exh gas temp.

[richie 2]

howdy...would header tube temp. from a heat gun tell me if im rich or lean? carb/bbc w/unleaded fuel. cant get a plug reading and unable to install a EGT meter. tks

[MR DERBY CITY]

Might work if your crew man is skinny enough to fit under the hood while you are making a run …..

[Jim Caughlin]

Originally Posted by MR DERBY CITY

Might work if your crew man is skinny enough to fit under the hood while you are making a run …..

Not only that but EGT raises very slowly, the temp you see at the finishline is more like what the engine saw at the 1/8 mile mark. EGT is more to see that all 8 cylinders are equal, Oxygen sensor is the tuning device.

[B Parker]

The best way is to read your plugs. Even if you have to when you get back into your pit area. If far from the end of the track have someone pull you back with a golf cart. If you can't read your plugs after a couple of runs find someone that can. BP

[SSDiv6]

Originally Posted by Jim Caughlin

Not only that but EGT raises very slowly, the temp you see at the finishline is more like what the engine saw at the 1/8 mile mark. EGT is more to see that all 8 cylinders are equal, Oxygen sensor is the tuning device.

Jim is correct. By the time you are in the top end and shut down the engine unless you have a data logger, the ambient air will cool down the headers. That's why I prefer an AFR with datalogging.

[richie 2]

great insight derby tks.. ive read that trying to read a plug using unleaded fuel is near impossiable. they presently show pretty clean, no colour what so ever.

[Charles Stewart]

Originally Posted by B Parker

The best way is to read your plugs. Even if you have to when you get back into your pit area. If far from the end of the track have someone pull you back with a golf cart. If you can't read your plugs after a couple of runs find someone that can. BP

This link will help you...
https://www.dragstuff.com/techarticl...ark-plugs.html

[Stan Weiss]

Even if you ran it long enough to get a true EGT reading.


Is EGT really a good indicator of A/F ratio?


Stan

[SSDiv6]

Originally Posted by Stan Weiss

Even if you ran it long enough to get a true EGT reading.

Is EGT really a good indicator of A/F ratio?

Stan

No.
Had a great discussion with Robin Wright on this subject and his findings based on his tenure with the Ford Factory Off-Road Truck Racing and while at GM with the development of the LS racing and COPO program when I was purchasing a digital dash and data logging system.

After our discussion, we agreed that a wideband AFR system with data logging provides a lot of more useful information for tuning than EGTs do.

Many Pro Stock teams and dyno operators have the Daytona Sensors WEGO system.

https://patterson-elite.com/data-rec...ng-aid-114001/

The display and data logging system I ended up purchasing was from RPM Performance Products with the AFR option.

[Jim Caughlin]

Originally Posted by Stan Weiss

Even if you ran it long enough to get a true EGT reading.


Is EGT really a good indicator of A/F ratio?


Stan

No, EGT raises very slowly and not an accurate method of checking A/F. Oxygen sensor is relatively quick and accurate. Millions of cars are driving down the road with their fuel injection being monitored by Oxygen sensors. One negative of Oxygen sensors is they don't live a long life with leaded fuels. Once they go bad, there is no fixing them so a somewhat expensive disposable part on a race fuel engine.