fuel
-
HOCKEYHOUSE10
- Posts: 5
- Joined: Mon Aug 22, 2022 8:29 am
fuel
First time owning a car from the 60s in a long time. Do I need to add anything to pump fuel such as lead for a 67 corvair?
Re: fuel
Now I'm new to the forum but, I do know fuel. I've been hauling and selling it for over 16 years. I work with the refineries to the buyers/sellers of fuel.
That being said, Most fuel has Ethanol (and Butane but that's another story). A carburated engine will run on this but non-ethanol fuels are better for the rubber seals and diaphragms found in carburetors. As far as Lead, It's not necessary. And if you wonder if you should buy 93 octane this is my opinion... If your car runs on Regular at 85 or 87 octane (depending on where you live) and can pull a hill and accelerate WITHOUT making the spark knocking noise, then you are fine to run Regular. If you do run higher octane fuel you may see an increase in your fuel mileage although the difference in today's fuel costs doesn't make up the difference. If you want to run higher octane fuel your engine can run cleaner as it helps to burn off carbon deposits. But this is up to you if you want to spend a higher price on fuel.
Now, Again, I'm new to the forum. I have a Corvair and run higher octane fuel as that is what my Dad says to use in "his" car. The engine has been beefed up so it has much more HP. But this is just the choice we make. The car doesn't get driven much at all so the extra cost is next to nothing.
Now if someone wants to chime in and say I'm completely screwy and don't know what I'm talking about when it comes to Corvairs this is fine with me. I can take it. I admit I'm a beginner when it comes to the Corvair. I just know fuel.
That being said, Most fuel has Ethanol (and Butane but that's another story). A carburated engine will run on this but non-ethanol fuels are better for the rubber seals and diaphragms found in carburetors. As far as Lead, It's not necessary. And if you wonder if you should buy 93 octane this is my opinion... If your car runs on Regular at 85 or 87 octane (depending on where you live) and can pull a hill and accelerate WITHOUT making the spark knocking noise, then you are fine to run Regular. If you do run higher octane fuel you may see an increase in your fuel mileage although the difference in today's fuel costs doesn't make up the difference. If you want to run higher octane fuel your engine can run cleaner as it helps to burn off carbon deposits. But this is up to you if you want to spend a higher price on fuel.
Now, Again, I'm new to the forum. I have a Corvair and run higher octane fuel as that is what my Dad says to use in "his" car. The engine has been beefed up so it has much more HP. But this is just the choice we make. The car doesn't get driven much at all so the extra cost is next to nothing.
Now if someone wants to chime in and say I'm completely screwy and don't know what I'm talking about when it comes to Corvairs this is fine with me. I can take it. I admit I'm a beginner when it comes to the Corvair. I just know fuel.
1963 Corvair Monza Convertible 140 4 speed.
Colorado Springs
Colorado Springs
Re: fuel
The "FUEL" issue discussion is as wild as "WHAT OIL TO USE".
As Gasman said --- YOU DON'T need a lead additive!. Ethyl (lead) additive is actually BAD for the engine, EXCEPT to lube valve seats and boost octane. The Corvair has hardened valve seats so unleaded fuel is NOT an issue.
The OCTANE rating is not simple. Back in the 60's we had octane ratings in RON. This rating was not that accurate in the real world, so the scientists came up with MON numbers that better predict how the average engine does over a wider range of conditions (real world), but they are different! For reasons that are still debated ---- it was decided that when octane rating had to be posted on gasoline pumps the number would be an AVERAGE of the old RON and new MON number. BTW this number is rarely used outside the U.S.A. and Canada for those with Corvairs in other countries.
So what octane to use???? Some basic math from online tables suggests today's regular pump gas works fine in the low compression base Corvair engine. The higher compression engines need at least 91 (RON MON average) octane. Across the U.S. most "Premium" fuel is 91-93 octane (RON MON). If you are running a turbo engine, then you'll need about 93 during boost for optimal timing. If you install a knock sensor to retard timing then 91 works. For those who suggest using aviation gasoline --- it's octane rating is calculated with a DIFFERENT formula, and it has additives that may be an issue in a car engine. It's also illegal to use in road vehicles since there is NO road tax on AVGAS.
