[Diy_efi] A/F mixture, EGT and engine damage

[Tim Marsteiner]

Both EGT probes are exactly 3" from the cylinder
heads.

http://www.superxtune.com/images/EGT.JPG

I have heard that going too rich can damage the engine
by "washing" the oil film off the cylinder walls. Is
there a safe lower limit on A/F or EGT ? 

Thanks,
Tim

--- Michael Richards <michael at fastmail.ca> wrote:
> Your EGTs do sound a little high but I don't know
> where your probe is 
> and I don't have a lot of motorcycle engine
> experience. If I had to 
> guess I'd say that maybe you aren't running enough
> ignition advance. 
> That mixture isn't what I'd characterise as too lean
> or too rich for an 
> NA engine.
> 
> -Michael
> 
> > Some owners of my type of motorcyle have reported
> > burnt exhaust valves and cracked cylinder heads. I
> > have logged data running one of the standard
> factory
> > tunes showing peak EGTs >1500 F and A/F > 13.2:1
> at
> > WOT. I have also recorded even higher EGTs (1663
> F) at
> > mid to low engine loads.
> > 
> > This page shows Avg EGT, Peak EGT and the number
> of
> > samples at each operating "cell" in the map (TPS
> vs
> > RPMs).
> > 
> > http://www.superxtune.com/images/8320Cyl2_egt.jpg
> > 
> > 
> > Any opinions on which of the above conditions is
> doing
> > the most (if any) damage?
> > 
> > At mid to low engine loads do you need to be
> concerned
> > with high EGT or should I just focus on richening
> up
> > the higher engine load points?
> 
>
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