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-   -   Exhaust Temp on Blown Alcohol Engine (https://www.racingjunk.com/forums/showthread.php?t=31577)

quickmotorsports 01-21-2012 12:36 PM

Exhaust Temp on Blown Alcohol Engine
 
Does anyone have an idea of what the average temp on the exhaust should be in a blown alcohol engine both at an idle and after running at around 7000rpm?

Any ideas would be great! Thanks!

markdunlap 01-21-2012 01:05 PM

Blown
 
572 KB with Brad heads and 14-71 high helix, 450 at idle, 950-1000 at 8000 RPM and still a little rich WOT. Truck pull application. 8 EGTs 2" from head into the Zoomies.

roadkill2 01-21-2012 06:56 PM

560" Alum "B" block, B-1 alum heads, 8-71, 570° @ idle, about 1050-1075 at 7000, drag app in a 2100# altered . . EGT @ 1 & 8 . .

My guess is somewhere between 1000 & 1125° . . any more than that and you're treading in dangerous water . . If you're above that, start looking at your plugs closely . . But that's just an opinion . .

zipper06 01-21-2012 10:26 PM

That's a tuff question, and i don't know what the right answer would be, as suggested 1,000 to 1,100 max.
What i do know is when i was running a 540" 1471 on alcohol. i mistakenly tacked the outher slip tubes to the inner tubes/ headers and after the pass the outer slip tubes wrinkeled up so much they looked like a corrigated hose, i never did that again. I'm thinking i was probable in the 1500/1600 degree range for them to do that (i didn't have an EGT setup), but that's where it ran best at 8,000 RPM's. That was a Rodex blk with Brodix solid heads, but 25 yrs ago.

zip.

maxpower671 01-23-2012 01:46 PM

my guess is 1100-1200 max degrees, 2" off of head..

better yet, just when the plating on the base of the plug threads starts burning off...the old NGK's that are gold(cad) colored are a lot easier to read 8)

roadkill2 01-23-2012 02:44 PM

On eyeballing the plugs . . "Back when" I always used 3 threads of color (or heat) as an indicator of a "Happy Motor' . . Anymore than that , along with a "brown" or dark tan insulator at the electrode, it was time to go for a fatter (smaller) pill . .


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