Originally posted by Racer254@Aug 24 2005, 11:17 AM Just remember, aluminum melts at 1220 F. Granted there are many other factors where you can get higher than that temp and be safe, but just an FYI.
any time you see temps over 1250 you should start to think about how bad is this...... 1~2 second blast at just over 1250 no problem, 1~2 miles at WOT at over 1250 = bad things..... Its not uncommon to see midrange temps close to 1200*, this is where you get your best fuel economy! if you could tune your motor to run 1200~1250 any time its under power you would have a sled that ran like EFI ! just remember 1250 is on the edge so if you miss your jetting change for the day you could burn down at WOT or on the needle (midrange power)!
i would never hold any sled wot fot 1 or two miles. i thought pistions melted more like around 1400deg.? i had my limits set at 1250 on my digitron when it flashed i shutter down. i could probably hold it for.75 mile. never got greedy on jetting also larger stingers on my twin pipes for mod motor. 2600 miles on this motor never broke it. and yes im sure every motor is different.
the best thing to do is check your plugs and piston wash , get it as close to perfect as you dare go ...then use your egt to fine tune the needles and mains , EGT as the only form of info is a dangerous way of tuneing! EGT probes take time to react to change and they are not known for being 100% accurate.
Umm yea I am well versed in jetting. Maybe I should have clarified that, as well as plug color and piston wash. My post was for baseline temps to look for as my last meltdown probably could have been avoided and I am looking to not do that again. I am pretty sure that the 3/4 mile blast @ WOT could've been just a bit much. Musta hadda buzz on.
Originally posted by bluebear@Aug 24 2005, 11:36 PM You need to tune your motor with plugs and piston wash and when you get a safe setup then check you EGT temps and use that as a baseline. Can't go off EGT's alone.
bb, you are absolutely right--ya can't go by EGT alone. The distance from the piston skirt to the probes is also a critical part pf the equation as is type of fuel used. That having been said all I'm attemting to do here is back up what you have said with some additional info
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