Fuel for Mid-year cars.

[A S.]

I am seeking to purchase a Mid- year vette, 1963-67 model. I have concerns about type of gas to use- ethanol, non- ethanol, octane rating, etc. Would most of these older Corvettes have been changed out to accommodate 10% ethanol gasoline being used on regular basis? Hoses , gaskets, fuel pumps, etc.? I am aware that fuel stabilizer would be a prudent additive if using ethanol gas.My engine choice is the 327/300 h.p. (p.s. non-ethanol fuel is difficult to find in my area).Thanks for a reply.

[Patrick B.]

Re: Fuel for Mid-year cars.

I think the worries about 10% ethanol gas in old Corvettes is exaggerated. Other than the systematic issues discussed here regarding mechanical fuel injection, occasional vapor lock and fuel evaporation in the carb bowls are the main nuisances. A few cars in a few places may require fuel line insulation and a carb base insulator, but most old Corvettes run fine on ordinary gas with ethanol. I have a 70 Corvette with a somewhat detuned 69 ZL-1 427, and it runs fine on ordinary premium gas in Virginia without any special hoses, gaskets or fuel pump. None of these old Corvettes start like modern cars. You have run the starter and pump the accelerator to get gas to the manifold, or you have to hold the accelerator down when it's flooded. But that was always the case with cars of that vintage, especially hot rodded ones without good chokes. A 327-300 is probably the least sensitive Corvette engine regarding gas and a good choice for a driver.

[Richard G.]

Re: Fuel for Mid-year cars.

I use premium fuel without ethanol whenever I can.
Seems to work fine but my 340HP has a felpro composition gasket which drops the compression a little.
I have ran ethanol fuel but only when I can't find any none-ethanol. Just run it close to empty and fill it up with none-ethanol next time.
Be sure to leave the tank full over the winter as it will discourage condensation formation in the fuel tank.
In my experience the 300hp had more issues with detonation than the High Compression counter parts because they lacked the cam overlap of the HP motors. Would appreciate others input on this as a lot of time has elapsed between cars and fuel has changed.
Be sure the distributor is set up correctly and back off the timing if you have to.
In my younger years my brother purchased a beautiful 66 Impala from the original owner. The old guy said he used regular gas. My brother, not having much money, took his word as gospel. Obviously the original owner didn't drive like my brother! My brother let it ping and destroyed the motor in less than 6 months. When we pulled the motor almost all the top ring lands were broken off the pistions!
BTW he still has no mechanical sense. Don't lend him your lawn mower! LOL.
Rick

[Jim L.]

Re: Fuel for Mid-year cars.

.My engine choice is the 327/300 h.p. (p.s. non-ethanol fuel is difficult to find in my area).Thanks for a reply.

A.T.,
My '63 has the 327/300 engine you prefer. I use California's version of E10 and do not have any issues. I don't add anything to the fuel ever. No fuel stabilizer.

I don't like E10 but I can't point to any problems that using it has ever caused.

Good luck in your search for a mid-year.

Jim

[Keith B.]

Re: Fuel for Mid-year cars.

a 300 should be able to run off corn based 87 with no problem if tuned correctly

[Alan D.]

Re: Fuel for Mid-year cars.

The major problem with the E10 is more apt to be your rubber parts - hoses including the fuel pump if old do not like the stuff.
However if you have rebuilt and replaced these fittings the new stuff was designed for E10 and you should be ready to go.
The major problems I've seen have been more often with boats since they seem to run longer old rubber lines.
Alan

[Edward J.]

Re: Fuel for Mid-year cars.

I believe the most of the problems I see is percolation / Vapor lock when a shut down on a hot day, I have seen it first hand on many cars. other wise car do seem to run normal on E10.

[Ed S.]

Re: Fuel for Mid-year cars.

