A combination of high oil temp and low pressure seems to plague lots of 914 owners.
Engine modifications for more power often exacerbate the problem.
Discussions frequently circle around the function of the primary pressure relief built into the crankcase near the oil filter.
One member described how he reamed the bore and made a new piston, which seems to have solved his low pressure.

I milled away a portion of a crankcase to have a better look inside the pressure relief circuit. What I found was significant wear, and evidence that the pressure relief was allowing oil to bypass the cooler most of the time.

Click to view attachment

My newest product is designed to solve this problem.

Click to view attachment

This little cylinder replaces the stock pressure relief piston and spring in the crankcase.
Primarily what it does is eliminate the oil cooler bypass so the oil goes thru the cooler all the time.
The precisely machined assembly will only allow oil above the preset peak pressure to bypass directly to the sump.
It's also easy to change the max pressure by altering the piston length.

Three prototypes have been made for testing.
We installed the first one in a customer's 2.5L street/track car this afternoon.
In the short time we ran the engine, improved oil pressure was immediately evident.
Further tests will be done to see the effect on oil temp, but we aren't having hot weather here yet.
The other two prototypes are being sent to people in warmer climates with competition cars, ready to put them to the test.
I expect the benefit to be quickly apparent.

Another great product Chris.

We're having consistent 90 degree days down here in Atlanta. If you want to test the prototype here let me know. Looks very interesting.

Let me know when they hit the market.
Jule

What, if any, modifications are required for installation? Can it be done to an assembled engine or installed block?

Way to go Chris!

good one...
interested in one for from the when they hit the market

I'll pm you... curious about a detail

Cool, I am in.

I am in.

I will also volunteer I have a bone stock 2.0 with about 800 miles on a crank up rebuild. I have a ir thermometer ect

Installation takes only a few minutes.
No modification of anything is required.
The hardest part will be loosening the cover.
Be prepared for about a tablespoon of oil to come out.

I would be very interested is this works well. Are you waiting for it to "prove" itself on a few test cases before making more?

Besides getting rid of the spring, any difference between this and the Weltmeister Oil Pressure Booster Kit? Easier install for sure as you don't have to mess around cutting the spring.

The whole oil pressure relief setup is the last thing on my list to get "fixed" to help my oil temps (without going external cooler).

Wow!! I'm in for at least 1. Maybe 3. Is it too early for an approximate cost projection??

I want some operating data before starting a production run.
They may be available as soon as July.

The Weltmeister kit still allows oil to bypass the cooler at relatively low oil pressures, and it doesn't solve the problem of wear inside the aluminum piston bore causing lower operating pressures across the entire rpm range.
My assembly completely blocks the cooler bypass circuit, and is designed to stop leakage past the piston.
Since the sleeve is steel, it will wear much more slowly.


Preliminary cost projection is around $75.

Very Cool!!!

I don't even own a T4...

Wow! Great!

I'm in for one when production starts up.

Thanks

It's not proven yet; there's not much data yet, but there are likely more than a few really talented people saying, "Why didn't I think of that."

Here's a tip of that dark stout to the creative, talented crew at Tangerine, great people.

So, are there any negatives for flowing oil through the cooler all the time, or is that what is supposed to happen?

I'll take two when you get these going.

Thanks,

The only negative would be if your oil doesn't get to a good operating temperature.
Actually, the stock system allows some oil through the cooler even when the bypass is open.

The stock system is essentially a viscosity based thermostat.
I think today's oils behave differently than what was in use back in the '70s
so the same arrangement doesn't work so well anymore.

No problems so far with mine but count me in for one too Chris. Great work as usual.

Chris - count me in for one as well.

I'm very interested, put me on the future buy list.

I've bored my 2.0 to a 2.4, currently using an external oil cooler and fan that's positioned under my rear right trunk area. So far so good but she always run hot before adding.

