Engines lubrication/Oil system

[Roy]

Is there any point to putting some sort of ignition cut on an engine, so when you crank a cold engine it doesnt fire.

Idea being to get some oil circulating thru the engine before you fire it. Or is there really nothing to be gained from cranking the engine half a dozen times before firing it.

[GTS-t VSPEC]

I can't see the benefit there really, all of our engine have survived many km's using the normal cold start method, so unless you want to fork out big bucks for a pre-heated dry sump then don't bother.

[4door_Sleeper]

Hi

This isn’t really my area, so please don’t take my word as gospel, buy surly if you crank the engine over you are still going to cause a similar amount of damage as you would if it were to fire up cold.

I too have been considering a system to give better protection for cold stars and recall that in the US in the 70's (Dodge Darts, 426 Hemi etc) they had a pressure loaded oil cylinder that they released prior to starting. (I think it filled slowly during normal operation via a one way valve, which can be released/bypassed prior to starting) The idea was that it primed all of the oil system.

Alternatively an electric pump that taps into your existing system could be used to prime the system.

I don’t know if you can buy such parts, or if in the long run it makes much difference, but it would give me piece of mind.

[Roy]

Yeh i have read how some drag cars have oil primer pumps.

A couple pf the reasons i thought about it is that having a high mount plain bearing turbo, it would ensure the bearings have some oil flow before spinning.

Also the fact that there is no spark would mean there is no actual loads on thing like bearings as there is no compression/ ignition/ expansion of fuel mixture.

So whilst the engine is turning over on the starter motor there is much reduced load as there is no bang sending the piston/rod down the bore and crank swinging.

Finally rigging up such a system could be as cheap as $5, by placing a toggle switch on the earth of the igniter??? or something similar (Would really have to look at a wiring diagram)

So provided it isnt doing any harm (battery life perhaps?) then it may only help, and also perhaps stop a thief who doesnt realise why the car wont turn over, and leaves quits once the battery is dead.

[Busky2k]

You shouldnt need an oil primer in most cases. You're pretty much wasting your time. Get a quality oil filter with a good anti-drainback valve and some 5W or 0W rated oil and you've got all the cold start protection you need.

If anything, a slow crank will not sufficiently oil up the system over a few seconds. It might take 10-20 seconds before its fully primed at cranking speed. And your bearings are still 1/2 dry during this period. You might aswell just start it and the oil pressure will be up in no time...

Just take it easy when the engine is cold. That is the key...

[Kinks]

don't bother with special measures.

if you cut ignition or fuel, you're still compressing air into the engine so there is some load. the engine won't fire but there's still some load. the starter motor is also very high torque and that loads the engine too.

You'd have to remove all the plugs and turn the engine over by hand many times until oil came up to truly have no load. I wouldn't worry about the turbo either, they don't spin fast at idle and again there's not much load on them.

Genuine filter with anti-drainback valve, 5W oil and let it idle for 30 seconds when you start it, then drive it off gently until it is warm. That's all you need, motors are designed to be cold started (not excessively but a reasonable usage) and with synthetic oil you won't get nearly as much drain off components as mineral oil (not that anyone w/ turbo cars uses mineral but compared to normal engines out there - my charade always used mineral and revved its tits off after 140,000km of hard use!)