[Teamsterdug]

Can someone tell me just exactly what type of fuel should be used in the straight 8 engines? How high of octane should I be shooting for. Are there brands or types of fuel that should not be used? How about the additives I see available from Buick speciality parts suppliers that are supposed to boost octane? No valve work updates have been done on the engine so we're talking original equipment here. I use CD2 lead additive. Tech help would be appreciated. Thanks.<p>[ 03-12-2002: Message edited by: Teamsternip ]

[our51super]

We use 87 octane and add one bottle of "Instead-O-Lead" with every fill-up. It's been working just fine for us.<BR>We get the Instead-O-Lead at Walmart.

[The Old Guy]

I have driven my 40 Super over 90,000 miles and have never used an additive. The straight eight had a compression ratio of less than 6.5 to 1 and will probably burn soft coal if it would fit through the carb. I have never heard any spark rattle and I burn the lowest octane fuel around. There is no reason to buy high octane for a low compression engine [img]images/icons/smile.gif" border="0[/img]

[Teamsterdug]

Thanks for the input. Its appreciated!

[Mr. Solutions]

Question for the Old Guy....<P>When you mention you have never used any additive, does this include any lead supplements / substitutes?? Just asking as I am sure MANY, including myself, add the lead supplements, having been lead to believe that it is a necessity on the older engines.<P>Thanks

[The Old Guy]

I have a good friend that was an engineer for Buick for years,and he informed me that a Buick would not suffer valve recession unless the engine was repeatedly run at high RPM under heavy load. I tested this theory by pulling an Airstream all over the country with my 57 Caballero in the 70s and when I removed a head to check, The valves were good enough that I reassembled the engine with no changes. Checking with the Dyno room at the Chevrolet six cylinder plant ,I found that those engines would suffer recession and was informed that Buick used a better grade of cast iron with more nickel in the mix ,and this was the difference.

[Teamsterdug]

That is very interesting. Glad to hear that Buick supposedly used the better metals. Maybe that's what accounts for all of the still running Buick in-line 8s and all the puked out chevy engines. My UNBIASED OPINION!

My Father owned several old Buick straight eights and often spoke of Buick KNOCK that has nothing to do with the spark directly; it has to do with the combustion chamber shape. A very interesting thing about this is Charles Kettering and many others ?solved ? the knock problem back in the 1920s and this led to the adoption of Tetraethyl lead in the gasoline. <BR> I will try to find the place on the net where I found this information and post the address information on this place. <BR> The thing I find very interesting about this immediate problem is the use of lead substitute additives to ?SAVE? the Buick straight eight engines. If you live in an area where they sell Blue Sunoco gasoline you must know that Sunoco has sold unleaded fuel for years. When leaded fuel was introduced in the late 1920s or early 1930s it had to be colored RED to show it was a leaded dangerous additive. Therefore I believe that Blue Sunoco was not red but BLUE to show that it did not contain lead, a dangerous additive that causes brain damage! If what I say is true employees of Sunoco must be laughing at the concern about the need for leaded fuel. Maybe someone will find a Sunoco representative and straiten me out as I now live in an area (Calif.) that is not represented by Sunoco filling stations. My point being that if Sunoco Blue was good enough for Buick?s before unleaded fuel was used due to smog regulations then why worry about it now? Sunoco where are you now when I need you? In a Quandary, M.L. Anderson

[Teamsterdug]

To Mr. Anderson...<BR>Looks like another check mark in the "don't bother with lead" column. thanks.<BR>Doug

[Teamsterdug]

to M.L. Anderson.....<BR> Thanks for offering the site. I checked it out. I'm getting so smart on this subject I may have to quit my day job!