Full flow oil system, is this bs or what? Options

[kdfoust]

I'll be getting my case back from RIMCO pretty soon and I'm thinking about the oil system. I'm planning to run a 30mm Schradeck (sp?) pump. I've read a number of threads about "full flow" oiling for TIV engines and I guess I don't get it.

For full flow on a TIV you do what?
Plug or modify the oil filter bypass valve that I've circled below? Then what?
Modify the oil pressure relief valve (new spring I guess) to accomodate higher pressure? Then what?

At what pressure does the stock cooler blow open like a pan of Pop-Magic pop corn?

TIA,
Kevin

[Mark Henry]

Oh boy…you can get several different opinions on this one…

“I” would plug the filter by-pass and put a T1 (single relief, heavier) spring in for the pressure relief valve. This I have done with no ill effects.

On my new engine I’m going to stretch the other relief spring (small one by the lifters) a ¼” or so. I’m also planning on reaming and match porting my oil galleys as much as I can.

[SLITS]

I always thought that full flow meant that all the oil went through the filter without a bypass under cold or high pressure situations.

Does this mean the "lean green machine" is going back on the road? BAJA Time!

[Mark Henry]

I always thought that full flow meant that all the oil went through the filter without a bypass under cold or high pressure situations.

Full flow just means that it can not bypass the filter.

You MUST retain the pressure relief valve (the one in the case) or you will blow out the cooler (or bypass the cooler depending how you block it).

[cgnj]

Tom Perso did this to his 2270 that was originally installed in his bug. That motor is now in his 914. Hopefully he'll post on this thread.

Carlos

[Jake Raby]

I do it to every engine that we build that goes upright! Getting the full flow fitting past the 914 engine mount is quite a job.

Doing this gets rid of the pesky restrictive stock filter housing and all its 90 degree passages and routes the oil through an external filter and cooler if you need.

[kdfoust]

It seems that there are a couple of methods here (bearing in mind this is a 914 application that will have the factory cooling shroud,etc.):

Method 1) Plug the existing oil filter bypass valve. Compensate on the oil pressure relief valve with a stronger(stretching exisiting also) spring.

Method 2) Some sort of external plate or plumbing that takes the factory filter housing away and sends oil to an external filter and/or cooler. Does this mean that you've blocked off the factory oil cooler and completely rely on the external cooler?

Am I getting it yet?

Kevin


PS
I wish this was called "full filtering" or something so us outsiders could decode it easier... (IMG:style_emoticons/default/wavey.gif)

[Mark Henry]

Method 1) Plug the existing oil filter bypass valve. Compensate on the oil pressure relief valve with a stronger(stretching exisiting also) spring.

OK... the oil filter bypass valve is just a safe guard in case the filter becomes plugged. All modern filters have this function built in and if you have a major failure (such as a flat cam) it will send metal shards straight to the bearings. There is less chance of this happening with the filter bypass disabled.

The stronger pressure relief spring is to compensate for the increased oil pressure of the 30mm pump.

Method 2) Some sort of external plate or plumbing that takes the factory filter housing away and sends oil to an external filter and/or cooler. Does this mean that you've blocked off the factory oil cooler and completely rely on the external cooler?

No, you can do this without removing (the function) the factory oil cooler and have an external filter and/or cooler.

On the upright conversions that Jake does, he uses a Gene Berg pressure relief cover (part # GB 239), this cover makes sure that the oil pressure never exceeds the burst point of the cooler.
BUT this cover is hard to use with a stock engine mount (the part that bolts to the case), as it's in the way.

I plan to build a new (modified) mount to get around this problem. Then you do away with the stock filter housing and use a plate or fitting to return the oil.

