"upgrade" 911 oil system to 964, 993?

[martensson]

Hi all & sorry for a poor title...

I'm not yet familiar enough with the brand & I dont want to "try" this.....

Just got my hands on a 911T 1971, (RS replica -74) in need of restoration. When checking the oil tank I found a lot of rust holes & so on. Lets just say I will not be putting it back on again.

Regarding the oil system then. The filter is located on the return line (scav. side) & not on the pressure side, making it easier to get dirt into the engine & causing damage. On the 964 & 993 I heard that they updated the oil system by adding a filter on the suction side as well, between tank & engine, right? Pls correct me if I'm wrong.
Would it be possible to ad an oil filter relocation kit on the oil line between the tank & the engine without causing any other problems? problems like poor suction, cavitation, or similar?! Any problems than may cause engine damage.

The plan is also to install a 3.2/3.6 engine. These engines have updated oil pumps, but would this be enough for an install like the one mentioned above?
Is the oil pump strong enough to suck oil through the additional filter without causing pressure drops, cavitation.....?

What else is different between the 911 & 964/993 regarding this matter?
Will a newer model oil tank fit in our -71?

[efhughes3]

I can't answer your questions. But, I can say Porsches (911's), are not known to have issues with oil filtration. When you look at how long these engines can run, and often do, I'd say the lube system works pretty well.

[martensson]

I'm not saying they are crap no no, but if you put it that way, then why did they change on the later ones??

The reason why I want to rebuild it is because I just saw how much dirt there was inside the tank, dirt that finally does end up inside the engine....

Lets just say i'm stubborn & want to do i

would it be possible???

[proffighter]

I did this on my '81 930Turbo. Look at Smartracing, they offer the 964 filter console and adapters etc...

[Chuck Moreland]

The 964/993 do not have a filter between the tank and engine, and you do not want to put one there either.

They do have a filter on the pressure side of the engine, after the pump. These engines sacrificed the on-engine oil cooler to make room for the extra filter.

You can do this if you want to. But you'll need to enhance the external oil cooling capacity to compensate.

However it sounds like your real problem is a deteriorated oil tank which is contaminating your oil. An added filter is an attempt to compensate for this basic problem.

Why not just replace with a good tank

[proffighter]

Oops, not red exactly, sorry.

It's like Chuck said, Filter is right after pump, replacing cooler... and that's what I did, because I had problems to get on temperature with front and rear cooler.

[martensson]

Originally Posted by proffighter

Oops, not red exactly, sorry.

It's like Chuck said, Filter is right after pump, replacing cooler... and that's what I did, because I had problems to get on temperature with front and rear cooler.

Originally Posted by Chuck Moreland

The 964/993 do not have a filter between the tank and engine, and you do not want to put one there either.

They do have a filter on the pressure side of the engine, after the pump. These engines sacrificed the on-engine oil cooler to make room for the extra filter.

You can do this if you want to. But you'll need to enhance the external oil cooling capacity to compensate.

However it sounds like your real problem is a deteriorated oil tank which is contaminating your oil. An added filter is an attempt to compensate for this basic problem.

Why not just replace with a good tank

Ah, ok Thanks for the info. So the oil system in general is a bit different then.
And no, i will not be "compensating" a dirty tank by adding a filter. I realized that dirt very easily MAY get into the engine & want to prevent this from happening. By this "upgrade" I want to assure the life of the engine by adding a "safety device" where its supposed to be, in this case, a filter on the pressure side.

As i mentioned in my first post, my old tank will NOT be put back again. Still, I do want to go through with this "upgrade" even if it means I have to relocate the oil cooler. It may be my first Porsche but its not my first car & not the firts one up for a rebuild. Even if there will be some problem solving issues during the build, I dont think they will come anywhere near what I have had to live with during my last project.

Originally Posted by proffighter

I did this on my '81 930Turbo. Look at Smartracing, they offer the 964 filter console and adapters etc...

