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  View original topic: Full-flowing a VW case according to?
tundrawolf Thu Feb 04, 2010 8:35 am

Hello,


I have been wondering, I am about to remove my engine for some top end service and want to split the case and full flow it.

My question is, according to dune-buggy.com, when you full flow the case, you are piping into a pressurized oil gallery.

Now, I have a question. Wouldn't that mean that the oil has to fill the lines to the filter, then fill the filter, then fill the other line before the crankshaft gets to see any pressurized oil? I understand there are check valves in the filter to prevent the oil from draining when the engine is off, but it seems to me that this is a bad idea.

It seems to me a better suggestion would be to tap into the return gallery, if possible. The gallery where the excess oil is returned to the sump. That way, the bearings are always pressurized with minimal oil travel. Worst case scenario the sump sees no return oil until the oil filter fills.

Could this be done and tapped into possibly at the oil relief valves?

chiprodriguez Thu Feb 04, 2010 10:01 am

The entire oiling system of the VW engine is pressurized that is regulated by the pressure relief plug(s) with the exception of the oil pick up tube in the sump. The oil return is tapped into the main artery on the left case half. As far as your no oil question, this is true only when you install a new set up and the system is dry. In that case, always crank the engine over with the coil wire disconnected until the oil light goes out. The system is now primed and ready to start. I usually do this same practice every time I change the oil. Priming the filter before you spin it on also helps if it's mounted vertically. Drilling and tapping the case can also be done without splitting the cases.

tundrawolf Thu Feb 04, 2010 10:05 am

Thanks for the reply. But how do you know if your one way check valve is functioning?

chiprodriguez Thu Feb 04, 2010 10:37 am

The full flow system will remain primed when you shut the engine off until the next time you go to start it. Just watch the oil pressure light/gauge when you first start it. It will react immediately (pressure). The only spin on filter that I know of that has a built in check valve is the Mann (black in color) filters. I use them in water cooled applications but is not necessary in air cooled full flow applications.

tundrawolf Thu Feb 04, 2010 11:37 am

I thought I have seen a ball style check valve in the VW full flow air filter housings. Do you know how long it takes for the oil to drain and the lines be empty? 3 days? A week? Sometimes my VW is not going to be used for several days on end. Is there maybe an inline check valve that could be used? I really want a spin on oil filter. Is there a gallery schematic that shows the full flow tap points?

mondshine Thu Feb 18, 2010 12:47 pm

Tundra-
Here's a couple of photos of the setup on my daily driver. It's not a spin on, but it is very easy and clean to service.
Look into the Canton Mecca filters at:
http://www.cantonracingproducts.com/cgi-bin/commerce.cgi?search=action&category=2502
I've used them for over 25 years and think they're the best.
My '74 Thing uses the large one, but my '71 Super uses the small one.
Here's a photo of the Beetle. You can see that it's nice and compact, and the lines are short. Inlet is at the bottom, outlet is visible. The element lifts out after removing the top.

I am using a Gene Berg standard oil pump cover; no bypass. The CM filters can take much more pressure than a VW can develop. The oil inlet on the engine is the usual 3/8" pipe thread. The fittings you can see in the previous photo lead to this inlet just out of view (at 7 o'clock on the pulley).
A 1 psi cracking pressure check valve (Kepner model 508 3/8" NPT X 1/2" JIC) is fitted to the outlet from the pump to prevent drain back into the pump. From there, oil flows through a short hose to a bulkhead fitting which secures the filter body to the rear engine tin.
Here's a photo of the bottom:

With this setup, oil pressure is excellent and immediate.
If you are paranoid about dry starts due to infrequent use, Canton Mecca makes a cap for the filter which allows connecting an Accusump to the system to pre-oil before startup. You'll need the check valve to do this.
My '74 Thing is set up that way...works great.
Good luck, Mondshine



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