I'm just throughing this out to see if my timing is correct and possible see if i solved my over heating issues. My motor is near road ready i found i had a crack in the back water jacket on the intake and got it welded up. My thernostat is 190 deg and my timing it 24 @ 3k total. I'm just learning about setting timing so my engine builder was there with me when setting it. When we set the timing he had me leave the radiator cap off this brought the temp to 200. Prior to setting the timing the motor was heating up fairly quickly and would stay about 205-210 then begin to climb to 230 at which time i would cut it off(this is sitting in the yard with dual electric fans). Since getting the intake back on i've put a 160 deg thermostat in. I'm assuming my timing was playing apart in the engine over heating but what is correct timing for a 455? My distributor is from dui but they say that its set at 24deg @ 3000 but wouldn't that mean my base timing is zero?

Thanks

 

I'm going to assume the 24 degrees in your dui is only the mechanical timing, you still need to add in your base timing. 24 degrees mechanical is perfect IMHO.

You'll want about 36 degrees total at 3000. So, in this case you'll want about 12 degrees of base timing to make the total of 36. That should be just right. It should'nt ping or knock at that setting.

The total timing is more important that the base timing. If you have a dial back timing light, set the total to be 36 at 3000. The intial base timing will be what ever it may be.

 

Its actually vacuum secondary. And just to be sure we're on the same page i set the dial on the back of the timing light to 24deg and made sure my tdc was on zero at 3k. Now the 36 total @ 3k is what i thought was correct and when i told my builder that he said that i could possible run into over heating issues with that and that 36deg was more for the track and not the street. I'm not able to get out on the car until sunday but i'm going to set it to 36 total with the dial timing light.

 

I usually set my timing at the factory setting which for all Olds engines 1964 to 1990 is 20* advanced at 1100 RPM's.

That 24* setting doesn't sound too far off, so you should be good

 

Many forget that the factory settings were with PREMIUM LEADED GAS!!
And todays crap varies from area to area!
I always tell someone serious about performance and mileage to stick w/ one brand of gas, one octane, at all times!
After which I time it 'by ear' - leave the dist. snug, but moveable, set @ factory specs.
Drive the car like you stole it - if it pings, retard it @ 2 degree increments 'til gone!
If not, advance 'til it does, and retard it 2 degrees.
Tighten the dist. when done!
Did this with a '83 Suburban I was driving 2-300 miles a day - 350, 700 trans w/3:73's, and averaged 16 MPG w/ mid range gas! Overheated with regular gas!
Seemed Shell was the best - off brands, the worse.
Works for me!!

 

Setting the timing when part of the centrifugal curve is in will be risky. You should set the total not over 36 deg at whatever rpm ensures all the advance is in. The vacuum advance must be disconnected as we want total centrifugal plus initial, only. Then see what you have before any centrifugal comes in; usually at an idle the centrifugal has not started yet and you should be able to have about 12 degrees there. The critical thing is to get the total correct first. Setting timing when part of the curve is in will not be reliable because some curves come in quicker vs. rpm than others, and slight errors in rpm will cause errors in your setting.