need oil line restrictor "how to"

redcoupe86 · 08-06-2008, 06:33 PM

I want to do this to my car so I ordered the 2 oil line restrictors and washers, but Im not sure that is all that I will need. I have new oil lines already but I'm not sure if I need another bolt that is longer or not because im not sure how the parts go together. Is there a good "how to" someone can direct me too . . .

Quicksilver · 08-06-2008, 09:11 PM

I assume you mean the cam oiling restrictors. You need 6 of the washers to swap them out. One under each restrictor and two for each side of the banjo fitting on each side.

emcon5 · emcon5's Garage

Are you having oil pressure problems?

Tom

jbrinkley · 08-07-2008, 04:09 AM

i recall something about you buying me some beer?
lol

be home next week

redcoupe86 · 08-07-2008, 04:12 AM

I dont think so, but my car has 118,000 miles on it and the oil pressure hangs around 1/2 to 3/4 bar when fully warmed up. The oil light has never come on and when I blip the gas the oil pressure jumps to 3 bar. I've also read this is a good upgrade to do.

Do you need to torque the restrictor and banjo bolts to a specific number or do you just snug them up good?

Quote:

Originally Posted by emcon5

Are you having oil pressure problems?

Tom

hcoles · 08-07-2008, 07:04 AM

I can't remember what I did re. torque... just put them in with the AL washers.. I would just make sure the area is very clean so no bits of grit fall in there

304065 · 08-07-2008, 09:09 AM

Everybody says this is a good upgrade but nobody has ever posted any actual data on cam wear. Considering that the oil from the spraybars cools the heads and valves, I wouldn't do it.

The factory 964 oil pump had a lot more capacity and this was divided among the various parts of the engine as follow (thanks Bill V, this originally from Bruce Anderson I think)

the 964 pump should be ~65 liters/min, distruibuted as follows
35 l/min for main and con rods
17 l/min for the piston squirters
13 l/min for cams, valve guides, rockers

OK, so everybody says "I had low oil pressure so I restricted the oil to the spraybars and my oil pressure went up" but if your pump can't deliver 13 liters per minute to the top end you are going to do damage. As I said, as far as I know none of the advocates of this mod have ever done any testing that would convince me to do this to my engine.

redcoupe86 · 08-07-2008, 09:27 AM

I did not realize that. I was basing this info int the "engine rebuild wizard" on this site and this info:

Oil Line Restrictors
A relatively recent upgrade has been identified by Lee Rice and Steve Grosekemper of the Porsche Club of America. All of the 911 Porsche engines from 1966 through 1989 use the same cam oil line adapter to connect the oil lines to the camshaft housings (Part # 901.105.361.00). In 1991, the factory replaced this adapter on the 911 Turbo with a new updated part that had a greatly reduced center orifice. This new part (Part #901.105.361.01) has a circumferential groove around the adapter to differentiate it from the original adapter.
This change was adopted to supposedly address oil foaming problems in the crankcase. This foaming occurs when there is an excess of oil in the crankcase, which becomes whipped up into a foam by the rotating internal components. The source of this excess oil originates from too much oil being fed to the camshaft housings. Excess oil is dropped from the rockers to the bottom of the camshaft housings, where it returns to the bottom of the engine crankcase.
The addition of this restrictor adapter adds a few benefits to the oil system of your 911 engine. It decreases the amount of potential foaming in the engine by reducing the flow of excess oil to the bottom of the crankcase. This decrease in excess oil and reduction of foaming allows the scavenge side of the oil pump to transfer oil out of the crankcase to the oil tank significantly faster. This maintains greater consistency in the oil tank level and generates more accurate oil level gauge readings. Reduction of foaming also reduces oil losses through the crankcase breather system.
In addition, the installation of the restrictors increases oil pressure throughout the system, without reducing the oil flow feeding the camshaft housings to inadequate levels. Oil pressure is higher at the main bearings, the rod bearings, the piston squirters, and also the pressure-fed Carrera chain tensioners. Engines that normally read low or near-zero oil pressure at warm idle, will show increases of 10-20 psi from simply installing the flow restrictors

Quote:

Originally Posted by john_cramer

Everybody says this is a good upgrade but nobody has ever posted any actual data on cam wear. Considering that the oil from the spraybars cools the heads and valves, I wouldn't do it.

