PM
This (http://zf-marine.com/ZFR/Transmissions/index.cfm?DS=Description&GN=ZF_63_IV) is the transmission used in the v-drives. They are capable of running in the same direction as engine rotation or opposite direction equally. To change propeller rotation, the shift mechanism is adjusted so the transmission is shifted to the position that gives the desired rotation, it's that simple. The owner's manual doesn't talk about forward/reverse with the shift linkage setup, it states "position A" as rotation same as engine, "position B" as opposite from engine.

tommcat
04-24-2006, 07:28 AM
i know they CAN go both directions. what confused me is, why would you want to?

east tx skier
04-24-2006, 10:40 AM
No on changing and yes on the bad idea. :twocents:

I said no for all practical purposes but to clarify, to do this, you'd need to change out the engine (rotation) to obtain the right hand rotation. This would be relevant to a direct drive machine.

I'd suggest learning to dock the boat with left hand rotation. It's not hard... :eek3: :uglyhamme

Another boat company that offers RH rotation boats does not do so with RH rotation engines. It's all in the transmission. But with our stock trannies, it might be easier to do it in the engine.

As for the why would you want to? Maybe so that the boat would ride more even without a spotter.

/got nuthin.

6ballsisall
04-24-2006, 10:46 AM
Another boat company that offers RH rotation boats does not do so with RH rotation engines. It's all in the transmission. But with our stock trannies, it might be easier to do it in the engine.


.


ICBW, but I am fairly certain that SN at least in older years did use Right Hand rotation engines.

east tx skier
04-24-2006, 10:49 AM
Yes, they did in earlier years. But their newer boats have left hand engine rotation. The rh prop rotation is achieved via the transmission. This is according to my local dealer whose only flaw is that they don't sell MC. :(

6ballsisall
04-24-2006, 10:50 AM
Yes, they did in earlier years. But their newer boats have left hand engine rotation. The rh prop rotation is achieved via the transmission. This is according to my local dealer whose only flaw is that they don't sell MC. :(


Very interesting..... Ok I am done for the day. i learned my new fact for the day :toast: :D

east tx skier
04-24-2006, 10:55 AM
Not sure exactly when that changed. I've got a friend with an 82 and he definitely has a RH rotation engine.

88 PS190
04-24-2006, 11:15 AM
With the DD velvet drive boats engine rotation will be the same as prop rotation, and the trans gets switched so that it locks forward gear by setting the pressure pump to the correct direction, you then add a prop for the correct rotation, and it works.

Offset on rudder should have minimal effect on performance, particularly at speed, it just can't be in the area behind the prop due to the turbulance, it'd cause a twitchy sensation on the steering.

Some of the newer trannies, particularly on V-Drives, don't do reverse in the same method that the velvet drive does, and if you've driven a velvet drive you'll know what i'm talking about. The velvet drives use a planetary drive for reverse, much like a differential, if you lock one wheel and run the shaft the other one can drift in reverse, it makes alot of noise, and is very ineffient, but also very simple.

Its more complex to have a true reverse gear, but is smoother and allows you to use either as forwards. If you mounted the new set ups in a boat that was symetrical front to back, you could run it the same in forwards or backwards to full throttle.'

In a velvet drive you'd go no where, and just cause damage going full reverse.

Storm861triple
04-24-2006, 11:22 AM
...why would you want to?
Good question, but the original poster has a good idea.

The current prop rotation is a "bad" idea for the simple reason that the prop torque forces the boat to list to the right/starboard/drivers side. That situation is exacerbated when you are cruising w/just a driver in the boat. Then you have prop torque, PLUS how ever many pounds of driver weight tipping the boat to the starboard side. Annoying, IMO. I don't know how profound that is on an X-30, but in my PS 190, it's quite noticable when I'm driving alone.

Going to a LH rotation prop would balance out the two forces; Driver weight and prop torque.

Changing the cam (crank not necessary) and plug wire routing is one way, but if I were doing it, I'd swap to this transmission:

http://www.pcmengines.com/powerplus.html (<Note the weight on the scale; 64 lbs!)

http://www.marineexhaustmanifolds.com/images/pcm/1721.JPG


Which weighs about 100 lbs LESS than ours, lets the engine sit level, and reverses prop rotation.

-Tom

Tom023
04-24-2006, 11:56 AM
The starboard list on an X30 with just a driver is quite annoying and actually causes the wake to wash out on the port side, even when I have the wife and kids on board. I moved my batteries from the starboard rear to port under the observer seat and it made an incredible difference, so now I don't have to drive around with the port ballast filled to get the boat level.

