911 fuel tank can I cut return pipe?

[stormlister]

I have a solid blockage in the return pipe of my 911 sc fuel tank. I have posted this before and was given lots of useful advice. I have tried all the methods for unblocking but none of these have worked. I have given tank to a repair shop who have cut a hole in the tank for access but we are still unable to unblock the pipe from the inside.

My question is can I bypass the swirl box and cut the return pipe so fuel returns directly into the tank? This might be the only way of making this tank useable.

Btw. I cannot see any holes in the swirl box except for the top . How does this work? How does fuel get into the swirl box?

Thanks

Mark

[sigchuck]

I'm not sure what your budget is, but I would seriously consider a Dansk replacement tank. I purchased one a couple months ago for a little over $300. My factory tank had a prior repair that was leaking (and would likely leak again even after a new repair, according to one of the only guys in DFW that welds fuel tanks).

The downside of the Dansk tank is the factory pre-filter won't work, but this can be remedied using an inline filter and some AN fittings between the tank and pump, all for less than the cost of a replacement Porsche pre-filter.

I have a few thousand miles on mine with no complaints.

[stormlister]

Yes I looked at the dansk tank but was put off by the lac of filter. The cost of the tank plus filter seemed much more than what I thought was going to be a simple job to unblock a pipe...what is the spec and cost if the inline filter and parts?

[sigchuck]

I went with a generic compact one from one of the big suppliers (Jegs or Summit), since they also have the correct AN fittings. I think you'll need a straight one (for the supply end) and then a 180 degree one for the pump side. I can't recall the size of the AN fitting, but it is whatever is closest to 1/2" ***I THINK***. Since most readily available fuel line is sized in standard, and AN fittings are standard, I went with whatever was closest to the metric supply line (which I think is 11.5mm or 12mm).

Depending on the condition of the front portion of your tunnel lines (between tunnel and fuel pump), you may also want to replace them now with the tank out. I highly recommend lines from Len Cummings (BoxsterGT). The job is still not very fun with the tank out, but I was able to do it with the engine and steering rack in the car.

[Mark Salvetti]

Turns out that Pelican sells an alternative to the Dansk tank, and it does have the swirl pot screen.
https://www.pelicanparts.com/More_Info/PELTMP9710.htm?pn=PEL-TMP-9710&bt=Y&fs=0&SVSVSI=793

I think someone recently posted that they are using this tank, but I can't find the thread.

Mark

[stormlister]

That’s really helpful. Reviews of tank are not 100% but I guess still better than the time and expense of a repair.

[E Sully]

You might be able to find one in the 911 Used parts forum. Post a wanted to buy ad. Some are too rusty internally, but good used tanks are occasionally listed.

[sigchuck]

I remember reading about the TMP tank. From what I recall, both the Dansk and TMP tank have metal swirl pots built in, but the TMP tank comes with the factory style, in tank strainer. I'm not sure that it IS the factory in tank strainer though (thread size, etc.).

I think it may have been unavailable earlier this year, and that the Dansk tank was significantly cheaper (1/3 or so). I also liked the idea of having the ability to change/clean the pre-pump filter without completely draining the tank (not that changing either one sounds all that fun).

The other issue I ran into with my tank was that there was corrosion in the seam where the top and bottom halves of the tank meet. My car is a lifetime southern vehicle with zero rust elsewhere in the chassis, but I think the combination of the crappy seam sealer (consistency of silicone caulk) and foam seal that sits between the tank and tub trapped moisture. I suspect you'd find a similar issue with any used tank, so it may be a matter of how much time you want to put into a tank restoration.

[chrismorse]

The TMP tank comes with a stock size brass fuel strainer/filter. It is a little rough, with a substantially more coarse screen. My original screen filter was in great shape, so I am using it in the new tank.
Importantly, the tank is Galvanized, (the Dansk is not), and comes with a good heavy coat of primer.

The reviews of the tank complained about the larger vent nipple on the tank and that it required a bit of adapting to fit the smaller ,earlier vent hose -no big deal.
This tank is designed to work with 84 and later front fuel pump and lines.

Cost was about $450.

I am going with Len Cummings lines and new fuel pump mount, to update the fuel supply system.

I lightly sanded the new tank and applied several coats of Herculiner bed liner to help protect the tank. The liner is a bit gritty looking, so, I am going to shoot some grey stone/chip guard for a better appearance and more protection.

Hth
chris

[sigchuck]

Interesting. I do think the Dansk tank I bought earlier this year was specifically advertised as being galvanized, so perhaps they've changed their processes.