I will check it out, thanks

Anything you Porsche enthusiasts may add is welcome. Now I have a better overview of the system but please, keep on adding.

appreciate everything you may add

[Bill Verburg]

Originally Posted by martensson

.....
Would it be possible to ad an oil filter relocation kit on the oil line between the tank & the engine without causing any other problems? problems like poor suction, cavitation, or similar?! Any problems than may cause engine damage.

The plan is also to install a 3.2/3.6 engine. These engines have updated oil pumps, but would this be enough for an install like the one mentioned above?
Is the oil pump strong enough to suck oil through the additional filter without causing pressure drops, cavitation.....?

What else is different between the 911 & 964/993 regarding this matter?
Will a newer model oil tank fit in our -71?

I am unfamiliar w/ the pre '72 oil systems but you can certainly replace the engine mounted oil cooler w/ a second oil filter setup, Smart Racing has all the parts needed.

here is a '73 up system, earlier will be somewhat similar, you can see that the filter is on the scavange side


here is a 993 system, #5 is where the engine mounted cooler was on the older 911s, 964 had neither a cooler nor a filter in that spot. There is a filter on both the scavenge and pressure sides of a 993 only on the scavenge side for 911 & 964


the oil tanks were moved for more favorable weight distribution, the extra filter was added to ensure oil purity to the 993 hyd lifters.

[Walt Fricke]

Martenson

Your '72 should have the oil tank in front of the right rear wheel, filled through a flap in the right rear fender. Is this what you have? That unique model used a special console for the filter and other stuff.

However, don't waste your time and money devising a way to add an extra oil filter between the pressure pump and the bearings. The stock system has a filter on the scavange side, so only clean oil gets into the tank. As long as the tank is clean, all is well. That has worked just fine for Porsche for many years.

If this is a race engine, with large oil coolers up front, you can remove the engine oil cooler and replace it with a filter. Simplest way to do that is with the 993 housing, but there are other ways. Engines cooled like that don't need (as the 964 and later engines didn't need) the engine oil cooler.

But without a large and efficient cooler mounted in the center of the front valance, or with very good ducting of air to it, you want to keep the engine oil cooler.

Walt

[efhughes3]

That was my original post, the oiling just isn't an issue, other than the op's perception. The system worked pretty well for decades....

[dad911]

I had an '77 'race car' with the tank relocated to the front, with aftermarket oil filters in the 'scavenge' line before the coolers. IMHO the advantage to this setup was to protect the cooler, tank, and some lines from debris if the engine grenaded. Not necessary in a street or typical track car.

[Walt Fricke]

You want filters? Here are two of the three I have on the track car. One before the two 964 oil coolers, and one between the coolers and the tank.



The third replaces the factory engine oil cooler, as a last ditch, just in case barrier when an engine blows up (though, come to think of it, why would I care at that point?).

But the dual purpose SC has done just fine with the stock filtration (aided by a front and center cooler).

Walt

[safe]

Welcome to Pelican Mårtensson, you have come to the right place. This is the best aircooled Porsche community in the world!
As you might already know you will need an external oilcooler anyway you play it. A large center front mounted Setrab will be the best. That's what the big gaping hole in the front valance is for. Porsche 911 & Carrera Oil Circulation - Page 9

(Martensson is from my hometown in Sweden.)

[martensson]

Originally Posted by Walt Fricke

Martenson

Your '72 should have the oil tank in front of the right rear wheel, filled through a flap in the right rear fender. Is this what you have? That unique model used a special console for the filter and other stuff.

However, don't waste your time and money devising a way to add an extra oil filter between the pressure pump and the bearings. The stock system has a filter on the scavange side, so only clean oil gets into the tank. As long as the tank is clean, all is well. That has worked just fine for Porsche for many years.

If this is a race engine, with large oil coolers up front, you can remove the engine oil cooler and replace it with a filter. Simplest way to do that is with the 993 housing, but there are other ways. Engines cooled like that don't need (as the 964 and later engines didn't need) the engine oil cooler.

