Race car oil change questions

[mike the snake]

I bought a race car a while back. I put it together, I got oil IN the engine no problem, and I've run the car a few times, but now it's time to change the oil.

This is my first Porsche. I have not needed to do any internal work on the engine, and the info I've needed so far I have found on-line or from friends, so I haven't bought the service manuals yet. I plan to buy these items when I refresh the engine or have a problem.

What it the best procedure for changing the oil?

The engine is a 3.5 with a 4 gallon sump tank in front. As it's dry sump, I assume pulling the drain plug in the engine won't cut it.

Do I simply draw the oil out of the sump tank with a pump and replace?

[cstreit]

Drain both the engine and the sump.

Oil level is checked with the oil hot and the car running with the car level.

[mike the snake]

OK thanks. I didn't know whether to just drain the sump. I assume the engine itself doesn't hold much oil.

I'm off to buy 4.5 gallons of Swepco!

[mike the snake]

OK, I'm picking the oil up today.

The car hasn't been started in a few weeks.

Should I start it and warm it up before draining the oil? That's what I normally do on regular cars.

[mike the snake]

Here's a pic of the sump tank. There's no easy way to drain the tank without making a mess of the car, so I plan to draw the fluid out of the tank with a pump.

This is my first dry sump car. When I drain the engine, does the fluid in the cooler and oil lines drain as well, or is it more of a closed system?

[DW SD]

Mike,
I would warm it up, yes. If you don't have a drain, I would suck it all out with an evacuation tool used for changing oil on boats. Drain the crankcase as normal.

Looks like a nice setup.

The only (easy) way the cooler and lines will drain is via gravity or pressurizing. I have elephant racing hardlines which have a schraeder valve used to blow oil out of the lines and cooler so as to collect it all in the tank. Unless you have something like that, you can either remove the fittings or just leave the residual, used oil. I'd probably leave it, unless the fittings to the cooler(s) are easy to access.

Doug

[mike the snake]

Thanks very much.

I bought the fluid pump and oil yesterday.

When I bought the car, it had been sitting for 3-4 years with the drivetrain out and partially apart, but every hole, and every line had been carefully plugged with rubber stoppers by the PO.
I reassembled the car, got the oil IN the car just fine. I've run the car at a few HPDE events and the oil in the car has probably 5-6 hours on it.

I'm changing the oil because it's about a year old, and it's time to change the oil whether I run the car or not.

I've seen cars with the schraeder valve and always wondered what it was for, well, you learn something new each day.

Thanks very much for the replies.

[Walt Fricke]

Mike

That is a very nice oil tank (and, I suspect from the workmanship, race car). Some custom work on it - even cut off and welded over an unused fitting, instead of just capping it! And the oil level gauge - I've not seen one like that in a track car, but makes sense, and given the quality of work no doubt the clear tube is of an appropriate material.

With that tube as your gauge, you don't really have to worry about the car being particularly level, though any garage you may be using is sure to be quite level enought. In fact, oil level is no where near as critical as it is with older 911s with the factory tank. Down a couple of quarts? So what - the oil in the tank will still be way above where it comes out.

That tank most likely has a drain plug at its bottom. It may be difficult to get an oil sucking tube all the way down there through the various baffles. The oil outlet is purposely above the very bottom. Though mine has a central tube which opens onto the very bottom.

In my track car I cut a hole through the sheet metal (just one layer where mine is mounted)so I could access the drain plug, and made a removeable cover for the aluminum air smoothing sheet I have under the front of the car so I could get at the plug. It works, but always gets some oil on things. Were I ever to redo it I'd make a sheet metal or something cylinder which had a gasket pretty much sealing it to the tank base (or just have an extension for the tank drain - it could thread into the plug hole, and the plug could be flush with the bottom of the car).

You can, of course, disassemble the tank and clean it. That's one of the nice things about that kind of tank - comes apart in the middle.

Instead of a permanent Schaeder valve anywhere, I just unplug the engine out oil line (which, on my car, rises up before going forward, so nothing much spills when disconnected where the Aeroquip line attaches) and screw in a fitting I made for this purpose: an air compressor fitting screwed into one end, and an AN male fitting screwed into the other end. It blows most of the oil in the two coolers and two filters which are before the oil tank into the tank. I usually have disconnected the oil return line at the engine, so this oil can be blown into a bucket. And pinched off or capped the oil tank breather.

