oil return line placement
 

Hi guys, newbie here looking for a quick answer.

I have a large pte 6765 billet turbo going onto my acura legend with a 3.5L v6.

I have a -10an fittings/line ready to tap the pan for the oil return line, but I'm confused on where on the pan should I tap it?

Do I want the oil return line to be submerged with oil or do I want it high in the pan? middle ground?

Thanks I read on hondatech it should be high as possible, then I read that it should be low. Can I get a quick answer please? I'd love to tap my pan and install it tonight.

you want the return to be high in the pan to keep oil from back filling into the oil drain tube.

thanks man i guess thats what i'll do unless someone says otherwise

^ i found this out the hard way on my S2000 build! mounted it just a smig too low and i had to tear the oil pan back off, weld the hole closed and redo it altogether. dont make my mistake measure twice cut once! haha

are there applications where the top of the pan is not high enough as well? thx

i suppose that could be the case for some vehicles. but if your not sure, find out how many quarts your car holds. then take off your oil pan and fill it up with that same amount of quarts but with water. and this way you can see where the oil line will be, and you can make sure to place it above that line.

or if you want a brand new oil pan that is pre-tapped, check out moroso oil pans. they may have a pan for your application. they are state side so idk if they would ship to you or not. may be worth checking into though, if you dont mind spending the extra money.

www.moroso.com

If your good, you can always drill and tap your block for an oil return line, if necessary because of the pans capacity.

good info, thx guys!

all good info but make sure its away from the pick up sump, the cavitation from the sump will create that back pressure up the drain so away from the sump !

Welcome, are you really from Greece? I am Greek as well, nice to see a fellow greek lol.

If you aren't afraid, then drill through the block, otherwise you will need to get crafty with your oil pan. Most stock turbo applications are made with a reilef through the block, check your application to see what suits best.

how hard is it to drill into a cast iron block anyways? :cool:

this site has become so backasswards...



you can drain anywhere in the pan. there is no significant drain from the turbo that will cause cavitation or any of this bullshit.

you think oil is going to become anti-gravity and suddenly go up your drain and back into the turbo? yes, there may be a slight amount in the turbo drain, but it will not go any higher than what the oil level will be inside the oil pan.

Not true.

Though it doesn't "flow" up your tube, there is volumetric constriction.

Have you ever filled an auto tranny? If so, you would know that the ATF will easily back up the dipstick fill tube, and all over your motor, because there is simply too much of a volume of liquid flowing into that tube, to effectively drain with the same speed to which it was filled.

When the car isn't running, your statement reigns true. But what happens once your car starts pumping oil into the turbo?

Even with 1/8th inch lines, there is a LOT of pressure going to the turbocharger. Without a proper, free flowing draiback, your turbo would fill with oil, pressurize, and blow oil out the seals. Not because it had weak seals, but because they merely aren't made to hold much pressure. If you ever take a turbo apart, you will notice there are oil reliefs and extra drainback slots cast into the center housing. If any one of those reliefs get cooked with oil (a symptom of premature shutdown) it will begin to pressuize the turbo, causing seal blow out.

If you notice, most factory turbo cars (and ALL the turbo cars I have seen) have a drainback in the block, ABOVE the oilpan and nearly parallel to the crank centerline. Why?

Because then there will never be oil sitting in the drainback, that has to free flow out the end of the tube, which could be as low as the bottom of the pan.