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View Full Version : Initial Start on 283 Timing Question/Help Serious Brain Cramp



scorpion1110
12-26-2017, 04:55 PM
Gentlemen (and ladies):

I need your help as I am having a serious brain cramp.

I am ready to fire the 283 but have been chasing a few assorted mini-demons.

I realized that my degreed damper and timing cover might not be exactly a perfect match. So I did a test to find TDC. I then used timing tape on the balancer to put zero in line with zero on the timing tab.

I am using a mechanical advance Accel 34000 distributor (no vacuum advance.)

Then I checked the distributor making sure that the rotor pointed at cylinder one. I marked the rotor position on the distributor with a sharpie. Then I transferred the mark to the cap. This told me where number one wire should be. I installed it and then sequenced the rest of the wires according to the correct firing order. A quick twist of the key and it fired- but only for a second as I just had a few drops of gas in the carbs.

Its the initial timing I need to get to which I believe is 13 degrees advanced. To get here on start up .......

do I, pull all the plugs and rotate motor until the timing tape is showing 13 degrees BTDC, then pop the distributor out, jog rotor so its pointing at number one again and then go through the sequence of installing cap and rotor and wires again? That would only move it like one or two teeth wouldn't it?

Or do I simply start it up, get it up to 2500, point the light on it and then adjust the distributor to get to about 32degrees? I know you should be all in at about 3000 and should be at 38 degrees timing correct?

Its like someone just erased my memory on this.

I have done this on at least 10 SBCs, and never had an issue, though this is the first one I built while on Chemo and trying to fire when that crap is still in my system.

Good you guys get me to the finish line on this?

many thanks,

S

chevynut
12-26-2017, 05:09 PM
If you know that your distributor is pointing at #1 cylinder when it's on the compression stroke, you don't need to pull the plugs again. You already have it timed close enough to get it running then, imo. I would put a timing light on it while cranking *even with no fuel)and make sure you're getting the advance you expect on cranking. If not, just turn the distributor to get it to the advance you want (counterclockwise = advance). Once it starts, you can do the fine tuning and check the advance at higher RPMs.

Rick_L
12-26-2017, 06:30 PM
You were kind of rambling around mentioning 13, 32, and 38°.

Once you've found TDC compression on the #1 cylinder, then you can manually set the distributor at 13° or whatever initial timing you want. Fire it up and check with a timing light.

I don't know what you have for compression ratio, fuel, etc. 13° initial may be borderline to being too much. 32° at 2500-3000 sounds like not enough, 38° might be borderline too much.

Sounds like if it fired but died you're in the ball park. If the carb is dry, I usually pour a little fuel right into the top of the carb so that there's enough to prime it until the mechanical pump provides enough fuel. Be careful with that so that you don't cause a fire. or that you don't pour too much in the engine, flooding it. Doesn't take a lot to do it right.

You didn't ask about this, but I would recommend a distributor that has both mechanical and vacuum advance for any street driven engine. Better part throttle response, better fuel mileage, no adverse effects. Just disconnect the vacuum hose and plug it for timing checks, then re-connect once the timing is set.