Efi - general oil injection question

[rvaha]

My current engine is 250 Merc EFi s#OG571005. I'm working with a reputable engine builder whose going to build a 2003 250 EFI. It has the downdraft intake and Motorola electronics (don't have s# yet). I'm told these years are strong Efi motors

Ive always ran oil injection on 3 liter. The new motor uses electric oil pump. He told me that in itself is probably fine but the Vst may not supply the engine with correct oil at the moment when the throttle is mashed. For example, if you idle for a few min the Vst would have at best 100 to 1 ratio. If I mash throttle its going to deliver the 100-1 until the Vst can catch up to the 50-1 ratio. So, for my use where I pull skiers and then idle a few would bypassing the oil injection and go premix 50-1 be a safer option?

Ive never seen this discussed but I've often wondered this myself. Thoughts?

[EuropeanAM]

There is a little more to the oil strategies than meets the eye... including some programming for sudden acceleration.

If it were me, I would be strongly encouraging you to RETAIN the oil injection (it must stay on the engine and functioning anyway, otherwise a fault will register).

[rvaha]

As always, thanks Don.

I would prefer to Not remove the oil injection. The engine builder is not saying should or shouldn't - just something to consider pros and cons and also driving habits.

So now I'm wondering - how does a Vst that holds over a pint of fuel and oil that's been idling for let's say 5 min and has oil of maybe 100 to 1 suddenly be able to give 50 to 1 to a full throttle takeoff that may be at the rev limiter is 5-10 seconds? Thanks for any additional info! Maybe I can learn something I've often considered.

[EuropeanAM]

PCM controls oil pump- so it's really not a "mechanical 100:1 fixed because the linkage says so".

Additionally, anytime there is a substantial increase in TPS percentage, the PCM presumes that the engine is headed to WOT, and dumps a high oil pump count immediately (some calibrations may vary, but in general it was a 50 shot oil pump count).

Of course, the inverse of your theory is also at play. When you come off plane @ WOT, the VST is filled with "50:1" fuel. At idle, that's approximately 7-8 minutes of runtime (give or take) before that is consumed.