On the back of tomfrom the north thread about somthing else.he mentioned about he has a warm up procedure before he puts he foot down.if in the mood of course. Me , i always start the car..have a little walk around.check.once a week check oil and water.then buy the time im bettled up music on shades.etc cars being running five mins already. Then its a slow drive for a couple miles. And yes i wont boot it untill the temps up were it should, and all is settled down.and to be ohnest i hardly boot it anyway.is the warmed up propley when the temp reads norm.or is that to soon.

:lol::lol:I can see you have personly rebuilt many engines Simon...i really need to put this to bed but i have a feeling you want the last word,here goes anyway. As you know in the oil filter housing there is a ball check valve to stop all the oil above draining from the top end. Every head ive took off and believe me its plenty, zed and none zed when turned upside down it fills the bench with oil and thats without draining the lifters Every Crankshaft ive lifted from a block there a river of oil still in the oil feed lines thats above the crank not below infact theres so much oil thats still left in blocks its a pain in the arse to clean out before it goes for its bore work then into the bath. All an engines oil DOES NOT all drain to the sump when parked over night and the damaging effects of long idle time on a cold engine imho and i stress imho is not oil related. Diesel engines can do 250,000 miles and still have intact bores when stripped as there fuel is oil....big Air compresser pumps from a cold start instantly run at max revs in a nano second with no problems due to lack of oil and run for 30 years plus every day,yea i strip and service these too for bread money;) I really believe the 1st 5 minutes from a cold start on a petrol engine when you dont get proper and full combustion untill hot and the cylinders are swamped with oil washing petrol are really bad.

 

Actually Bri, I've rebuilt about 10 engines. 3 V6 Vauxhall engines, one of which I stuffed in my Astra Convertible, a couple of 2.08 8v (20ne) items a gaggle of shitty CVH Ford engines and an old motorbike engine when I was at college doing my Engineering and Product design courses. Probably not as many as you, but I'm not quite the novice you think I am. :p

 

I get what you're saying and I agree. I still maintain that oil drains out of the heads to a certain extent (why else does oil read higher when the engine is cold/rested :p ). Oil is far thicker at cold-start, meaning it won't flow as well or have the right properties as warm oil, which is why it's good to just get in the car and drive....engine oil needs heat to operate properly AND flow efficiently, that is fact. :) That is all I am saying. :)

Is it not the case, that although a higher oil pressure is shown when the oil is cold, the flow rate may still be the same?

Surely it's just showing that more effort is required to move the required amount of oil around the system!

I would like to think that the oil pump has the scope to cope with a wide range of conditions

Once warm, the viscosity changes allowing less energy needed to circulate.

In short, drive it sensibly till warm before you give it hell and after you've given it a trashing drive it gently, I think if it as coming into land. Think of an aeroplane, it climbs it goes along and then it descends, that's how you should drive your zed, warm up, exercise and cool down.

That's all that really matters, that and good maintaince. Quality oil and filter changes at regular intervals, I change my oil and filter in the spring before I start driving it.

We must factor in the very poor combustion of fuel when an engines cold too Noel with regards to excessive bore wash.

 

Excessive bore wash occurs when a cylinder doesn't fire, or average mixtures are incredibly rich (as in

 

It's definitely better to just get in the car & drive though.