Timing for 75 350 delta

[royale 75]

I need to get a book covering specs on this thing! Went to time it tonight and forgot the underhood decal is gone. No place to get the timing spec this time of night. Any help at their olds fans?

[rocketraider]

1975 shop manual wants 20 degrees BTDC @ 1100 rpm for a 350-4bbl Olds engine, with distributor vacuum advance hose disconnected and plugged, air cleaner removed and manifold vacuum fitting for ThermAC plugged.

I always thought some of those early HEI basic timing settings were awfully high, but the spec shows a total advance of about 39 degrees at 4000 rpm which isn't excessive. Actually almost lazy, considering I used to time my points engines at 8-10 degrees base @ 650 rpm, then curve the distributor for 36-38 degrees total by 3200 rpm. Sometimes when I could get really good gas, I'd take it up to 14 or so.

Good luck, and if you think 20 is too much, drop it to where you're comfortable and engine still runs well. The old trick of setting timing for highest idle vacuum still works.

[royale 75]

Thanks. I must admit I don't know what the ThermAC is but suppose it should be easy to narrow down. I checked the timing and it was right at 18 with just dist vacuum disconnected. I bumped it a smidge, just cuz I think this 350 should have more spunk than it does. Just redid the exhaust with high flow low restriction and it helped a bit. Next step is the quadrajet. Looks like its never been off during its 80k miles! Higher flow heads after that. Never heard of the vaccuum at idle fact - am heading out now to throw the gauge on it. Thanks again. BTW - looks like you folks in Va had a pretty tough winter! My old stomping ground - now Fla.

[rocketraider]

ThermAC is the thermostatic air cleaner. The vacuum source for it is a manifold fitting behind the carb.

Yup- it's been a hateful winter here in the Commonwealth. Below normal cold temps (global warming my arse), five ice/snow storms with heavy tree and powerline damage, and now the ground is saturated to the point a stiff breeze will push a tree over. Guvnah Warner's drought should be over, I think.

I used to laugh about people who moved south for winter. Now I understand.

[royale 75]

Spring shouldn't be far away! Just checked the bacuun trick and it doesn't seem to work. I accidently had the thermac disconnected as thats where I chose to put the vac gauge! Set her to 20 and will test on the way to work in the morning. People give me a hard time about putting miles on this delta (80k orig) but I just love to drive the old ones and this time of the year is when you can really enjory the ragtops! Too hot in summer, need A/C . I deal with new ones all day (I manufacture OEM speed, temp and fluid level sensors)and really enjoy the relative simplicity of the older stuff. Low mileage cars are readily available down here so what the heck. Thanks again for the advice.