As far as the pliable (rubber) seals/hose go ---- While there are exceptions, up to 10% ethanol isn't an issue for most pliable fuel items, although they won't last as long. That said, use ethanol rated items when you can. BTW Some companies sell fuel hose that is rated for 100% ethanol like "GATES Barricade" fuel hose. Some of the vendors are now selling the "BLUE VITON" carburetor accelerator pump cups that last longer.
BTW ethanol will NOT corrode carburetors! It is the denatured additives (required by law so it's undrinkable) that might, and they vary by location. In most areas it is NOT an issue, but it is why most new cars use stainless steel fuel for metal fuel parts. Water condensation causes corrosion. Water condensation has been an issue WAY before ethanol was added. So even non-ethanol gas accumulates water in gasoline. In fact ethanol additive is used in cold climate vehicles to absorb water so it doesn't freeze up gasoline lines - called gasoline antifreeze. Bottom line --- keep the tank full went parked for a while (keeps moist air out of tank) and DO NOT use gasoline that sits in a tank over four months (possible eight months with an ethanol fuel preservative).
So keep the tank clean and fill up with up to 10% ethanol fuel and drive the car enough to keep the gas fresh. If you can get high octane non-ethanol fuel that's fine, but it is NOT like the old leaded gasoline as the distillation method for higher octane results in more volatile compounds (BUTANE is one as Gasman said). Finally --- I've been running 10% ethanol gasoline in my 140HP for a decade without issue. The old black accelerator cups quit about ever five years (of course they also quit with non-ethanol fuels). Last year I installed the blue Viton accelerator cups, we will see how they last.
As Gasman said --- YOU DON'T need a lead additive!. Ethyl (lead) additive is actually BAD for the engine, EXCEPT to lube valve seats and boost octane. The Corvair has hardened valve seats so unleaded fuel is NOT an issue.
The OCTANE rating is not simple. Back in the 60's we had octane ratings in RON. This rating was not that accurate in the real world, so the scientists came up with MON numbers that better predict how the average engine does over a wider range of conditions (real world), but they are different! For reasons that are still debated ---- it was decided that when octane rating had to be posted on gasoline pumps the number would be an AVERAGE of the old RON and new MON number. BTW this number is rarely used outside the U.S.A. and Canada for those with Corvairs in other countries.
So what octane to use???? Some basic math from online tables suggests today's regular pump gas works fine in the low compression base Corvair engine. The higher compression engines need at least 91 (RON MON average) octane. Across the U.S. most "Premium" fuel is 91-93 octane (RON MON). If you are running a turbo engine, then you'll need about 93 during boost for optimal timing. If you install a knock sensor to retard timing then 91 works. For those who suggest using aviation gasoline --- it's octane rating is calculated with a DIFFERENT formula, and it has additives that may be an issue in a car engine. It's also illegal to use in road vehicles since there is NO road tax on AVGAS.
As far as the pliable (rubber) seals/hose go ---- While there are exceptions, up to 10% ethanol isn't an issue for most pliable fuel items, although they won't last as long. That said, use ethanol rated items when you can. BTW Some companies sell fuel hose that is rated for 100% ethanol like "GATES Barricade" fuel hose. Some of the vendors are now selling the "BLUE VITON" carburetor accelerator pump cups that last longer.
BTW ethanol will NOT corrode carburetors! It is the denatured additives (required by law so it's undrinkable) that might, and they vary by location. In most areas it is NOT an issue, but it is why most new cars use stainless steel fuel for metal fuel parts. Water condensation causes corrosion. Water condensation has been an issue WAY before ethanol was added. So even non-ethanol gas accumulates water in gasoline. In fact ethanol additive is used in cold climate vehicles to absorb water so it doesn't freeze up gasoline lines - called gasoline antifreeze. Bottom line --- keep the tank full went parked for a while (keeps moist air out of tank) and DO NOT use gasoline that sits in a tank over four months (possible eight months with an ethanol fuel preservative).
So keep the tank clean and fill up with up to 10% ethanol fuel and drive the car enough to keep the gas fresh. If you can get high octane non-ethanol fuel that's fine, but it is NOT like the old leaded gasoline as the distillation method for higher octane results in more volatile compounds (BUTANE is one as Gasman said). Finally --- I've been running 10% ethanol gasoline in my 140HP for a decade without issue. The old black accelerator cups quit about ever five years (of course they also quit with non-ethanol fuels). Last year I installed the blue Viton accelerator cups, we will see how they last.
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