227 Improving Oil supply

Andre mentions previous work on the older Toyota 4AGE engines and issues with oil through the vent. Have you ever added an additional drain to one of these engines, and if so, could you provide some info on what your setup was like, or where you located the drain?

Thanks

I've never personally added an oil drain as all my 4AGEs either ran the small port 16V head which had the external oil drain, or the 20V heads. If you do a quick google search you'll find plenty of info on adding an external oil drain to the big port heads.

Andre:

I appreciate your reply. Yes, I'm using the big port 16V heads. I've been adding a drain in the heads, I see lots of poor work posted online, I was curious to see what what an experienced builder like your self may have done.

I wish your courses were out 25 years ago when I first got into this trade. Keep up the great work.

Thanks again.

I had to add an extra drain in the back of the head (RWD application) or the head would full with oil. This was originally on a wet sump build with an accusump. Just drilled a big hole as low as possible, drilled and tapped and tapped a couple of holes and fitted a -12 (I think) union.

Solved the issue.

This was carried over when I dry sumped the engine, no idea if it still needed it.

The car (AE86) needed this even when it was raced on road tyres.

Adding two small journal bearing turbos to a V6 suv engine which doesn't have any aftermarket support for oil pump upgrades... Should I worry about oil supply to the rest of the engine as adding two turbos to the stock oiling system is pretty much like adding two oil leaks and may starve the rest of the engine?

or should I go through the trouble of custom making a dry sump?

I would be. Presumably the turbos are going to need an oil supply, which, as you said, will be "taking" oil supply from the rest of the system. Will probably depend on how much reserve the oil pump has, and the rest of the oil system. If you can't get a bigger pump I would be very careful with the rest of the system (bearing clearances, new pump, possible head restrictors, decent size oil coolers, smooth all transitions, decent pipe diameters, accusump etc) and log and check oil pressure and temperature very thoroughly until you are sure it is OK. And fit a VERY BIG oil pressure warning light attached to a "high" low pressure switch (or ECU).

Engine would've been a new build with forged rods and pistons, new stock pump probably shimmed for some more pressure, head already has some restrictors in it but was considering some smaller ones. Oil cooler would pretty much add to the problem as it would drop oil pressure as well and accusump will help with a temporary drop in pressure not help with flow requirements. I'm leaning more to the trouble of building a 3 stage dry sump for it but just wondered if anyone was in the same situation as me and didn't notice much change in a non performance engine with two turbos.