TRBenj
04-24-2006, 12:18 PM
Not sure exactly when that changed. I've got a friend with an 82 and he definitely has a RH rotation engine.

Most Correct Crafts use RH props. Before the 1.23:1 PCM PowerPlus tranny was introduced in '89, the motors were reverse rotation. The 1.23 tranny reverses the rotation, so all motors that use it are standard rotation engines (like my '90).

The few exceptions are the Chevy motors (454 in Barefoot Nautique, the 350 and 307 were options in the 70's-80's). I believe these boats used standard rotation and LH props. Not sure about the older boats with the rarer Chryslers, as there are a few out there with 318's and 340's.

There has been talk about reversing the pump in the tranny to allow the use of a LH motor and a RH prop for those that are re-powering. Not sure if this is possible or not.

Storm861triple
04-24-2006, 12:32 PM
There has been talk about reversing the pump in the tranny to allow the use of a LH motor and a RH prop for those that are re-powering. Not sure if this is possible or not.
That won't work. The trans is not a "fluid drive" w/a pump providing motive force. There IS a pump, and it does pump fluid, but the function is to provide hydraulic pressure to move actuators (pistons) that engage clutch packs. There are two clutch packs in the trans; one which DIRECTLY couples the input shaft and the output shaft, making them turn as one. The second clutch engages a planetary gearset (which is why it make that noise in reverse). The use of the planet set is how you get reverse. In neutral, neither clutch is engaged so the input shaft spins nothing, except the pump, which is just pumping fluid back to tank.

You COULD rework the shift linkage to engage the reverse planet set when you shift into "Forward" onteh shift lever, and you would have a RH rotation at the prop. However, the trans is not designed for continuous load on the reverse planet set, and asside from being incredibly noisy all the time the planet set in the trans would eventually fail.

-Tom

east tx skier
04-24-2006, 02:20 PM
That won't work. The trans is not a "fluid drive" w/a pump providing motive force. There IS a pump, and it does pump fluid, but the function is to provide hydraulic pressure to move actuators (pistons) that engage clutch packs. There are two clutch packs in the trans; one which DIRECTLY couples the input shaft and the output shaft, making them turn as one. The second clutch engages a planetary gearset (which is why it make that noise in reverse). The use of the planet set is how you get reverse. In neutral, neither clutch is engaged so the input shaft spins nothing, except the pump, which is just pumping fluid back to tank.

You COULD rework the shift linkage to engage the reverse planet set when you shift into "Forward" onteh shift lever, and you would have a RH rotation at the prop. However, the trans is not designed for continuous load on the reverse planet set, and asside from being incredibly noisy all the time the planet set in the trans would eventually fail.

-Tom

Thomas, this may be a dumb question, but would that be essentially the same as putting a rh prop on there and driving it hard in reverse?

88 PS190
04-24-2006, 03:06 PM
No no.

Here is the low down on the velvet drive.

There is a pump, it chooses the direction of fluid pressure. Essentially when the engine is turning there is pressure in the tranny. Depending on which way the engine turns the pump gets indexed so its always turning in the pressurized direction. (not backwards)

This pressure is then controlled by valves, connected to the shift linkage. When the linkage is turned to F and the pump is indexed correctly it locks the tranny into forward gear. When it is N the assembly is unlocked (this is where you get shafts turning in neutral, there is still some contact, just not locked together, and if you have glaze they contact a bit and the shaft creeps)

Now, if you want to use a velvet drive tranny you set the pump to the correct direction of rotation, and bolt it to the engine. You then attach a matching direction prop to it. And the engine turns the tranny, which rotates in the same direction when on the input and output onto the shaft, or if you go to reverse, the pressure causes the tranny to shift into putting the output through a planetary gear (differential style)

If you put it w/ an opp prop and same engine and run in reverse then the prop goes the other direction than the engine. If you change the pump index, and engine and prop then forwards is still forwards, and the trans spins the other direction on input and output.

These trans are very simple items.

The velvet drive trans will work on either LH or RH setups, so long as you set the pump to the right index direction to always have positive pressure, and give it a propellor w/ the correct Prop Pitch.

Storm861triple
04-24-2006, 04:50 PM
East TX, what I said would be exactly the same, but read the post below for more clarification....

BTW, Not a dumb question at all. :)

-Tom

Storm861triple
04-24-2006, 04:57 PM
88PS, you and I are saying the same thing, pretty much, but in a different way. The only thing you have added to what I said, is that if you run the ENGINE backwards, you can index the pump in it's housing and the trans will work equally well for RH rotation, still using the "forward clutch pack".

I misunderstood TRBenj's post, and your answer is correct in response to his post. Sorry about the mix up.

-Tom