However, because of the issues with buckets and whatnot, I often first pump the tank out, then do the blowing bit. It seems that I have the engine out for this or that reason before it is time for a "routine" race motor oil change anyway.

Plus I have no thermostats in this system. If you have one (other than the engine cooler one), you may have to disconnect at other, messier, places in order to blow out the cooler or coolers.

And, except after an engine disaster, it isn't all that important to get all of the old oil out anyway. Mostly you are just replacing the additive package which has worn out if you use a synthetic.

How much oil comes out of the engine drain plug (or sump cover plate when removed) depends on how long the engine has been sitting silent. Oil under gravity pressure slowly migrates from the external tank into the sump until some sort of balance between oil friction and gravity is achieved. With a synthetic I wonder how important it is to have the engine hot. I don't worry about this any more.

Best to drain the tank first, though. Which is a good thing about pumping it out - you can use a very large container without worrying about pans under things overflowing. I use a hardware store rotary pump you run with an electric drill, with some miscellaneous hose attached to each side. Works fine and, like the blowout part of things, can be left on for as long as you want.

Walt

[mike the snake]

Thanks Walt!

My car does have a thermostat, and a huge oil cooler.

This is just going to be an exchange of oil, everything is fine so I'm not going to be concerned with getting every drop out.

I'm planning on just sucking what I can out of the tank, draining what I can out of the engine, and filling it back up to where it was.

The workmanship on the entire car is jewel-like. I lucked out in buying the car from the builder. The car was a featured car in Excellence magazine.

[dicklague]

Great looking car.....seems to be well put together as well.

Congrats and enjoy it.

[KTL]

That's a Peterson Fluid Systems oil tank. Very nice install. Peterson will make whatever you want in terms of fitting locations and the like. All you have to do is tell them. Check out their site at petersonfluidsystems.com

That tank should indeed have a drain plug on the very bottom, so do check for it. But as Walt so smartly pointed out, not everyone is prepared with the right sized drain pan to catch 4 gal gushing out when you pull the plug!

[Walt Fricke]

Peterson is one of the amenities of living in the Denver metro area. Their local retail operation (the Peterson stuff plus a fairly typical circle track assortment of stuff made by others) is under the name of Morton's Motorsports. Mr. M died a while back, but Mrs. M kept it going. As far as I know, the two are really the same company, or at least under common ownership and they make the Peterson parts here.

[Tyson Schmidt]

An easier way to drain the oil tank would be to remove the suction line from the engine.

Of course this will only work properly if the entire suction line from the tank to the engine is level, and has no "humps" in it's path.

But this way you won't make a mess inside the car, as it will all be done back under the engine. Maybe raise the nose of the car higher than the rear to make sure it all drains out.

[mike the snake]

Thanks for the replies.

I'm hoping that I can get a tube down the center of the tank to the bottom so I can draw the oil from the tank. This will exchange most of the oil in the system, and I plan to change the oil often enough that I don't think it's necessary to completely drain the system. It is highly filtered.

The oil in the car now has maybe 6 hours on it.

[TRE Cup]

Dave built a great car and it was a treat every time he ran with POC in So Cal. I am pretty sure there is a drain plug on the bottom of that tank. Jack the car up and look for the access hole in the chassis for it

[mike the snake]

Thanks, I was very lucky to have bought such a nice car.

I hope to make it down south in the future.

Presently I am getting new tires, installing new brakes, and changing the oil, then the car will get a corner balance/alignment check, then it will be ready again.

I raced my first race in a friend's car at the Thunderhill 24 hours of Lemons, where I learned the track pretty well. I'm really looking forward to running my car there, Dave ran 1.55's at TH, I can only hope to go as fast.

[johnman001]

While it may well be a peterson oil tank, it looks remarkably similar to Patterson oil tanks made in California. The similarities end when you look at the O-ring joining the upper half to the lower half of the tank. The Peterson tanks have a small diameter 9" O-ring while the Patterson tanks use a 7/16" diameter 9" o-ring.

It's a nice looking set-up.

I have a couple cars set up with the Patterson tanks. The internal baffles would prevent one from drawing the oil up from the bottom of the tank. I would assume that the Peterson tanks are similar inside. What I have done is to drill a strategically placed hole in the front trunk directly under the drain fitting. This lets all the oil out of the tank. Later I replaced the drain plug with a ball valve set-up with a plug at the end. Oil changes are much easier now.