But without a large and efficient cooler mounted in the center of the front valance, or with very good ducting of air to it, you want to keep the engine oil cooler.

Walt

I actually have my tank behind the rear wheel & the filler cap inside the engine bay and its a -71

It's settled then, I will probably replace the engine mounted oil cooler with a filter & mount an external cooler up front. Hoses, fittings & a good cooler will cost me little enough not to worry about the costs, strange enough not near to the $880 for a kit here on pelican parts. Guiding the air through the cooler is also an essential part of the process, not just a good cooler, but when I'm there I will start worrying about it.

Originally Posted by safe

Welcome to Pelican Mårtensson, you have come to the right place. This is the best aircooled Porsche community in the world!
As you might already know you will need an external oilcooler anyway you play it. A large center front mounted Setrab will be the best. That's what the big gaping hole in the front valance is for. Porsche 911 & Carrera Oil Circulation - Page 9

(Martensson is from my hometown in Sweden.)

Hey Magnus, nice to see you here & thanks for all your help so far

[martensson]

regarding front mounted oil cooler.
How big are the connections on the Porsche external oil thermostatic valve?
Yes, I heard these are the best, so this one will be used

In other words, I'm looking for an external oil thermostatic valve. Will check the pelican store, don't remember if they sell these......

[Walt Fricke]

M: (that way I won't misspell it)

If you remove the engine mounted oil cooler, I suggest you add your front cooler in a fiberglass spoiler suitable for your body style, similar to this for the later style:



My wife (driving) didn't think to take the license plate off, so well does this cooler perform. I usually forget to do that also.

That is really the only way to get oil temperatures under control in a 3.0 or 3.2 engine. The fender mount systems don't get enough air flow no matter what you do if you are racing. The fans only help at idle. While I left my improved fender mount cooler in place in the 33 car, and plumbed the center mount cooler ahead of it in series, some racers have removed the fender cooler entirely and report good results.

But all of the guys I race with a basically stock body style retain the engine oil cooler on our dual purpose streetable cars.

Think about it - how can debris get into the engine's oiling system? The oil that enters the stock tank gets filtered! You can drop dirt in through the oil tank filler cap, I suppose, if you are really careless. And the rubber oil line from the tank to the engine could theoretically disintegrate internally and produce chunks, though I've never heard of that, they just age and split and you replace them. That's about all moving the filter will do for you.

Now the stock filters have a pressure bypass. If your engine slowly disintegrates (but still runs well enough that you don't just shut it off), eventually the filter will clog, and the bypass will open as the lesser of evils I guess (though I wonder if its real purpose is to deal with thick cold oil). Your second filter might catch some of this, until it, too, clogged and either bypassed or stopped the oil flowing. Practically speaking, I don't think anything short of throwing a rod or dropping a valve would create enough debris to clog a filter and operate the bypass.

I think your concerns are misdirected due to the fact that the oil tank in the car you bought was full of crud. That is not normal or inevitable at all.

Porsche obviously believed the 3.6 motors had efficient enough front oil cooling that the engine mounted cooler was unnecessary. And the 3.6 has a larger oil pump (the 3.2 pump is no larger than the late 2.7 pumps). Same size as the 930 turbo pump, though not quite as race worthy by most accounts.

But the guys who race 3.2s (and smaller motors) here in basically stock bodied 911s usually retain the engine mounted cooler. Our street 3.2 could heat up in stop and go traffic in warm weather (though that was at altitudes over 5,000 feet, which doesn't help cooling).

The 3.6 cooler (964 variety, anyway, which is what I have) is really good. My track only car has two of them plumbed in parallel, and I have no engine oil cooler. I distrust thermostats, so I have to be careful on cold days, and probably operate at a lower temperature (90 degrees C often) than is most efficient for power.




I don't have a straight-on picture, but these coolers exhaust through the hood, so the flow is really good. The coolers are good enough just sitting there to hold the temperatures down while idling sitting on the grid with only convection for air flow on a hot day!

