Advice on use of leaded fuel vs high octane.

[dsmtuned]

Originally Posted by hotrod

You can buy leaded race fuel here in Colorado from several fuel suppliers. Adding a couple gallons to the tank every few hundred miles should work for you. I'm not sure if that engine had soft valve seats or hard inserts so cannot say with certainty how much risk you have there. The real question is how many miles you plan on putting on the engine, will it be an occasional use only or a regular driver car.

At the time that car came out pump premium was in the mid 90 octane range so todays premium is not that far off the mark. By the late 1960s pump premium was nearly 100 octane so high performance engines built in that time period are more at risk for detonation damage if intended to run on leaded premium of the day.

Post up the exact engine CID and compression ratio of you know it, and I will check my 1958 motor manual to see if I can tell you anything useful about the heads.

Did the car have the owners manual ?

Larry

Thanks Larry.

Yeah I guess I could run some Bandimere 110 leaded.

Here are the specs on the engine;
Model Designation: Oldsmobile Starfire Ninety-Eight
Wheel base: 126
Valve Location: In Head
Bore and Stroke: 3-7/8 x 3-7/16
Piston displacement, Cubic Inches: 324.31
Compression ratio: 8.50
Maximum Brake Horsepower: 202 @ 4000 RPM
Maximum Torque Lbs.Ft. 340 @ 2400 RPM
Normal Oil Pressure Pounds: 40

I don't plan on putting more than about 1500 miles per year on this car. It's just for crusing and won't be a race car.

I don't have an owner's manual, but I do have a few resources on the car. I haven't found anything other than "use the highest grade fuel available." Well that doesn't mean much considering that the fuels are different 50 years later.

I'd appreciate any insight you have Larry!

-Craig

PS- sorry I never got that Bandi video of your car to you. My camcorder took a dump that day...