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Are all Skidoo/Seadoo Rotary Valves Gear Spline's the same Size, and OD?

This Carbon Tech Rotary Valve on Amazon says:

  • Space-age technology for your Ski-Doo
  • Carbon fiber rotary valve is stronger than steel and weighs half as much
  • These valves can stand up to the toughest punishment and will not harm your engine
  • 155 deg. great for low/mid rpm; 159 deg. for mid/tapered; 163 deg. and 169 deg. for superstock to modified snowmobiles.
  • -----------------------------------------------------------------------------------------------------------

So I take it, there are other Degree Valves out there, or you can Custom cut your own. Does anyone have a 2D/3D CAD Model of the Skidoo RV Valve?

Anybody used one of these Carbon Tech RV Valves, Good/Bad?

Here is a 163 Degree Rotary Valve.
 

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There has to be a lot of different ones because there is like 700 for sale on ebay under skidoo rv. LOL

As far as the gears go on the RV I know that some were all one piece and some you could remove and change.
 

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I have ued the Carbon tech Rotary discs and found that they like to twist the center out of the Disc! I

I have a 169 degree Carbon tech Disc that I use for a pattern to cut a stock disc. You can use them if you want but when they come apart they make a mess in the cases.

The true size of the discs Are in any of the racers hand book from 1992 to 1999!
 

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Have never tried them but can sure imagine the mess they would cause if one did come apart at high RPM, would most certainly require a total tear down if bits and pieces went through the engine. That said

carbon fibre composites have successfully replaced a lot of metal parts will great results. Could be this is the future after a bit more evolution of the product.
 

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Discussion Starter · #7 ·
I have ued the Carbon tech Rotary discs and found that they like to twist the center out of the Disc! I

I have a 169 degree Carbon tech Disc that I use for a pattern to cut a stock disc. You can use them if you want but when they come apart they make a mess in the cases.

The true size of the discs Are in any of the racers hand book from 1992 to 1999!
Ok, Thanks for all the input. I wondered if they held up under stress. I was also thinking if you had the correct dimensions, you could probably Laser/Water Jet your own.
 

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Used one on a '95 583 trail sled. Miles on them would wear them down and it would get thin.

-grover
 

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Used one on a '95 583 trail sled. Miles on them would wear them down and it would get thin.

-grover
Are all Skidoo/Seadoo Rotary Valves Gear Spline's the same Size, and OD?

This Carbon Tech Rotary Valve on Amazon says:

  • Space-age technology for your Ski-Doo
  • Carbon fiber rotary valve is stronger than steel and weighs half as much
  • These valves can stand up to the toughest punishment and will not harm your engine
  • 155 deg. great for low/mid rpm; 159 deg. for mid/tapered; 163 deg. and 169 deg. for superstock to modified snowmobiles.
  • -----------------------------------------------------------------------------------------------------------

So I take it, there are other Degree Valves out there, or you can Custom cut your own. Does anyone have a 2D/3D CAD Model of the Skidoo RV Valve?

Anybody used one of these Carbon Tech RV Valves, Good/Bad?

Here is a 163 Degree Rotary Valve.
From Skidoo There were Originally were 8 different cuts most are not available any more, now I just buy the one I can get the easiest then use my Carbon tech disc for a template and cut my own! When your cutting a new disc make sure you use a RV gear to keep the drive teeth lined up to keep the timing the same as the stock disc! There are different ways to do it but I clamp my disc between two blocks of wood and cut them with a grinder!
 

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Discussion Starter · #11 ·
From Skidoo There were Originally were 8 different cuts most are not available any more, now I just buy the one I can get the easiest then use my Carbon tech disc for a template and cut my own! When your cutting a new disc make sure you use a RV gear to keep the drive teeth lined up to keep the timing the same as the stock disc! There are different ways to do it but I clamp my disc between two blocks of wood and cut them with a grinder!
Ok, my local welding shop guy has a small 4' x 5' CNC Water Jet, and he cuts things pretty cheap. If I can find the RV Spec's, I might try and have him cut me one to see how it turns out. I use the Free 2D CAD program from www.emachineshop.com to draw simple parts. It also allows you to view it in 3D. Drawing the RV Disc into CAD is fairly easy, and fast, doing the Center Gear teeth is what would take me some time to do. The Water Jet use's DXF CAD files.

Anyone know the Metal Type Spec's of the Stock ones, like maybe 316 Stainless?

If your looking at the RV Valve area, with the Mag End to the right, is the bottom of the right Intake always considered ZERO Degrees, and then go left?
 

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Ok, my local welding shop guy has a small 4' x 5' CNC Water Jet, and he cuts things pretty cheap. If I can find the RV Spec's, I might try and have him cut me one to see how it turns out. I use the Free 2D CAD program from www.emachineshop.com to draw simple parts. It also allows you to view it in 3D. Drawing the RV Disc into CAD is fairly easy, and fast, doing the Center Gear teeth is what would take me some time to do. The Water Jet use's DXF CAD files.

Anyone know the Metal Type Spec's of the Stock ones, like maybe 316 Stainless?

If your looking at the RV Valve area, with the Mag End to the right, is the bottom of the right Intake always considered ZERO Degrees, and then go left?
put your red '0" line on the top of the Mag side port, every disc has a small number and a large number! now come back down the degree wheel the amount that is listed for the small number1 place a mark here

This is were the leading edge of the disc will be with the Mag cylinder at top dead! you can check the timing by rotating the Engine the Degree wheel should match the degrees listed for the Disc your using!
 

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The RV degree wheels I'm finding are not splined for the cross shaft. Is the hole in the center tight enough for a friction fit? What keeps the RV degree wheel from slipping on the shaft and throwing your measurements off?

Anyone have an opinion if the Carbon Tech RV's would be good enough for a race motor that sees little miles and regular maintenance?

Is there a carbon RV that is comparable to the 207 RV?

Is there a source for 207 RV's or do you just buy a less aggressive RV and cut your own?

Were more aggressive RV's available through the SkiDoo race department.

Anyone willing to share top secret info about what would be an optimum RV for a 580 cc twin piped motor. Something spinning 8500 RPM and 150psi of compression.

Thanks
 

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There is no need for the degree wheel to have splines, it is only used for a static measurement from the port.

I have no experience with the Carbon Tech valves. There may be lots in service with no issues but the horror stories you do here are enough to make me stay clear of them. Considering a stock valve basically never fail why take a chance?

Everyone working on these engines should get a copy of the rotary valve guide that Bombardier put out. It shows actual size of every disk so you can identify what you have. Theres all the timing info as well. Or better yet get the racers hand book like Mydoo suggested.
 

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you can grind whatever you want out of a plain old 470-521 valve. We used to have a stack of custom ground ones a foot tall for the race sleds. Just mark it out and either cut it or just grind it down with a bench grinder, they aren't THAT important to be absolutely perfect.
The reason I like to keep the drive teeth lined up wit a stock disc is to keep the disc Isa metrical so I can flip the disc to get the marks aligned, When I build an engine I like to assemble the engine with out crank case sealer then flip the engine up side down and remove the bottom this war I can lift the crank and turn it to align the RV gear so the marks align perfectly this way the engine will always run the same every time it is rebuilt! After the marks all line up I seal the bottom and torque the cases!
 
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