Blenheim operating limits and checklists

[Redroach]

to be honest, I don't think the Blen belongs to that altitude... she starts struggling at 7000 feet for me and won't do anymore without carb heat above that
But if you insist, slap on the heaters and go for auto-lean mixture, that would be my tip... although you're somewhat limited in terms of boost when going lean.

Anyways, I think there's still interest in working startup procedures, so here is what works for me:
-[OPTIONAL]The Autopilot knows how to lock the wheel brake. Hit it for a few seconds and look for the lever on the steering column until its done... the AP will begin startup procedures instantly, so for max. realism, don't do that
-select "Inner" tanks for both tank selectors, located at your 4 o'clock. Above these selectors, there is a 3rd one, which is, I believe, for cross-feeding in case of engine failure. It doesn't hurt (so far) to switch it to 'on'. To get the corresponding tank content displayed, switch the fuel level gauges to 'inner' - on your 8 o'clock high.
-pull back on your stick to be able to see the magneto switches. Activate them all.
-activate carburetor heaters, located on your 8 o'clock low, right beneath the pilot seat. I just switch them on/off rather than having them on a slider, so for me its 0%-100%.
-set mixture to the lower half (pulled towards you) of the quadrant, getting 'auto rich' mixture. See Blackdog's postings in this thread.
-set prop pitch to 'fine' - slider all the way up (!)
-set radiator full open, just as a precautionary measure
-throttle to 5-10%
-start left and right engine individually. You may get some mileage from actuating the primer pump, located to the right of the pilot's seat. For me, it's somewhat ambiguous.
-if you've got both engines running, wait a minute and do something else in between, like calibrating your gyro. The engines are rather precarious in the first minute or so, so don't choke them.
-[OPTIONAL]You may close your radiators in order to get temperatures high faster. However, that's a bit tricky and you shouldn't, under no circumstances, forget to re-open them fully for take off. That WILL kill your engine fast. I just leave them open until at cruising altitude.
-switch off carb heaters to get an extra kick for take-off (with them on, engines run a little bit too 'rich')
-If the engines run solidly, rev them up to 40% (step on the wheelbrake of course) in order to get oil temperatures up to 40deg.
-back to idle/10%, grant the engines a little rest
-rev up to around 70% (so that you can still hold the blen with the brakes) and watch the engines going crazy, revving up and down on their own. Wait until you've got stable rpm on both engines.
-back to idle/10%, again, a little resting...again, a safety measure
-activate the boost cut-out in order to get higher boost for Take-off. This is again somewhat risky as you can blow your gaskets in 30 seconds or less. YMMV.
-step off your brake and throttle up for take off. Go full throttle but don't go into the extra-boost region yet. With no airflow over the engines, this will kill them even faster.
-once going 60-70mph, I normally go into extra boost. Not the full 9lbs, rather around 7-8 and only very briefly, for about 20-30sec. max. as airflow is still somewhat scarce.
-lift off at 80-90mph, raise your gear immediately. Don't pull up immediately, let her build up a little speed, probably for quite a while. Deactivate boost cut-out.
-compensate for rudder mis-trim: for me, it's at least 40 clicks 'left' in order to get her flying somewhat straight.
-Now, it's your decision: I normally go for coarse pitch quite early, in exchange for extra-bad climbing performance until I picked up some speed. However, you may very well be able to stay a bit longer at fine pitch if you monitor engine temps properly.
-switch carb heaters back on. I just feel safer with them.
-my cruise settings: around 6000ft, throttle 50-60% auto-lean mix (switching at around 5k ft), coarse pitch, 180-200mph, engine temps arond 220-230deg (don't exceed 250!), rads 1/4 open, carb heat on, well-trimmed to get a good bombing approach.