I'm in the process of building a new sled, and would like to go ball bearing. I have access to a gt2860rs, and a t3/t4 ball bearing, and i'm wondering if anyone here knows what these require for pressure, and volume. Garrett says 30-40 psi, but I believe they come with a restictor built in, and many of the kits for sleds have a very small electric pump (~5 psi from what I can find). I would love to go Comp oil less, but can't get myself to shell out the cash they get for them. This is a drag only sled that will see boost (7-10 psi) for less than 10 seconds per pass, and will have a stand alone oiling system as its a 2 stroke.

 

because of the short amount of use time would a walbro fuel pump and fuel reg work ???

 

That has been considered... On our other sleds (journal bearing) we were running shur-flo pumps, a fuel reg, or just a fixed orifice bypass, and it worked great, but would like to simplify things on this build. Many of the kits run the small pump, and no reg, but I just discovered they're $300 pumps. I may go back to that setup (or try the Walbro) with another journal, or just cough up the money for an oil less. The oil less would make things very easy.

 

You have to watch the viscosity differences with oil and gas. They are worlds apart, and that difference affects filters, regulators, and pumps. I would never trust a fuel system pump on oil. Oil pumps are usually gear rotor positive displacement pumps that take considerable shaft torque to move the sticky oil (viscous liquid), while fuel pumps are centrifugal or diaphram. Some diaphram or plunger piston pumps will work OK on oil or gas, but I would test it.

 

THIS^^^^^^^


If you want to go with your own remote oil supply system, put in a turbowerxs exa pump. Its a gear pump that can be used for, I believe, up to 50psi oil feed, but I'm not sure what the flow rate is at that pressure.

http://turbowerx.com/Scavenge_Pumps/Exa-Pump/Exa-Pump.html

 

Good point. The pump I'm looking at using is a vane type, and most are using a 10wt oil, so I may give it a try.

 

Just to put some numbers on it (I used to design some automotive and marine gauges and things), if I recall correctly, gasoline has a typical viscosity of 0.5 to 1 cts.

Thin motor oil should be a few thousand.

So thin SAE 10 motor oil is somewhere about 4000 times "thicker" than gasoline.

There is a substantial difference in pump design requirements, so being 4000 times thicker, you run a substantial risk of not having the correct pressure and/or flow.

 

I have built 3 other sleds using shur-flo pumps, and haven't had a failure in about 7 seasons of racing, so that will be my fallback if the vane pump doesn't work. They're about 1/3 the cost of the turbowerx, and about the same size.

 

Thanks for the info, I understand that there is a major difference between gasoline, and even thin oil, and this thread has gotten a little off track.. lol. If I go back to a jb turbo i'll most likely go back to the shur-flo, but was curious the lubrication needs of a bb turbo. It appears that they will be fine with a very limited oil supply.

 

If I were to try the vane pump i'll do plenty of testing with the oil I plan to run before destroying a good turbo.

 

Hope my last few posts didn't come across wrong.... I appreciate all the info, but feel I have a pretty good grasp on the stand alone oil setup, I was hoping to find some real world experience with bb oiling.

 

Well, that number you are looking for would probably have to come from the turbo's manufacturer. Some units have an oil restriction orifice built into the CHRA, but that depends. (But you already know all this.)

 

I agree, and have read up on what Garrett recommends, but there seems to be a big discrepancy between that and what most of the kit manufactures are doing, and getting any accurate info from them is proving pretty tough. As a drag only sled the bb turbo doesn't help a great deal if I still have to run the same bulky pump and tank, and the jb turbos have been bulletproof so far.