Can anyone give some info on where to put the prob of the egt meter, a freind said to go about 2" from flange and use #6 header tube,what I need to know what header tube would be the best. It is on a 70 dart with 340 and 1-3/4" headers and I'm running e-85. Thanks Jay----

2" is about right...I was told on a BB use #5. Not sure on a SB.

Why the 2"?

At work (engine lab) we put all our egt directly after the flange. Also a tip to getting a good reading is to angle the probe so that the tip points away from the head, as to follow the flow of gases.

i have egt's on all 8 tubes. whats the deal on only using 1?

1 1/2 to 2 inches from the flange and the tip in middle of exhaust stream , I read a front cyl. a middle cyl and a rear cyl. middle cyls (4&6)(3&5)will read a little hotter usualy than the ends

Thanks for the info. Jay-----

I always put them in exactly at 1" from the flange
surface with the tip of the probe(this is the point
that does the reading) in the center of the tube, I
use a vernier caliper to set them... if they are all
the same depth you can also use them to balance the
intake manifold.... this is the way we did it in the
exhaust lab for years

Looking forward to some info from the experienced.
I am currently running a SB with Eddy heads on the dyno.
-EGT in all header tubes. Probe depth set with caliper, should be pretty equal. The bungs are welded with some tolerance. But we are talking about maybe .1 inch difference in height.
-Wideband O2 in the collectors
-Summit brand Air Gap manifold
-600 Eddy carb.

I have almost 180°F difference in EGT between the cylinders at part throttle. Cylinder 6 being the hottest. Can this be normal? I expected the Airgap to have decent fuel distribution...
Also I was impressed in how much difference external influences make. Depending on where I place my dyno fan I can easily move EGT of some cylinders by 100°F+

Any comments?

Thanks
Flo

What system are you guys using?

I am using generic Ni-CrNi-probes with Siemens S200 modules for A/D transfer.

With higher loads it seems to even out (less than 50F difference), but still cyl 6 is hottest.

all of mine have been approx. 2" from the cyl. head. I have one probe on each car at the moment #1 cylinder on dragster and #7 cyl. on doorcar.

If I just have one sensor I put it 2" away and on #5 cylinder.

This is a dyno setup. The ET200 modules (I screwed up with the "S200", it is a S5 / S7 control system, but ET200 modules) are part of the whole dyno control system which made of Siemens parts.

Not sure what PLC means... may be a translation problem, I am in Germany. We call this type of industrial comtrol euipment SPS ("Speicherprogrammierbare Steuerung" which I would translate to something like "memory programmable control system"). It essentially is a real time computer with several bus systems.

Still curious what is the commonly accepted EGT difference between cylinders on a carburated setup. In part throttle and under full load.

Greets
Flo

Still curious what is the commonly accepted EGT difference between cylinders on a carburated setup. In part throttle and under full load.

Greets
Flo

---

I have gotten it with in 20* F doing intake work
(runner balance)as for a stock manifold that would
most likely be much higher, I would say in the 80*F
range.... but they are all different

before my Indy intake manifold was reworked i used to see 60*+ diff between cylinders, now that the manifold is fixed it avarages about 20-25* diff at low rpms & 10-15* at high.

thanks for the numbers!
I am far from that unfortunately... is cylinder no. 6 supposed to be the hottest?
I am also curious about the measurement precision. Just moving around the cooling fan moves it up more than 50F (!)

a little trick i did to reduce the temps on 3&5 and 4&6 was to drill a hole in the head gasket in this area to allow more water flow. i think the hole was 5/16 th. this made a considerable difference to the pyro readings for these cylinders.