Thread: Advance or Retard?

Originally Posted by Aaron IIA

I would continue to run it on 91 and retard the ignition just enough to stop it pinging on heavy load. Retarding the ignition will actually make it run cooler. If you retard it too much, the exhaust manifold will run hot though. When advanced, the fire burns early, so there is more time for the heat to be absorbed into the water jacket, so will run hot. When retarded, the fire burns late, so it is still burning while the gasses enter the exhaust manifold. This holds true for petrol and diesel engines.
You may find that you may need to time it with 0deg advance. I would not bother with the timing marks too much, as unless they are the flywheel mounted types, I have found them to be mounted wrong.
Aaron.

In 4 decades of Mechanicing I have Never seen a timing mark moved from its correct position, and I'm not interested in all you people who say otherwise UNLESS you have photos to prove it, maybe we should send this one to Mythbusters, Regards Frank.

I was working on a friend's 253 which was running a bit rough. I got out the timing light, and timed it per the timing mark. This made it much worse. I then timed it by the advance it a bit until it pings under load then retard it a little bit until it stops pinging under load method. This made it run really well. Had a look at where the timong mark was now - about 30 deg advanced. So if it was timed according to the mark, it would have been about 30 deg retarded, hence why it ran really bad. The timing mark was on the front pulley. These are a harmonic balancer. I am assuming that the outer half may have rotated relative to the inner half. Another more likely option may have been that there was no keyway in the shaft. I can try and get some photos of it if you really want.
Aaron.

Originally Posted by Tank

In 4 decades of Mechanicing I have Never seen a timing mark moved from its correct position, and I'm not interested in all you people who say otherwise UNLESS you have photos to prove it, maybe we should send this one to Mythbusters, Regards Frank.

You've never seen a slipped balancer

Retard it till it stops pinging

holdens were the worst for a slipped balancer........

they had a two piece crankshaft pulley with a layer of rubber between the two parts.....
and the timing mark was on the outer piece.......which could spin around on the rubber......
the only way to set the timing on these was by ear......otherwise you had to first replace the pulley
to get the timing marks in the correct position......and then you could use a timing light.......


and.......advancing the timing WILL cause an engine to run hotter.......
not retarding.......

Originally Posted by Aaron IIA

I was working on a friend's 253 which was running a bit rough. I got out the timing light, and timed it per the timing mark. This made it much worse. I then timed it by the advance it a bit until it pings under load then retard it a little bit until it stops pinging under load method. This made it run really well. Had a look at where the timong mark was now - about 30 deg advanced. So if it was timed according to the mark, it would have been about 30 deg retarded, hence why it ran really bad. The timing mark was on the front pulley. These are a harmonic balancer. I am assuming that the outer half may have rotated relative to the inner half. Another more likely option may have been that there was no keyway in the shaft. I can try and get some photos of it if you really want.
Aaron.

Maybe the plug leads were a position out, it was definitely (timing light) connected to #1, I connected the timing light to my Disco V8 the outher day and wondered why I couldnt see the timing mark, why, beacause I had it connected to #2, used to Ford engines that have a proper firing order, 1 to 4 , drivers side and 5 to 8 passenger side, Regards Frank.

Originally Posted by rovercare

You've never seen a slipped balancer

Never, I 've seen outer rings come off, but never seen a balancer/dampner lose the rubber ring and have the outer ring stay on, where's the pics, Regards Frank.

Originally Posted by DEFENDERZOOK

holdens were the worst for a slipped balancer........

they had a two piece crankshaft pulley with a layer of rubber between the two parts.....
and the timing mark was on the outer piece.......which could spin around on the rubber......
the only way to set the timing on these was by ear......otherwise you had to first replace the pulley
to get the timing marks in the correct position......and then you could use a timing light.......


and.......advancing the timing WILL cause an engine to run hotter.......
not retarding.......

Just about all production Vibration dampners/balancers are 2 piece with a vulcanised rubber ring holding the outer balance ring on, when that rubber ring breaks the outer ring will fall off.If anyone was timing an engine the first thing you would think they would do is check that the timing mark on the balancer was visible, usually by rotating the engine from the bolt in the crank snout, surely if the outer ring was loose it would have to be noticed. I've never seen a balancer with a broken rubber ring stay in place (not fall off) and on externally balanced engines the Vibration would be a sure sign that something was amiss. As I said It didn't happen without pics, Regards Frank.