Fuel octane question

[Ross Wooldridge]

Hey all,

Just for a laugh, I filled my 66 T&C up with local airport gas - 100LL (100 octane, low lead).

I'm not being silly am I? Am I going to hurt anything?

The car seems to really like it, no more pinging on mid to high speed accelleration, and the idle is smoother.

Just thought I'd ask here.

 

[Big_John]

Not gonna hurt a thing.

Long ago, I read an article that explained that higher octane fuel burns slower and to make the most power, you want the octane that is right at the "knock" level. I wish I could find the article again... I know exactly what happened to the magazine and it's gone for good.. It was a Car Craft from the mid 70's and the author was Pepe Estrada.

 

[Ross Wooldridge]

That's what I understood, but I just needed reassurance and a refresher.

 

[Boydsdodge]

Hey all,

Just for a laugh, I filled my 66 T&C up with local airport gas - 100LL (100 octane, low lead).

I'm not being silly am I? Am I going to hurt anything?

The car seems to really like it, no more pinging on mid to high speed accelleration, and the idle is smoother.

Just thought I'd ask here.

You're all good, problem is that it is an addictive and costly drug to get you and your car hooked on.

 

[Toolmanmike]

Yep, no worries but dang that's unnecessary. I would try some (not a whole tank full) of 92 octane (or whatever is close). If it doesn't ping all the way down the block you are good with the cheaper stuff. Because it isn't a race car, you may be able to get by with the cheaper gas and a few degrees less timing. It's worth a try. What engine do you have and what is the compression ratio. I should have asked that first.

 

[Ross Wooldridge]

Yep, no worries but dang that's unnecessary. I would try some (not a whole tank full) of 92 octane (or whatever is close). If it doesn't ping all the way down the block you are good with the cheaper stuff. Because it isn't a race car, you may be able to get by with the cheaper gas and a few degrees less timing. It's worth a try. What engine do you have and what is the compression ratio. I should have asked that first.

Already running 94 and it still pings with the timing retarded about as far as I want to go, especially when it gets warmed up...

I think there is a fair amount of carbon deposits which exacerbate the issue.

I'm going to see if I can go with a blend... for now I'm going to enjoy it.

 

[Toolmanmike]

Already running 94 and it still pings with the timing retarded about as far as I want to go, especially when it gets warmed up...

I think there is a fair amount of carbon deposits which exacerbate the issue.

I'm going to see if I can go with a blend... for now I'm going to enjoy it.

Carbon deposits? Trickling a little carbon blaster down the carb may help.