I am at final stage of completing my 2.7 911 engine install project. All external oil lines are AN12 stainless steel braided hoses and fittings. I have the scavenger oil feeding directly into an oil filter which is mounted to a bracket with 1/2" fittings for the in and out and for the nipple that the filter screws onto. While starting the engine, as soon as rpm's exceed about 2000 the filter O ring pops out and oil leaks massively. Same result after several attempts. I have a K&N filter that has a large O ring that is not as secure in it's groove as say FRAM filters I am familiar with, and which worked well with this bracket fitting when I had my Type IV in the car. I will be installing a new bracket shortly that has 1/2" in and out hose fittings but a 3/4" nipple for a new typical 911 filter which has a matching 3/4" screw on female fitting. I decided not to install an oil thermostat as I live in a warm climate here in S Cal. Any advice will be welcome.

I think 1/2" is to small as stock would be 5/8" internally in the tank. This would increase oil pressure to a certain degree. That said something else seems wrong.

Is something stuck on the oil bypass on the engine? Also i would use the oc54 filter myself.

Could you explain how you have the oil filter mounted better,
Is it on the tank?
Or are you talking about a remote filter adapter like how you would do full Flow on a T1 or 4?

What brand and # filter are you using?

Fram filters are shit, I used to be a HP-1 lemming till I cut one open.

The oil filter bracket is located on the original battery tray - battery is now in front of car.

I know your trying to save money, but if you bought an aftermarket six tank from mb911 your car would most likely be running now. I would be surprised if it's related to the engine.

duplicate post

Not sure what you mean by oil filter bracket.... I'm assuming you mean remote filter adapter.?

Yes, like this:


Click to view attachment

Should that remote require a Mann filter designed for a 4?

If your going to go that route, I would check out how Patrick Motorsports does it.
http://www.patrickmotorsports.com/part/rem...ount-set-an-12/
They also list the project cars with pictures on how they use the remote oil filter console.
Stock oil tank would be less work....

You can use a type 4 fillter, Mann, Bosch, NAPA gold.

You will pop the O-ring on any cheap filter with even a VW type one oil pump.

Way under sized for the large 911 /6 oil pump. You should at least use a remote filter adapter for a tractor/hydraulics.

Patrick's console looks like a well made part, but has the same oil in and out AN 12 fittings I will have on my new bracket, and I am guessing that it has a 3/4" nipple for screwing on the filter. I have a new MAHLE filter which has a 3/4" female "nipple". I am going to cautiously try this filter with the new "3/4" bracket/adapter combination before changing to other solutions you have suggested.
Do you have a "adapter for tractor/hydraulics" reference? - I will look on Google.

Same thing you have but in 1" NPT, any hydraulic supply house.

I should have mentioned my new filter is a MAHLE OC54 from Pelican 911 catalog.

Your a brave man sir keith

Putting all this stuff together yourself

By the way the old motor is goin great .

Thanks and I am pleased you are enjoying the 2.36 Ltr.

If it's a mahle I'd look elsewhere than the filter, after the filter it's suppose to just dump into the tank, no real restriction.

Just a thought do you have the flow into the filter backwards?
It could be messing with the filter by-pass valve.

Mark, Thanks for all your input.

First, flow direction is correct, - this is a remote filter mounting, and is first in line from the scavenger pump - oil flows on to the front cooler, then back to a custom built tank located in the engine compartment - no thermostat - S. Cal!

Next I owe you an apology - the inside non-threaded plumbing in toy old bracket -picture above, is 3/8'" diam, just measured again, and the inlet and outlet ports are 3/8"NPT. My new bracket, just delivered, has 1/2"NPT inlet and outlet ports with corresponding internal plumbing non threaded - much better than smaller old bracket. the filter spin on nipple however is the same 3/4"-16 as the older unit. I need to get AN12 fittings to connect the hoses to these larger 1/2' ports and a good filter to spin on - tomorrow will report back.

1/2" NPT is still a tad small IMO.
All the AN-12 stuff (which is correct size for a front cooler) is wasted, as you flow will be restricted to 1/2"

The filter adapter should be AN-10 or 5/8" sized, which is right about the stock tank/filter size.

Keith came by to pick up the Patrick sourced Peterson inline style filter on my bench (on the right.) It has AN-12 ends and should let the oil flow as planned.

I wish Keith good luck on a Monday start-up with no more major oil issues.

Click to view attachment

Mark is right on.. I have now sold 20 tanks and have factory drawings.. Most people run to small and it should be 5/8" .


Not sure I would jeopardize the expensive engine with any thing less then what factory stock was. I actually now make all my tanks with 3/4" id tubing because of the possibility of larger engine requirements.

Good call Mark the smallest pipe in the system is the return ,things must be matched up ,no wonder things are going to .
Good luck Keith,you will get there.

WIX 51515R.....made for high pressure that we get with 20W50 oil, especially when cold....

Installed the in-line filter that Larmo sold to me, problem solved Click to view attachment