Drain to Oil Pan from Catch Can, which side of pan?

[mitch32]

Hello,

So I wanted to drain my oil catch can to my oil pan. I was told that the oil drain mod from the head only really helps to vent the crankcase, so with my catch can going to the oil pan I should achieve this. The theory is that the crankcase ventalation will allow the stock drain to drain the head properly. Now I'm not sure where to weld in the drain on the crankcase, whether I should drain it to the exhaust or intake side, and also the height of the drain (below the baffle, above the oil line?). Need advice ASAP as I'm going to the welder next week.

Thanks
Mitch

[Allan74]

I don't know if this helps or not, but Rob@RIPS put mine on the Intake side and from what I can see on all his pans, he uses the intake side also.

[BNR32]

The guy who started the big head oil drain thread on SAU also said intake side.

[mcfly]

If i was to use an external head drain I would want it below the oil level.


Just thought about that. is the crank case pressurizes oil is going to go into the head. I think the oil drain is a bad idea frankly every way I think about it.

Makes plenty of sense when you are scavenging the head with a dry sump though.

[BNR32]

Oh ya? Care to explain the reasoning for that?

Edit: Just went back to the SAU thread and nothing was mentioned about being above the oil level. What was said was "Since the crank turns clockwise (looking from the front) plumbing the oil return into the top LHS of the sump would be logical. That way it is feeding into the partial vacuum created by the crank spinning." Maybe I need sleep, previous post edited.

Here is the thread I was reading: http://www.skylinesaustralia.com/forums/Oil-Control-Rb-s-Circui-t110680.html

Sydneykid usually seems to know what he is talking about, and he swears by them, but I guess there are many ways to skin a cat. Drysump....drool.....

[mitch32]

I widened the drains at the back of the motor pretty hardcore, it easily has the cross-sectional area of 4 dash10AN lines. So drainage should not be a problem. I was thinking of doing this just to balance the pressures. The RB26 is the only engine I've ever heard people do this external drain, and as I think about it I think more and more how it can't really do too much. Best option is dry sump, second is a quality oil pump with an extended sump, and also accusump is a decent option (which I will end up doing).

[TriniGT]

For me it will be Tomei pump, restrictor, oil cooler, catch can with sump drain and separator for water from condensation and oil (need to figure which side of the sump). Accusump as well for good measure.

[mitch32]

It seems more and more people are running accusump. Its good for pre-oiling too and its cheap! Sucks that if you lose pressure at 7000rpm the accusump will only put the pressure its preset at (most run 2.5bar), but any oil pressure is better then no oil pressure. With that said I ran my car right before my rebuild at 7500rpm with 2.5bar without an issue, my bearings were in perfect shape.

For me it will be Tomei pump, restrictor, oil cooler, catch can with sump drain and separator for water from condensation and oil (need to figure which side of the sump). Accusump as well for good measure.

[Bladerunner]

I widened the drains at the back of the motor pretty hardcore, it easily has the cross-sectional area of 4 dash10AN lines. So drainage should not be a problem. I was thinking of doing this just to balance the pressures. The RB26 is the only engine I've ever heard people do this external drain, and as I think about it I think more and more how it can't really do too much. Best option is dry sump, second is a quality oil pump with an extended sump, and also accusump is a decent option (which I will end up doing).

By 4 dash10AN lines, you mean you ported the oil drains the whole way down or just at the opening so it's like a bottle neck, which is not 4dash10AN lines. Just curious if what you did actually equals that all the way down.

[mitch32]

I didn't touch the oil drains that are beside the cylinder walls. I only ported the rear oil drain and yes all the way down from the head to the block to the pan. A -10AN line doesn't have a huge cross-sectional area, its probably around 10mm. There are two drains at the back of the motor so they both got ported. The oil from these ends up at the back of the oil pan, so its not like the external oil drain. I'll probably end up doing the rear head drain just cause its cheap insurance, Super Taikyu cars ran without a external head drain and with a stock sized oil sump (food for thought).

[giannis rb]

you can use the oil return from turbo to the engine block.easy with T