Having problems with your Oldsmobile 98 ?

I do my own auto care and have had conflicting information on these specs, recently purchased a olds 98 with a 455engine and single point distributor, point gap was at 19 the timing was at 10 and the plug gap was 35, the car doesent run all that well, so i did some research on google and found a slew of specifications for 455 engines from 1968 thru 1975. and im really not sure what year the 455 is. the block has a F casting on it and the heads are cast with the letter G. google says 16 on the

Posted / edited by AnonymousUser on : 18-03-2019

Answers :

The point gap sounds too big at 19. I would set the points at .012 to start, and increase in .001 increments until you find the sweet spot. With the old ignition system, .035 on the plugs may be more than it can handle. If I remember right, the big blocks didn't like a lot of timing. But 4 degrees seems a little slow. Try this old hot rodders trick. With the engine idling and the vacuum advance hooked up, loosen the distributor hold down and turn the distributor to advance the timing very slowly while listening to the engine. When the timing reaches the point where the engine just begins to miss slightly, back off on the distributor just a little. Take the beast out for a test drive and see if it performs any better. If it does, check the timing and see where it's at. Make sure the vacuum advance is unplugged when checking the timing. I'm thinking the engine would run best at around 14 degrees BTDC on the timing. If the engine pings at this setting, use premium fuel with a little octane booster. I used to use a fast advance kit in the distributor, which consisted of lighter springs and heavier advance weights, Then I would max out the timing and plug off the vacuum advance. The engine would really come alive. I was only getting 10mpg, but gas was 32 cents a gallon.
The point gap sounds good the timing could go up a bit to 8 plugs at 35 sounds better remember you can move the timing a bit to get a little better performance once the vechicle is at opperating temp you can powerbrake it to see if its sluggush or pinning if sluggish advance a bit if pinning back it down till it doesnt ping any more then shut the car off and restart if the the starter drags abit back the timing down a degree or two the exact numbers wont really apply due to wear on the engine and timing assy this is the easiest way to get the best performance
Repair Help & Product Troubleshooting for Oldsmobile 98

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