C1 37 1/2 gallon fuel tank

[David B.]

After noticing the reader interest regarding the '64 N03 tank thread it might be interesting to open a similar thread for C1 cars and perhaps fill in some pieces missing from Michael Johnson's Chapter article. As a former owner of both C1 and C2 cars equipped with the 37 1/2 (36 1/2) fuel tank I was able to obtain some rather interesting information years ago direct from the source.

The first "big" tank was originally designed by Chevrolet Engineering in early 1956 under print L-45998 part #3725408. It was originally designed to be 40 gallons. This amount was based upon the track length at LeMans and the tank size was calculated to reduce the number of pit stops required to complete the entire race. When this size tank was initially installed in a mock up in the design stdio it was discovered there was too much interference with the seat frames and top cover. As a result the top of the tank was reconfigured and modified to 37 1/2 gallons. There was more to the story when the use of the hard top in '57 came into play but that is another story/thread. Chevrolet records show a 37 1/2 gal. tank shipped to Sebring 3-6-56 to be installed in the Corvettes being prepared for the end of March race. To fulfill SCCA requirements Chevrolet announced in a low key manner "Factory Optional Equipment for the 1956 Corvette" this included HD brakes, springs, suspension, mag wheels, shorter steering column and rear axle ratios for limited slip differential etc. This particular size tank would be utilized again at Sebring in 1957 and at LeMans in 1960 and 1962. While Chevrolet printed an official announcement in 1956 there is no evidence the 37 1/2 gal. tank was ever installed on the production line for the entire C1 period.

The 24 gallon tank referenced in Michael Johnson's article was designed starting 5-8-59 with minimum changes made 7-21-59 and a final drawing 3-31-60. Because of this time frame it is unlikely this tank was available in 1959. Original GM Production records DO NOT LISTthe 24 gallon tank as a production option LPO1625. In addition, production records show it was never installed on the assembly line in 1959, 1960 or 1961 but it was available over the parts counter as part #3772977. 1962 was the only year that offered this fuel tank as an option RPO-488 on a C1 and as previously mentioned 65 were produced.

As my Dad used to tell me "Dave you don't know what your talking about" so with that thought ringing in my ears who can back up my Dad?

[Mike E.]

Re: C1 37 1/2 gallon fuel tank

Dave, in your middle paragraph, on the C1 37 1/2 gallon tanks, you neglected Gulf Oil's use of them at Sebring in 1961 and 1962. Also, could you differentiate as to which of those were metal and which were fiberglass? Seems like both you and I have owned one of each!

[Loren L.]

Re: C1 37 1/2 gallon fuel tank

Don't know about backing up your Dad, but a 28 Nov 1961 letter from ZAD to WT Burwell (ccs to Barr, Rosenberger, etc.) "to make additional Corvette heavy duty equipment for 1962", a re-authorization, if you will, for HD front and rear springs, third stabilizer bar, special brakes, 37 gallon
tank and Halibrand wheels. On page 2, there appears:

"In regard to 24 Gallon tank, LPO 1625, 10 were produced in 1960 and 25 in 1961. I feel that no more, but rather less 37 Gallon Tanks
will be required."

Granted this does Not say they were produced on the line, but Gamble states that both Camoradi cars were delivered with 24 Gallon Tanks,
with the holes cut in the extreme lower corners for clearance. When the 37 gallon tanks arrived, Camoradi installed them. The work order for the 37 gallon tanks called for SIX tanks, apparently apportioned 2 to Cunningham, 2 to Camoradi, 1 to Delmo Johnson and later, after the post Sebring Camoradi fire, a third tank for Cunningham's Le Mans only car.
As a computer illiterate, I can snail mail copies but nothing more than that.