For those that have made up their own AN oil lines, are you running an internal support coil on the suction line between the tank and engine?

http://www.aeroquip.cc/fbm3414-fitsdashsize-16.aspx

You dont need it. It is for extreeme vacuum systems. The vacuum in the oil system is from the oil pump to the sump pick up tube. The hoses to the cooler is all pressure and not vacuum. -16 (1") is really big too. You will loose velocity through a line that big. I would use -12 at the largest (3/4").

If you are using the stock 914/6 tank in stock location the AN-16 (or even -20) is the way to go. That said, there is a reasonable substitute available for the stock 914/6, 2 piece rubber feed line. It saves the hassle of macthing up fittings which is a PITA.

All bets are off if you're using an after market tank mounted up front.

I have to agree with the entire above. I am running 16AN on the tank outlet to the engine without any internal spring strengthener. Return lines are 12AN with a thermo/bypass valve and front oil cooler. I like to stick as close to the original as possible so I am using a 911 oil tank to match the design needs of the 3.2 engine I have installed.

As I understand it the inlet to the engine is basically gravity feed with the pressure taking place in the engine and the scavenge section moving the oil from the engine back through the system to the tank. The engine pressure and scavenge sides appears to apply pressure to move the oil through the entire system except for the oil tank outlet/engine inlet hose.

Please correct me if I am wrong in my understanding.

Steve Hurt

My apologies, I should have provided more info. This is a Patrick tank in the stock location. This is for the feed line from the oil tank to the connection under the cooler which is -16AN. I was under the impression that this line would be under some amount of vacuum and wanted to be sure it didn't collapse. I am using Aeroquip Startlite hose which is rated to -20 in. Hg. and 300 deg. F.

AFAIK, the stock hose doesn't have any internal support to it. Just me being anal.

Anybody tried a small strap wrench to get the fitting on the bottom of the tank tight?

Don't need one, the steel belting gives plenty of support. I've run that configuration from the stock tank location since 1999 with no problems. The biggest itches are that the things runs about 1/8 in from the left exhaust header and, with a 993 engine and a sandwich adapter for my auxiliary cooler, has to be removed to change the oil filter.

If I were doing it again I'd go -20AN there... good when the oil is cold.

Good luck

The feed line from the tank to engine is a "vacuum" (pull) line. Gravity alone can't move 50 approx liters of oil per minute that the 911 pump is capable of moving. The actual oil inlet's highest point is at the top of the case....right underneath the engine mounted thermostat. Or, in other words, it sucks.

The scavenge side is pressure....a bunch..... till it exits the oil filter. BTW, use a filter with a high pressure by-pass. Mahle OC-54 is a good one.

I used to install the tank with the line already tightened. As you can see in the pic, access is no longer a problem. The rubber line that I used did tend to kink at the second half of it's S curve. I took care of that with 3 external hose clamps.....on the left in the pic.....nuthin' wrong with being anal/paranoid.

Thanks JP. I'm jealous of your ability to remove the rear fender.

In the meantime, I think a 1-1/2" crowfoot wrench may do the trick.

This is kinda interesting. While doing a cross reference, I found that the OC-54 crossed to a Purolator L30260 which has a 20-25psi bypass. Purolator also makes a L30255 which has a 28-30psi bypass but it's shown as "Availability limited to existing inventory."

I prefer Baldwin industrial filters. The BT292 has a 30 psi bypass.

A long time ago a fella posted on Pelican that he rigged a pressure gauge on his scavenge side. He got peak pressures on a cold motor of 165 psi. He didn't give a hot pressure, unfortunately.

You can run any filter you want, I ran the OC-54.....the water is right over here, mr. horse..

The stock 911 line from the oil tank to the oil pump is just a wimpy rubber hose no stronger than fuel line and they never have any problems with crushing. One car I work on has a huge GT3 oil pump and the stock rubber hose does just fine. Not a single issue in 8 years of racing on the same hose. No threaded fittings either, just plain old hose clamps.

I agree, the cross reference proves your point on the bypass psi.