[Vintage-race] engine warm up routine??

[christopher h. kang, md]

sigh, i'm still learning about my new race motor:
 
how and how long does one expect to have to warm up a dry sumped engine (1.6ltr,lotus TC,dry sumped, 2gal in the oil tank, full race cams LT 1,16) in order to be up to "operating temp". 

I ask because after my last race (avg 70deg F ambient), i seem to have chewed up a bearing somewhere (tear down to be done). I warmed it up in the paddock for about 10min, noted that the oil temp was about 
60-70deg C-usual about 90deg. took it easy on the track for a lap, then kept it 2k below redline for a few laps. The oil cooler air intake was blocked off. radiator intake unchanged.

nota bene: i get the vintage list via the digest form so individual replies will hit the spam blocker which i will manually overide.

thanks for any suggestions


christopher