Tried to time the 307 to spec and it does not like it at all! It idles way too fast and struggles to start. 20 degrees seems to be too far advanced. It does like 10 degrees....like the 305 and starts on a dime. Did Olds put "sleeper" 305's in 1983? Maybe a worn timing chain? Anyone have any thoughts? Help sure would be appreciated.


1983 Cutlass Supreme Brougham, 307, Q-Jet.........Bone Stock!

 

I wouldnt leave it at 20 because that is way to high. leave it around 10 to 12 degrees and youll get the best results. and im not sure about the sleeper

 

Its definetely a 307, I just don't understand why it is supposed to be 20 degrees when it is highly apparent that timing doesnt work. I've even heard of guys going 23 or 24 degrees w/higher octane fuel. Maybe slack in the timing chain? I have it at 12 degrees now and it feels nice. Just want to make sure Im getting the best performance out of it.

 

Stock HEI timing for Oldsmobile is 20° BTDC @ 1100 RPM. Always has been. They re-curved the HEI from the olds points and removed mechanical advance from it. This was an attempt at emission control. There could be many issues in a 30 year old engine as to why is doesn't like the original timing. Carbon build up, timing chain issues, or the harmonic balancer could have spun. Don't just dial the timing back and call it good. You need to find out why the problem is there and correct it the right way.