Hi guys,
I was wondering if anyone out there can tell me what exhaust temp I should be seeing??
I have melted the #3 exhaust valve on 2 engines... the first was a stock motor with over 190k miles on it so I wasn't real concerned with it. But then in June I blew the same valve in a stock rebuild with only 5 race weekends and about 3-4 test days on it. I finally got another motor together and went to a test day 2 weeks ago and got some numbers...
I drilled a small hole in the #3 primary tube about 10 inches away from the head and hose-clamped a thermocouple into it. Recorded things with a Mychron 3.
I decided to see if I could get any change in temp by trying to trick the ecu (using a stock ecu from an automatic car) into putting more fuel into the cylinders by lowering the voltage reading it sees from the O2 sensor.
with the stock O2 hookup I got up to about 2000F in full throttle on the straights, with my modification installed it only dropped to 1950F and I cut the voltage going to the ecu down to 75% of normal, so it pretty much seems like my modification did nothing.
Any ideas? Are these temps normal? If so, what brand of valves are you guys using to withstand this?
Thanks,
Mike