16th Feb 2009, 00:32

Nope, you're wrong.

The 350 V8 had no problems. Olds was forced to drop the 455 (another awesome engine) in 1977 due to CAFE fuel economy standards.

The 403 was essentially a Oldsmobile 350 with larger (4.351") pistons, compared to the 350's (4.057 inch diameter) pistons. I believe it actually did have the biggest diameter pistons of any V8 to go in an American passenger car.

All of Oldsmobiles final V8 engines had the same block and same stroke length (3.385 inches). There were no water jackets between the pistons on the 403, which at times led to overheating problems. The 350 (gas), 307, and 260 were not as powerful but much more reliable than the 403.

The 403 was not a bad motor, but as with all V8's of the mid to late 1970's it was choked to death with silly emission regulations, tiny intake and exhaust ports combined with low compression from the start. With it's short stroke and huge bore, the 403 engine could have been a real powerhouse. Original and aftermarket parts are scarce for the 403, while the 350 and 455 are some very sought after motors.

Oldsmobile's 350 is a much more sought after motor. It was simple, reliable, strong, and very economical for its size.

It is also a little more powerful than the Chevy 350 of that era, and far better than the Buick 350. And for those who didn't know: yes Oldsmobile, Chevy, Pontiac, and Buick made there own smallblock 350's back then, completely different from one another.

I own a 1978 Delta 88 with a Olds 350 that still is capable of over 21 MPG highway with the old TH350 3 speed automatic. 223,000 miles, doesn't burn a drop of oil, and still runs like a swiss watch after 31 years.

FYI, the formula to find the cubic inches of any motor: (bore x bore) x stroke x.7854 x number of cylinders.

16th Feb 2009, 00:34

Also the Oldsmobile 350 was the standard motor in the 1977-1979 Oldsmobile Ninety-Eight.