Just because the POH states you "can" apply full power the moment the engine will do so without hesitation doesn't mean you should. It just said you can, nothing more nothing less.
I am pretty sure, but I am not going to try it, that all the flat engines particularly the fuel injected ones are more than capable of coming off the starter motor dead cold and straight through to full power without hesitation.
The only engines I have operated that will stumble on a cold morning are the 985, 1340 and 1820, (the entirety of my round engine experience) they seem to lean snuff out if you open the throttle to quick when they're cold and the air is really frosty and atomisation is quite poor.
Incidentally the 1340 I operated (Ag) used to be set to idle around 450 rpm from start up on a cold winter morning and there it would sit for up to 20 minutes until the 70w oil would reach 40c then you could open the throttle. Reason being the super charger bearing spinning at 10:1 of crank speed (4500 rpm at 450 rpm) could burn (coke) the oil onto the bearing races in the cold oil.
The hell you say.....but trying to spin a bearing in a thick medium at speed and an enormous amount of friction is created, the result of which is heat.
Well so the overhaul boys would tell me.
We did suffer the odd glazed cylinder from time to time though, no probs, pop it off hone it and good to go. Maybe that's were the notion of glazing cylinders by waiting for the oil to reach the green came from??
For those (Aussie Bob?) that are implying bad things will happen if you close the cowl flaps to assist with a warm up. Care to explain what those bad things might be or do we wish to leave that statement hanging so that those not in the know form their own opinion on what those things might be. I see a little bit of lee way here with regard to cowl flap ops in frosty conditions, but it is important to explain the why's.
My knowledge of the bad things comes from APS and John Schwanner (of the Skyranch Engineering Manual fame) but I'll let you explain to the masses why it can be bad in certain circumstances and the issues it creates.
Last edited by Obidiah; 1st Apr 2015 at 23:31.