If you absolutely have to use ethanol gas it is not like the end of the world - but..... there are issues. 1. C2 fuel systems are non-vented, meaning vapors will be released into the atmosphere - including the atmosphere of your garage. 2. Since it is not a sealed system moisture will get into the tank and be absorbed by the alcohol. Eventually..... eventually..... rust will form in the tank & the fuel lines. To minimize moisture in the tank keep the tank as full as possible - reduce the surface area of the gas in the tank. 3. Alcohol has a lower boiling point than gas. When you turn your engine off the manifold and carb will get heat soaked - you may not get full blown percolation in the carb bowls along with leaks but you will likely get the strong odor of gas in the garage after you shut it down. 4. Rubber lines and gaskets in old cars (C2s) is not created to withstand the effects of alcohol. Monitor for leaks often. Get a 10 pound ABC fire extinguisher - and carry it around. I see from your profile you are in Virginia - look a the Pure Gas website or phone app to find gas stations in VA that sell non ethanol gas. There are many all over the state - you will be surprised how much better your car will run on ethanol free gas.

[Duke W.]

Re: Fuel for Mid-year cars.

"a 300 should be able to run off corn based 87 with no problem if tuned correctly"


...not if it still has the OE CR, which was about 10:1 true, however, many engines have been rebuilt over decades with "low compression" and may operate detonation-free on 87 PON. The only way to know in most cases is to test.

If the car is kept garaged and rarely exposed to condensing humidity, water absorption and its associated problems should not be an issue, however, the car should be driven enough to consume AT LEAST one full tank of fuel per year.

E10 was introduced in some markets back in the early eighties, if not earlier, and since that time elastomers have been formulated to resist degradation due to ethanol, but if your rubber fuel hoses are over 40 years old they need to be replaced, PERIOD!

The biggest problem with E10 is percolation due to the greater percentage of components that reach their boiling points at lower temperature than straight gasoline, and the archives have many discussions including steps to mitigate percolation.

...bottom line is that E10 may or may not cause some issues, usually minor, but new owners need to get some driving time in their local driving environment and go from there.

Duke

[Elliott P.]

Re: Fuel for Mid-year cars.



Ethanol is a contentious subject, at least in gasoline. Many opinions, lots of conflicting experience, some facts, and the real truth is probably not knowable. Personally, I think Ed pretty well nails it. (Really only one quibble: the C2 has a vented system which Ed properly describes.) Yes, use ethanol-free gas if you can get it, but 91 octane may be tough. Among other things, the ethanol is used to enhance the octane rating, so the refiners love it, because they get away with less refining. And of course the corn-state farmers and congressmen love it because they get more money (follow-the-money), rather than being limited to just eatin and drinkin the stuff.

Ethanol will cause old elastomers to degrade in such things as fuel lines, fuel-pump diaphragms, carburetor accelerator-pumps, some gaskets, and fail. Ethanol will absorb moisture from the atmosphere that can then separate and cause erratic performance and rusting of components and contamination. Over time, ethanol/water/gasoline solution can result in phase separation that significantly deteriorates the performance of the fuel and makes it even more corrosive to components. And there is the percolation problems described with the ethanol/lower-octane gas.

If you are regularly driving your old car (old Corvette) year round and you have replaced suspect elastomers, you may not have a serious problem other than the occasional vapor-lock, hard starting, occasional dieseling when shutting off, and the engine running a bit hotter. If, like most Corvette drivers, you tend to do seasonal/limited driving, then you may suffer the consequences of old stale fuel, which can really damage the car. Here I differ from Al, and never put over 5 gallons of ethanol debased fuel in my C2, and make sure that it gets used up within a month or two to avoid stale gas. (I think 6 months would be stretching it, even with an additive.)

I do use a fuel additive that has a good established reputation for treating the ethanol problems: STA-BIL 360 Performance. The 360 goes beyond the original STA-BIL in protecting the exposed components (fuel tank and carburetor) that are not submerged in fuel, and the additive significantly reduces the moisture absorption from the atmosphere (so you do not need to keep tank full of old fuel). Bell Performance has a newer equivalent ethanol fuel additive on the market: ETHANOL DEFENSE, with claims similar to STA-BIL 360 Performance, but I have not tried it. You can find much more info on these products by Googling.

