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Best Octane Level for Stude 289 Engines

Hi Guys, I 've been doing some esearch on octane ratings and what level is best for different engines. The "professional" consensus seems to be that an engine with a 7.0 to 7.5 tot 1 compression ratio will operate optimally at 87 octane (regular unleaded) and higher compresstion ratios require more octane accordingly. So the 289 V8 originally came out in 1956 with a standard 7.5 to 1 ratio, and the compression rate steadily increased over successive years to over 9.25 or 10 depending on whether it was an R1 or R2. What's the consensus of the group? Methinks my 56 Hawk "should" run just fine on cheapo 87 octane regular without any knock, and I should run 92 or 93 premium in my 63 GT Hawk. What are you guys using in your engines?

-George-

63 GT Hawk 63 Champ 56 Sky Hawk
Reply to
reichsrundfunk
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87 is working just fine in my 259 '61 lark. Lou
Reply to
Larkylou

Yep, I've never had a problem because of octane running regular in a Stude.

Now vapor lock with the funky stuff they sells as gas these days is something else again, but higher octane would make a difference.

Jeff DeWitt

Reply to
Jeff DeWitt

I have been using 87 in my '63 Cruiser with no issues.

Chip

Reply to
cjdaytonjrnospam

My 289's run well on 87..

Reply to
jbreen

I run 92 or 93 in my 302 inch Stude with about 9.5 compression. The real answer is whatever runs in your car without pinging.

Reply to
Alex Magdaleno

My cars run OK on regular but run much better on Hi test, and I seem to get better milage with it. I also have a large lead fishing sinker rolling around in my gas tank hoping some lead will absorb into the gas. NT

Reply to
nthornton

Reply to
itraseecab

So has anyone else used the bottled Octane booster? So far I've been pretty lucky using Hi Oct (93) but thought I'd put a bottle in the trunk just in case I couldn't get high octane gas. Somebody told me that it can get pretty scary using it..Years ago we just went out and bought 5 gallons of 100 oct Aviation gas and dumped it in the tank and then filled up the rest with hi-octane. Of course back then it was still leaded and they would sell it to you..Now it is hard to get it unless you know someone there.. Just curious

Reply to
mcavanti

If it won't run on "regular," it ain't gonna be in my flock.

That said, I had a '63 Lark 259/auto that I had freshened up the engine and when gas was cheap, ($1 per gal for ultra premium in 1999), I really cranked up the timing and ran high test. It ran like a scalded ape!

Alas, gas prices began to rise and my selection options drop back to regular but the car ran fine and regularly got up to 24 mpg on the highway.

Regular should be fine except for "R" series engines.

JT

Reply to
Grumpy AuContraire

Off and on I've actually used octane booster but I do not think I ever saw any difference in performance, so I just stopped buying it.

-George-

63 GT Hawk 63 Champ 56 Sky Hawk
Reply to
reichsrundfunk

When in collage many yars ago, the local Sunoco Station used to sell

100 Octane Gas. ( They blended the gas to obtain other ratings.) I ran the timing advanced until it kicked back against the starter. Fast as hell until I burned some valves.

Geno

64 R2 Aavnti 64 Daytona Convertible
Reply to
jeep4cyl

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