The factory 964 oil pump had a lot more capacity and this was divided among the various parts of the engine as follow (thanks Bill V, this originally from Bruce Anderson I think)

the 964 pump should be ~65 liters/min, distruibuted as follows
35 l/min for main and con rods
17 l/min for the piston squirters
13 l/min for cams, valve guides, rockers

OK, so everybody says "I had low oil pressure so I restricted the oil to the spraybars and my oil pressure went up" but if your pump can't deliver 13 liters per minute to the top end you are going to do damage. As I said, as far as I know none of the advocates of this mod have ever done any testing that would convince me to do this to my engine.

hcoles · 08-07-2008, 09:48 AM

not sure if redcoupe is saying to change or leave as is... from a non technical arguement standpoint - Porsche would not have listed this as a recommended change unless there was a very strong compleling set of reasons to do the change along with associated testing/etc. My idle went from about .5 and is now 1bar hot... and I like that the bottom end along with squirters are getting more oil. Valve guides are cheap.

304065 · 08-07-2008, 10:03 AM

Where did Porsche list this as a recommended change? Nobody has ever produced a service bulletin from the Factory saying you should do this-- that is a conjecture on behalf of Rice and Grosekemper based on the appearance of a revised part for the 964 engine.

Here is a link to the article everyone references. http://www.dietersmotorsports.com/tech/2002/3-2002.htm I am not persuaded that just because oil still sprays out of the spraybar, that means enough oil is present to cool the heads and valvetrain.

Again, if somebody can show me that the oil volume is greater than 6.5 liters per minute per side through the reduced orifice I'll install the set I have sitting in my spares box. That could be demonstrated easily:

1. Get a spare oil line and remove the rubber part leaving just the banjo fitting. Disconnect the banjo end of the exisitng oil line. Using the original "intermediate piece" connect the spare banjo fitting to the cam box. To this, connect a source of engine oil, such as a five gallon pail, to that end. Before connecting the banjo, perform a test to verify that the gravity flow from the pail is greater than 6.5 liters (1.7 gallons) in one minute.

2. Fit the revised "intermediate piece" to the exisitng line, and put a hose over the threads with a clamp, run this to another bucket.

Start the engine, let it run for one minute and shut it off. Also clamp off the flow of oil to the banjo end.

You would note the level in the bucket and convert to liters. Simple enough test to see what the flow is through the restrictor. Now repeat the test with the original intermediate piece in place.

Miguel Antonett · 08-07-2008, 10:25 AM

Never understood WHY to install an oil restrictor. Our cars are cooled by air/oil WHY restrict the oil flow???? It makes no sense.

Quicksilver · 08-07-2008, 11:34 AM

Porsche superseded the old part number to the new one with the restriction. I would take that as it being a part that doesn't need to be changed but if you are they want you using the updated restrictor.

304065 · 08-07-2008, 11:44 AM

Porsche supersedes part numbers all the time, it's not because they care about the owners of older cars, it's because they don't want to stock inventory that never turns over. A good example, right next door to the "intermediate piece" is the NLA case-to-cam-oil-line fitting called 901 107 375 00. In the old engines this is an 1/8" NPT to M12x1.0 fitting. The "new" version of the same part number is an M12x1.0 on both ends, no way it's ever fitting in the case.

Anyway, I wouldn't interpret anything from the supercede. Don't even get me started on the heater boxes. . .

hcoles · 08-07-2008, 12:16 PM

ok... I don't have the hard or soft copy of the official memo....may have bad memory from all the threads and reading of the Wayne book. Point taken re. that a supercede listing may not be technically correct.. I guess at this point I haven't seen installing restictiors has killed a street/DE engine... that's not a reason that it is ok either.