What do you think all the variances are about?
The simple way to tell is going through 500' AMSL you should get 1250-1300dF EGT or there about on each cylinder. But with the following stipulations. WOT/2700/Full rich, sea level & ISA day, static mag timing at 25dBTDC, 8.5:1 CR engine, all plugs in good order, no induction leaks, even half reasonable F/A ratio's (i.e.less than perfect GAMI spread).
I presume you meant 5000', not 500'?
(EDITED: correction...I think you meant 500' AGL, not MSL, in which case your statement makes more sense...but my situation is unchanged, as below...essentially no change in measured values in the 1st 500' of takeoff...I'm there before turning crosswind
)
I don't know about WOT/2700 at 5000' because I never do that. But looking at my data, at 1000', WOT/2700/full rich (I've never seen an ISA day
, so we'll have to fudge that), 25 BTDC, 8.5:1, plugs just cleaned and gapped at annual, no leaks, GAMI spreads 0.1 or thereabouts, I get EGTs of (hey, guess what?) 1250-1280 (but I thought exact values of EGTs didn't matter because placement could affect the reading????). I also have CHTs < 400 (or just a tad above 400 on hot summer days, easily fixed by lowering the nose). Most recent flight had 15.5 gph.
So I've got values that seem to match the other 5 with the same engine/prop combo, are in line with whatever info we can glean from Lycoming, meet your EGT criteria, keep the cylinders reasonably cool and below 400...what's wrong here? What would upping the FF rate at full rich do "better"?
And...this is how the thing came from the factory, so is Lycoming all wet on how to set up their engines?
And...what would I do about it, anyway? I'm not going to tear apart my FI servo, I get good (28 psi engine-driven pump only, > 30 psi w/ boost pump) fuel pressure, mixture control is on the mechanical stop on the servo...what else would I do? Change the injectors to ones with bigger ports? I'm serious...I don't know what I'd change if what I have is wrong.
Two other things (sorry for the lengthy post with multiple questions)...I see "FF should be HP/10". Hmmmm...sounds like a "magic number" to me (and everyone admits it's just a rule of thumb). HP is an artificial number, not tied to any fundamental constants. 10 is, as always, a nice, round number, easy to remember, but again, arbitrary. So I'm not accepting that HP/10 is anything other than what a lot of people like.
And...help me out here...why do you say "normal full rich of around 0.57 - 0.58"? That may be correct, but why? Is it to avoid the "red cube" or red square or whatever people are calling it?
This would all be moot if Lycoming would just publish what the FF value should be...