Full-flow oil filtering

[912s]

After reading chickybok’s – “Stage One Complete” just know I again started wondering about adding a full-flow setup to my car.

David’s full-flow setup raises a question, it appears to be he is taking oil from the pump cover going thru the filter and then returning to the engine at the left of the distributor without the addition of an external cooler?

Is this how others here are doing this? From what reading I've been doing - "Duane Spencer & Vic Skirmants", both talk about coming out of the pump cover and then returning thru the side of the timing cover.

Also an external cooler - is it only necessary in a car that will be raced? Or is it better to fit one into the full-flow setup and remove the stock cooler for better cooling on the #3 cylinder?

One more thing - pressure relief. Is it necessary to put a pressure relief valve between the pump cover and filter for cold starting to avoid excess pressure blowing off lines? Do you return the oil to the pump so it will eventually get filtered? Can this cause the engine to be oil starved when cold?

I don’t have any intention of racing it just a desire to filter ALL of my oil and maybe make the engine last longer for the daily commute(75-80mph).

Thanks,

[craign]

Check this thread on another BBS on just this topic.


http://www.hillmanimages.com/mailman/sc912.pl?read=1076

Craig

[chickybok]

Hi

My full flow system is not coming from the cover. I know quite a few VW systems set up like this but with the 912 the block has be machined in two places. The first is just left of the distributor and the other is into the left side of the block.

I will try and take some more close up pictures of the point of exit/entry.
Hopefully this weekend.

david

[Roland Kunz]

Hello

The full flow system is basically to have a full flow oilfilter on the 356/912 engines. You also can add a external oilcooler but on a normal engine the stock coolingsystem works well enough.
However I always integrate a thermostatically full flow oilcooler.
The problem with the full flowsystem is that the cold oil can exceed over 30 bar pressure wich normaly bursts the oilfilter or a other weak link.

I normaly use the mocal thermostat on the filter wich has a open bypass to the rear so if the oilsystem has a overpressure bypass using the oilcoolersystem as expansionvalve ( some 8 m Oilines will soak the exedding overpressure )
The other way is a overpressurebypass wich has a bleedline going back to the case ( where the stock oilline was ).

Full flow systems major bebefit is that you have the dirt outside the engine and don´t pump it trough the oil galerys into the bearings.

If you go to improve the engine power output you have to make some alternations to the oilsystem to improve the bearing lubrication and do some other small changes needed for High Performance engines who have to rev much higher then the stock units.

Grüsse

[mein12]

Hello,

I have used my full flow set-up for ten years. I have gone with and without external coolers depending on what type of motor I was running at the time.
I have never used a themostat because the proper high pressure lines and filter will not burst. Use can use a Redline or fram HP-1 filter with no worries.
The system I use exits the the engine at the pump cover and then continues to the oil filter. From there it re-enters the case through the side of the timing cover.
I currently use no external cooling and have had no problems this summer in Ca. .
I prefer this set-up over returning through the small ports at the top of the case. The flow rate is reduced to a point that is not acceptable at high revs.
I hope this helps.... JMB

[Roland Kunz]

Hello

If you have a race application you can run without thermostate.

On street engines you always need a thermostate to have the engine run into the best temperaturerange. To cold is worser for the engine then to hot. So the best for the enginelife is a very short heat up cycle.

The thermostat is needed mainly for that but it also works as a pressure relief. However we have to use the FRAM racing filter as normal filters still can burst.

Grüsse