5.7 4b/ Gas tank Help

[joeyman15]

Hey guys i need some input, i am fixing a 20 foot sunbird with a 5.7 mercruiser. Well it needed a new floor and stringers so were in the middle of that right now. Last night we pulled the gas tank to give us room for the stringers and there were about 5 small holes in it. It's a alum tank and has pits all over it. I plan on keeping the boat so i don't want to put it back in there even if i could fix the holes.

So here is the problem the tank is 40 gal is 22" long/54"wide/9 1/2"deep. Well i can't find a tank anywhere that matches it. The only one i found that will fit in there is a 25 gal tank. But will 25 gal be enough with my motor? If anyone know of a tank that would fit or if 25 gal would be enough gas please let me know.

 

[Don S]

Re: 5.7 4b/ Gas tank Help

Moving to boat topics and questions (not engine topics)

 

[mkast]

Re: 5.7 4b/ Gas tank Help

Aluminum tanks aren't cheap, as you found out.
Twenty-five gallons will be more than enough, all you have to do is remember, twenty-five gallons!
You can cross the pond, you just can't cross the lake.

 

[Mischief Managed]

Re: 5.7 4b/ Gas tank Help

Someone I know had the same problem with an older Rinker. They found a manufacturer's name and serial number on the tank and were able to get a brand new, exact replacement from the OEM supplier.

 

[joeyman15]

Re: 5.7 4b/ Gas tank Help

I wouldn't mind putting the 25 gal tank in there, i just don't know how far or how long it would last. I would hate to have to fill up more than once a day.

 

[Bigprairie1]

Re: 5.7 4b/ Gas tank Help

What about taking it to a shop that repairs gas/fuel tanks? I've seen those businesses out there quite often.
They would know where to start, what to do and may be less expensive than a complete new one. Perhaps worth a look?
Good Luck
BP

 

[Silvertip]

Re: 5.7 4b/ Gas tank Help

A 25 gallon tank will last 62% as long as your 40 gallon tank did. If you have no idea how far the 40 gallon tank took you, then it really doesn't matter how far the 25 will take you. The gas gauge is your friend in this case.

 

[fishmen111]

Re: 5.7 4b/ Gas tank Help

Are the tank dimensions you gave the max you can use, or is there a little extra room? It sure would be nice to put a poly tank in.

 

[fixb52s]

Re: 5.7 4b/ Gas tank Help

My 21 gal. fuel tank is in the same condition as yours. I took it to a place to have it "fixed" and it still leaked. More pinholes appeared! It is a good thing I put fuel in it before I finished the deck.​

I also could not find an off the shelf replacement. I am getting one built. There are a lot of companies out there that will build them. A 21 gallon tank is not cheap ($310) but I know there will be a new tank under there.​

Note: I was waiting for a quote from the company I mentioned earlier (Florida Marine Tank) , but so far after a week I heard nothing. I called and they said they would "get back to me". I contacted Sunrise Marine Tanks in Venice. I sent them the drawings today, and within an hour had a firm quote. I will also have the tank by next Wed. Now that is service!​

 

[joeyman15]

Re: 5.7 4b/ Gas tank Help

25 wide and 10 deep are my max. I can go longer if i need to i think up to 60 or so. keep in mind that 25 wide would be touching the stringers, would that be a problem?

 

[fishmen111]

Re: 5.7 4b/ Gas tank Help

Joey, Moeller makes a 52 gallon tank that is 24x60x10 that you might check out. I could not find anything here on iboats, but Overton's has it. It is model #30458. If you are using blended fuel, it is my understanding that the ethanol and the water it traps is the cause of the aluminum pitting. They actually have warning labels on the pumps here just for boat owners with metal tanks.

 

[joeyman15]

Re: 5.7 4b/ Gas tank Help

Thanks i think i am going to buy the 50 GAL tank, i would rather have a non-metal one now.