ratman

what cylinder should i install my pyrometers in on bbc 577 n/a's?
what temp should i be running wfo ? thx, in advance. ratman

articfriends

iTrader: (1)

I had gaffrigs in mine lightning headers in # 7&#8 but the sucked because they read 1500plus degrees all the time when on plane,I added more fuel to get them down to 1250degrees and boat ran like a turd,fouled plugs etc,Smitty

ratman

i have one for each engine...whitch hole tends to run hottest on bbc? thx in advance, ratman

ratman

ttt

KNOT-RIGHT

I would use them as a guide only.
type of Intake plays a roll aswell as N/A or forced induction.

N/A Cyl 7 would be the leaner.
However if you are gonna reuse this exhaust for roots
supercharging you may take that into consideration.
Flip a roots supercharger and see it feeds the back cylinders first which would make the front cylinders lean. The
way the carbs sit on top of the roots also plays a roll on it
I would not go over 1350F
My front cylinders run the leanest

# 2 # 7 would be the choice

remember the lower the CR the higher the EGTs
the higher the CR the lower the EGTs
the leaner A/F Ratio the higher EGTs
the richer A/F Ratio the lower EGTs

Hope this helps
Oh put the thermo couple as close to the head as possible
READ THE PLUGS!
Gerry

JCPERF

I would dyno the engines and find out your hottest cylinders.

Wobble

#2 on a merc dual plane intake motor, on any other type intake it could be any. My dyno results with port matched merlin single plane gave very even egt's. BUT that was with dyno headers.

KNOT-RIGHT

JCPERF You should put one in your Avitar it looks pretty hot.
Well over 1500F

JCPERF

carney

I ran them in 5 and or 7