[Fot] EGT's again

[Tim Murphy]

We have a TR4 with about 11:1 CR.  Our EGT's are mounted on #1 and #4 header
pipes about 1-1/2 to 1-3/4 inches from the cylinder head.  They are not
exactly equal.  #1 and #4 header pipes were used because they were a lot
easier to get the probes on.  At 3000 RPM "idle" (no load) we get between
800 and 1000 degrees.  Down the straights we get between 1300 and 1400
degrees, WOT in 4th.

One note for what it's worth: the pistons are being cooled every cycle by
the incoming charge whereas the EGT probes do not get any appreciable
cooling.  Even the exhaust ports get some cooling from the water jacket.

Tim

-----Original Message-----
From: fot-bounces at autox.team.net [mailto:fot-bounces at autox.team.net] On
Behalf Of toodamnfunky at comcast.net
Sent: Wednesday, May 22, 2013 3:24 PM
To: fot
Subject: [Fot] EGT's again

Fot, 

I know this has been brought up before but I don't know if there is any
consensus. 

The question is two parts. 

EGT probe location and what are considered normal temps. Westach users guide
will say the probes should be located 

6" from the manifold but Sam H says you start getting flakey readings out
there so he suggests 6" from the valve. 

That's right about where I'm at but I am seeing 1250 F on the EGT's but yet
my plugs are telling a richer story. 

It's been suggested that any less than 3" from the manifold and the probe is
right in the flame coming out of the valve and thus 

reading artificially high. 



So, just curious as to where peo ple locate thier probes and what kind of
EGT's they see. 

When I read threads from other makes I hear about people considering 1400F
as normal. 

It seems that if that were a true reading there would be some piston melting
going on. 



Thanks again for the input, 

jim g 
_______________________________________________
fot at autox.team.net

http://www.fot-racing.com

Donate: http://www.team.net/donate.html
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums
Unsubscribe/Manage:
http://autox.team.net/mailman/options/fot/timmurph@fastbytes.com