73 1/2 fuel tank

hot442 · 02-08-2004, 07:12 AM

New project is a 73 1/2 911 that has been sitting a good while. I pulled the fuel tank sender and it looks like I will have to replace the tank. Question is what year models can I use with the CIS system. This is my first Porsche project and I am not sure if the tanks changed with the model year changes. I have heard that the earlier MFI tanks are different but not sure how long the CIS tanks remained the same.

Thanks for your help, Steve

Zuff911 · Zuff911's Garage

The 73 1/2 tank is specific to that model. The CIS requires different tank construction in order to get the correct flow characteristics. The 73 tank also has a section molded into it to fit the full size spare tire which I belieive changed in 74. I think all the short nose cars had space saver spares and different tanks. What exactly do you think is wrong with your tank?

-brad

hot442 · 02-08-2004, 08:23 AM

Fuel sat in it for several years but only half full. Area above the liquid level appears to be rusted and there is some evidence of rust on the bottom of the tank under the coating but it is fairly small. When I pulled the sender the crud that accumulated on it was pretty ugly. I might be able to get away with cleaning and sealing it but if a clean replacement was available at a decent price it would be an easier fix.

hot442 · 02-08-2004, 10:12 AM

If I am willing to go to a space saver spare what years do I have to choose from?

Randy Webb · 02-08-2004, 11:38 AM

'74 up to prob. at least 85 (the end of the SC's and CIS). I'm not sure any of those will fit tho -- the short nose cars might be different. You might try getting one for cheap from a junker so you can resell if it doesn't fit. There are soem quick and easy rust repair sealers folks have posted about.

BTW, does naybody know if the 73.5 gas tank is much heavier than the earlier (non-CIS) ones?