The Cal-look Lounge

i can't remember in which topic this item has been discussed but i remember reading about this mod of routing oil from the bottom of rocker cover #3 and 4 to the sump.
now, i will be running a racetrim sump and as some might know there's a (i think) M18 thread which in my opinion would facilitate this mod ideally. i will be running stock rocker covers which aren't as flat as, say, empi covers, but i think a fitting can be fitted, right?  ;D

however, though this idea has been playing around in my head for a while, i can't remember if it was for breather purposes or a different purpose.

please let me know any thoughts on this idea.  :)

Search and you will find.

To make a long story short, no need to "vent" the covers back to the sump unless you get rid of the case pressure first.

Best rgs
BB

i'm well aware of the search function, thanks, but like i said i'm not sure where it was mention ???
and naturally i will run a breather box to the rocker covers and oil filler, but i'm not sure it's venting, it was more about rerouting oil back to the sump.

a related open topic, i suppose:
http://cal-look.no/lounge/index.php/topic,7081.0.html (http://cal-look.no/lounge/index.php/topic,7081.0.html)

Sorry, here you have a link; http://cal-look.no/lounge/index.php/topic,7304.0.html

thanks kalle, i will read through that thread carefully  ;)

i always thought the "drain back" mod was for when the driver side vc gets overfilled

a gentleman by the name Mufflermike made a vid of this, revving and filling it up

and then on a separate note
the vented valvecovers (vents upwards)   is for "breather" purposes  into the breather box/tank

not sure if doing both would work though

hope a discussiun on it pushes thru

(the thread i made,  the first link never gotten anything LOL!!)

Muffler Mike`s video show you that it is the 3/4 side that fills up. If you add "breather" hose the oil will continue up the hose and into your breather box. A return line to the sump will not help unless you get rid of the pressure in the case, hence my first answer above here.

yes i understand that ,

thats why i threw the hypo question,  breather fitting on the 3/4 to breather box and drain back..  why both isnt used and if ever you could..

ur answer answered it LOL just added further question (to further ur answer)

thanks man

If you do not have a breather vent on the 3/4 side but just a return to the sump then surely the oil will return down the tube as the crankcase pressure in the valve cover and in the sump will equalize and then gravity will add the extra needed to pull the oil down the return line back to the sump?particularly when the oil level drops at high rpm?

I have had the fitting welded onto my sump[-10 size] for the 4inch engine but still have to do the valve cover,but my intention is to try this and see if it works :)

cheers richie,uk

sounds interesting richie!
so, then i should vent the oil filler and 1/2 side to a breather box and fit a return line from the bottom of the 3/4 rocker cover to the sump?

does anyone know what thread a racetrim sump has? it's most likely not metric...

Hi richie

Do you mean that the oil from valvecover will only return down to the sump (when the oil level gets down) if you do not have a breather line to the box?

Udo

Udo

I have been told that if you have a breather line as well as an oil return it can siphon up the breather line and empty oil from the sump instead of using the pressure in the valve cover to force it back down to the sump,it will push poil back down all the time the engine is running

cheers richie

For this to work well, wouldn't the drain back need to be above the oil level in the block? And in the case of a wet sump VW, that doesn't give much angle for gravity to take the oil back down. I see this as being a worthwhile mod for a dry sump motor, but pointless for a wet sump. Discuss :)

No need on dry sump motor to drain back to anywhere,its already being sucked out the covers,on a turbo engine lots of people put the drain back into the sump and it works fine.

Anything to help the oil back to the sump is a good thing and as I mentioned,when the oil level drops enough it will drop back through gravity alone,the pressure in the valve cover will also help push it down the return line,same as it pushes it up the breather hose,and if you have a type 3 oil hole in the case you can run it to there,part of it is above the oil level,this is where I do my turbo returns to.

cheers richie,uk

the oil like water will find its own level, so it will drain out of the rocker covers down towards the sump, but i don't think it will empty the oil line, the top level in the oil line will be the same as the top level in the case.

correct, if it's all down to gravity instead of suction the oil line will be flooded, and it would make any sense  ;)
i do wonder what those racetrim sumps were threaded for though....

Why do I bother

I think it's 3/8" NPT... been a while though.

Tig weld some AN-8 bungs on the sump, or play with NPT / AN-8 adapters.

Under acceleration wont having the return at the rear (pulley end) of the sump just allow oil from the sump to force its way into the head ? Or is the pressure in the valve cover area enough to overcome this effect ?

I have my oil-pick-up extension directed to the rear (bottom) of the sump, just to pick up as much oil as possible.
The valve covers have breathers, so there is minimal pressure. I don't drive my car at WARP speeds, and never had any problems.

richie,uk spreads a different light on this issue, which makes totally sence.

Thanks for doing so.

Good question, especially as i never read posts correctly.  But as you point out the pressure in the covers will help push down the oil.  Stupid me.

I would change the valve guides if there was developing pressure out in the heads. In fact, don't some people have problems with getting the VC gaskets sucked in? Or is that just bad valve covers...
The oil will find its level in the tube and act as a extension to the sump, and that is JUST as good as having the oil in the sump.

Crankcase pressure from the push rod tubes?that is affected by valve guides?  If I could run a boost line to the valve cover and force the oil back down would that help :o  ;)






Agreed :)

cheers richie,uk

Some pics of my setup.

That is my point too Richie, the pressure develops in the crank case so get rid of it there... only other way of getting pressure up in the heads is the valve guides ;)

You are right... motivation helps :)

Listen to Richie. I know it pains you to do so, but he's done more than most of you even think about – and probably has the bank balance to prove it!  ;D
Another factor to bear in mind is that with a deep sump it is usual to run with the oil level well below the 'full' mark on the stock dipstick. With the engine running the oil level will be very low in the stock sump, with most of the oil retained in the sump extension. So, a drain line back to the stock sump will, for the most part, be above the oil level anyway.

Thats a great idea, never thought of using the type 3 block off as a return...

don't! you will have my hairstyle in no-time.  ;)

I like your hairstyle ;)

;D