The Stovebolt Site Forums The Shop Area The HiPo Shop Steel or Polyethylene Gas Tank?

What are the pros and cons of polyethylene vs. steel gas tanks?

I was planning to use the Tanks Inc. steel 23 x 17 universal truck tank for a rear mounted tank with a side filler. Looking at their web site it appears that they no longer make that item.

I plan to make a filler door on the drivers side rear fender.

one rusts, the other doesnt. one can be repaired if punctured, one cant

In 56 years of operation, my stock steel gas tank is still not rusty. Neither are the gas tanks in my '68 Corvette nor '68 Firebird. But I guess for some people it could be a problem, especially in the midwest where roads are salted in the winter. This isn't a problem typically in the southwest.

this on our 3104. used steel one from tanks and stock filler neck
http://s67.photobucket.com/albums/h298/1951otter/?action=view&current=0465700-R1-035-16.jpg
http://s67.photobucket.com/albums/h...&current=3100lockinghoodlatch-05.jpg
http://s67.photobucket.com/albums/h298/1951otter/?action=view&current=18.jpg
http://s67.photobucket.com/albums/h...&current=3100lockinghoodlatch-02.jpg
even through my tank fits between the rails i may have to angle it a slight bit to allow the axle to have move clearance.

You will get all kinds of opinions on this subject.True the steel ones will rust,and poly tanks can be repaired.To the best of my knowledge the manufacturers of new trucks have been using poly tanks for years.For the way I use my trucks,taking them to cruisins and shows on good roads,I would go with the poly tank,which should be priced much cheaper than steel.Also lighter.

I went with a poly 16gal tank from summit for my 52 3/4 ton. I mounted it directly behind the rear axle but inorder for the fittings to safely clear the swing of the axle I moved the rear crossmember back about 2-3 inches. Its a very nice tank and I believe it was well worth the money. It has a foam insert that keeps the fuel from sloshing around and keeps the tank from busting in a impact and also came with a fuel level sender. Fits nicely inbetween the frame rails and will be filled with a fuel door in the bed floor. http://store.summitracing.com/partdetail.asp?part=SUM%2D290108&view=1&N=700+150+4294920243+4294894961+

I did the same with a aluminum tank from summit.

Lot's of good comments.

Jim, maybe the 1951 has a parallel frame but the 1946 and older angle closer together in the front than the rear. After several attempts I decided not to place the tank between the frame and the drive shaft because it was too tight.

Nobody mentions if the plastic would get brittle over time so I guess that is not an issue. The poly will rebound if impacted where the steel will dent.

I talked to Tanks Inc early this week and the steel model USPT-G is on severe back order and not discontinued so they pulled it off the web site. That one is a really good fit in the raised area of the last crossmember. If I go with the poly it will sit a couple of inches down but is a little bit thinner tank so it may not make much difference.

Thank you. Keep the comment soming if you have some.

drummin52 or others,

The Summit comes with a 0-90 ohm sending unit, so did you get an new dash gauge?

Im going custom as far as the gauges go. A new speedometer in the stock speedometer location, a tachometer in the location of the stock combination gauge and then 4 2-1/8" gauges where the radio speaker grille was. This is of coarse on my 52.



On thing I noticed with the poly tank is the fact that when you have gas in the tank, on hot days, the tank swells a little bit. At the moment Im trying to think of a way to relieve the pressure in the tank, but not provide an exit for the fuel incase of a turn over.

Newer vehicles have a vac hose that runs from the tank back to the engine and connects to a vac source like on the intake manifold. In line on this vent line is a evap solenoid that is normally closed so as to not create a vacuum leak. When the engine gets to a higher rpm, the evap solenoid is energized and opens allowing the built up fumes to be burnt. Obviously this is done by computer and would be kind of hard to adapt to a non computer controlled vehicle.

The summit tank, and most other poly tanks as I would imagine, have a connection on top of the tank for a return line/vent. I was thinking of making a vent tube by bending some steel fuel/brake line and running it so it does a 180 out of the tank, pointing down at the ground and ending about 2 inches lower than the bottom of the tank. This way, with the tube ending lower than the bottom of the tank, I would think (or hope) that in the case of a roll over, the vent tube would then be high enough that the fuel would not leak out of the tank. Thats just a senario playing out in my head, I have to do an experiment before I go through the work of making the vent line for my tank.

I did read in the owners/installation manual that swelling and sagging of a poly tank is normal. Didn't say anything about tendency to become brittle.

doesn't summit have some vents that will close if rolled over or something like that.

the fuel filler cap has a vent in it that will let air in as fuel is used but will not let fuel out if turned upside down. Im pretty sure Its not made to let the pressure out.

The one thing you should look at like one Bolter said is what are you going to used the truck for daily driver, show it, work truck etc.. If for work-daily driver you should consider a steel or S/S tank and if you decide on those two. For Shows, Racing etc. Poly or Aluminum. You also should consider a skid plate to protect the bottom of these tanks in case you should run over a foreign object on the road that could puncher your tank. Used Steel tanks can be boiled out and coated. New Steel tanks come Galvinised, S/S tanks are a little expensive but will last a life time. Aluminum tanks tend to have stress cracks after a while of steady driving on the roads and as for Poly tanks I would be afraid of it catching Fire or Rupturing in a accident. I for one believe in safety over the cost of losing a loved one. Be sides I do not have that long here on earth to break another one in! It has only taken me 36 years! LOL!
Just my though here fellow Bolters.
62Blue
Don

Funny, my 2004 Silverado has a steel tank....with a poly shield to protect it.


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Yah...... I'd like to get a side tank off of a semi for my truck!