Been searching around, PM has one, but it's 30mm to 12AN. Looking to see if anyone still makes the 901 107 820 02 hard oil return line for 914-6's?

Anybody have a source?

My oil lines are a friggen mess. Working to get them sorted out.

Edit - April 30th: Updated title and description to help make this searchable.

Found a reproduction at AA and fine to buy it. Anyone have any feedback on it?

@mb911 made some. He placed the factory fitting on for me.

https://914-6werkshop.com/

Talked to him about that, we weren't sure if his line would work with factory HE's. Said his line was a little larger diameter than stock.

Anybody have experience with Ben's oil line and stock 914-6 heater boxes?

Talking specifically about #18:

I think you can buy the from sunset porche

I think I’ve got one. I’ll check

Remember stock will be the smaller size 26mm vs the 30mm fittings

Good point, thanks.

I have a factory 914-6 oil tank and looking to use all factory oil lines if possible.

Then you will want stock oil line sizing for sure.

In the parts diagram above, do I really need both 19 and 19-1? Memory (fails often) seems to recall only one soft hose from cooler to tank?

definitely two hoses from tank to cooler.
45 degree attached to tank, 90 degree at other end to chassis hook, then straight
fitting on a curved hose to cooler.
Aftermarket hoses 'tank-to-cooler' have an extra coupler between hoses.
The tubing from block toward bottom of tank is tough to find.
I have nothing to offer.

Not sure if this can help but we had to change to a bigger diameter to deal with the 3.0s demand for more oil flow. We had the old one that was from the 2.5 SS Eng. that #41 had

Call Eric and tell him that I Bob Burton said you can have it if he still has it. This is just for you as I loved the write up on putting the hard top for your blue car that I should have bought years ago

Best Bob B

This helps a ton you guys, thanks!

Just a 2.7 so I think the factory size lines will be okay.

For my Carrera 3.0, I used PMs hard line to the bulkhead then AN12 to the thermostat. Worked out well.

At what point are the 26mm original line sizes insufficient? I assume the power output is more important than actual engine displacement. However, with stock tank and oil cooler fittings creating a limiting factor it is important in the planning to know when the oil cooling system needs to be changed to cope with additional flow requirements.

Ok so here is the details on this that I find very interesting. The case on 2.0-3.2 for sure are 22mm and then a 22mm to either 26 or 30mm adaptor are used. So no matter what thats a dead head. Then you look at a 914-6 tank regardless of brand they all have .625" ports for the filter console. The factory plumbing within the tank is also .625 OD. So no matter what anyone says about going bigger lines it is kind of silly. The only thing that would make sense would be larger would allow for the foamy oil to expand. Kind of odd but thats the deal.

The later 911 tanks had bigger internal passages for the bigger oil lines. So if you are using a stock 914 tank, you have a restriction, no matter how big the lines are. My 4.0 has the same tank as the factory six, and I have no issues with oil starvation. Yes, it has the bigger lines, but it has an adapter to hook them to the stock tank.

So larger lines, such as for a front oil cooler, only help to reduce the pumping restriction inherent in long lines. Other significant restrictions could be in front cooler cores & fittings, and thermostats. I have both the early 911S (69-71) oil filter console with thermostat and connecting lines, and a later (73+?) thermostat to choose from.

Think Ben hit the nail on the head. If any part of your oversized system reduces to a smaller factory fitting, only as good as the weakest link.

Really good thread with a lot of info!

I agree that Ben is mostly correct. The smallest part tends to be pretty limiting, but that does not mean you should not make anything else larger. In hydraulics, if the flow moves from a wide cross-section to a narrower cross-section the flow must speed up. One has to take a look at the system as a whole. The ability of the pump to produce both pressure and flow. If the flow is restricted, then the pressure may increase to help compensate. The viscosity of the oil which depends on characteristics and temperature. The pressure drop through each component in the system is added up and the total pressure drop is what is important in the end.

Maybe someone should start making oil tanks with larger internal plumbing for the bigger oil lines. They could just gut a late 911 tank to determine the plumbing size Porsche used.


I would buy one for my 4.0.

Clay

Increased performance and displacement require additional oil and oil cooling.
that the whole affair is limited by the smallest restriction.
Make sure you have the larger coupling on the engine.
What we can know is oil pressure and oil temperature.
A 911 gauge with real numbers is an absolute.

Mine are larger in the plumbing area just not where the filter console connects.

+1, agreed. For most of us with street use /6 conversions it probably does not matter, on the track would be different

Click to view attachment
@Root_Werks Here’s what I have. PM me if interested

To clarify what the restrictions are is as follows. The engine case fitting, and the filter consoles.. the rest is so you all can sleep better of you will. There is no way to enlarge the case from the pump scavenge side to allow for bigger flow.. The filter console you could enlarge

I ordered a "factory" hard line from AA and hopefully picking up the original factory hardline from Perry. Be curious to compare the two.

I think in all the 914-6 conversions I did years ago, probably never used 100% factory lines. It was always what I could get a hold of at the time. Learning experience for me.

Yes, very informative. I am building the plumbing now with the assistance of Ben Mc. First time, but with all the help from other /6 conversion guys I am sure it will go somewhat smooth.