Ignition Timing Vs. Compression Ratio
11-29-2005, 10:27 PM
#61
TECH Fanatic
iTrader: (4)
Join Date: May 2002
Location: Fairview Heights Illinois
Posts: 1,851
Likes: 0
Received 0 Likes
on
0 Posts
Compressing the A/F mix tighter adds heat energy to the equation.
The efficiency line where SA and compression cross depends primarily on the fuel, secondarily on the design of the chamber, and third on the thermal management around the chamber.
With a slow burning fuel like C16 or methanol the engine would be a turd with low compression, no matter how much advance you throw at it.
In a vehicle where the engine will be heavily loaded for any amount of time you're not going to get away with high compression on pump gas due to the heat factor.
There are a lot of "tricks" to push the limits on compression and they work, but for the most part you have to find the best balance for the fuel that you use.
A general answer is that yes you can make more power with higher cylinder pressures and less advance up to a certain point, which is usually determined by the fuel being used and the temperatures involved. The power-adder cars prove this all the time, but in their case the higher cylinder pressure isn't exactly the same as increased static ratio.
The efficiency line where SA and compression cross depends primarily on the fuel, secondarily on the design of the chamber, and third on the thermal management around the chamber.
With a slow burning fuel like C16 or methanol the engine would be a turd with low compression, no matter how much advance you throw at it.
In a vehicle where the engine will be heavily loaded for any amount of time you're not going to get away with high compression on pump gas due to the heat factor.
There are a lot of "tricks" to push the limits on compression and they work, but for the most part you have to find the best balance for the fuel that you use.
A general answer is that yes you can make more power with higher cylinder pressures and less advance up to a certain point, which is usually determined by the fuel being used and the temperatures involved. The power-adder cars prove this all the time, but in their case the higher cylinder pressure isn't exactly the same as increased static ratio.
