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Oil filter questions

Posted: July 10th, 2013, 12:57 am
by Jeremy Soule
Vee oil filter.
I have heard the term “Full flow oil filter” but not sure what that means, does that refer to the filter itself or the housing that holds the filter? I am putting together a FST that came without an engine. The filter that came on the car is rather small with no part number visible…. Which leads to a more interesting question, our standard oil pressure tap is in the block between the pump and the oil cooler/oil filter. Would it be better to check the oil pressure after the cooler/filter, and before the main bearings?
Thanks for your answers. Jeremy, FST Tucson Az.

Re: Oil filter questions

Posted: July 10th, 2013, 6:47 am
by Ed Womer
Hi Jeremy, without knowing where the filter is located it would be hard to figure out what it would be but a AC Delco PF53 which comes on a Saturn car which I have will also work on a remote oil cooler bracket and it is the filter that I used on my car for the last 10 years.
As for the location of the pressure guage I would let it at the stock location since then it would be easy to compare to any other engine.
Ed

Re: Oil filter questions

Posted: July 10th, 2013, 8:38 am
by FV80
Jeremy,
To directly answer your question.. "full flow" means that *ALL* the oil flows through the filter (and/or oil cooler). That means that the block has to be replumbed such that the oil filter (and/or cooler) is 'inline' before the oil enters the block/case. As designed, the oil is pumped from the pickup through THE CASE - to the main oil galley and also to the 'BYPASS' port at the top of the block between cylinders 3 and 4. "excess" oil goes into the bypass and CAN go through an oil filter, oil cooler or both - but most of that oil goes to the bearings .. at least when the engine is HOT. In order to go "full flow", the oil has to be pumped OUT of the oil pump - generally by a special pump cover plate - it can then go through whatever else you want it to pass through before it enters the case again .. and generally, the bypass port is blocked off when that is done.

Hope that helps you to understand .. and I hope I have explained it well enough.

Steve, FV80

Re: Oil filter questions

Posted: July 10th, 2013, 9:10 am
by SR Racing
Jeremy, Do a web search with the following and you will get several pics of non-full flow, verses full flow systems. I think once you see them it will all make sense : vw full flow oil system diagram

Ed and Steve are correct and there are many ways to convert to a full flow system.

Re: Oil filter questions

Posted: July 10th, 2013, 4:35 pm
by brian
Jeremy, oil pressure is a constant throughout the motor. OP is resistance to flow and generally reflects the highest resistance in the entire system. The relief piston nearest to the flywheel is the pressure controller in our motors and will pop off at some pressure. Using a higher spring in this piston can increase overall oil pressure but doesn't necessarily mean greater engine life. Stiffer springs will cause cold oil pressure to be much higher and caution must be used during cold am track sessions.

Filters are generally chosen by thread on the oil filter mount and size of gasket. Within that criteria, I look for the largest flow openings in the filter. If you open a few boxes at the part store, you will see a lot of variation in size and pattern of oil flow openings, go for max flow. Some folks choose not to use FRAM since quality can be challenged. NAPA carries a gold label that is quite good so is WIX.

Re: Oil filter questions

Posted: July 10th, 2013, 8:16 pm
by Jeremy Soule
Ed, Steve Jim and Brian,Thanks for your replies. I did do the web search, I get it now, the cases and pump/cover have to be reconfigured to get full flow filtration otherwise a percentage of the oil is dumped back into the sump.
Here is where I’m at. In my quest for track time I purchased a cheap buggy with running engine for $300 kept some parts sold some parts…. the racer now runs and drives and I’ll take it to the local autocross for a shakedown shortly then on to the road course. The oil filter as the car came to me was mounted way out back where the rain light would be (this is Arizona) with about 3 feet of hose each way so I am presently mounting it in the case area. At this point I think I won’t reconfigure to a full flow filtration. Later I will do a full “race” motor and have it done right.
So with a factory “bypass oil system” and an aftermarket oil cooler and filter plumbed to the stock oil cooler location in your estimation what percentage of oil is being filtered and cooled assuming warm oil and say 4500 RPM? Jeremy

Re: Oil filter questions

Posted: July 10th, 2013, 10:31 pm
by FV80
Jeremy Soule wrote:...So with a factory “bypass oil system” and an aftermarket oil cooler and filter plumbed to the stock oil cooler location in your estimation what percentage of oil is being filtered and cooled assuming warm oil and say 4500 RPM? Jeremy
Jeremy,
Sorry - I can't answer your question as asked. What I can tell you is that I (and most others that I know) do NOT run "full flow" systems. There are issues with full flow - mostly about excessive pressure on cold days and no way to "relieve" it as well as "any leak" is majorly catastrophic. I ran full flow, briefly about 25 years ago and then changed to a bypass filter/cooler set up - it seems to be more reliable and "adequate" to get the job done. That said, there are a number of folks that swear by the full flow concept as well. IMHO, the extra plumbing required by full flow is more trouble than it's worth...
ymmv,
Steve, FV80

Re: Oil filter questions

Posted: July 11th, 2013, 11:37 am
by SR Racing
I agree with Stevan. There is no real advantage to a full flow system on a Vee. The bypass valve only comes into play when pressures exceed 50+ lbs, and that is GOOD. Adjusting the spring (increasing tension) only increases the PEAK observed oil pressure (when cold). It will not affect normal at temp track pressures. If for some reason you had a defective bypass valve that leaked excessively, a full flow system would hide the problem. Stay non-full flow and save weight, money and trouble.

Re: Oil filter questions

Posted: July 12th, 2013, 1:40 am
by Jeremy Soule
Very interesting, “If it aint broke….”
The last few days I’ve noticed quite a few type I’s driving around town in +100 deg. weather, of course they are not seeing the high RPM of our formula car engines but the engine is pushing a heavier car and in stop and go driving too. Quite a testament to the original oiling design.
Thanks all. Jeremy

Re: Oil filter questions

Posted: July 12th, 2013, 8:04 am
by FV80
The biggest difference in the vehicles you see driving around in street traffic is that they are running the FAN HOUSING AND FAN that VW built. It works GREAT and is VERY effective -- it just costs the engine about 6 HP at street speeds and becomes obscene as you pass about 5000 RPM. When we remove that assembly for FV racing, we introduce a whole host of new problems for ourselves regarding cooling the engine and the oil....

Steve, FV80

Re: Oil filter questions

Posted: July 12th, 2013, 2:50 pm
by brian
I have noticed that hanging several pounds of stuff, ie filter, block and cooler, on the original platform can lead to case failures and cracks. This is more probable if you are running a used case that may had a groove worn in on the platform by stock sheet metal.

I agree with the guys about full flow being a bit more work but I prefer filtering ALL the oil before it goes into the engine. It will prevent FOD damage to bearings and extend life. It adds to total capacity as well and generally cool better. You make the call but don't go cheap. Use quality hose and fittings. The econ push on hose works well and is cheaper.