Retrofitting a '72 oil tank

[Chuck Moreland]

Just thinking out loud....

Has anyone retrofit a '72 tank to some other year? Would love to do this to my '73 to improve weight distribution and overall coolness factor.

I expect the '72 tanks are cash intensive though. What about taking a regular tank and mounting it ass-backwards. Shorten the filler kneck, put on a filter relocation kit, the fittings would now point in the right direction, graft a gas tank filler door to the fender. Hmmmm...

[304065]

I'm guessing that if you are concerned about the weight of the oil in the right rear corner, you would be a good candidate for a total relocation of the oil tank to the smuggler's box.

Check out what the folks at Smartracing offer- www.smart-racing.com - I have also seen GT cars relocate the oil sump to the front end, complete with Oberg (diesel-truck-style) filter.

[Jack Olsen]

Racers put a tank in the smuggler's trunk. I have AC in there, though, so I've considered (even bought, actually) a 993 tank.

[Bill Verburg]

A L.I. guy has put the complete 964 oil system, tank and all into his 86 Carrera 3.6 transplant. He relly went all out, MOTEC, TWM etc.

[Joeaksa]

Always liked the position on my 72 oil tank and wish that the factory would have kept it there. Lots easier to check, fill and maintain and work with when it had the outside filler.

On the other hand evidently they had too many stupid people who cannot read the "OIL" sign inside and it got filled with fuel and destroyed the motor.

Moving the weight forward sure seems like a good idea and I would love to have the -72 system on a newer car, but not ready to gut my A/C to get there. The price on -72 tanks is a lot higher than the others, probably due to the volumn of tanks that the factory produced.

Joe

[Chuck Moreland]

I'm familiar with the relocation to the smugglers box and the SmartRacing tank. That's a fairly intrusive changeout since you need to run at least a -20 line for the suction side. The cars I've seen all run this through the cabin since there isn't room under the car.

Here is one such setup:





That's not really were I am going with this car. It's not a dedicated track car and I intend to keep it very usable for street duty.

The '72 setup seems like a good solution. Truth is I was seeking a '72 when I bought for exactly this reason. Didn't find the right one.

At this point I am just browsing. I figure someone has already blazed a path here.

Now to stir a little controversy -

Although plenty of guys will line up to disagree with me, I believe the '72 setup is a better weight distribution than the smugglers box.

There is nothing wrong with a 60/40 weight distribution provided the suspension is properly setup. 60/40 does not cause lift throttle oversteer. The problem is excessive polar moment due to having too much mass at the extreme back end of the car, too far away from the center of mass. The goal is to reduce the polar moment, not to put weight on the front wheels.

This goal is achieved by shifting mass from the ends to the center of mass of the car, not by shifting to the front of the car. Taking weight off the back end and moving it to the front does not reduce the polar moment.

The center of mass is approximately between the jack receivers. The '72 tank position is pretty much right on. It would have been better if it was centered width-wise but then no rear seat.

Note, the factory race cars put the oil tank in the rear seat - not the smuggler's box.

Let the flames begin.

[304065]

Interesting point about polar moment, I agree. Where did you get the reference for the center of mass, is it published anywhere? If the "datum" is between the jack receivers then I would think that relocating to the smuggler's box would move the oil tank mass slightly closer to the datum than the right rear fender. But I certainly agree, the '72 location forward of the rear wheel is closer to the datum than both. Wasn't it the same way with the 911R?

I do question the extent to which the difference in location would be noticeable or justify the conversion expense for a car that remains usable for street duty however. But I would never discourage anybody from enhancing the cool factor of a long-hood car!

By the way, nice pictures of Calzia's car. The article in Excellence really opened my eyes to his "scientific" approach to weight reduction. I see he has a few copies available where the right seat used to be!

[Chuck Moreland]

Hi John

My information about the jack points is approximate and my own conclusion. It stands to reason the factory put the jack points there for that reason. Plus you may notice the car jacks straight up when lifted by the reciever, no tipping. The exact center of mass would depend on options and equipment.

Jim's car is impressive. I saw it earlier this year and took pictures of many details on the car. It is well done.

[Early_S_Man]

Actually, Chuck, your reasoning makes perfect sense! The only change I would suggest is one that complements the idea, and that would be moving the battery to the driver's side rear seat area to balance out the oil tank, as the '68-'82 Corvettes had, and VW Beetles had forever! A battery there could actually result in a slight weight savings, net, because of the shorter, heavy battery cable needed to the starter! An Optima battery would also eliminate the battery fumes problem Beetles suffered from when overcharged, too.

[pwd72s]

Chuck, Gary Emory build a 911R replica for a historic racer customer. As you know, this entails a forward oil tank, much in the same location as the '72 tank. I was fortunate enough to be there when the car was being built, and Gary showed the tank to a group of us. It was a custom built work of art, welded aluminum, special baffles for better performance. The body mods needed would be pretty straightforward for the "R" look, because the cap is exposed. But, oh, that tank...it was drop dead gorgeous, a work of art in it's own right. Anyway, if you want to talk to someone who has been there, done that? Gary would be the guy...

[ohecht]

Old thread, I know, but what about a location like what (I think) the 993s have (in front of the engine-mounted oil cooler?).

Has anyone made more progress or tried other things for this idea? My motivation is to use room in the right rear fender for turbos, exhaust, or intercoolers as I work on a long-term TT project.

Thanks,

Olivier

[Rufblackbird]

I just bought a '72 that had a SC motor put in, along with the oil tank and lines. Would this mean I'd have to find a '72 tank to put it back where it belongs?

[Slider79SC]

A friend of mine that built a wild 78 Turbo car (700+ hp) installed a 964 tank because of going to twin turbo’s (the stock oil tank is in the way). The 964 tank installs in the same location as the 72 and doesn’t require an oil filler door. The oil filler tube resides in the engine compartment next to the passenger side hinge for the deck lid. He had new ends fit to the factory hard lines and it was done.

I can try and see if he has pictures of the installation.

[Slider79SC]

[ohecht]

Thanks, Slider. Is it the 964 or 993 tanks that are in the non-standard location? Do you have any pictures of that part of the car, or of the turbos, etc.?

It looks like he made oil sumps for the turbos; how did he scavenge the oil?

Olivier

[Grady Clay]

Try this thread:
oil tank location
Oil Tank location

Best,
Grady

[Slider79SC]

Olivier,

I can ask if he has pics of the oil tank during installation, and I am sure it was a 964 tank.

The oil sump tanks have since been changed for a better design and I will get pics of those in the next few weeks. He is using Garrett (sp) turbos.

[ohecht]

That is an unusual sump design. Is it enough of a downward path for the oil to avoid it backing up into the turbo housings?

I am also using Garretts, and I would love to ask your friend more about some of his design. It looks like I could use the piece he is using to transition the exhaust to the turbine housing.

Thanks,

Olivier

[Slider79SC]

The sump design wasn't what he originally wanted and he changed it in the last month or so. I think he went towards a more traditional design lke what would be seen on a normal 3.3 turbo setup. I will try and get pics for you this next week if he has the car at his shop.

The exhaust headers are custom one off headers (with heat) from GHL that he had them make.

You can see the headers a little better in this pic. This is before all the taillights and wiring were hooked back from being painted so please excuse the wiring hanging down.

[KobaltBlau]

I'm not sure if Slider mentioned this but the engine is 3.6 based, if you couldn't tell by the plastic covers...

I'm not seeing mufflers!

edit: Goran will be right over to comment on these pics!