Hello fellow third-gener's, hoping you guys can offer some technical advice on timing. So here is the deal, the engine is a 355 SBC and has a HEI distributor. My mechanic friend came by and set the timing by ear. We did take it for test runs after each adjustment. The car starts nice and when I shut it off it fires right back up nicely. So it could be bang on but I am the kind of guy who likes to know what the timing is at exactly so I want to set the timing using a timing light. My question is how can I set the timing with a timing light when there is no timing marks or sticker on the harmonic balancer? I am not sure what size balancer is on the 355.....does the size of the balancer matter? I mean I have seen those harmonic balancer timing tapes from mr. gasket(timing sticker that goes on the balancer) but I was thinking the size of the balancer when it comes to the timing tape would matter....wouldn't it? Thanks for any help.

onthedownlow

 

Are you absolutely sure there's no mark on it? There may not be a colored mark but there should be at least a groove or some sort of marking on the balancer. Find the groove and color it in with a paint pen, then use the timing light.

 

Hi there, sorry it took me so long to get back to my own thread. Yes there is a mark on the balancer. It looks like a line. Does that line represent zero degrees? What should my timing be set to? 13-18 degrees btdc? Thanks for any help.

onthedownlow

 

You can get a dial back timing light, this allows you to change the timing light flashes. Lets say you want to run 36* at 3500rpm, you set the timing light to 36*, rev the engine to 3500, then line the timing mark up to zero on the timing tab.
It would be helpful to figure out where your friend set the timing, even if you have to make your own marks.

 

Your timing should be set where yourt motor likes it - there is no definitive answer for "where" - otherwise there wouldn't be any need to change it.

Spend $15 on a timing light. loosen dist bolt just enough to barely be able to twist it, then set timing at 10*BTDC. Take the light with you, and drive - do a WOT run - if you don't hear any pinging (spark knock), then bump it up to 12 and WOT again - no pinging again up to 14, then WOT again. Keep doing this until you hear pinging. If say you hear it at 16, then come back down to 15, the WOT again - if no pinging, then come back down to 13 and lock it in.

In othr words, you want your timing as advanced as it can be, without pinging at WOT. Then you want to come down 2 degrees when you hear the pinging (2 degrees a safety margin since a car can spark knock even if the human ear can't hear it).

Make sense?

 

Great advice Camaronewbie, thanks gonna get on this asap.

onthedownlow

 

sorry to steal your thread but my car is having similar problems, it wont hold an idle unless the rpms are high (squirted some carb cleaner and seems to be a vacuum leak at base) but it also seems to be spark knocking on the 8th cyl even after i shut the car down? i was told that the aftermarket distributor that was put on the car wasnt timed exactly right so how could i time it? would i NEED a timing light or can i just loosen it and turn it until the idle goes down a bit and i cant hear the pinging?

OH, and i looked for timing marks and i saw a horse shoe shaped thing on the block but nothing on the wheel, is there one on there?