Fuel tank question - 911E/911S vs. 911T

[obrut]

hi all

i was experiencing some fuel surge/power cutout in my 2.8RSR (MFI) engined 911ST rally car at the track today. started occurring when the needle was slightly above empty (low fuel warning light not on).

before i start looking at swirl pots etc i though i would check if cars delivered with MFI had different tanks to those delivered with cars. (my car started life as a carb'd 70T)

any ideas?

[Chuck Miller]

Ryan,

I believe all the 'standard' tank cars had the same tank.....

However, I and others have had the same problem with our MFI cars when on the track side loading the cars with anything under 1/4 tank on board.....

When I'm running at the track I try to keep my tank at least at 1/2 all day.

I'd like to hear from others about if they've encountered this .....

Cheers

[Jappy]

Ryan,
I had the same issue at Winton with slightly less than 1/4 tank, seems that if I keep it above that no issues at all. From memory was worse on right hand corners?

Michael

[obrut]

thanks guys - looks like its time to look at a swirl pot

(i can't bring myself to lug all that heavy fuel around!)

[Todsimpson]

I have the later sc tank in my '71, and I relocated the fuel pump to the front as well. Big improvement.

I can run the tank down to about 1/4 tank at the track now, while the old tank was a little under half before I'd get fuel starvation in left hand corners.

[Flieger]

So a 1971 911S would not have the swirl pot?

[Grady Clay]

Only cars with CIS have a swirl pot.
The "tank to find" is from a '73.5 CIS car as it uses a standard spare. From the topside it appears the same. From the bottom it has the obvious center screen filter.

Best,
Grady

[Chuck Miller]

Live and learn........

Thanks Grady...... Holiday cheers to you and yours...

I love our message board......

[obrut]

thanks grady.

looks like i will be fitting a swirl pot to my existing tank (as i have just converted it to centre fill)

[Grady Clay]

Ryan,

You can salvage a swirl pot from any CIS fuel tank (I assume DME also). You might look for the latest one possible with both fuel fittings using threaded connections for safety.

There are several good Pelican threads about swirl pots complete with diagrams and images of cut-apart tanks.

Search this forum (Ely S) for a post of mine about center-fill safety. It is more about fuel cells but has exact application for your 911.

Chuck, there isn't a day where I don't learn how much I don't know. The problem is that it seems to happen more often.

Best,
Grady