Barn of Parts Frozen Roll Over Valve Solution

[hibshman25]

The frozen roll over valve has plagued some and I'm sure contributes to finding a weakly bonded area of the RTV oil tank seal. Many have removed the roll over valve with success and just vented the breather line to atmosphere. If not vented properly the line could also freeze over and plug so I've come up with another solution.

I'm making a custom fill cap that is drilled and tapped to accept a pressure relief valve. The oil tank is a good heat sink and by utilizing a billet aluminum cap this heat will easily transfer and should keep the relief valve free of any ice. Even if reliefe valve has a little ice build up it should thaw quite quickly. Will likely use valve with a test ring so one could easily just test it to ensure it is free and not froze. In a worse case scenario if you can't free it with the test ring, you simply unthread the cap and take into motel to thaw it out.

Will be hooking up a pressure gauge to the cap this week to see how much pressure builds in the tank under normal circumstances and then will size relief valve just above that operating pressure.

Here's my theory. I think the freeze up occurs when the sled cools down in cold temps after a ride. Upon start up the pressure builds in tank until roll over gets a chance to thaw out. The relief valve will bleed off pressure until engine bay heat thaws out the roll over valve.

 

[MrSled]

The frozen roll over valve has plagued some and I'm sure contributes to finding a weakly bonded area of the RTV oil tank seal. Many have removed the roll over valve with success and just vented the breather line to atmosphere. If not vented properly the line could also freeze over and plug so I've come up with another solution.

I'm making a custom fill cap that is drilled and tapped to accept a pressure relief valve. The oil tank is a good heat sink and by utilizing a billet aluminum cap this heat will easily transfer and should keep the relief valve free of any ice. Even if reliefe valve has a little ice build up it should thaw quite quickly. Will likely use valve with a test ring so one could easily just test it to ensure it is free and not froze. In a worse case scenario if you can't free it with the test ring, you simply unthread the cap and take into motel to thaw it out.

Will be hooking up a pressure gauge to the cap this week to see how much pressure builds in the tank under normal circumstances and then will size relief valve just above that operating pressure.

Here's my theory. I think the freeze up occurs when the sled cools down in cold temps after a ride. Upon start up the pressure builds in tank until roll over gets a chance to thaw out. The relief valve will bleed off pressure until engine bay heat thaws out the roll over valve.

View attachment 149451

The testing I have done the roll over valve pops at 1 lb or less so that relief valve should maybe at about 10lbs max, but the problem I have is that when that pops will it spray oil vapor all over the hot exhaust and turbo? I have not tested operating pressure but it cant be much if the rollover valve opens that easy.

 

[snowfever27]

I’ll take one!

 

[hibshman25]

The testing I have done the roll over valve pops at 1 lb or less so that relief valve should maybe at about 10lbs max, but the problem I have is that when that pops will it spray oil vapor all over the hot exhaust and turbo? I have not tested operating pressure but it cant be much if the rollover valve opens that easy.

A relief valve with a side discharge hole would allow us to direct the pressure away from exhaust if oriented correctly.

 

[hibshman25]

Threaded a pressure gauge into one of my plugs to check the operating pressure in tank when sled is running. It reads only about 2 psi of pressure. If pressure is that low then I am thinking a 5 psi relief valve would be perfect. If the valve does get activated 5 psi of pressure will be a very minimal spray.

I ordered in a 5 psi valve with side discharge and did a test fit up to ensure it will clear the panel. Was not able to find one with a test ring suitable for extreme cold. The valve shown in picture is good for -30F.

 

[hibshman25]

Today I pinched vent hose shut to simulate frozen roll over valve and started the sled. Left it running and walked away from it for few minutes. When I got back to it the relief valve was cycling open to relieve pressure. Going to repeat this but with guage to see just how high pressure builds.

Ps...i have my rubber oil tank gasket on this sled so will be good test for it too!

 

[rla1]

Awesome testing for all possibilities, are you going to test gasket without having relief valve on tank and block vent hose?

 

[MrSled]

Today I pinched vent hose shut to simulate frozen roll over valve and started the sled. Left it running and walked away from it for few minutes. When I got back to it the relief valve was cycling open to relieve pressure. Going to repeat this but with guage to see just how high pressure builds.

Ps...i have my rubber oil tank gasket on this sled so will be good test for it too!

When will these be ready for sale on the site?

 

[fourload]

You are going to sell a ton of these if it works as advertised. Easy fix and good to -30. Let us know when it is for sale.

 

[NYTurbo]

It's usually the hose to the roll over valve that freezes, one would think that little pressure relief valve would be no different ?

 

[hibshman25]

It's usually the those to the roll over valve that freezes, one would think that little pressure relief valve would be no different ?

Moisture really cant accumulate in the valve mounted vertically so less likely to freeze. Roll over valve lays on its side so moisture can’t drain via gravity.

If it were to freeze my theory is it will thaw out quickly as heat transfers to it from oil tank.

Guys that are conscientious of things could very easily remove plug and warm it up...like the pre red relay days!

 

[hibshman25]

Curious as to just how much pressure builds in the tanks with a frozen roll over valve, I put a pressure guage on tank this morning with the pinched off vent hose and fired it up. I was quite shocked as to how much pressure built up in a matter of few minutes!! It climbed up to 55 PSI while sled just sat and idled.

I've heard some first hand accounts of Winders catching fire, and I suspect 55 psi of pressure misting oil past the RTV seal onto the exhaust would be a very logical explanation.

 

[rla1]

Sounds like a good test for your oil tank gasket.I am guessing that your gasket held its seal ?

 

[Chris Rose]

Curious as to just how much pressure builds in the tanks with a frozen roll over valve, I put a pressure guage on tank this morning with the pinched off vent hose and fired it up. I was quite shocked as to how much pressure built up in a matter of few minutes!! It climbed up to 55 PSI while sled just sat and idled.

I've heard some first hand accounts of Winders catching fire, and I suspect 55 psi of pressure misting oil past the RTV seal onto the exhaust would be a very logical explanation.

View attachment 149577

Another good reason to get rid of the factory valve assembly!

 

[1nc 2000]

Curious as to just how much pressure builds in the tanks with a frozen roll over valve, I put a pressure guage on tank this morning with the pinched off vent hose and fired it up. I was quite shocked as to how much pressure built up in a matter of few minutes!! It climbed up to 55 PSI while sled just sat and idled.

I've heard some first hand accounts of Winders catching fire, and I suspect 55 psi of pressure misting oil past the RTV seal onto the exhaust would be a very logical explanation.

I wonder what the max pressure the scavenge pump puts out from the engine to tank.
Most likely higher than the engine oil pump so the engine wont starve for oil. The good thing about this is it wont blow the seals out on the engine due to the valve cover vent line.
Nice work.