I always thought this was more due to allowing the oil to make its way up the cylinder bore. nissan i'm told have always built their engines so that on startup, oil is injected up into the cylinder bores to prevent friction on startup. maybe someone can elaborate on this if it's correct?
The NA's have oil nozzles aiming up onto the underside of the pistons. Thats a cooling strategy. Interestingly, the turbo engines dont have them. Rods often have a small bleed hole allowing oil to sling up. I dont know with the VG's. Enough oil slings off the crankpins to adequately lubricate the bores below the rings. E
I thought the TT's had hollow pistons, with the squirters angled to direct oil into the underside of the piston? But yeah as Tas said this is for cooling.
Actually the latest research says it all has to with the expansion of the valves and is critical for multivalve engines Also the corrosive nature of the gases at start up But there is just so much shit to wade through on this particular subject its not funny - that's why I posted this here!
my brother had a similar situation, so to entertain( shit the neighbour ) right off he'd come down the street at full noise, hit the auto door button, do a big handbrakey into the driveway, like blues brothers and the neighbour stopped ringing the EPA
few points - ever wondered why taxi's last so long - even if you let the car sit idling to warm up the engine, your gearbox, diff etc is still cold - start engine , let oil circulate 30sec - 1min - start driving vehicle normally/slowly till operating temps are reached - :br:
Years ago this was probably true but with modern oils and engines it should be Ok to start and drive straight away, but I wouldn't rev hard or let the engine labour until it's warmed up properly. I heard back in the 60's that Petters tested two (admittedly diesel) engines, one started and left to idle only and the other started and raced to max revs straight away and held there. The Idling engine seized first. So I heard Not sure what that proves but I don't think idling for an extended time while cold is doing much good.
