What is the optimum EGT?

On my dyno, I never use EGT’s to tune with, I use them to check fuel distribution. I get the A/F one of 2 ways. 1. O2 sensor (this takes the average of all 4 cylinders, someday I buy the upgrade for 8 O2 sensors. ) 2. Measure the lbs. of air and fuel flowing into the engine.

The EGT’s can be all over the place based on timing and A/f ratio.

Get the A/f right then adjust the timing for the most power.

Joe

EGT temps depend on many things, fuel type, ignition timing, cam overlap, as well as probally several other things I can't think of right now. On my airplane I would lean it out until it reach max EGT and then started miss and to go colder, I then would fatten it up enough to make it run from 25 to 75 F colder than peak EGT The big thing to look at is how much spread there is, I like to see no more than 50F difference on all 8 cylinders, that is relly hard to get on a single four carb. set up I would start out fat and then slwoly, a little bit at a time, lean it out to get max power, go past that maybe one jet size to make sure you got the most power from jetting. Be ready to change that tune up once you get the motor in the car and run it at the track be open minded and test, test, and test somemore One of the dyno operator I used in SO CA was really big about wanting to advancing the ignition timing to cool the EGT down when breaking in the cam at 1500 to 2000 RPM I usually wouldn't, that irritated him, I would tell him this ain't no Cheverolet, George Last thing, I have heard of motors burning up the pistons at 900 to 1200F degrees EGT and the same motor not hurting a thing with EGT at 1700F One of the airplane guru like to see EGT in the 1400 F range at peak power on the N/A motors, the higher altitudes run cooler EGT than you do down low, under 8000 Ft above sea level Use the spark plugs and time slips to tune the car for best 1/4 MPH