This problem is not going away and it will get worse. My lovely nanny-state of California is already using E15 (15%) ethanol which is the current limit allowed by the EPA. And those corn-huskers are suing the EPA to eliminate that limit (after all it is their bowl-of-rice).

I have a Top-Flight 1965 Corvette coupe L79 (350 HP) with AC that sees limited driving, and it runs great when I am moving, but overheats if I get stuck in traffic. This is common among older cars with AC, and slow parades are killers. So I am considering how to discreetly put an electric radiator fan in that can be removed as needed for NCRS judging (so far, it aint purty). And I can not find any legal ethanol-free gas anywhere near the San Francisco Bay area.

BTW: I would be concerned about detuning a 300 HP Corvette to run on 87 octane fuel as some have suggested above. If you get it there, will you be happy with performance? When looking, I set the bar at 350 HP since that was the highest HP that year still with hydraulic lifters, and 91 octane fresh fuel seems to be fine.

BTW2: Make that an ABC Halotron 1 fire extinguisher (no mess).

[Larry E.]

Re: Fuel for Mid-year cars.

This subject comes up all the time. Bottom line for me is>
Yes they will "run" on the current gasoline at the pumps. But>
IF YOU TRY AV GAS (100 LL) YOU WILL NEVER GO BACK TO THE
ABOVE GAS. IT WILL MAKE YOU CAR RUN/PERFORM LIKE NEVER BEFORE;
PLUS THE FACT IT WILL HAVE SUPERIOR LONGEVITY ON DETERIORATION.
JMHO-LARRY

[Frank D.]

Re: Fuel for Mid-year cars.

This nonsense recycles every few months or so....here are the plugs from my 1961 270hp solid lifter original motor after many, many miles of 87 octane, ethanol gas. The plugs in my 250hp 63 look similar... I buy non-ethanol when I happen to run into it but don't make special trips to find it. I can't speak to F/I cars, never had one...

Any car that has had the typical fuel components rebuilt in the last 10 years (carb, fuel pump, fuel lines) will have ethanol resistant components...

[Jim L.]

Re: Fuel for Mid-year cars.

. My lovely nanny-state of California is already using E15 (15%) ethanol which is the current limit allowed by the EPA. And those corn-huskers are suing the EPA to eliminate that limit (after all it is their bowl-of-rice)..

Really? Where can you currently buy E15?

I searched the C.A.R.B web page for E15 info and this is what I found:

:

Ethanol up to 10 percent is the only oxygenate currently allowed in gasoline used in California. In order to increase the amount of ethanol allowed in gasoline a multimedia evaluation must be approved in accordance with Health and Safety Code section 43830.8.

The above is from the "CalEPA Fuels Guidance Document" dated October 2018.

You can read the entire paper here:

https://ww2.arb.ca.gov/sites/default/files/2018-10/CalEPA_Fuels_Guidance_Document_10-2-18.pdf

[Bill M.]

Re: Fuel for Mid-year cars.

I have my 2 mid years 30 and 15 years I have been using Sunoco 93 forever only had a problem with the carburetor on the 67 it leaked like a stuck pig about 15 years ago had it rebuilt not restored and it has been fine ever since. I fill the tanks to the top and add a preservative. I start the cars every 2 or 3 weeks to keep the mice on the run. Use plenty of bounce and peppermint oil to get rid of them also.

[Elliott P.]

Re: Fuel for Mid-year cars.

Jim, I refer you to a report in Hemmings (the bible) dated April 15, 2019, regarding use of E15 and the suit to have even that limit removed @ https://www.hemmings.com/blog/2019/0...ign=2019-08-15 . Due to the increased oxygenation of the E15 resulting in cleaner burning fuel, nanny-California jumped on it (except in summer). Your report is dated October 2, 2018. BTW, sub-sim rule noted in report stands for substantially similar, which is a bit of a crock as it is.