What gas to use for 1965 Ford galaxie
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Never heard this logic before. Care to explain the thinking?
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You said high compression might need 89.
High compression motors usually need higher octane fuel. I don’t consider 89 high octane fuel though.
The variable is what exactly “high compression” is…
High compression motors usually need higher octane fuel. I don’t consider 89 high octane fuel though.
The variable is what exactly “high compression” is…
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You can find ethanol free gas using this link…
Pure-gas.org - ethanol-free gasoline in the U.S. and Canada
Pure-gas.org is the definitive web site listing stations that sell pure gasoline in the U.S. and Canada.
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Not true for the state where I live, far less than 10% of the stations listed are 110 octane. All the rest are 89/90/91 and some have 93.
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The higher the octane number the slower the burn, that is how it eliminates detonation. So the lower the octane the faster it burns. If your timing is set correctly and you have no detonation with 87 Octane you can use it. If it pings or detonates then use a higher octane. But if you intend to drive it a lot and do not have hardened valve seats you need a lead substitute! If your engine is higher than 9.5:1 compression you will need high-octane fuel like 90-93.
Most stations around me have 87, 89, 90-91, and a few have 93.
I own a 1968 Galaxie 500, 2-door hardtop with a 390 and C6 tans. and under 13,000 miles Originally a 2bbl but I added an OEM steel 4 bbl intake ad a Holley 4bbl. I THINK the compression is 9:1, maybe 9.5:1. I need to look that up to be sure. I have not removed the heads to install hardened valve seats so I use a lead substitute.
When I first obtained it I used 87-90 unleaded with a lead substitute. In the fall and spring, I used 87. When temps got to 90 degrees I would get a little detonation and went to 89-90 octane. But that is using pump gas with 10% ethanol.
I live near Columbus, Ohio. and now we have Sheetz fuel stations and they have non-ethanol fuel that is 90 octane and only about 30 CENTS MORE A GALLON. I also used marine fuel from a marina in the past that is 91 octane non-ethanol but it is a Pain InThe A** to get fuel in cans and then fill it up. You can also use this website to find stations that have non-ethanol fuel near you: Pure-gas.org - ethanol-free gasoline in the U.S. and Canada
Most stations around me have 87, 89, 90-91, and a few have 93.
I own a 1968 Galaxie 500, 2-door hardtop with a 390 and C6 tans. and under 13,000 miles Originally a 2bbl but I added an OEM steel 4 bbl intake ad a Holley 4bbl. I THINK the compression is 9:1, maybe 9.5:1. I need to look that up to be sure. I have not removed the heads to install hardened valve seats so I use a lead substitute.
When I first obtained it I used 87-90 unleaded with a lead substitute. In the fall and spring, I used 87. When temps got to 90 degrees I would get a little detonation and went to 89-90 octane. But that is using pump gas with 10% ethanol.
I live near Columbus, Ohio. and now we have Sheetz fuel stations and they have non-ethanol fuel that is 90 octane and only about 30 CENTS MORE A GALLON. I also used marine fuel from a marina in the past that is 91 octane non-ethanol but it is a Pain InThe A** to get fuel in cans and then fill it up. You can also use this website to find stations that have non-ethanol fuel near you: Pure-gas.org - ethanol-free gasoline in the U.S. and Canada
octane does not control burn time. only resistance to spontaneous combustion. the higher the compression, the more likely to have pressures high enough to light the fire before the spark occurs.
burn time is more a result of timing and fuel mix
burn time is more a result of timing and fuel mix
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I have to agree with @extech, and might defuse this common internet lore with some deeper tech that some could want, rather than "because he said so". 
"Octane" resists auto-ignition from heat (the source) and compression or pressure that makes heat. It is listed in the US as AKI (anti-knock index) relative to the chemical (octane) resistance to detonation under similar conditions. If the engine is built to require higher octane, then it may det with lower octane if in proper tune. If the engine is not built for higher octane, it will not require it, nor will running more octane improve power or performance. That is, unless it is not in proper tune or has other issues primarily affecting heat, any of which will need attention to correct.
Second is that Ford has always used hardened valve seats, at least since the 1950s. Early heads were flame-hardened, and later ones by induction. This is why we see no production changes at the advent of unleaded fuel, and why replacement "hardened seats" are made of the same stuff as the heads (nodular/ductile iron alloys).
While there could be a slight benefit to lead, it was primarily the source of octane in the day (tetra-ethyl lead), not as a valve lubricant or coolant. Those benefits were small at best, and if you have any shortened valve or seat life, the first direction to look is ignition timing and control as the primary suspect, possibly coupled with over-fueling. Hopefully, all of this helps explain why some Fords are happily cruising with hundreds of thousands of miles on them, while others (with the same factory parts and fuels) are damaging valves and seats in far less time. If it was all about the lead or additives, they would all fail predictably.
Yeah... no. As-mentioned, the burn speed is relatively unaffected by octane rating in gasoline. Detonation ("knock" or "ping") is not caused by burn speed, but by secondary auto-ignition due to heat, after the spark ignition. Ignition before the spark is called pre-ignition (yes, it's a real thing, with very different effects). Detonation is kicked-off by heat from various contributing sources such as pressure from dynamic compression (valve timing) and engine temperature, along with many other factors also related to temperature, most of which are directly affected by ignition timing that controls when it makes pressure and associated heat.
"Octane" resists auto-ignition from heat (the source) and compression or pressure that makes heat. It is listed in the US as AKI (anti-knock index) relative to the chemical (octane) resistance to detonation under similar conditions. If the engine is built to require higher octane, then it may det with lower octane if in proper tune. If the engine is not built for higher octane, it will not require it, nor will running more octane improve power or performance. That is, unless it is not in proper tune or has other issues primarily affecting heat, any of which will need attention to correct.
This is also untrue, for a couple primary reasons. First is that the ignition timing is the predominant influence over valve and seat life. Based on industry research, if you have short valve life the most likely issue is your timing is not set correctly, or advance systems not working properly. The distant second most-common cause is running consistently too rich.
Second is that Ford has always used hardened valve seats, at least since the 1950s. Early heads were flame-hardened, and later ones by induction. This is why we see no production changes at the advent of unleaded fuel, and why replacement "hardened seats" are made of the same stuff as the heads (nodular/ductile iron alloys).
While there could be a slight benefit to lead, it was primarily the source of octane in the day (tetra-ethyl lead), not as a valve lubricant or coolant. Those benefits were small at best, and if you have any shortened valve or seat life, the first direction to look is ignition timing and control as the primary suspect, possibly coupled with over-fueling. Hopefully, all of this helps explain why some Fords are happily cruising with hundreds of thousands of miles on them, while others (with the same factory parts and fuels) are damaging valves and seats in far less time. If it was all about the lead or additives, they would all fail predictably.
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