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post #1 of 12 (permalink) Old 04-25-2011, 08:56 PM Thread Starter
 
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68 2bbl 400

I have one of these and i was jut wondering if it is possible to run 93 octane gas safely in this engine since it has a 8.6:1 compression ratio? (i am a little new to restoring)
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post #2 of 12 (permalink) Old 04-25-2011, 09:11 PM
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Your engine will thank you......



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post #3 of 12 (permalink) Old 04-25-2011, 09:37 PM Thread Starter
 
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haha ill take that as a yes thank you.
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post #4 of 12 (permalink) Old 04-26-2011, 05:27 AM
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With that compression ratio you should be able to run 87 octane, every penny counts.



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post #5 of 12 (permalink) Old 04-26-2011, 02:03 PM
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Originally Posted by 68goatragtop View Post
I have one of these and i was jut wondering if it is possible to run 93 octane gas safely in this engine since it has a 8.6:1 compression ratio? (i am a little new to restoring)
Yessir. It's always safe to give an engine MORE octane than it "needs".

However, the reverse is the path that leadeth to (engine) destruction.

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post #6 of 12 (permalink) Old 04-26-2011, 04:05 PM Thread Starter
 
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WEll thank you guys from your input i really appreciate it!
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post #7 of 12 (permalink) Old 04-26-2011, 07:48 PM
 
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There is no reason to run 93 octain on a 8.6-1 motor unless you have an advanced curve kit in it or are running a bunch of timing to it. If you have it at stock timing it will run just fine on 87. If it doesn't ping, it doesn't need better gas.

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post #8 of 12 (permalink) Old 04-26-2011, 08:11 PM Thread Starter
 
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oh ok awesome thanks again!
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post #9 of 12 (permalink) Old 04-26-2011, 08:15 PM
 
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No need for 93, 87 will work fine just like Jet said. Its an added expense that isnt necessary. The only way it will ping is if it is full of carbon or oil leaking past the rings/valve seals. Ive run 9:1 455s on 87 without issue, so a 400 at 8.6 is no problem.
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post #10 of 12 (permalink) Old 04-26-2011, 09:22 PM
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I don't know. I have a low compression 455 that seems to run much better on 91(best we have here) than it does on 87 and better yet when I run an octane boost with the 91. The motor was rebuilt right before I bought it. Bored .030 with a mild cam. No specs on the cam.

I guess my recommendation would be to run 87 and 93 octane and you decide what makes it run the best. Keeping in mind that 93 octane will not hurt a thing except your wallet......



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