Perfect timing as I've been prepping a case for an engine build. I'll take one for sure after all the testing is done!

Wow. This is timely. I think that this is exactly what's going on with the motor in my 912E.
I'll take 2 Chris.

I am in as well. Chris has some great stuff!

Looking forward to seeing the testing first hand.

Interested!

Harvey

How about a full flow system with an external cooler?

would this raise the pressure?

Makes sense.. sounds like a great invention.. can't wait to see the the results.

Is there a concern of a cooler or cooler seal blow out with colder, more viscous oil being shunted directly through/to the cooler? I love the concept

There's no change in pressure to the cooler when the bypass opens/closes.
The oil simply follows the path of least resistance.

Cool, thanks for the reply. I figured a smart guy like you thought of this

Very interesting. I saw your brainstorming in the paddock.



Or a couple of shims under the spring and above that screw....

Nice, I would be interested in 2 if it works out.
Any chance of it also working in a type 1 case?

Yeah, I had more than a bit of skepticism in my quest...
http://www.914world.com/bbs2/index.php?sho...=210207&hl=

This is a great Idea. In my scoping into the hole I didn't see a lot of precision in the bores, which seemed surprising given how everything else seems pretty durn precise.

I have used the MPS diaphragms and they are super, so I bet this will be a real winner. Great work Chris!

I've been having oil pressure issues in a fresh engine I built where the light starts flickering after about 45 mins of driving while using 10w-40 oil. I took apart a few cases i had laying around and I found there are two different size pistons and springs. I had searched on here for these items but I couldnt find anything. Here are the pics of the two different sizes
Click to view attachment

Click to view attachment

Does anyone know why there are two different sizes?

I'd like to try Foley's item to see if it cures my problem

I saw that short piston for the first time recently.
It came out of a bus engine case which is still at my shop.
Ed (ejm)) said that it would have had hydro lifters.
It had a fairly low operating pressure, and now that the new assembly is installed, I think it had a lot of "blowby".

I have a large type one melling in my car and have always had GREAT oil pressure. Using a 911 gauge have had 55-60 psi when hot at cruising speeds, 32-3600 rpm. Mysteriously on occasion it would 'stick' at something less than 45psi/3barr, no matter what the revs-and run higher oil temps.
Now it's doing it all the time. I run 10w40 in winter and recently changed to my summer grade. With new oil&filter it still says 45 psi hot or cold.
I'm sure that this is the fix I need.

Testing day at Sebring. It going to be a scorcher.

How'd it go?

Check this link from the paddock. Seabird had oil pressure issues before getting to test it out properly.

http://www.914world.com/bbs2/index.php?showtopic=236133

hmm. sign me up too if it works out...

I talked with Seabird on the phone this morning.
He was at the track again last weekend.
The oil pressure problem related to new Accusump installation was cured.
His data indicated that oil pressures and temps stayed within the desired parameters through two on-track sessions on a hot Florida day.

I'm starting production of the pressure relief assemblies this week.
Price is $74.95, delivered.
They won't be on the website right away but I've provided a shopping cart button in my Whats New at Tangerine Racing Products thread in the Member Vendor forum.

Just ordered, I have 2 cars that can benefit form this.
Thanks

Chris - I just ordered one! Thanks!! Jon

What are the "desired parameters"?

Chris,

Does this completely eliminate the high pressure bypass for the oil cooler, or just require high(er) pressure before bypass?

I have witnessed one blown oil cooler at the track due to low temps and too high of revs too soon after startup.

Stu,
The stock relief circuit doesn't ever prevent full pressure to the cooler.
It simply allows oil to take a shorter path when the pressure is high.

My assembly completely eliminates the cooler bypass, and increases the pressure where excess oil is bypassed directly to the sump.

Chris! Thanks for the tip for removing the 12 pt socket from the side of the case with a 3/8" extension! That worked perfectly. Now, speaking of that valve, will it still be needed with this new modification?