05-21-2006, 07:16 AM #1
UNDERSTANDING ENGINE TIMING (BASIC RULES) !!
Please keep this in mind when advancing your timing. This goes for any internal combustion engine.
These are simple basic rules to remember !
Retarded timing raises Exhaust Gas Temperatures.
Please keep in mind also of these basic timing rules......
1. Temperature. -- High outside air temp. and/or high engine temp. restrict how far advanced timing can be.
2. Engine load -- High engine loads, especially at low RPM restrict how far advanced timing can be.
3. Octane rating of fuel -- The Octane rating of a fuel restricts how far advanced timing can be. (Low octane rating requires a more retarded ignition timing and a high Octane rating allows a more advanced timing to be used, keeping in mind that compression ratio also has control of the available Octane rating that can be used.)
4. Fuel mixture can effect what ignition timing can be used.
5. Spark plug heat range can effect what ignition timing can be used.
6. RPM effects what ignition timing can be used.
7. A mixture of water riding conditions (flat or rough), riding habits, combustion chamber design, squish, engine condition, engine modifications (electrical and mechanical), intake and exhaust system design all can effect what ignition timing can be used.
8. The BIG restrictor of ignition timing is "Abnormal Combustion" (knock, detonation/preignition)
Remember these basic facts.
Low Octane fuel burns fast and not so smoothly.
High Octane fuel burns slower and much smother.
High compression and high combustion chamber pressure speeds up the combustion process.
Lean mixtures burn hotter than rich mixtures.
Octane rating is a anti knock rating, nothing more nothing less.
The combustion process should be a controlled burn not an explosion.
In general you could say that the most power you can get from any engine as far as ignition timing goes is that timing that is just short of causing "Abnormal combustion". There lays your tool.
If you are careful, it is an inexpensive tool.
If you are not careful it will be a VERY expensive tool.
Here is a good link to read also
Here are some good detonation pics
05-21-2006, 10:56 AM #2
Damn Billy!! Very Good Information. Have you ever thought about producing a manual with all the stuff you have ever put out onto this forum??
It could all be condensed into one PDF File for everyone to download and keep. You are amazing at this dude!!
05-22-2006, 06:32 PM #3Originally Posted by ABBOTT
Darn Right. GOOD STUFF!
05-22-2006, 07:11 PM #4
thats the beauty of this forum.....
Everyone keep posting and asking questions as we all learn something new everyday.
Nobody here knows everything, but together, we can get pretty much get anything answered as there is a wealth of information from everyone here !!
Lots of experience coast to coast and around the globe !
This forum is still young and it is already a huge Database of information for anyone to research information
05-22-2006, 10:01 PM #5
i had to make this one a sticky---very good stuff. Many will need to see this ---may as well make it easy to find.
08-20-2006, 06:39 PM #6
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