redlinefidelitynine

iTrader: (1)

Anybody ever tried putting fuel cell foam in their original tank? Thought this might be an easier approach to replacing the pump strainer every so many months because of rust, tank liner erosion, and cutting out in turns; other than just installing a fuel cell..
My car apparently say for a long time w. 1/3 tank of gas and it has surface "eruptions" on the top (inside) of the tank which is only surface rust.. and id rather not buy a new one... figured id fill the area around the pump in the baffles, should take care of it (if not the whole thing ~ 30-40 bucks worth of foam roughly). would act as a pre strainer too and is easily cleaned. beats spending 100+ more on a new tank.

Curious if anyone else has tried this w. success.. if not ill be sure to post it up.

Chris

Turbo II Rotor

iTrader: (2)

Don't fuel cells have a bladder in them to prevent the fuel from coming in contact with the foam?

CompuBob

all of the cell's I've seen just go right in the tank.

I also have tank problems, rust caused the filter on the pump to clog and break open, then the fuel filter got clogged and broke open, so my injectors are probably clogged, which is why it cuts out above 5k, and I'm guessing the baffles are rusted out and broken off because any left turns at a decent speed the car just cuts out for a few seconds.

if I can find a new tank, I will just replace it.

jgrewe

iTrader: (1)

Remove and clean your tank with muratic acid, that will get the rust. Then rinse it well with water. After the water pour a quart of rubbing alcohol and slosh that around and pour it out. Let the tank dry and you could put it back just like that.

Or, the next step to complete the process so you never have to worry about it again would be to seal the inside of the tank. The absolute best stuff on the market is Bill Hirsch's gas tank sealer. Its about $25 a quart and 2 quarts would be plenty. It is one of the few that is alcohol resistant and with all the ethanol in our fuel now that is very important. It will seal pin holes and even bigger holes can be plugged with a 'metal' epoxy after cleaning. The gas will never get to whatever you plug the holes with so anything that bonds to metal is fine.

I just did the gas tank on my '59 Austin Healey and I saved a few hundred bucks over buying a new tank. This thing had holes all over it all over the bottom after I cleaned it with the acid.

Evil Aviator

Fuel cell foam will not cure any of your problems other than maybe helping a bit with cutting out in turns. The rust will still end up in your strainer, and I think this is probably the primary problem with cutting out in turns since I have never seen this condition in any FC RX-7 in good condition. You would be better off spending your time and money cleaning and resealing the tank. If you are hugely concerned about the engine cutting out in violent cornering, then you need to install a surge tank.

No, the foam blocks are actually inside the bladder. The foam is there primarily for explosion resistance, but it also helps keep the fuel from sloshing around.

redlinefidelitynine

iTrader: (1)

true to all the above... im going to try it anyway just to see how it works.. inevidably ill need to clean out that tank w. some harsh chemicals - but you know how rust works on bare metal; Once its there, its bound to come back. Cream sealers seem to be the way to go, but until i get under the car to do the swap, the tanks gonna be stuffed. between all the vac leaks i fixed and this tank job, it runs a hell of alot better...

Compubob - i was thinking the exact same thing - but in over analyzing the whole thing - i neglected to realize there is a fuel filter under the hood AND strainers in the injectors as there are in every FI system.. if any rust made it through, were talkin about microns here. im gonna cut open that high pressure filter and see what goodies are in there for me to see. if you havent had that top end off in a while you might wanna check out "stuff" anyway. 70k miles and had split pintle caps and rock hard seals and vac lines everywhere - (no wonder it ran like poop - on top of the blowd pump strainer)
chris