[ThinAir]

In the Grassroots Motorsports Magazine "Project 914" story on their engine they say this:

Shine Racing Service "removes the oil filter bypass assembly. From the factory, Porsche provided a ball-and-spring assembly to allow oil to flow around the oil filter should it become clogged. While this sounds great in theory, adding something as simple as an external oil cooler will change the pressure to this bypass, causing the oil to simply go around the filter. While we are not presently using an external oil cooler, this oil filter bypass modification is something that Shine does to every 914 engine he builds."

The specific location that they show in the picture is in the top of the oil filter mount. From what I've seen elsewhere about this it simply a matter of taking a punch of some kind and closing up the space.

It seems to me that if you are already in the habit of changing your oil & filter regularly and generally watching over your baby (like adjusting valves regularly and always inspecting the oil screen for debris) that no longer having the relief would be no big deal because the likelihood is so low that you would ever have a clogged filter.

[kdfoust]

Hey Ernie:

Is this what they work on (circled in red)?

Kevin

[ThinAir]

Kevin - That's the place! From the picture in the magazine it looks like they did more than just use a punch to close it up because the surface looks very smooth. Unfortunately the text I quoted previously is all they say about it and the web page about the project doesn't add any more (http://www.grassrootsmotorsports.com/914.html) I'm not sure where I saw something about just using a punch.

[kdfoust]

Okay so I get the mods that you do to have full flow oiling.

Now my question is: why?

It seems that the oil will in general see the filter excepting under plugged filter condition or in very high viscosity oil (cold,cold days for example) situations.

Is oil filtration at the root cause level of the top failure modes for TIV engines?

Thanks,
Kevin

[ChrisFoley]

It doesn't take much pressure to open the bypass, as the spring isn't very stiff.
I removed the ball and spring assy, inserted an aluminum plug and tig welded it shut, on one for a customer. The aluminum doesn't weld too good though - crappy casting.

[mightyohm]

I had no idea there was a valve in there!!

I will have to go look at that. Very interesting!

[Brad Roberts]

Wait until you see a car blow the filter off at the track... pretty exciting and messy.

We run remote filter setups in the 4cyl race cars (the real race engines). I have never seen an issue with a full prepped stock injected race 2.0 engine.


B

[ThinAir]

We run remote filter setups in the 4cyl race cars (the real race engines). I have never seen an issue with a full prepped stock injected race 2.0 engine.

So Brad - does this mean it's a non-issue and you shouldn't worry about making this modification or it's a non-issue because clogged oil filters occur so rarely (IMG:style_emoticons/default/huh.gif)
I'm confused (IMG:style_emoticons/default/wacko.gif)

[Jake Raby]

Blowing filters only happens on cold oil......... I have measured oil pressure over 300 PSI in the main oil line on fire up on a cold morning in my dyno cell!

[machina]

what are we talking when we say cold.

down here 40deg might happen once a year on a race weekend. Usually it is like 90.

dr

[Mark Henry]

I've blown filters before and on very mild hipo engines.
Any engine running a T1 26 or 30mm pump has the potential of popping the oil filter, especially on a cold morning. Better use a good filter.

About 2 months ago on a beetle engine with a FF schadek 26mm pump I ballooned the can and popped the seal. It shot oil 40 feet across the shop plastered the ceiling, wall, floor, 2 bugs and of course my 914. What a mess and piss off, my own fault, I've been cheating for a while and breaking in engines with a cheaper filter. This only took about 3 seconds as I hit the kill switch right away.

I've never had a problem with a Fram HP1, K&N or the Wix filters. These are all Ford V8 filters, the generic number is PH-8A, but never use a FLAPS PH-8A. These are all for the remote filter adaptor.
I know DD will chime in saying Fram sucks (I doubt if he has ever used an actual HP1) but they have never popped on me. The Fram HP1 is just the cheap PH-8A in a heavy can, for 3 times the coin. Still it has to be better for the bearings than a blown filter.

I bet the track guys love it when you oil down the track.

[Jake Raby]

Just don't rev the engine when its cold, and run synthethics.....

Synthetic oils are much thinner and don't blow filters nearly as bad.