Anyway, since you don't have an engine, I'd concentrate on rounding up the factory external thermostat and the factory oil lines to carry the hot oil forward and the cool oil back and into your new oil tank. When you hit upon a cooler you want to use, and a location for it, you can do the rest of the plumbing. And when you purchase an engine, you can work on connecting the the tank to the motor, and the motor to the thermostat. Your 2.2's crossover pipe, I think, will be a good start on that. Sticking to factory stuff back by the engine will solve compatibility issues.

You can purchase adapters which will allow you to go from the large Porsche DIN fittings up front to the AN fittings we in the US all use for lines to go to our special coolers. The 964 cooler has DIN fittings, but they can be unscrewed, and AN fittings substituted. Or you can keep it DIN - I'm sure the shops which hot rod our cars in Europe have that all figured out.

Sorry about the car's year - you said '71 right in the first post and I mixed that up along the way in my mind.

Walt

[safe]

Originally Posted by martensson

regarding front mounted oil cooler.
How big are the connections on the Porsche external oil thermostatic valve?

Porsche uses an odd M30. They are hard to find, Swedol (local shop) doesn't have anything like that. You can buy this; 930-207-111-05-M20 to scavenge the connections and press on new hoses, if you plan on doing something custom.

[Walt Fricke]

Magnus

In the States we can purchase M30 to AN adapters, both male and female. They work fine. Are AN hoses/fittings used in Europe for custom work?

Walt

[martensson]

Thanks Walt for the info & time taken to explain, appreciated!

Probably upsetting 99% of the pelican users I will state the following.
A Porsche enthusiast would say that its the best car in the world, no problems & nothing negative with it what so ever.

As a car enthusiast I would say, its a very crappy system & I would never have guessed that a brand like Porsche would come up with a solution like this. Even if it worked for decades...its still not a good system.
Is there a reason why, what I know of right now without thinking twice, other brands put their filters on the pressure side?
Is there a reason why all the Porsche enthusiasts tell me that I have to rebuid my engine if it has passed 15 000 km?
Excessive oil leakage, broken studs, worn down cylinders and so on....

Is there a reason why the later models not only relocated their oil filters but also added an extra filter, besides the added mechanical parts that required it?

I'm honestly not trying to say that Porsches are crappy, BUT they do have "darker spots".
Yes, dirt may enter the engine if a person would be uncareful. In my case I would say that I "woke up" & realized the problems with not having a filter on the pressure side. Not ONLY because of a dirty & rusty tank.
The placement of the tank, deterioration of metal in tank over time, dirt through the filler cap, deteriorated rubber hoses...bl bla bla...you get my point.
The placement of the tank bothered me since I saw where the greatest damage has been made, on the front bottom area. Getting dirt & gravel thrown up on it can cause a hole and oil will leak out, best case scenario. Worst case, the debries may get sucket inside the engine....

Of course, I could also specify problems & faults on my other cars i own, but thats not what the topis is about. On the other hand, since I am an Audi enthusiast...Audi have no faults Who am I trying to kid, of course they have!

From an engineers point of view, yes maybe it has been like that for decades, but now I wish to "update" it & put a filter on the pressure side!

The location of the oil cooler will be descided after conducting some tests......otherwise yes, the car has the 74 front spoiler & therefore has a good spot where to mpunt the oil cooler!

Thank you all!

[efhughes3]

There are certainly things to improve on a 911, but oil system and oil tank location are not anywhere near the top of the list.

Not to be disrespectful, but you need to talk to someone who knows Porsches better. To say they need rebuilds at 15000km is simply wrong. It is wrong even at 150000km. These engines can and DO last for many, many miles.

You'll see that over the years, there were some teething problems as the engines evolved, but there are well-known fixes at each point, and typically Porsche re-designed as needed to fix faults as they surfaced.

Please talk to some people who truly know these cars. I think you're going to spend too much time trying to re-engineer a fine, yet quirky car, when you should be enjoying the driimg experience.